Dynamic Failure Mode Selection in Rate Sensitive Metal Alloys

本研究的目的是研究控制速率敏感金属合金动态本构和失效行为的物理现象。将开发一种轴向/扭转分裂霍普金森杆，用于研究此类合金在多轴动态加载下的热力学本构和局部化行为。重点将放在检查与预缺口板试件的不对称冲击载荷相关的破坏模式转变现象（动态开裂vs动态剪切带）。各种高速光学和热成像诊断技术将同时用于记录变形，局部化和失效期间的机械和温度场。

The purpose of this research is to study the physical phenomena controlling the dynamic constitutive and failure behavior of rate sensitive metals alloys. A combined axial/torsional split Hopkinson bar will be developed and used to investigate the thermomechanical constitutive and localization behavior of such alloys when they are subjected to multi-axial dynamic loading. Emphasis will be placed on examining the phenomenon of failure mode transition (dynamic cracking vs. dynamic shear banding) associated with asymmetric impact loading of pre-notched plate specimens. A variety of high speed optical and thermographic diagnostic techniques will be used simultaneously to record mechanical and temperature fields during deformation, localization and failure.