基于有限元灵敏度分析的锻造成形微观组织优化设计

The microstructure optimal design using sensitivity analysis methods in forging process

采用有限元、灵敏度分析与工程优化算法相结合的方法,以能充满型腔且少无飞边的终锻件的晶粒度分布均匀化为目标,以预成形形状为优化对象,对锻造成形过程的微观组织进行了优化设计。采用三次B样条函数描述预成形模具形状,并以B样条函数的控制点坐标为设计变量,给出了锻造过程微观组织演变的模型,建立了衡量锻件充型性能及微观组织分布均匀化的目标函数,推导了目标函数对设计变量的灵敏度,给出了优化设计步骤。并以一典型H型锻件为例,对锻件的微观组织进行了优化,取得了较好的结果。

The microstructure optimal design in hot forging process is presented at the aim of obtaining the net-shape parts and the uniformity of the grain distribution in the final parts by means of changing the preform die shapes, using the finite element method, sensitivity analysis and the engineering optimization algorithm. The preform die shape is represented by cubic B-spline curves and the control points of B-spline are used as the design variables. The model of the microstructure evolution and the objective function are established. The sensitivity of the objective function with respect to the design variables is developed and the optimization procedure is given. Finally, the forming process of a typical H-shaped axisymmetric disk is illustrated as an example and it shows good results.