叶片精锻三维刚粘塑性热力耦合有限元模拟系统

Investigation in 3D-CTM Software for Simulating Precision Forging Process of Aero-Engine Blade

采用基于边界构形的内缩法,实现了三维畸变网格的重新划分;提出了初矢修正法对触模节点的位置进行修正,解决了由于离散的模具网格的法矢不连续造成的"死锁"问题;采用准静态迭代法简化了速度场和温度场耦合计算过程;特别是针对减速因子β的选取,建立了适用于三维复杂成形过程刚粘塑性罚函数法有限元三次因子法的计算公式,并结合进退搜索法提出了改进的三次因子快速算法,提高了模拟计算效率和稳定性.在此基础之上,开发了面向叶片精锻过程的三维刚粘塑性热力耦合有限元模拟分析系统(3D-CTM).系统的可靠性得到了圆柱体镦粗的验证.对单榫头叶片精锻过程的模拟分析结果表明,3D-CTM是模拟分析叶片精锻过程的可靠工具.

3D-CTM(Coupled Thermo-Mechanical Forming Simulation) software for precision forging process of aero-engine blade was developed. The key technologies of 3D coupled rigid-viscoplastic thermo-mechanical FEM simulation of blade forging process were studied systematically. By using the remeshing method of contracting from the boundary to the inner, new mesh system from old distorted mesh system can be obtained. A method of modifying the position of nodes touching on the die according to its original normal was proposed to avoid dead lock problem due to uncontinuity of normal of scatted die meshes. The pseudo-static iterative algorithm was used to simplify the coupled thermo-mechanical computation. In particular, formulations to determine relaxation factor β was established for rigid viscoplastic FEM adopting penalty function method, and an improved cubic factor rapid algorithm derived from these formulations was proposed by combining with the advantage of advance and retreat search method. Finally, by applying the 3D-CTM to the precision forging process of the blade with tenon, the results show that the system is reliable.