A crystal plasticity finite element(CPFE)model was established and 2D simulations were carried out to study the relationship between microvoids and the microplasticity deformation behavior of the dual-phase titanium a...A crystal plasticity finite element(CPFE)model was established and 2D simulations were carried out to study the relationship between microvoids and the microplasticity deformation behavior of the dual-phase titanium alloy under high cyclic loading.Results show that geometrically necessary dislocations(GND)tend to accumulate around the microvoids,leading to an increment of average GND density.The influence of curvature in the tip plastic zone(TPZ)on GND density is greater than that of the size of the microvoid.As the curvature in TPZ and the size of the microvoid increase,the cumulative shear strain(CSS)in the primaryα,secondaryα,andβphases increases.Shear deformation in the prismatic slip system is dominant in the primaryαphase.As the distance between the microvoids increases,the interactive influence of the microvoids on the cumulative shear strain decreases.展开更多
The SHTBT （split Hopkinson tensile bar test） is used for the determination of mechanical material properties at high strain rates, in this case within 10^2-10^3 s^-1. The duration of impact loading is within the ran...The SHTBT （split Hopkinson tensile bar test） is used for the determination of mechanical material properties at high strain rates, in this case within 10^2-10^3 s^-1. The duration of impact loading is within the range of 40-100 μS. The principle of SHTBT is based on the measurement and evaluation of impact loading that is common in high strain rate processes. Strain gauges are usually used to record impact loading. In this case, cylindrical capacitance detectors were used. Plastic deformation of metallic materials and alloys is a complex process that depends on a number of factors with the effect of strain rate being of particular importance. Dynamical tests are used for determination of mechanical properties; therefore, SHTBT is often used for these experiments. The present paper deals with possibilities of testing device for flat bars adapted at Hopkinson test. The aim of this work is concentrated on strain rate influence on 1.4301 austenitic steel, too.展开更多
The aim of this study is to investigate the dynamic stress-strain relation for the hybrid composite （nylon ＋carbon）. Three groups of specimens are used with different number of carbon layers. The specimens were sub...The aim of this study is to investigate the dynamic stress-strain relation for the hybrid composite （nylon ＋carbon）. Three groups of specimens are used with different number of carbon layers. The specimens were subjected to high velocity impact with different strain rates. SHPB （split Hopkinson pressure bar） is used in this investigation. The results show that, the stress-strain relation various with the strain rate. The maximum stress and strain are proportion directly with the strain rate. Also, the results revealed that, as the number of carbon layer increased, the maximum strain decreased.展开更多
基金the National Key Research and Development Program of China(No.2021YFB3702603).
文摘A crystal plasticity finite element(CPFE)model was established and 2D simulations were carried out to study the relationship between microvoids and the microplasticity deformation behavior of the dual-phase titanium alloy under high cyclic loading.Results show that geometrically necessary dislocations(GND)tend to accumulate around the microvoids,leading to an increment of average GND density.The influence of curvature in the tip plastic zone(TPZ)on GND density is greater than that of the size of the microvoid.As the curvature in TPZ and the size of the microvoid increase,the cumulative shear strain(CSS)in the primaryα,secondaryα,andβphases increases.Shear deformation in the prismatic slip system is dominant in the primaryαphase.As the distance between the microvoids increases,the interactive influence of the microvoids on the cumulative shear strain decreases.
文摘The SHTBT （split Hopkinson tensile bar test） is used for the determination of mechanical material properties at high strain rates, in this case within 10^2-10^3 s^-1. The duration of impact loading is within the range of 40-100 μS. The principle of SHTBT is based on the measurement and evaluation of impact loading that is common in high strain rate processes. Strain gauges are usually used to record impact loading. In this case, cylindrical capacitance detectors were used. Plastic deformation of metallic materials and alloys is a complex process that depends on a number of factors with the effect of strain rate being of particular importance. Dynamical tests are used for determination of mechanical properties; therefore, SHTBT is often used for these experiments. The present paper deals with possibilities of testing device for flat bars adapted at Hopkinson test. The aim of this work is concentrated on strain rate influence on 1.4301 austenitic steel, too.
文摘The aim of this study is to investigate the dynamic stress-strain relation for the hybrid composite （nylon ＋carbon）. Three groups of specimens are used with different number of carbon layers. The specimens were subjected to high velocity impact with different strain rates. SHPB （split Hopkinson pressure bar） is used in this investigation. The results show that, the stress-strain relation various with the strain rate. The maximum stress and strain are proportion directly with the strain rate. Also, the results revealed that, as the number of carbon layer increased, the maximum strain decreased.
