Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic...Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM.展开更多
Roll flattening theory is an important part of plate shape control theories for 20-high mill. In order to improve the accuracy of roll flattening calculation for 20-high mill, a new and more accurate roll flattening m...Roll flattening theory is an important part of plate shape control theories for 20-high mill. In order to improve the accuracy of roll flattening calculation for 20-high mill, a new and more accurate roll flattening model was proposed. In this model, the roll barrel was considered as a finite length semi-infinite body. Based on the boundary integral equation method, the numerical solution of the finite length semi-infinite body under the distributed force was obtained and an accurate roll flattening model was established. Coupled with roll bending model and strip plastic deformation, a new and more accurate plate control model for 20-high mill was established. Moreover, the effects of the first intermediate roll taper angle and taper length were analyzed. The tension distribution calculated by analytical model was consistent with the experimental results.展开更多
The penalty function method of continuum shape optimization and its sensitivity analysis technique are presented. A relatively simple integrated shape optimization system is developed and used to optimize the design o...The penalty function method of continuum shape optimization and its sensitivity analysis technique are presented. A relatively simple integrated shape optimization system is developed and used to optimize the design of the inner frame shape of a three-axis test table. The result shows that the method converges well, and the system is stable and reliable.展开更多
Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniqu...Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniques is crucial for the manufacture of key components,including blades,discs,shafts,and gears.However,machining THSAs pose significant challenges,including high cutting forces and temperatures,which lead to rapid tool wear,reduced efficiency,and compromised surface integrity.This review thoroughly explores the current landscape and future directions of cutting techniques for THSAs in aero-engines.It examines the principles,mechanisms,and benefits of energy-assisted cutting technologies like laser-assisted machining and cryogenic cooling.The review assesses various tool preparation methods,their effects on tool performance,and strategies for precise shape and surface integrity control.It also outlines intelligent monitoring technologies for machining process status,covering aspects such as tool wear,surface roughness,and chatter,contributing to intelligent manufacturing.Additionally,it highlights emerging trends and potential future developments,including multi-energy assisted cutting mechanisms,advanced cutting tools,and collaborative control of structure shape and surface integrity,alongside intelligent monitoring software and hardware.This review serves as a reference for achieving efficient and high-quality manufacturing of THSAs in aero-engines.展开更多
In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution...In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution and accuracy than conventional extensometers.However,the relation between the magnification ratio and the structure size of the displacement amplifier is a bottleneck of sensing device design.Addressing this,the magnification ratio of a mechanical displacement amplifier is analytically derived based on its geometry structure.Six prototypes of the displacement amplifier made in propathene are manufactured,and an experimental system is set up to validate the accuracy of the established magnification ratio equation.Theoretical magnification ratios and experimental magnification ratios are compared and agree well,which verifies that the proposed equation is reliable.This analytical equation provides an effective design method for bridge-shaped mechanical displacement amplifiers with an expected magnification ratio.展开更多
As a virtual representation of a specific physical asset,the digital twin has great potential for realizing the life cycle maintenance management of a dynamic system.Nevertheless,the dynamic stress concentration is ge...As a virtual representation of a specific physical asset,the digital twin has great potential for realizing the life cycle maintenance management of a dynamic system.Nevertheless,the dynamic stress concentration is generated since the state of the dynamic system changes over time.This generation of dynamic stress concentration has hindered the exploitation of the digital twin to reflect the dynamic behaviors of systems in practical engineering applications.In this context,this paper is interested in achieving real-time performance prediction of dynamic systems by developing a new digital twin framework that includes simulation data,measuring data,multi-level fusion modeling(M-LFM),visualization techniques,and fatigue analysis.To leverage its capacity,the M-LFM method combines the advantages of different surrogate models and integrates simulation and measured data,which can improve the prediction accuracy of dynamic stress concentration.A telescopic boom crane is used as an example to verify the proposed framework for stress prediction and fatigue analysis of the complex dynamic system.The results show that the M-LFM method has better performance in the computational efficiency and calculation accuracy of the stress prediction compared with the polynomial response surface method and the kriging method.In other words,the proposed framework can leverage the advantages of digital twins in a dynamic system:damage monitoring,safety assessment,and other aspects and then promote the development of digital twins in industrial fields.展开更多
基金This project is supported by National Natural Science Foundation of China(No.50175031).
