Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery systems for achieving high energy density and excellent safety for energy storage in the future.However,current existed...Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery systems for achieving high energy density and excellent safety for energy storage in the future.However,current existed solid-state electrolytes(SSEs)are still difficult to meet the practical application requirements of SSLMBs.In this review,based on the analysis of main problems and challenges faced by the development of SSEs,the ingenious application and latest progresses including specific suggestions of various polymer fibers and their membrane products in solving these issues are emphatically reviewed.Firstly,the inherent defects of inorganic and organic electrolytes are pointed out.Then,the application strategies of polymer fibers/fiber membranes in strengthening strength,reducing thickness,enhancing thermal stability,increasing the film formability,improving ion conductivity and optimizing interface stability are discussed in detail from two aspects of improving physical structure properties and electrochemical performances.Finally,the researches and development trends of the intelligent applications of high-performance polymer fibers in SSEs is prospected.This review intends to provide timely and important guidance for the design and development of polymer fiber composite SSEs for SSLMBs.展开更多
The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and respons...The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and responsive attributes to chemical and physical stimuli,and are characterized by diverse microscopic structures.Multidimensional fiber microstructures have been fabricated by sophisticated preparation technologies,such as electrospinning,wet spinning,and microfluidic spinning,resulting in SPFs with responsiveness to various stimuli,such as thermal,pH,light,electricity,moisture,magnetic field,and multiple stimuli-responsive properties.In the past decade,cross-disciplinary developments in the refinement,intellectualization,and functionalization of SPFs and notable progress in the fibers'microstructure and stimuli-responsive properties have enabled wide applications in biomedicine,smart textiles,sensors,and water treatment.Herein,to comprehensively facilitate SPFs development in multidisciplinary and multifunctional domains,we elaborate on the correlation among material classification,microstructures formed by common preparation processes,stimuli-responsive properties,and their comprehensive applications.Finally,we aim to inspire scientists with diverse research backgrounds to apply multidisciplinary knowledge to promote the development and industrialization of SPFs.展开更多
Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and d...Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.展开更多
In order to study the fatigue failure mode and fatigue life laws of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer （ FRP ） sheets, fatigue experiments are carried out, considering two hybrid ratios ...In order to study the fatigue failure mode and fatigue life laws of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer （ FRP ） sheets, fatigue experiments are carried out, considering two hybrid ratios of 1 ： 1 and 2：1 under different stress levels from 0.6 to 0.95. The results show that fractures occur first in carbon fibers or aramid fibers for the specimens with hybrid ratio of 1： 1, namely B1A1 and B1C1, while a fracture occurs first in basalt fibers for the specimens with a hybrid ratio of 2： 1, namely B2A1 and B2C1. The fatigue lives of the hybrid FRP sheets increase with the improvement of the content of carbon fibers or aramid fibers, and the influence of the carbon fibers content improvement to fatigue life is more significant. The fatigue performance of B2A1 is relatively worse, while the fatigue performance of B1C1 and B2C1 is relatively better. Finally, a new fatigue stiffness degradation model with dual variables and double inflection points is presented, which is applicable to both hybrid and normal FRP sheets.展开更多
Polymer semiconductors with highly crystalline forms,such as crystalline nanowires and fibers,are critical for charge carrier transport in organic field-effect transistors(OFET).However,the highly crystalline form usu...Polymer semiconductors with highly crystalline forms,such as crystalline nanowires and fibers,are critical for charge carrier transport in organic field-effect transistors(OFET).However,the highly crystalline form usually requires high-quality molecular orderliness,which still remains a great challenge,especially in single fibers of extremely high-molecular-weight semiconducting polymers.In this study,we present an anodic aluminum oxide(AAO)template-assisted method to fabricate highly crystalline N-alkyl diketopyrrolopyrrole dithienylthieno[3,2-b]thiophene(DPP-DTT)single fibers.Grazing-incidence X-ray diffraction and selected area electron diffraction show obvious diffraction patterns for single-crystal-like characteristics,indicating the highly ordered molecular chains and highly crystalline structures of the single DPP-DTT fibers.OFET based on the single-crystal-like DPP-DTT fiber exhibits the highest charge carrier mobility of up to 14.2 cm^(2)V^(−1)s^(-1)and an average mobility of approximately 7.8 cm^(2)V^(−1)s^(-1),which is significantly improved compared with DPP-DTT thin film-based devices.Besides,the fiber-based OFET also exhibit a high light responsivity of 4.0.103 A W^(−1).This work demonstrates a facile and effective method for fabricating single-crystal-like fibers of high-molecular-weight polymer semiconductors and corresponding high-performance OFET devices.Furthermore,it also expands application of AAO template method for achieving crystalline semiconducting polymer fibers and provide a new perspective for the study on polymer crystallization.展开更多
