钒合金加载变形和损伤演化的数值模拟

Numerical Simulation on Deformation and Damage Evolution in Vanadium Alloy During Tension Loading

钒合金具有良好的高温强度、低辐照活化和抗辐照肿胀等特性,使其成为核工程中的一种重要结构材料。为评估V-5Cr-5Ti合金应力作用下的变形和损伤演化特征,开展了光滑和有缺口两种形状合金试样拉伸加载过程的试验和数值模拟研究,并对断口形貌进行了扫描电镜(SEM)观察。根据拉伸试验拟合钒合金的材料本构参数,数值模拟获得试样加载过程的应力-应变分布和颈缩区的损伤演化,将数值模拟获得的载荷-位移曲线与试验测试对比,结果表明二者在弹性和塑性阶段的变形曲线均非常一致,扫描电镜观察获得了两种形状试样的静态拉伸断裂机制。

Vanadium alloy has become an important structural material for its good strength at elevated temperature, low irradiation activity and irradiation swelling resist ance. For evaluating the deformation and damage evolution in V-SCr-STi alloy under stress state, the tension test and numerical simulation for V-SCr-STi alloy specimens with smooth and notch were developed, and the fracture planes were observed by SEM. The parameters in the constitution law for vanadium alloy were deduced from the experi- ment. The stress and strain distributions and the damage evolution in the specimens were simulated numerically during tension loading. Comparing the loading-displacement curve from simulation with that from experiment, it is shown that they are very identi cal in the state of elastic and plastic deformation, so the finite element model and the parameters in the constitution law and damage model are verified. The static tension fracture mechanisms for the smooth and notch specimens were obtained by SEM.