论文标题
通过将交替最小化与局部最小化算法相结合的速率损伤模型平衡粘度解的近似
Approximation of balanced viscosity solutions of a rate-independent damage model by combining alternate minimization with a local minimization algorithm
论文作者
论文摘要
数十年来,裂纹的建模一直是一个深入研究的主题 - 从机械和数学的角度来看。就锋利裂纹/接口的建模而言,由此产生的自由边界问题在数值上非常具有挑战性。因此,从相位理论意义上讲,弥漫性近似已经变得非常流行。在本文中,重点是与速率无关的伤害模型。由于总体上所产生的相田能是非凸的,因此我们面临相位场变量的不连续演变。必须仔细选择解决方案概念,以预测身体上合理的不连续性。我们在这里关注平衡粘度解决方案的概念,并开发了一种收敛方案,该方案将替代最小化与由于Mielke/Efendiev引起的局部最小化Ansatz结合在一起,[EM06]。我们证明了增量溶液与平衡粘度解决方案的收敛性。此外,实施了离散概念,几个精心选择的示例显示了这种组合方法的性能。特别是,研究了局部最小化方案中不同规范和弧长参数的影响。
The modeling of cracks has been an intensely researched topic for decades - both from the mechanical as well as from the mathematics point of view. As far as the modeling of sharp cracks/interfaces is concerned, the resulting free boundary problem is numerically very challenging. For this reason, diffuse approximations in the sense of phase-field theories have become very popular. Within this paper, the focus is on rate-independent damage models. Since the resulting phase-field energies in general are non-convex, we are faced with a discontinuous evolution of the phase-field variable. Solution concepts have to be carefully chosen in order to predict discontinuities that are physically reasonable. We focus here on the concept of balanced viscosity solutions and develop a convergence scheme that combines alternate minimization with a local minimization ansatz due to Mielke/Efendiev, [EM06]. We proof the convergence of the incremental solutions to balanced viscosity solutions. Moreover, the discretization concept is implemented and several carefully selected examples show the performance of this combined approach. Particularly, the effect of different norms and arc-length parameters in the local minimization scheme is investigated.