The mechanical response of polyethylene nano-fibers with the same chain length but different chain numbers are studied by using steered molecular dynamics simulations.The shrinking or stretching forces acted on the ch...The mechanical response of polyethylene nano-fibers with the same chain length but different chain numbers are studied by using steered molecular dynamics simulations.The shrinking or stretching forces acted on the chain ends are investigated according to the chain-end distance and temperature under isothermal or continuous warming-cooling conditions,respectively.An inflection point is found in the ForceDistance response when temperature is below 500 K.This inflection point is related to the balance between entropy force and inter-monomer interaction and it reflects the strong effect of crystallization on the mechanical response of the nano-fibers.The force at inflection point is also affected by the buckling effect due to increased stiffness when crystallization occurs.The two stages found in the Force-Temperature response and the difference between the shrinking and stretching forces indicate the hysteresis of crystallization and melting.The forces at different shrinking and stretching rates reveal the entropy contribution upon the mechanical response,indicated by the Ramachandran plot of dihedrals.The chain-conformation entropy is majorly contributed by dihedrals and is quantified by the information entropy of dihedrals,which has a highly similarity to the mechanical Force-Temperature response.The enlarged forces in multiple chains over a single chain are attributed to the enhanced dihedral-conformation entropy.Our study provides a new insight to the dynamically mechanical response of polymer nano-fibers according to the effect of crystallization and entropy contribution.展开更多
This work is aimed at studying the strengthening of reinforced concrete (R. C.) beams using prestressed glass fi- ber-reinforced polymer (PGFRP). Carbon fiber-reinforced polymer (CFRP) has recently become popular for ...This work is aimed at studying the strengthening of reinforced concrete (R. C.) beams using prestressed glass fi- ber-reinforced polymer (PGFRP). Carbon fiber-reinforced polymer (CFRP) has recently become popular for use as repair or rehabilitation material for deteriorated R. C. structures, but because CFRP material is very stiff, the difference in CFRP sheet and concrete material properties is not favorable for transferring the prestress from CFRP sheets to R. C. members. Glass fi- ber-reinforced polymer (GFRP) sheets with Modulus of Elasticity quite close to that of concrete was chosen in this study. The load-carrying capacities (ultimate loads) and the deflections of strengthened R. C. beams using GFRP and PGFRP sheets were tested and compared. T- and ⊥-shaped beams were used as the under-strengthened and over-strengthened beams. The GFRP sheets were prestressed to one-half their tensile capacities before being bonded to the T- and ⊥-shaped R. C. beams. The prestressed tension in the PGFRP sheets caused cambers in the R. C. beams without cracks on the tensile faces. The PGFRP sheets also enhanced the load-carrying capacity. The test results indicated that T-shaped beams with GFRP sheets increased in load-carrying capacity by 55% while the same beams with PGFRP sheets could increase load-carrying capacity by 100%. The ⊥-shaped beams with GFRP sheets could increase load-carrying capacity by 97% while the same beams with PGFRP sheets could increase the loading-carrying capacity by 117%. Under the same external loads, beams with GFRP sheets underwent larger deflections than beams with PGFRP sheets. While GFRP sheets strengthen R. C. beams, PGFRP sheets decrease the beams’ ductility, especially for the over-strengthened beams (⊥-shaped beams).展开更多
This paper discusses a new fibrous composite known as continuous basalt fiber reinforced polymer /plastic(BFRP).Compared with other fiber reinforced polymer/plastic,BFRP has many advantages,such as ductility,high ther...This paper discusses a new fibrous composite known as continuous basalt fiber reinforced polymer /plastic(BFRP).Compared with other fiber reinforced polymer/plastic,BFRP has many advantages,such as ductility,high thermal resistance,corrosion resistance and economic cost.To test mechanical properties and failure modes of flexural members strengthened with BFRP,flexural experiment is conducted on four two-span T-section continuous beams strengthened with BFRP and one un-strengthened comparative beam.The experimental result shows that the strengthened beams perform remarkably in terms of yield strength,ultimate strength and ductility.BFRP has good prospects in retrofitting and strengthening of concrete structures which require good ductility and corrosion resistance.展开更多
The galvanic corrosion behavior of carbon fiber reinforced polymers （CFRPs） GM-CFRP and Tepex-CFRP in contact with a Zn-coated DP590 steel in solution containing 0.9 wt% NaCl＋ 0.1 wt% CaCl2 ＋ 0.075 wt% NaHCO3 was ...The galvanic corrosion behavior of carbon fiber reinforced polymers （CFRPs） GM-CFRP and Tepex-CFRP in contact with a Zn-coated DP590 steel in solution containing 0.9 wt% NaCl＋ 0.1 wt% CaCl2 ＋ 0.075 wt% NaHCO3 was investigated. The results showed that the GM-CFRP/steel couple was initially more resistant to galvanic corrosion, but its galvanic corrosion activity gradually became higher than the Tepex-CFRP/steel couple. The different galvanic behaviors of these two couples were discussed based on the electrochemical performance of GM-CFRP, Tepex-CFRP and DP590 coupons in the testing solution.展开更多
Carbon fiber reinforced polymer(CFRP) and AZ31B Mg alloy were joined by the friction self-piercing riveting(F-SPR) with different steel rivet shank sizes. With the increase of rivet shank size, lap shear fracture load...Carbon fiber reinforced polymer(CFRP) and AZ31B Mg alloy were joined by the friction self-piercing riveting(F-SPR) with different steel rivet shank sizes. With the increase of rivet shank size, lap shear fracture load and mechanical interlock distance increased. Ultrafine grains were formed at the joint in AZ31B as a result of dynamic recrystallization, which contributed to the higher hardness. Fatigue life of the CFRP-AZ31B joint was studied at various peak loads of 0.5, 1, 2, and 3 kN and compared with the resistance spot welded AZ31B-AZ31B from the open literature. The fatigue performance was better at higher peak load(>2 kN) and comparable to that of resistance spot welding of AZ31B to AZ31B at lower peak loads(<1 kN). From fractography, the crack initiation for lower peak load(<1 kN) case was observed at the fretting positions on the top and bottom surfaces of AZ31B sheet. When peak load was increased, fretting between the rivet and the top of AZ31B became more dominant to initiate a crack during fatigue testing.展开更多
