Effect of Grain Size, Second Phases and Texture in the Dynamic Failure of Ceramics

本研究采用实验与理论相结合的方法，利用冲击载荷研究微观结构特征对陶瓷破坏的影响。实验方法采用新颖的板和冲击实验，可以选择应力脉冲的大小和持续时间，从而使损伤事件稳定，并且可以在明确定义的变形历史下监测其演变。因此，可以识别损伤演化而不是最终累积损伤。这些结果将形成的基础上，全面了解过程中发生的非弹性变形和制定基于物理的本构方程。干涉测量的速度历史将用于公式模型的检验。测量速度历史和数值计算速度历史之间的相关性将通过使用考虑观察到的破坏机制的非弹性模型对实验进行数值模拟来完成。＊＊＊

9523113 Espinosa The proposed research deals with a combined experimental and theoretical approach using impact loading to study the influence of microstructural features on failure of ceramics. The experimental approach uses novel plate and impact experiments where the magnitude and duration of stress pulses can be selected so that the damage event is stable and its evolution can be monitored under well defined deformation histories. As a result, damage evolution rather than final accumulated damage can be identified. These results will form the basis for comprehensive understanding of the processes occurring during inelastic deformation and formulation of physically based constitutive equations. Interferometrically measured velocity histories will be used in the examination of formulated models. Correlation between measured and numerically computed velocity histories will be accomplished by performing numerical simulations of the experiments with inelastic models accounting for the observed failure mechanisms. ***