空心涡轮叶片精铸模具陶芯夹紧布局优化方法

Optimization method for clamping layout of ceramic core in wax pattern die of hollow turbine blade

针对空心涡轮叶片精铸蜡型模压过程中的陶芯夹紧问题,提出一种基于空间形封闭模型的陶芯型面夹紧点布局优化方法。首先,利用有限元仿真技术建立了空心涡轮叶片蜡型压制过程陶芯载荷预测模型;其次,根据刚体运动学理论给出了陶芯限位点布局形封闭判定条件;最后,以满足空间形封闭以及陶芯与限位元件接触压力要求为约束条件,提出基于粒子群算法的陶芯夹紧点布局优化策略。实例验证表明,相较于工程设计中常规的陶芯夹紧方案,利用所提方法优化得到的陶芯夹紧方案不仅可以保证陶芯与限位元件接触压力满足设计要求,还能进一步减少夹紧点数目。

Aiming at the clamping problem of ceramic core in wax pattern die of hollow turbine blade,a form-closurebased optimization method was proposed.A prediction model which the load on ceramic core in wax injection could be calculated was developed with finite element technique.A form-closure criterion to judge whether a clamping layout could fix the ceramic core or not was established based on rigid body kinematics.By utilizing the form-closure criterion and the contact forces between ceramic core and fix rods as constraints,a clamping layout optimization method was developed based on particle swarm optimization algorithm.The verification results showed that the layout of ceramic core optimized with the proposed method could meet the design requirements of keeping the contact pressures between ceramic core and fix rods,and reduce the number of clamping rods by comparing with the layout employed in engineering application.