The mechanical behavior of concrete-filled glass fiber reinforced polymer(GFRP)-steel tube structures under combined seismic loading is investigated in this study. Four same-sized specimens with different GFRP layout ...The mechanical behavior of concrete-filled glass fiber reinforced polymer(GFRP)-steel tube structures under combined seismic loading is investigated in this study. Four same-sized specimens with different GFRP layout modes were tested by a quasi-static test system. Finite element analysis(FEA) was also undertaken and the results were presented. Results of the numerical simulation compared well with those from experimental tests. Parametric analysis was conducted by using the FE models to evaluate the effects of GFRP thickness, axial compression rate, and cross sectional steel ratio. The experimental and numerical results show that the technique of GFRP strengthening is effective in improving the seismic performance of traditional concrete-filled steel tubes, with variations related to different GFRP layout modes.展开更多
A damage mechanics fatigue life prediction model for the fiber reinforced polymer lamina is established. The stiffness matrix of the lamina is derived by elastic constants of fiber and matrix. Two independent damage d...A damage mechanics fatigue life prediction model for the fiber reinforced polymer lamina is established. The stiffness matrix of the lamina is derived by elastic constants of fiber and matrix. Two independent damage degrees of fiber and matrix are introduced to establish constitutive relations with damage. The damage driving forces and damage evolution equations for fiber and matrix are derived respectively. Fatigue tests on 0° and 90° unidirectional laminates are conducted respectively to identify parameters in damage evolution equations of fiber and matrix. The failure criterion of the lamina is presented. Finally, the life prediction model for lamina is proposed.展开更多
Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP speci...Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP specimens with 0,2,4,6,8 g/m^(2)AP were tested under uniaxial compression.Those flexible AP fibers,filling the resin-rich regions and further constructing the fiber bridging at the ply interfaces,can effectively suppress delamination growth and lead to very good improvements both in the compressive strength and the elastic modulus.The CFRP specimen with an optimum interlay thickness has a distinct shear failure mode instead of the typical delamination cracking along the direction of continuous carbon fibers.Compressive Strengths After Impacts(CAI)of 12.35 J were also measured,up to 90%improvement in CAI has been observed.It is concluded those ultra-thin interlays of non-woven AP micro/nano-fibers are beneficial to design and manufacture“high strength”CFRP composites.展开更多
Combined with fiber Bragg grating(FBG)sensing technology,four glass fiber reinforced polymer(GFRP)anti-floating anchors and four steel anti-floating anchors were tested for on-site destructive failure to investigate t...Combined with fiber Bragg grating(FBG)sensing technology,four glass fiber reinforced polymer(GFRP)anti-floating anchors and four steel anti-floating anchors were tested for on-site destructive failure to investigate the anchoring performance and the bonding characteristics between GFRP anti-floating anchor and concrete floor.The test results show that bending GFRP anchor will be broken at the common boundary between vertical anchorage section and bending section during the pullout process,and the spring-back load provided by the rupture contributes to a decrease of bearing capacity and an inflection point on the load-slip curve.The loaddisplacement curve of the straight anchor GFRP anti-floating anchor is smoother and has better predictability than the same type of steel anchor.Additionally,different forms of GFRP anti-floating bolt have different bondslip constitutive relations.By introducing the sliding-slip correction factor of bending bolt,constitutive models describing the rising-section of sliding-slip relation of bending and straight-anchored GFRP anti-floating bolt are established respectively.The model can fit the test results rightly.展开更多
Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the i...Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the issues in the Resin-Rich Region(RRR)and Interfacial Transition Region(ITR)of fiber reinforced polymer composites,the characteristic Aramid Pulp(AP)fibers with micro-fiber trunk and nano-fiber branches were manufactured into multiple non-woven ultra-thin interleaving at the interlayers of BFRP composites via compression molding to reinforce the flexural strengths and elastic moduli.AP fibers were introduced into RRR to form interleaving at the interlayer,the brittle epoxy adhesive layer was improved and enabled to avoid cracking under a low external load.Free fiber branches of AP were also embedded into BF layer to construct quasi-vertical fiber bridging behaviors in ITR,stronger mechanical interlocking was created to prevent crack propagation along the bonding interface of BF/epoxy.Three-point bending testing results showed the interleaving film with 4 g/m^(2)AP exhibited the best effect among various areal densities and yielded average 315.75 MPa in flexural strength and 21.38 GPa in elastic modulus,having a 63.4%increment and a 47.1%increment respectively compared with the bases.Overall,the simple and low-cost AP interleaving is confirmed as an effective method in improving interlayer structure and flexural performance of BFRP composites,which may be considered to manufacture high-performance laminated fiber reinforced polymer composites in civil aviation industry.展开更多
A new testing methodology was developed to quantitively study galvanic corrosion of AZ31B and thermoset carbon-fiber–reinforced polymer spot-joined by a friction self-piercing riveting process.Pre-defined areas of AZ...A new testing methodology was developed to quantitively study galvanic corrosion of AZ31B and thermoset carbon-fiber–reinforced polymer spot-joined by a friction self-piercing riveting process.Pre-defined areas of AZ31B in the joint were exposed in 0.1 M NaCl solution over time.Massive galvanic corrosion of AZ31B was observed as exposure time increased.The measured volume loss was converted into corrosion current that was at least 48 times greater than the corrosion current of AZ31B without galvanic coupling.Ninety percent of the mechanical joint integrity was retained for corroded F-SPR joints to 200 h and then decreased because of the massive volume loss of AZ31B。展开更多
