Uniaxial strain hardening exponent is not suitable for describing the strain hardening behaviors of the anisotropic materials, especially when material deforms in the multi-axial stress states. In this work, a novel m...Uniaxial strain hardening exponent is not suitable for describing the strain hardening behaviors of the anisotropic materials, especially when material deforms in the multi-axial stress states. In this work, a novel method was proposed to estimate the equivalent strain hardening exponent of anisotropic materials based on an equivalent energy method. By performing extensive finite element (FE) simulations of the spherical indentation on anisotropic materials, dimensionless function was proposed to correlate the strain hardening exponent of anisotropic materials with the indentation imprint parameters. And then, a mathematic expression on the strain hardening exponent of anisotropic materials with the indentation imprint was established to estimate the equivalent strain hardening exponent of anisotropic materials by directly solving this dimensionless function. Additionally, Meyer equation was modified to determine the yield stress of anisotropic materials. The effectiveness and reliability of the new method were verified by the numerical examples and by its application on the TC1M engineering material.展开更多
A new method for determining two key parameters(threshold pressure and permeability)for fabricating metal matrix composites was proposed based on the equation-solving method.An infiltration experimental device was dev...A new method for determining two key parameters(threshold pressure and permeability)for fabricating metal matrix composites was proposed based on the equation-solving method.An infiltration experimental device was devised to measure the infiltration behavior precisely with controllable infiltration velocity.Two experiments with alloy Pb-Sn infiltrating into Al2O3 preform were conducted independently under two different pressures so as to get two different infiltration curves.Two sets of coefficients which are functions of threshold pressure and permeability can be obtained through curve fitting method.By solving the two-variable equation set,two unknown variables were determined.It is shown that the determined threshold pressure and permeability are very close to the calculated ones and are also verified by another independent infiltration experiment.The proposed method is also feasible to determine the key infiltration parameters for other metal matrix composite systems.展开更多
Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical propert...Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.展开更多
基金Project(51675431)supported by the National Natural Science Foundation of China
文摘Uniaxial strain hardening exponent is not suitable for describing the strain hardening behaviors of the anisotropic materials, especially when material deforms in the multi-axial stress states. In this work, a novel method was proposed to estimate the equivalent strain hardening exponent of anisotropic materials based on an equivalent energy method. By performing extensive finite element (FE) simulations of the spherical indentation on anisotropic materials, dimensionless function was proposed to correlate the strain hardening exponent of anisotropic materials with the indentation imprint parameters. And then, a mathematic expression on the strain hardening exponent of anisotropic materials with the indentation imprint was established to estimate the equivalent strain hardening exponent of anisotropic materials by directly solving this dimensionless function. Additionally, Meyer equation was modified to determine the yield stress of anisotropic materials. The effectiveness and reliability of the new method were verified by the numerical examples and by its application on the TC1M engineering material.
基金Project(51575447) supported by the National Natural Science Foundation of ChinaProject supported by Top University around World Visiting Plan for Young Teacher’s Cultivating in NWPU,China
文摘A new method for determining two key parameters(threshold pressure and permeability)for fabricating metal matrix composites was proposed based on the equation-solving method.An infiltration experimental device was devised to measure the infiltration behavior precisely with controllable infiltration velocity.Two experiments with alloy Pb-Sn infiltrating into Al2O3 preform were conducted independently under two different pressures so as to get two different infiltration curves.Two sets of coefficients which are functions of threshold pressure and permeability can be obtained through curve fitting method.By solving the two-variable equation set,two unknown variables were determined.It is shown that the determined threshold pressure and permeability are very close to the calculated ones and are also verified by another independent infiltration experiment.The proposed method is also feasible to determine the key infiltration parameters for other metal matrix composite systems.
文摘Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.
