The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress function...The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress functions required to compute stresses in terms of a set of unknown coefficients for the specified displacement expressions satisfying the prescribed boundary conditions. The assumed Coulomb friction between the plate and the pin was used to provide the solution and iteration was also used to determine the extent of contact region. The results from present study showed good agreement with the available results in literature for all the joint configurations evaluated.展开更多
The tensile behavior of graphene nanoplatelets(GNPs)in epoxy composite under tensile loadings was characterized using uniaxial tensile test at various strain rates ranging from 0.0356 to 0.14/min at room temperature.T...The tensile behavior of graphene nanoplatelets(GNPs)in epoxy composite under tensile loadings was characterized using uniaxial tensile test at various strain rates ranging from 0.0356 to 0.14/min at room temperature.The stresses and the accompanied strains were measured with load cell and an extensometer,respectively.This investigation covers the effect of the amount of graphene in graphene/epoxy composite material system.The uniaxial tensile tests were done to investigate the tensile behavior of the material beyond ultimate tensile strength.The results showed that both the manufacturing and experimental procedure developed are excellent methods to characterize the response of GNP/epoxy composite to tensile loadings.Additionally,the results show a clear strain rate and amount of GNP in epoxy dependencies in the material response.展开更多
The fracture characteristics of graphene nano-platelets(GNP)in epoxy composite under high strain loadings were investigated using impact test at room temperature.The energy required to create a new surface was measure...The fracture characteristics of graphene nano-platelets(GNP)in epoxy composite under high strain loadings were investigated using impact test at room temperature.The energy required to create a new surface was measured with load cell and the accompanied plain strain fracture toughness was calculated.The investigation covered the effect of the amount of graphene in graphene/epoxy composite material system on the fracture behavior of the material.The results showed that both the manufacturing and experimental procedures developed were excellent to quickly and precisely characterize the response of GNP/epoxy composite to impact loadings.Furthermore,the results showed clear dependencies of the material response on the amount of GNP in epoxy.展开更多
The reactive force field was used to study the molecular dynamics of cross-linked EPON 862 （diglycidyl ether of bisphenol-F） and DETDA （diethylene toluene diamine） system in order to predict its thermo-mechanical ...The reactive force field was used to study the molecular dynamics of cross-linked EPON 862 （diglycidyl ether of bisphenol-F） and DETDA （diethylene toluene diamine） system in order to predict its thermo-mechanical behavior under different loading conditions. The approach for building the EPON 862/DETDA structures, cross-linking, and equilibration of the systems, and the evaluation of the models are presented. The mechanical properties such as Young＇s and shear moduli, Poisson ratio, and yields strength as well as thermal properties such as glass transition temperature and coefficient of thermal expansion are predicted. The results are in close agreement with both experimental data and simulated results in literature.展开更多
A two-dimensioual stress analysis was developed to evaluate the failure of composite joints using characteristic length method. In this study, the accuracy of characteristic length method on the prediction of failure ...A two-dimensioual stress analysis was developed to evaluate the failure of composite joints using characteristic length method. In this study, the accuracy of characteristic length method on the prediction of failure strength and failure mode using different failure criteria was investigated. The stresses required for evaluating the joints were computed from stress functions obtained from displacement expressions that satisfy boundary conditions of the hole. The available experimental data for joint strength in literature were compared with the predicted failure loads and modes of failure for different composite pinned joints. No single failure criterion utilized to evaluate the failure gave a universally best fit across the three joints evaluated. However, the accuracy of characterizing the joints failure varies with joint laminate and choice of failure criterions.展开更多
文摘The development of an analytic solution in terms of laminate parameters is presented for contact stresses and joint strength in pin-loaded orthotropic plates. This involved the determination of complex stress functions required to compute stresses in terms of a set of unknown coefficients for the specified displacement expressions satisfying the prescribed boundary conditions. The assumed Coulomb friction between the plate and the pin was used to provide the solution and iteration was also used to determine the extent of contact region. The results from present study showed good agreement with the available results in literature for all the joint configurations evaluated.
文摘The tensile behavior of graphene nanoplatelets(GNPs)in epoxy composite under tensile loadings was characterized using uniaxial tensile test at various strain rates ranging from 0.0356 to 0.14/min at room temperature.The stresses and the accompanied strains were measured with load cell and an extensometer,respectively.This investigation covers the effect of the amount of graphene in graphene/epoxy composite material system.The uniaxial tensile tests were done to investigate the tensile behavior of the material beyond ultimate tensile strength.The results showed that both the manufacturing and experimental procedure developed are excellent methods to characterize the response of GNP/epoxy composite to tensile loadings.Additionally,the results show a clear strain rate and amount of GNP in epoxy dependencies in the material response.
文摘The fracture characteristics of graphene nano-platelets(GNP)in epoxy composite under high strain loadings were investigated using impact test at room temperature.The energy required to create a new surface was measured with load cell and the accompanied plain strain fracture toughness was calculated.The investigation covered the effect of the amount of graphene in graphene/epoxy composite material system on the fracture behavior of the material.The results showed that both the manufacturing and experimental procedures developed were excellent to quickly and precisely characterize the response of GNP/epoxy composite to impact loadings.Furthermore,the results showed clear dependencies of the material response on the amount of GNP in epoxy.
文摘The reactive force field was used to study the molecular dynamics of cross-linked EPON 862 （diglycidyl ether of bisphenol-F） and DETDA （diethylene toluene diamine） system in order to predict its thermo-mechanical behavior under different loading conditions. The approach for building the EPON 862/DETDA structures, cross-linking, and equilibration of the systems, and the evaluation of the models are presented. The mechanical properties such as Young＇s and shear moduli, Poisson ratio, and yields strength as well as thermal properties such as glass transition temperature and coefficient of thermal expansion are predicted. The results are in close agreement with both experimental data and simulated results in literature.
文摘A two-dimensioual stress analysis was developed to evaluate the failure of composite joints using characteristic length method. In this study, the accuracy of characteristic length method on the prediction of failure strength and failure mode using different failure criteria was investigated. The stresses required for evaluating the joints were computed from stress functions obtained from displacement expressions that satisfy boundary conditions of the hole. The available experimental data for joint strength in literature were compared with the predicted failure loads and modes of failure for different composite pinned joints. No single failure criterion utilized to evaluate the failure gave a universally best fit across the three joints evaluated. However, the accuracy of characterizing the joints failure varies with joint laminate and choice of failure criterions.
