论文标题
自我指导的在线机器学习拓扑优化
Self-Directed Online Machine Learning for Topology Optimization
论文作者
论文摘要
通过在给定域中最佳分发材料来优化拓扑优化需要非毕业优化者来解决高度复杂的问题。但是,随着数百个设计变量或更多的涉及,解决此类问题将需要数百万个有限元方法(FEM)计算,其计算成本又大且不切实际。在这里,我们报告了自我指导的在线学习优化(SOLO),该优化(SOLO)将深层神经网络(DNN)与FEM计算集成在一起。 DNN将目标学习并替换为设计变量的函数。基于DNN的最佳预测,动态生成少量的培训数据。 DNN适应了新的培训数据,并在感兴趣的区域提供了更好的预测,直到收敛为止。通过迭代,DNN预测的最佳预测被证明融合到了真正的全局最佳最佳。我们的算法通过四种类型的问题进行了测试,包括合规性最小化,流体结构优化,传热增强和桁架优化。与直接使用启发式方法相比,它将计算时间减少了2〜5个数量级,并且超过了我们实验中测试的所有最新算法。这种方法可以解决大型多维优化问题。
Topology optimization by optimally distributing materials in a given domain requires non-gradient optimizers to solve highly complicated problems. However, with hundreds of design variables or more involved, solving such problems would require millions of Finite Element Method (FEM) calculations whose computational cost is huge and impractical. Here we report Self-directed Online Learning Optimization (SOLO) which integrates Deep Neural Network (DNN) with FEM calculations. A DNN learns and substitutes the objective as a function of design variables. A small number of training data is generated dynamically based on the DNN's prediction of the optimum. The DNN adapts to the new training data and gives better prediction in the region of interest until convergence. The optimum predicted by the DNN is proved to converge to the true global optimum through iterations. Our algorithm was tested by four types of problems including compliance minimization, fluid-structure optimization, heat transfer enhancement and truss optimization. It reduced the computational time by 2 ~ 5 orders of magnitude compared with directly using heuristic methods, and outperformed all state-of-the-art algorithms tested in our experiments. This approach enables solving large multi-dimensional optimization problems.