基于响应曲面法的预成形模具优化设计

Preforming die optimization design based on response surface methodology

采用响应曲面法对预成形模具形状进行了优化设计,以终锻件能够完全充满型腔且飞边最小为优化目标,建立了数学建模。以工字型锻件为例,设计出了直线、圆弧和曲线3种预锻模形状,提取了直线的角度、圆弧的半径、四次曲线的拐点位置为设计变量。以Deform 2D为有限元模拟软件,对每种预锻模形状进行锻造过程模拟,根据模拟出的实验数据求得目标函数值。用曲线拟合软件1st Opt对形状设计变量和目标函数值之间的相互关系进行曲线拟合,得到相应的曲线方程,并对曲线方程求最优解,从而获得最佳角度为41°,最佳半径为109.1 mm,最佳拐点位置为0.3。通过对3种最优预锻模形状的比较,得出四次曲线型预锻模为最佳预锻模形状。

The shape of preforming die was optimized by response surface method, and a mathematic model was established with the opti- mization goal of fully filling the cavity and the minimum flash for finished forging. For I - shaped forging, the shapes of preforming die with straight line, arc and curve were designed respectively, and angles of the straight line, radius of arc, and the locations of inflection point of four curves were extracted as the design variables. Then, the forging process with three different preforming dies was simulated by finite element software Deform 2D, and the value of objective function could be obtained based on the calculated data. Furthermore, the relationship between design value and objective function was fit by the curvilinear fitting software 1 st Opt, and the curvilinear fitting equa- tion was confirmed. Finally, the optimal solutions of the equation with the optimal angle （41°）, optimal radius （109. 1 mm） and optimal turning point position （0. 3 ） were obtained. By comparing three optimal shapes of preforming die, Quartic curve type is the best one.