Session: 01-06-02: Impact, Fatigue, Damage and Fracture of Composite Structures 2

Paper Number: 152461

152461 - Accelerating Compression After Impact (Cai) Predictions With a Hybrid Implicit-Explicit (Himex) Progressive Damage Analysis Scheme 

Fiber-reinforced polymer (FRP) composites are vulnerable to impact loadings. Impact events ranging from low-velocity impact (LVI) to high-velocity impact (HVI) may cause detrimental degradation of the composite structure’s load-bearing capacity. Compression after impact (CAI) tests and modeling are usually performed to analyze the impact damage tolerance of FRP composites. Computational CAI models are typically based on damage predicted or characterized by impact modeling and testing. Explicit finite element analysis (FEA) algorithms are frequently used for CAI modeling due to their high robustness. However, the efficiency of explicit algorithms is severely limited by the small time increment sizes to achieve necessary numerical stability. Contrarily, implicit FEA algorithms are of remarkably higher efficiency but often suffer from numerical convergence issues, particularly in cases of high material nonlinearity induced by damage initiation and propagation in impacted FRP composites. This study proposes a hybrid implicit-explicit (HIMEX) scheme for the progressive damage analysis of impact damage development under CAI loading. Initially, the CAI model is seeded with LVI damage according to a novel damage transferring algorithm, and the progressive damage analysis is conducted with an implicit algorithm. A stress monitoring subroutine is developed to bookkeep critical stress states and trigger the switching between the implicit algorithm and an explicit algorithm. The smooth algorithm switching is enabled by a stress-transferring subroutine to reduce spurious numerical oscillations. After switching to the explicit algorithm, the progressive damage analysis will effectively predict the ultimate CAI loading capacity and the propagation LVI damage. The developed HIMEX scheme in this study adds to the CAI analysis capabilities, leading to accurate and fundamentally faster predictions of the LVI damage tolerance and a deeper understanding of hidden damage mechanisms in FRP composites influenced by unique impact damage patterns.

Presenting Author: Shiyao Lin University of Texas at Arlington

Presenting Author Biography: Dr. Shiyao Lin is an Assistant Professor in the Department of Mechanical and Aerospace Engineering (MAE) at the University of Texas at Arlington (UTA). He is also a member of the Institute for Predictive Performance Methodologies (IPPM) at the UTA Research Institute (UTARI). Before joining UTA, Dr. Lin worked as a senior failure analysis R&D engineer at Intel Corporation and a postdoctoral research associate at the University of Michigan.
Dr. Lin obtained his Ph.D. degree from the University of Michigan in Aerospace Engineering and his M.S. and B.S. degrees in Naval Architecture and Ocean Engineering from Huazhong University of Science and Technology (HUST).