The development of recycled aggregate concrete(RAC)provides a new approach to limiting the waste of natural resources.In the present study,the mechanical properties and deformability of RACs were improved by adding ba...The development of recycled aggregate concrete(RAC)provides a new approach to limiting the waste of natural resources.In the present study,the mechanical properties and deformability of RACs were improved by adding basalt fibers(BFs)and using external restraints,such as a fiber-reinforced polymer(FRP)jacket or a PVC pipe.Samples were tested under axial compression.The results showed that RAC(50%replacement of aggregate)containing 0.2%BFs had the best mechanical properties.Using either BFs or PVC reinforcement had a slight effect on the loadbearing capacity and mode of failure.With different levels of BFs,the compressive strengths of the specimens reinforced with 1-layer and 3-layer basalt fiber reinforced polymer(BFRP)increased by 6.7%–10.5%and 16.5%–23.7%,respectively,and the ultimate strains increased by 48.5%–80.7%and 97.1%–141.1%,respectively.The peak stress of the 3-layer BFRP-PVC increased by 42.2%,and the ultimate strain improved by 131.3%,relative to the control.This reinforcement combined the high tensile strength of BFRP,which improved the post-peak behavior,and PVC,which enhanced the structural durability.In addition,to investigate the influence of the various constraints on compressive behavior,the stress-strain response was analyzed.Based on the analysis of experimental results,a peak stress-strain model and an amended ultimate stress-strain model were proposed.The models were verified as well;the result showed that the predictions from calculations are generally consistent with the experimental data(error within 10%).The results of this study provide a theoretical basis and reference for future applications of fiber-reinforced recycled concrete.展开更多
This paper studied the preparation and mechanical properties of glass fiber reinforced polymer-matrix composite rings prepared by filament winding assisted by ultraviolet(UV)curing.A ray-tracing method was used to cal...This paper studied the preparation and mechanical properties of glass fiber reinforced polymer-matrix composite rings prepared by filament winding assisted by ultraviolet(UV)curing.A ray-tracing method was used to calculate the penetration ability of UV light in the resin casting,and then a typical composite ring with dual⁃curing characteristics was prepared by UV-assisted curing.The effects of winding speed and thermal initiator concentration on the distribution of fiber fraction and mechanical properties were studied.Microscopic morphology was used for the observation of the differences in fiber volume fraction.Mechanical properties tests and scanning electron micrographs were performed to investigate the failure and damage mechanisms of the composite ring samples.The ray tracing results indicate that the UV light can pass through a single yarn thickness and the energy transmitted is sufficient to cure the back side quickly.The experimental results show that the mechanical properties of the composite ring prepared in this paper are comparable to those of the heat-cured samples,which is sufficient to meet the requirements of the flywheel.展开更多
The stowing and deploying experiment was conducted for three 700 mm long thin-walled tubes,and the structural behavior characteristics parameters were measured clearly,including strain,deformation and wrapping moment....The stowing and deploying experiment was conducted for three 700 mm long thin-walled tubes,and the structural behavior characteristics parameters were measured clearly,including strain,deformation and wrapping moment.3D finite element models(FEM)were built subsequently and explicit dynamic method was used to simulate the stowing and deploying of the lenticular carbon fiber reinforced polymer(CFRP)thin-walled tubular space boom,which was designed as four-ply(45°/-45°/45°/-45°)lay-up.The stress and energy during the wrapping process were got and compared with different wrapping angular velocity,the reasonable wrapping angular velocity and effective method were conformed,and structural behavior characteristics were obtained.The results were compared and discussed as well,and the results show that the numerical results by 0.628 rad/s velocity agree well with the measured values.In this paper,the numerical procedure and experimental results are valuable to the optimization design of CFRP thin-walled tubular space boom and future research.展开更多
Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of...Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of bonding techniques adopted to strengthen timber beams using FRP to achieve larger spans.Different methods of bonding between FRP and timber beams have been summarized with a focus on the influencing factors and their effects as well as relevant bond-slip models proposed for fundamental understanding.Experimental investigations to evaluate the flexural performance of timber beams strengthened by FRP bars,sheets and wraps have also been critically reviewed to identify key influencing parameters.Limited research available on the shear performance of FRP reinforced timber beams have been analyzed to determine the influencing factors of the shear performance in timber-FRP beams.The paper finally presents an overall summary of the current-state-of-the-art and proposes some future research directions in the field.展开更多
基金supported by the National Natural Science Foundation of China(52203066,51973157,61904123)Tianjin Natural Science Foundation(18JCQNJC02900)+3 种基金Tianjin Research Innovation Project for Postgraduate Students(2021YJSB234)Science and Technology Plans of Tianjin(19PTSYJC00010)Science&Technology Development Fund of Tianjin Education Commission for Higher Education(Grant No.2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University。
文摘Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery systems for achieving high energy density and excellent safety for energy storage in the future.However,current existed solid-state electrolytes(SSEs)are still difficult to meet the practical application requirements of SSLMBs.In this review,based on the analysis of main problems and challenges faced by the development of SSEs,the ingenious application and latest progresses including specific suggestions of various polymer fibers and their membrane products in solving these issues are emphatically reviewed.Firstly,the inherent defects of inorganic and organic electrolytes are pointed out.Then,the application strategies of polymer fibers/fiber membranes in strengthening strength,reducing thickness,enhancing thermal stability,increasing the film formability,improving ion conductivity and optimizing interface stability are discussed in detail from two aspects of improving physical structure properties and electrochemical performances.Finally,the researches and development trends of the intelligent applications of high-performance polymer fibers in SSEs is prospected.This review intends to provide timely and important guidance for the design and development of polymer fiber composite SSEs for SSLMBs.
