精冲时材料在狭窄的凸模、凹模间隙附近形成局部塑性剪切带，极易产生断裂、塌角过大等成形缺陷。本文在MSC/MARC中建立了轴对称精冲有限元模型，利用混合位移－压力的更新拉各朗日有限元方法对精冲局部剧烈塑性变形进行模拟，克服了剪切自锁和体积自锁，结合基于应变梯度、表面曲率的网格自适应技术，精确捕捉了应变集中现象。并通过MARC用户子程序实现了Schiffmann损伤功密度的半耦合计算，预测了精冲过程中材料损伤的发展，并预测了不同工艺参数下的零件塌角高度、光亮带高度和精冲力，最后利用模拟得出的最佳工艺参数获得了合格的零件。
Local plastic shearing band is initialized near blanking clearance during fine-blanking, and forming failures such as ductile fracture and large roll-over usually occur. By using MSC/MARC software, an axisymmetric FE model is created, and mixed u-p updated Lagrange FEM is used to simulate the severe plastic deformation, which could overcome shear locking and volume locking. Together with adaptive remeshing technique based on strain gradient and surface curvature, the strain localization phenomenon could be captured. Schiffmann damage work density model is used to predict the developments of damage and fracture in sheet metal. The height of roll-over, height of burnish band and fine-blanking force are predicted, and qualified part was obtained using optimized process parameters from simulation.
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