Fatigue Life Prediction of Notched Details Using SWT Model and LEFM-Based Approach

Abstract

The fatigue crack initiation life of unwelded steel components accounts for the majority of the total fatigue life, and the accurate prediction of it is of vital importance. In this study, a numerical model utilizing the extended finite element method (XFEM) and Smith–Watson–Topper (SWT) model is established to predict the fatigue crack initiation life of notched details extensively used in orthotropic steel deck bridges. Using the user subroutine UDMGINI in Abaqus, a new algorithm was proposed to calculate the damage parameter of SWT under high-cycle fatigue loads. The virtual crack-closure technique (VCCT) was introduced to monitor crack propagation. Nineteen tests were performed, and the results were used to validate the proposed algorithm and XFEM model. The simulation results show that the proposed XFEM model with UDMGINI and VCCT can reasonably predict the fatigue lives of the notched specimens within the regime of high-cycle fatigue with a load ratio of 0.1. The error for the prediction of fatigue initiation life ranges from −27.5% to 41.1%, and the prediction of total fatigue life has a good agreement with the experimental results with a scatter factor of around 2.

Failure Mechanism of Tensile CFRP Composite Plates with Variable Hole Diameter

“…In addition, the study proposes a new method for determining the crack initiation and failure loads of the composite plate under tension, and the results obtained thereby are verified numerically. A review of the literature shows that many studies have used XFEM for isotropic materials [ 41 , 42 , 43 , 44 ]. However, there is a lack of studies describing the failure of real sandwich composites (CFRPs) using the numerical XFEM technique.…”

Numerical and Experimental Study of Crack Propagation in the Tensile Composite Plate with the Open Hole

“…The novelty of the research problem undertaken in this study is that it describes the phenomenon of fracture and the failure of composite structures using a currently popular XFEM. A literature review demonstrates that numerous studies were devoted to the application of XFEM for isotropic materials [50][51][52][53]. However, there is a lack of studies describing the failure of real layered composites (CFRP) using the numerical XFEM technique.…”