板料成形过程中工艺辅助面的设计与优化(英文)

板料成形过程中工艺辅助面对成形件质量有着重要意义 ,但其设计非常费时 ,并且需要根据实验和数值模拟不断修正。本文提出一种工艺辅助面设计优化的方法。根据预期的工件形状 ,CAD软件会自动生成具有一阶连续的工艺辅助面。这些辅助面由 4个几何参数确定并且在随后的优化中将其作为设计变量。有限元网格划分在有用工件和初始辅助面上 ,在优化过程中将这些网格映射到改变了的工艺辅助面上而不需要重新划分网格。优化过程中采用可行域二次序列规划算法 (FSQP) ,并采用两个目标函数 :第一个是厚度函数 ,以使工件厚度变化最小 ;第二个是表面质量目标函数 ,以避免工件外表面的擦伤。FSQP算法和我们的快速逆法成形求解器相结合而得到一个高效的优化程序。本文提出的辅助面设计优化方法在方盒件和减震器罩上得到了成功的应用。

Design and optimization of addendum surfaces in sheet deep drawing process

The addendum surfaces are very important for the product quality in sheet forming process, but their design is very time-consuming and requires tedious trial-error corrections.In this paper, a methodology is proposed for the design and optimization of addendum surfaces using a forming modelling solver. Starting with the desired workpiece, the addendum surfaces with C1 continuity are automatically generated. These surfaces are characterised by four geometrical dimensions, taken as the design variables in the optimization procedure. During the optimization, the finite element mesh created on the initial addendum surfaces is mapped onto the modified ones without remeshing operation. The Feasible Sequential Quadratic Programming (FSQP) is adopted as the optimization algorithm. Two objective functions are considered: the thickness function to minimize the thickness variation on the workpiece, the aspect function aiming to avoid the scratching defects. The FSQP is combined with our fast forming solver called "Inverse Approach" and this leads to a very efficient optimization procedure.