Dissertation Title: Asynchronous Variational Integrators for the Phase Field Approach to Dynamic Fracture

Date: 2023/11/13

Dissertation Title: Asynchronous Variational Integrators for the Phase Field Approach to Dynamic Fracture

Speaker: Zongwu Niu, Ph.D. candidate at UM-SJTU Joint Institute

Time: November 13th from 2:00 p.m., 2023 (Beijing Time)

Location: Room 414B, Longbin Building

Abstract

This dissertation proposed asynchronous variational integrators for the phase field approach to dynamic fracture. First, a hybrid explicit-implicit asynchronous scheme is proposed and two important phase field variants are studied. Furthermore, an explicit-explicit asynchronous formulation with time adaptivity is developed, accounting for the rate-dependent phase field model. Finally, the AVI is extended to contact problems involving elastoplastic solids with non-associated plasticity model with volumetric hardening. These asynchronous formulations allow each element in the mesh to have dependent local time step and updates the elements and nodes asynchronously, which speeds up the computational efficiency significantly.

Biography

Zongwu Niu received the B.S. degree from Henan university of science and technology in 2016 and the M.S. degree from Zheng Zhou University in 2019. He is a Ph.D. candidate in the University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai, China. He is under supervision of Prof. Yongxing Shen, studying the asynchronous variational integrators for the phase field approach to dynamic fracture.