文摘Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM.
基金Item Sponsored by National Natural Science Foundation of China(51474190)Natural Sceince Foundation of Hebei Province of China(E2015203311)
文摘Roll flattening theory is an important part of plate shape control theories for 20-high mill. In order to improve the accuracy of roll flattening calculation for 20-high mill, a new and more accurate roll flattening model was proposed. In this model, the roll barrel was considered as a finite length semi-infinite body. Based on the boundary integral equation method, the numerical solution of the finite length semi-infinite body under the distributed force was obtained and an accurate roll flattening model was established. Coupled with roll bending model and strip plastic deformation, a new and more accurate plate control model for 20-high mill was established. Moreover, the effects of the first intermediate roll taper angle and taper length were analyzed. The tension distribution calculated by analytical model was consistent with the experimental results.
文摘The penalty function method of continuum shape optimization and its sensitivity analysis technique are presented. A relatively simple integrated shape optimization system is developed and used to optimize the design of the inner frame shape of a three-axis test table. The result shows that the method converges well, and the system is stable and reliable.
基金National Natural Science Foundation of China(Nos.92160301,92060203,52175415,and 52205475)Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20210295)Fundamental Research Funds for the Central Universities(Nos.NS2023028 and NG2024015)。
文摘Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniques is crucial for the manufacture of key components,including blades,discs,shafts,and gears.However,machining THSAs pose significant challenges,including high cutting forces and temperatures,which lead to rapid tool wear,reduced efficiency,and compromised surface integrity.This review thoroughly explores the current landscape and future directions of cutting techniques for THSAs in aero-engines.It examines the principles,mechanisms,and benefits of energy-assisted cutting technologies like laser-assisted machining and cryogenic cooling.The review assesses various tool preparation methods,their effects on tool performance,and strategies for precise shape and surface integrity control.It also outlines intelligent monitoring technologies for machining process status,covering aspects such as tool wear,surface roughness,and chatter,contributing to intelligent manufacturing.Additionally,it highlights emerging trends and potential future developments,including multi-energy assisted cutting mechanisms,advanced cutting tools,and collaborative control of structure shape and surface integrity,alongside intelligent monitoring software and hardware.This review serves as a reference for achieving efficient and high-quality manufacturing of THSAs in aero-engines.
基金supported by the 111 Project of China(No.B13020)the Shanghai Pujiang Program(No.15PJD010)
文摘In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution and accuracy than conventional extensometers.However,the relation between the magnification ratio and the structure size of the displacement amplifier is a bottleneck of sensing device design.Addressing this,the magnification ratio of a mechanical displacement amplifier is analytically derived based on its geometry structure.Six prototypes of the displacement amplifier made in propathene are manufactured,and an experimental system is set up to validate the accuracy of the established magnification ratio equation.Theoretical magnification ratios and experimental magnification ratios are compared and agree well,which verifies that the proposed equation is reliable.This analytical equation provides an effective design method for bridge-shaped mechanical displacement amplifiers with an expected magnification ratio.
基金supported by the National Key R&D Program of China(Grant No.2018YFB1700704)the National Natural Science Foundation of China(Grant No.52075068).
文摘As a virtual representation of a specific physical asset,the digital twin has great potential for realizing the life cycle maintenance management of a dynamic system.Nevertheless,the dynamic stress concentration is generated since the state of the dynamic system changes over time.This generation of dynamic stress concentration has hindered the exploitation of the digital twin to reflect the dynamic behaviors of systems in practical engineering applications.In this context,this paper is interested in achieving real-time performance prediction of dynamic systems by developing a new digital twin framework that includes simulation data,measuring data,multi-level fusion modeling(M-LFM),visualization techniques,and fatigue analysis.To leverage its capacity,the M-LFM method combines the advantages of different surrogate models and integrates simulation and measured data,which can improve the prediction accuracy of dynamic stress concentration.A telescopic boom crane is used as an example to verify the proposed framework for stress prediction and fatigue analysis of the complex dynamic system.The results show that the M-LFM method has better performance in the computational efficiency and calculation accuracy of the stress prediction compared with the polynomial response surface method and the kriging method.In other words,the proposed framework can leverage the advantages of digital twins in a dynamic system:damage monitoring,safety assessment,and other aspects and then promote the development of digital twins in industrial fields.
