转轮叶片热模压成形压力中心的动态计算

Dynamic calculation of pressure center during hydraulic turbine blade hot forging

为确保实际生产中压力中心的波动始终处于设定的公差范围之内,提出一种基于刚塑性有限单元法,通过实时节点力的计算来获取非均匀厚度板料成形压力中心的动态算法。推导了相应的计算列式,采用DEFORM软件二次开发实现了该算法。同时,建立了水轮机转轮叶片热模压成形过程的有限元模型,结合上述算法给出了具体的压力中心坐标值,为压力中心的优化提供了必要的数值基础。

To keep the fluctuate of pressure center within the range of pre-defined dimension tolerances, an algorithm based on node forces through FEA was presented, which could be adopted in non-constant thickness sheet metal forming process to calculate the pressure center dynamically. The equations were also introduced and embedded into DE- FORM user routines. An FEA model for hot forming process of hydraulic blade was simulated, then calculated pres- sure center was revealed at any predefined time steps. This can be the pre-work of the optimizations of pressure center.