材料构型力学及其在复杂缺陷系统中的应用

MATERIAL CONFIGURATIONAL MECHANICS WITH APPLICATION TO COMPLEX DEFECTS

基于材料构型力学描述复杂缺陷力学系统中的破坏行为,可以为预测材料临界失效载荷和评估结构完整性提供新的思路.首先,通过对拉格朗日能量密度函数的梯度、散度、旋度操作分别获取3类材料构型应力张量的定义式、平衡方程、物理意义以及其对应的守恒积分表达式.其次,基于材料构型力学概念建立描述材料屈服的屈服准则、预测裂纹起裂的断裂准则、以及评估复杂缺陷系统最终失效的破坏准则.然后,利用数字散斑图像相关技术,开发材料构型力学相关参量的无损测量方法.最后,将材料构型力学概念应用于纳米损伤力学和铁电多晶材料的断裂力学中,为此类新型材料的损伤水平评估提供理论支撑.

Material configurational mechanics with application to describe the failure behavior of complex defects does provide an innovative way to predict the failure criteria load and assess the integrity of structures.First,the definitions of material configurational stress as well as the equilibrium equation,physical meaning,and the corresponding invariant integrals are obtained by the gradient,divergence,and curl operation of the Lagrangian function,respectively.Second,the material yielding,fracture,and final failure criteria are newly proposed within the frame of material configurational mechanics.Next,the proposed experimental technique provides an effective and convenient tool to evaluate the material configurational quantities by Digital Image Correlation.Finally,the concept of material configurational mechanics is used to evaluate the damage level of functional materials or structures,such as nano material and ferroelectrics.