基金funded by the National Natural Science Foundation of China(Grant No.92271112).
文摘The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and responsive attributes to chemical and physical stimuli,and are characterized by diverse microscopic structures.Multidimensional fiber microstructures have been fabricated by sophisticated preparation technologies,such as electrospinning,wet spinning,and microfluidic spinning,resulting in SPFs with responsiveness to various stimuli,such as thermal,pH,light,electricity,moisture,magnetic field,and multiple stimuli-responsive properties.In the past decade,cross-disciplinary developments in the refinement,intellectualization,and functionalization of SPFs and notable progress in the fibers'microstructure and stimuli-responsive properties have enabled wide applications in biomedicine,smart textiles,sensors,and water treatment.Herein,to comprehensively facilitate SPFs development in multidisciplinary and multifunctional domains,we elaborate on the correlation among material classification,microstructures formed by common preparation processes,stimuli-responsive properties,and their comprehensive applications.Finally,we aim to inspire scientists with diverse research backgrounds to apply multidisciplinary knowledge to promote the development and industrialization of SPFs.
文摘Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.
基金The National Natural Science Foundation of China(No.51108238)
文摘In order to study the fatigue failure mode and fatigue life laws of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer （ FRP ） sheets, fatigue experiments are carried out, considering two hybrid ratios of 1 ： 1 and 2：1 under different stress levels from 0.6 to 0.95. The results show that fractures occur first in carbon fibers or aramid fibers for the specimens with hybrid ratio of 1： 1, namely B1A1 and B1C1, while a fracture occurs first in basalt fibers for the specimens with a hybrid ratio of 2： 1, namely B2A1 and B2C1. The fatigue lives of the hybrid FRP sheets increase with the improvement of the content of carbon fibers or aramid fibers, and the influence of the carbon fibers content improvement to fatigue life is more significant. The fatigue performance of B2A1 is relatively worse, while the fatigue performance of B1C1 and B2C1 is relatively better. Finally, a new fatigue stiffness degradation model with dual variables and double inflection points is presented, which is applicable to both hybrid and normal FRP sheets.
基金the National Natural Science Foundation of China(Grant No.61890940,51903051)the Natural Science Foundation of Shanghai(Grant 22ZR1407800).
文摘Polymer semiconductors with highly crystalline forms,such as crystalline nanowires and fibers,are critical for charge carrier transport in organic field-effect transistors(OFET).However,the highly crystalline form usually requires high-quality molecular orderliness,which still remains a great challenge,especially in single fibers of extremely high-molecular-weight semiconducting polymers.In this study,we present an anodic aluminum oxide(AAO)template-assisted method to fabricate highly crystalline N-alkyl diketopyrrolopyrrole dithienylthieno[3,2-b]thiophene(DPP-DTT)single fibers.Grazing-incidence X-ray diffraction and selected area electron diffraction show obvious diffraction patterns for single-crystal-like characteristics,indicating the highly ordered molecular chains and highly crystalline structures of the single DPP-DTT fibers.OFET based on the single-crystal-like DPP-DTT fiber exhibits the highest charge carrier mobility of up to 14.2 cm^(2)V^(−1)s^(-1)and an average mobility of approximately 7.8 cm^(2)V^(−1)s^(-1),which is significantly improved compared with DPP-DTT thin film-based devices.Besides,the fiber-based OFET also exhibit a high light responsivity of 4.0.103 A W^(−1).This work demonstrates a facile and effective method for fabricating single-crystal-like fibers of high-molecular-weight polymer semiconductors and corresponding high-performance OFET devices.Furthermore,it also expands application of AAO template method for achieving crystalline semiconducting polymer fibers and provide a new perspective for the study on polymer crystallization.
