Parametric optimization is an important product design technique, especially in the context of the modern parametric feature-based CAD paradigm. Realizing its full potential, however, requires a closed loop between CAD and CAE (i.e., CAD/CAE integration) with automatic design modifications and simulation updates. Conventionally the approach of model conversion is often employed to form the loop, but this way of working is hard to automate and requires manual inputs. As a result, the overall optimization process is too laborious to be acceptable. To address this issue, a new method for parametric optimization is introduced in this paper, based on a unified model representation scheme called eXtended Voxels (XVoxels). This scheme hybridizes feature models and voxel models into a new concept of semantic voxels, where the voxel part is responsible for FEM solving, and the semantic part is responsible for high-level information to capture both design and simulation intents. As such, it can establish a direct mapping between design models and analysis models, which in turn enables automatic updates on simulation results for design modifications, and vice versa -- effectively a closed loop between CAD and CAE. In addition, robust and efficient geometric algorithms for manipulating XVoxel models and efficient numerical methods (based on the recent finite cell method) for simulating XVoxel models are provided. The presented method has been validated by a series of case studies of increasing complexity to demonstrate its effectiveness. In particular, a computational efficiency improvement of up to 55.8 times the existing FCM method has been seen.
翻译:参数化优化是一种重要的产品设计技术,特别是在现代参数特征CAD范式的背景下。实现其全部潜力需要CAD和CAE之间的闭环(即CAD/CAE集成),具有自动设计修改和模拟更新的功能。通常使用模型转换的方法来形成闭环;但是,这种工作方法难以自动化,并且需要手动输入。因此,整个优化过程太费力以至于无法被接受。为了解决这个问题,本文介绍了一种基于统一模型表示方案的参数化优化方法,称为扩展体素(XVoxels)。该方案将特征模型和体素模型混合成语义体素的新概念。其中,体素部分负责有限元求解,语义部分负责高级信息以捕捉设计和模拟意图。因此,它可以建立设计模型和分析模型之间的直接映射,从而实现设计修改的模拟结果自动更新,反之亦然——有效地实现了CAD和CAE之间的闭环。此外,本文提供了用于操作XVoxel模型的稳健高效的几何算法和用于模拟XVoxel模型的高效数值方法(基于最近的有限单元法)。该方法已经通过一系列不断增加复杂度的案例研究进行了验证以证明其有效性。特别地,看到了高达55.8倍现有FCM方法的计算效率提高。