To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decay...To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decaying rule of the stress σ , strain ε , strain rate ε · and density ρ with time and space is obtained. By the theory of dynamics, the impact response characteristics of the material is analyzed and discussed.展开更多
One-stage light gas gun was utilized to study the dynamic mechanical properties of AD90 alumina subjected to the shock loading. Manganin gauges were adopted to obtain the stress-time histories. The velocity interferom...One-stage light gas gun was utilized to study the dynamic mechanical properties of AD90 alumina subjected to the shock loading. Manganin gauges were adopted to obtain the stress-time histories. The velocity interferometer system for any reflector （VISAR） was used to obtain the free surface velocity profile and determine the Hugoniot elastic limit. The Hugoniot curves were fitted with the experimental data. From Hugoniot curves the compressive behaviors of AD90 alumina were found to change typically from elastic to ＂plastic＂. The dynamic mechanical behaviors for alumina under impact loadings were analyzed by using the path line principle of Lagrange analysis, including the nonlinear characteristics, the strain rate dependence, the dispersion and declination of shock wave in the material. A damage model applicable to ceramics subjected to dynamic compressive loading has been developed. The model was based on the damage micromechanics and wing crack nucleation and growth. The effects of parameters of both the micro-cracks nucleation and the initial crack size on the dynamic fracture strength were discussed. The results of the dynamic damage evolution model were compared with the experimental results and a good agreement was found.展开更多
The dynamic response of polycrystalline alumina was investigated in the pressure range of 0 - 13 GPa by planar impact experiments. Velocity interferometer system for any reflector（VISAR） was used to obtain free surf...The dynamic response of polycrystalline alumina was investigated in the pressure range of 0 - 13 GPa by planar impact experiments. Velocity interferometer system for any reflector（VISAR） was used to obtain free surface velocity profile and determine the Hugoniot elastic limit, and manganin gauges were employed to obtain the stress-time histories and determine Hugoniot curve. Both the free surface particle velocity profiles and Hugoniot curves indicate the dispersion of the ＂plastic＂ wave for alumina. With the measured stress histories, the complete histories of strain, particle velocity, specific volume and specific internal energy are gained by using path line principle of Lagrange analysis. The dynamic mechanical behaviors for alumina under impact loading are analyzed, such as nonlinear characteristic, strain rate dependence, dispersion and declination of shock wavein the material.展开更多
文摘To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decaying rule of the stress σ , strain ε , strain rate ε · and density ρ with time and space is obtained. By the theory of dynamics, the impact response characteristics of the material is analyzed and discussed.
基金The project supported by the National Natural Science Foundation of China(10632080,10625208,10772027)
文摘One-stage light gas gun was utilized to study the dynamic mechanical properties of AD90 alumina subjected to the shock loading. Manganin gauges were adopted to obtain the stress-time histories. The velocity interferometer system for any reflector （VISAR） was used to obtain the free surface velocity profile and determine the Hugoniot elastic limit. The Hugoniot curves were fitted with the experimental data. From Hugoniot curves the compressive behaviors of AD90 alumina were found to change typically from elastic to ＂plastic＂. The dynamic mechanical behaviors for alumina under impact loadings were analyzed by using the path line principle of Lagrange analysis, including the nonlinear characteristics, the strain rate dependence, the dispersion and declination of shock wave in the material. A damage model applicable to ceramics subjected to dynamic compressive loading has been developed. The model was based on the damage micromechanics and wing crack nucleation and growth. The effects of parameters of both the micro-cracks nucleation and the initial crack size on the dynamic fracture strength were discussed. The results of the dynamic damage evolution model were compared with the experimental results and a good agreement was found.
基金the National Natural Science Foundation of China (10625208)
文摘The dynamic response of polycrystalline alumina was investigated in the pressure range of 0 - 13 GPa by planar impact experiments. Velocity interferometer system for any reflector（VISAR） was used to obtain free surface velocity profile and determine the Hugoniot elastic limit, and manganin gauges were employed to obtain the stress-time histories and determine Hugoniot curve. Both the free surface particle velocity profiles and Hugoniot curves indicate the dispersion of the ＂plastic＂ wave for alumina. With the measured stress histories, the complete histories of strain, particle velocity, specific volume and specific internal energy are gained by using path line principle of Lagrange analysis. The dynamic mechanical behaviors for alumina under impact loading are analyzed, such as nonlinear characteristic, strain rate dependence, dispersion and declination of shock wavein the material.