基金financially supported by the National Natural Science Foundation of China(Nos.21873093 and 22103080)。
文摘The mechanical response of polyethylene nano-fibers with the same chain length but different chain numbers are studied by using steered molecular dynamics simulations.The shrinking or stretching forces acted on the chain ends are investigated according to the chain-end distance and temperature under isothermal or continuous warming-cooling conditions,respectively.An inflection point is found in the ForceDistance response when temperature is below 500 K.This inflection point is related to the balance between entropy force and inter-monomer interaction and it reflects the strong effect of crystallization on the mechanical response of the nano-fibers.The force at inflection point is also affected by the buckling effect due to increased stiffness when crystallization occurs.The two stages found in the Force-Temperature response and the difference between the shrinking and stretching forces indicate the hysteresis of crystallization and melting.The forces at different shrinking and stretching rates reveal the entropy contribution upon the mechanical response,indicated by the Ramachandran plot of dihedrals.The chain-conformation entropy is majorly contributed by dihedrals and is quantified by the information entropy of dihedrals,which has a highly similarity to the mechanical Force-Temperature response.The enlarged forces in multiple chains over a single chain are attributed to the enhanced dihedral-conformation entropy.Our study provides a new insight to the dynamically mechanical response of polymer nano-fibers according to the effect of crystallization and entropy contribution.
文摘This work is aimed at studying the strengthening of reinforced concrete (R. C.) beams using prestressed glass fi- ber-reinforced polymer (PGFRP). Carbon fiber-reinforced polymer (CFRP) has recently become popular for use as repair or rehabilitation material for deteriorated R. C. structures, but because CFRP material is very stiff, the difference in CFRP sheet and concrete material properties is not favorable for transferring the prestress from CFRP sheets to R. C. members. Glass fi- ber-reinforced polymer (GFRP) sheets with Modulus of Elasticity quite close to that of concrete was chosen in this study. The load-carrying capacities (ultimate loads) and the deflections of strengthened R. C. beams using GFRP and PGFRP sheets were tested and compared. T- and ⊥-shaped beams were used as the under-strengthened and over-strengthened beams. The GFRP sheets were prestressed to one-half their tensile capacities before being bonded to the T- and ⊥-shaped R. C. beams. The prestressed tension in the PGFRP sheets caused cambers in the R. C. beams without cracks on the tensile faces. The PGFRP sheets also enhanced the load-carrying capacity. The test results indicated that T-shaped beams with GFRP sheets increased in load-carrying capacity by 55% while the same beams with PGFRP sheets could increase load-carrying capacity by 100%. The ⊥-shaped beams with GFRP sheets could increase load-carrying capacity by 97% while the same beams with PGFRP sheets could increase the loading-carrying capacity by 117%. Under the same external loads, beams with GFRP sheets underwent larger deflections than beams with PGFRP sheets. While GFRP sheets strengthen R. C. beams, PGFRP sheets decrease the beams’ ductility, especially for the over-strengthened beams (⊥-shaped beams).
基金the National Key Technology Research and Development Program(No.2009BAJ28B02)
文摘This paper discusses a new fibrous composite known as continuous basalt fiber reinforced polymer /plastic(BFRP).Compared with other fiber reinforced polymer/plastic,BFRP has many advantages,such as ductility,high thermal resistance,corrosion resistance and economic cost.To test mechanical properties and failure modes of flexural members strengthened with BFRP,flexural experiment is conducted on four two-span T-section continuous beams strengthened with BFRP and one un-strengthened comparative beam.The experimental result shows that the strengthened beams perform remarkably in terms of yield strength,ultimate strength and ductility.BFRP has good prospects in retrofitting and strengthening of concrete structures which require good ductility and corrosion resistance.
文摘The galvanic corrosion behavior of carbon fiber reinforced polymers （CFRPs） GM-CFRP and Tepex-CFRP in contact with a Zn-coated DP590 steel in solution containing 0.9 wt% NaCl＋ 0.1 wt% CaCl2 ＋ 0.075 wt% NaHCO3 was investigated. The results showed that the GM-CFRP/steel couple was initially more resistant to galvanic corrosion, but its galvanic corrosion activity gradually became higher than the Tepex-CFRP/steel couple. The different galvanic behaviors of these two couples were discussed based on the electrochemical performance of GM-CFRP, Tepex-CFRP and DP590 coupons in the testing solution.
基金financially sponsored by the US Department Energy Vehicle Technologies Office, as part of the Joining Core Program。
文摘Carbon fiber reinforced polymer(CFRP) and AZ31B Mg alloy were joined by the friction self-piercing riveting(F-SPR) with different steel rivet shank sizes. With the increase of rivet shank size, lap shear fracture load and mechanical interlock distance increased. Ultrafine grains were formed at the joint in AZ31B as a result of dynamic recrystallization, which contributed to the higher hardness. Fatigue life of the CFRP-AZ31B joint was studied at various peak loads of 0.5, 1, 2, and 3 kN and compared with the resistance spot welded AZ31B-AZ31B from the open literature. The fatigue performance was better at higher peak load(>2 kN) and comparable to that of resistance spot welding of AZ31B to AZ31B at lower peak loads(<1 kN). From fractography, the crack initiation for lower peak load(<1 kN) case was observed at the fretting positions on the top and bottom surfaces of AZ31B sheet. When peak load was increased, fretting between the rivet and the top of AZ31B became more dominant to initiate a crack during fatigue testing.
