X形管内高压成形过程的加载路径优化

Optimization on loading path in hydroforming process for X-type tube

加载路径对X形管内高压成形质量至关重要,只有加载路径的各参数匹配得当,才能获得合格的成形件。利用DYNAFORM软件模拟不同加载路径下X形管的成形性能。并基于Box-Behnken Design试验设计和响应面法,以内压力、轴向进给量、背向位移量以及摩擦因数为试验因素,分别建立以最小壁厚、支管高度和极限圆角半径为目标的响应面模型。通过方差分析和回归方程分析,对X形管内高压成形过程的加载路径进行设计和优化,有效地改善了壁厚分布、减小了极限圆角半径、提高了支管高度。采用软件的数值优化功能筛选出最优的加载路径,并在此加载路径下对X形管内高压成形模拟结果和试验结果进行对比,发现误差在5%以内,并且壁厚分布具有一致性,说明了该加载路径优化方法具有较高的准确性和较好的可行性。

The loading path is very important to the hydroforming quality of X-type tube.Only when the various parameters of the loading path are properly matched,the qualified formed parts can be obtained.Therefore,the formability of X-type tube under different loading paths was simulated by software DYNAFORM.Then,based on the test design of Box-Behnken Design and response surface method,taking the internal pressure,axial feeding amount,back displacement and friction coefficient as the main test factors and the minimum wall thickness,branch pipe height and ultimate fillet radius as the objectives,the response surface model was established,and the loading path of X-type tube hydroforming process was designed and optimized by the analysis of variance and regression equation,which improved the wall thickness distribution,reduced the ultimate fillet radius and increased the branch pipe height.Furthermore,the optimal loading path was selected by the numerical optimization function of software,and under this loading path,the simulation results of X-type tube hydroforming were compared with the test results.The result shows that the error is less than 5%,and the wall thickness distribution is consistent,which indicates that the loading path optimization method has high accuracy and good feasibility.