厚壁圆筒中多条绝热剪切带自组织行为数值模拟

针对304L不锈钢厚壁圆筒内聚压缩过程中出现的多条绝热剪切带自组织行为开展数值模拟研究.在宏观本构中通过引入概率因子描述材料内部微观结构导致的屈服应力分布不均匀性，数值模拟成功再现厚壁圆筒内聚压缩过程中多条绝热剪切带的起始和传播过程.实验研究发现，厚壁圆筒内绝热剪切带的发展方向在45°和135°两族中出现一族占优的“单旋性”现象.304L不锈钢柱壳初始样品的微观表征结果显示，柱壳内表存在一个加工硬化层，该加工硬化层内材料的晶粒表现出特定取向的旋转和损伤特性.数值建模中，使用带有特定取向的周期性单旋扰动描述加工层内晶粒特定去向的旋转、损伤特性，模拟结果成功再现厚壁圆筒中多条剪切带的单旋模式.

Modeling Self-Organization of Shear Bands in 304LSS

The collapse of a 304L stainless steel thick-walled cylinder (TWC) was numerically studied. A probability factor satisfied with Gauss distribution was introduced into the macroscopic constitutive relationship to provide perturbation in modeling. The initiation and propagation of multiple shear bands was successfully triggered by the probability factor in simulation. Periodical single direction spiral perturbations were adopted to characterize the features of grain rotation in the work-hardened layer. The single direction spiral pattern of multiple shear bands in TWC was successfully replicated.