基金Project supported by the National Natural Science Foundation of China(No.51178068)the Fundamental Research Funds for the Central Universities of China(No.3132013315)
文摘The mechanical behavior of concrete-filled glass fiber reinforced polymer(GFRP)-steel tube structures under combined seismic loading is investigated in this study. Four same-sized specimens with different GFRP layout modes were tested by a quasi-static test system. Finite element analysis(FEA) was also undertaken and the results were presented. Results of the numerical simulation compared well with those from experimental tests. Parametric analysis was conducted by using the FE models to evaluate the effects of GFRP thickness, axial compression rate, and cross sectional steel ratio. The experimental and numerical results show that the technique of GFRP strengthening is effective in improving the seismic performance of traditional concrete-filled steel tubes, with variations related to different GFRP layout modes.
基金supported by the FanZhou Science and Research Foundation for Young Scholars
文摘A damage mechanics fatigue life prediction model for the fiber reinforced polymer lamina is established. The stiffness matrix of the lamina is derived by elastic constants of fiber and matrix. Two independent damage degrees of fiber and matrix are introduced to establish constitutive relations with damage. The damage driving forces and damage evolution equations for fiber and matrix are derived respectively. Fatigue tests on 0° and 90° unidirectional laminates are conducted respectively to identify parameters in damage evolution equations of fiber and matrix. The failure criterion of the lamina is presented. Finally, the life prediction model for lamina is proposed.
基金the National Natural Science Foundation of China(No.52102115)the Fundamental Research Funds of Southwestern University of Science and Technology,China(No.20zx7141).
文摘Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP specimens with 0,2,4,6,8 g/m^(2)AP were tested under uniaxial compression.Those flexible AP fibers,filling the resin-rich regions and further constructing the fiber bridging at the ply interfaces,can effectively suppress delamination growth and lead to very good improvements both in the compressive strength and the elastic modulus.The CFRP specimen with an optimum interlay thickness has a distinct shear failure mode instead of the typical delamination cracking along the direction of continuous carbon fibers.Compressive Strengths After Impacts(CAI)of 12.35 J were also measured,up to 90%improvement in CAI has been observed.It is concluded those ultra-thin interlays of non-woven AP micro/nano-fibers are beneficial to design and manufacture“high strength”CFRP composites.
基金the National Natural Science Foundation of China(Nos.51708316 and 51778312)the China Postdoctoral Science Foundation(No.2018M632641)+1 种基金the Shandong Provincial Key Research and Development Program(Nos.2017GSF16107 and 2018GSF117008)the Shandong Provincial Natural Science Foundation(Nos.ZR2016EEQ08 and ZR2017PEE006)。
文摘Combined with fiber Bragg grating(FBG)sensing technology,four glass fiber reinforced polymer(GFRP)anti-floating anchors and four steel anti-floating anchors were tested for on-site destructive failure to investigate the anchoring performance and the bonding characteristics between GFRP anti-floating anchor and concrete floor.The test results show that bending GFRP anchor will be broken at the common boundary between vertical anchorage section and bending section during the pullout process,and the spring-back load provided by the rupture contributes to a decrease of bearing capacity and an inflection point on the load-slip curve.The loaddisplacement curve of the straight anchor GFRP anti-floating anchor is smoother and has better predictability than the same type of steel anchor.Additionally,different forms of GFRP anti-floating bolt have different bondslip constitutive relations.By introducing the sliding-slip correction factor of bending bolt,constitutive models describing the rising-section of sliding-slip relation of bending and straight-anchored GFRP anti-floating bolt are established respectively.The model can fit the test results rightly.
基金supported financially by the National Natural Science Foundations of China(No.52102115)the Overseas High-End Talent Introduction Project of Sichuan Province,China(No.2023JDGD0013)the Natural Science Foundations of Sichuan Province,China(No.2023NSFSC0961)。
文摘Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the issues in the Resin-Rich Region(RRR)and Interfacial Transition Region(ITR)of fiber reinforced polymer composites,the characteristic Aramid Pulp(AP)fibers with micro-fiber trunk and nano-fiber branches were manufactured into multiple non-woven ultra-thin interleaving at the interlayers of BFRP composites via compression molding to reinforce the flexural strengths and elastic moduli.AP fibers were introduced into RRR to form interleaving at the interlayer,the brittle epoxy adhesive layer was improved and enabled to avoid cracking under a low external load.Free fiber branches of AP were also embedded into BF layer to construct quasi-vertical fiber bridging behaviors in ITR,stronger mechanical interlocking was created to prevent crack propagation along the bonding interface of BF/epoxy.Three-point bending testing results showed the interleaving film with 4 g/m^(2)AP exhibited the best effect among various areal densities and yielded average 315.75 MPa in flexural strength and 21.38 GPa in elastic modulus,having a 63.4%increment and a 47.1%increment respectively compared with the bases.Overall,the simple and low-cost AP interleaving is confirmed as an effective method in improving interlayer structure and flexural performance of BFRP composites,which may be considered to manufacture high-performance laminated fiber reinforced polymer composites in civil aviation industry.
基金financially sponsored by the US Department Energy Vehicle Technologies Office, as part of the Joining Core Programmanaged by UT-Battelle LLC for the US Department of Energy under Contract DE-AC05-00OR22725。
文摘A new testing methodology was developed to quantitively study galvanic corrosion of AZ31B and thermoset carbon-fiber–reinforced polymer spot-joined by a friction self-piercing riveting process.Pre-defined areas of AZ31B in the joint were exposed in 0.1 M NaCl solution over time.Massive galvanic corrosion of AZ31B was observed as exposure time increased.The measured volume loss was converted into corrosion current that was at least 48 times greater than the corrosion current of AZ31B without galvanic coupling.Ninety percent of the mechanical joint integrity was retained for corroded F-SPR joints to 200 h and then decreased because of the massive volume loss of AZ31B。
基金supported by the Natural Science Foundation Project of Liaoning Provincial Department of Education of China under Grant No.JJL201915404,Zhejiang Provincial Natural Science Foundation of China under Grant No.LQ22E080024 and Zhejiang Province Department of Education Fund of China under Grant No.Y202146776.
