论文标题
一种神经网络增强的再现核粒子方法,用于建模应变定位
A Neural Network-enhanced Reproducing Kernel Particle Method for Modeling Strain Localization
论文作者
论文摘要
在损坏的固体中对局部密集型变形进行建模需要高度完善的离散化才能准确预测,这大大增加了计算成本。尽管可以采用自适应模型的改进来提高效率,但基于网格的传统方法在建模不断发展的本地化时执行操作很麻烦。在这项工作中,提出了神经网络增强的再现核粒子方法(NN-rkpm),其中,溶液过渡的位置,方向和形状通过NN近似通过块级神经网络优化自动捕获。阻塞参数化网络中的权重和偏差控制定位的位置和方向。设计的基本四核NN块能够捕获三连接或四连杆连接拓扑模式,而更复杂的定位拓扑模式则由多个四主NN块的叠加来捕获。然后,将标准的RK近似值用于近似溶液的平滑部分,这比使用常规方法捕获尖锐的解决方案过渡所需的高分辨率离散化允许更加粗糙的离散化。还引入了神经网络近似的正则化,以实现与离散化无关的材料响应。提出的NN-RKPM的有效性通过一系列数值验证验证。
Modeling the localized intensive deformation in a damaged solid requires highly refined discretization for accurate prediction, which significantly increases the computational cost. Although adaptive model refinement can be employed for enhanced effectiveness, it is cumbersome for the traditional mesh-based methods to perform while modeling the evolving localizations. In this work, neural network-enhanced reproducing kernel particle method (NN-RKPM) is proposed, where the location, orientation, and shape of the solution transition near a localization is automatically captured by the NN approximation via a block-level neural network optimization. The weights and biases in the blocked parametrization network control the location and orientation of the localization. The designed basic four-kernel NN block is capable of capturing a triple junction or a quadruple junction topological pattern, while more complicated localization topological patters are captured by the superposition of multiple four-kernel NN blocks. The standard RK approximation is then utilized to approximate the smooth part of the solution, which permits a much coarser discretization than the high-resolution discretization needed to capture sharp solution transitions with the conventional methods. A regularization of the neural network approximation is additionally introduced for discretization-independent material responses. The effectiveness of the proposed NN-RKPM is verified by a series of numerical verifications.