基于MIST方法的梯度点阵结构优化设计方法

Optimization Method for Gradient Lattice Structure Based on MIST

文中提出了一种基于移动阈值切面法(Moving Iso-Surface Threshold,MIST)的梯度点阵结构优化方法。优化模型以点阵结构杆件总应变能为目标函数、杆件截面积为优化变量对杆件粗细进行优化,优化目标为总应变能最小。通过长度特征参数对点阵结构疏密分布进行描述,选取长度特征参数作为优化变量,对点阵结构的疏密分布进行优化,进而提出一套包含两类变量的协同优化方法,实现了杆件粗细与疏密分布的协同优化。通过对均质点阵结构进行优化,获得了非均质的梯度点阵结构。最后通过二维和三维算例验证了方法的有效性。

In this paper,an optimization method for gradient lattice structures based on MIST is proposed.The thickness of the lattice structure rods are optimized by choosing the total strain energy of the rods as the objective function and the cross-sectional area of the rods as the optimization variable.The optimization goal is to minimize the total strain energy.The length feature parameter is used to describe the density distribution of the lattice structure.The density distribution is optimized by choosing the length feature parameter as the optimization variable.Then a concurrent optimization method with two types of variables is proposed to optimize the rod thickness and the density distribution at the same time.By optimizing the uniform lattice structure,the non-uniform gradient lattice structure is obtained.Finally 2D and 3D numerical examples are presented to demonstrate the effectiveness of the proposed method.