文摘The development of recycled aggregate concrete(RAC)provides a new approach to limiting the waste of natural resources.In the present study,the mechanical properties and deformability of RACs were improved by adding basalt fibers(BFs)and using external restraints,such as a fiber-reinforced polymer(FRP)jacket or a PVC pipe.Samples were tested under axial compression.The results showed that RAC(50%replacement of aggregate)containing 0.2%BFs had the best mechanical properties.Using either BFs or PVC reinforcement had a slight effect on the loadbearing capacity and mode of failure.With different levels of BFs,the compressive strengths of the specimens reinforced with 1-layer and 3-layer basalt fiber reinforced polymer(BFRP)increased by 6.7%–10.5%and 16.5%–23.7%,respectively,and the ultimate strains increased by 48.5%–80.7%and 97.1%–141.1%,respectively.The peak stress of the 3-layer BFRP-PVC increased by 42.2%,and the ultimate strain improved by 131.3%,relative to the control.This reinforcement combined the high tensile strength of BFRP,which improved the post-peak behavior,and PVC,which enhanced the structural durability.In addition,to investigate the influence of the various constraints on compressive behavior,the stress-strain response was analyzed.Based on the analysis of experimental results,a peak stress-strain model and an amended ultimate stress-strain model were proposed.The models were verified as well;the result showed that the predictions from calculations are generally consistent with the experimental data(error within 10%).The results of this study provide a theoretical basis and reference for future applications of fiber-reinforced recycled concrete.
基金supported by the National Key Laboratory of Science and Technology on Helicopter Transmission(Nanjing University of Aeronautics and Astronautics)(No.HTL-A-20K01)the Pretension and Relaxation Mechanism of Thermoplastic Prepreg Tape Winding with Tension Used to Hi-Speed Permanent Magnet Machine Sleeve(No.51903249)the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Fundamental Research Funds for the Central Universities。
文摘This paper studied the preparation and mechanical properties of glass fiber reinforced polymer-matrix composite rings prepared by filament winding assisted by ultraviolet(UV)curing.A ray-tracing method was used to calculate the penetration ability of UV light in the resin casting,and then a typical composite ring with dual⁃curing characteristics was prepared by UV-assisted curing.The effects of winding speed and thermal initiator concentration on the distribution of fiber fraction and mechanical properties were studied.Microscopic morphology was used for the observation of the differences in fiber volume fraction.Mechanical properties tests and scanning electron micrographs were performed to investigate the failure and damage mechanisms of the composite ring samples.The ray tracing results indicate that the UV light can pass through a single yarn thickness and the energy transmitted is sufficient to cure the back side quickly.The experimental results show that the mechanical properties of the composite ring prepared in this paper are comparable to those of the heat-cured samples,which is sufficient to meet the requirements of the flywheel.
基金the National Natural Science Foundation of China(No.50878128)the Shanghai Aerospace Foundation(No.HTJ10-15)
文摘The stowing and deploying experiment was conducted for three 700 mm long thin-walled tubes,and the structural behavior characteristics parameters were measured clearly,including strain,deformation and wrapping moment.3D finite element models(FEM)were built subsequently and explicit dynamic method was used to simulate the stowing and deploying of the lenticular carbon fiber reinforced polymer(CFRP)thin-walled tubular space boom,which was designed as four-ply(45°/-45°/45°/-45°)lay-up.The stress and energy during the wrapping process were got and compared with different wrapping angular velocity,the reasonable wrapping angular velocity and effective method were conformed,and structural behavior characteristics were obtained.The results were compared and discussed as well,and the results show that the numerical results by 0.628 rad/s velocity agree well with the measured values.In this paper,the numerical procedure and experimental results are valuable to the optimization design of CFRP thin-walled tubular space boom and future research.
基金the National Natural Science Foundation of China(Nos.51878354&51308301)the Natural Science Foundation of Jiangsu Province(Nos.BK20181402&BK20130978)+1 种基金Six Talent Peak High-Level Projects of Jiangsu Province(No.JZ029)Qinglan Project of Jiangsu Higher Education Institutions and the Ministry of Housing and Urban-Rural Science Project of Jiangsu Province under Grant No.JS2021ZD10。
文摘Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of bonding techniques adopted to strengthen timber beams using FRP to achieve larger spans.Different methods of bonding between FRP and timber beams have been summarized with a focus on the influencing factors and their effects as well as relevant bond-slip models proposed for fundamental understanding.Experimental investigations to evaluate the flexural performance of timber beams strengthened by FRP bars,sheets and wraps have also been critically reviewed to identify key influencing parameters.Limited research available on the shear performance of FRP reinforced timber beams have been analyzed to determine the influencing factors of the shear performance in timber-FRP beams.The paper finally presents an overall summary of the current-state-of-the-art and proposes some future research directions in the field.
