Adaptive Finite Element Prediction of Fatigue Life and Crack Path in 2D Structural Components

Abdullateef H. Bashiri,Abdulnaser M. Alshoaibi

doi:10.3390/met10101316

Abdullateef H. Bashiri, Abdulnaser M. Alshoaibi

Open Access

https://doi.org/10.3390/met10101316

Copy DOI

Journal: Metals	Publication Date: Oct 1, 2020
Citations: 8	License type: CC BY 4.0

Affiliation: Jazan University

Abstract

The existence of a hole near a growing fatigue crack can cause the crack trajectory to deviate. Unless the hole is too close to the crack, the crack is arrested at the edge of the hole and does not progress further. The purpose of this paper was to predict the crack propagation and lifetime of two-dimension geometries for linear elastic materials in mixed-mode loading using a finite element source code program written in Visual Fortran language. The finite element mesh is generated using the advancing front method. The onset criterion of crack propagation was based on the equivalent stress intensity factor which provides the most important parameter that must be accurately estimated for the mixed-mode loading condition. The maximum circumferential stress theory was used as a direction criterion. The modified compact tension (MCTS) was studied to demonstrate the influence of the hole’s presence on the direction of crack growth and fatigue life for different configurations. The Paris’ law model has been employed to evaluate the mixed-mode fatigue life for MCTS in different configurations under the linear elastic fracture mechanics (LEFMs) assumption. The framework involves a progressive crack extension study of stress intensity factors (SIFs), crack growth direction, and fatigue life estimation. The results show that the fatigue growth was attracted to the hole either changes its direction to reach the hole or floats by the hole and grows as the hole is missed. The results of the study agree with several crack propagation experiments in the literature revealing similar crack propagation trajectory observations.

Highlights

To maintain an acceptable level of durability over the entire operational time, the fatigue crack growth in engineering structures should be monitored
The finite element method (FEM) research has been shown to offer a reliable justification for experimental dynamic crack propagation in two-dimensional situations
If a crack trajectory is associated with a hole, it has first been found that it avoids the hole with a dynamic load and falls into the hole loaded by a similar quasi-static one [7]

Summary

Introduction

To maintain an acceptable level of durability over the entire operational time, the fatigue crack growth in engineering structures should be monitored. Many experimental methods are used today to study the propagation of cracks in steel plates. Most of the experimental approaches to find an effective solution are destructive, expensive, and time-consuming. To overcome these challenges, scientists have proposed several analytical and finite element techniques to quickly find final solutions [1,2,3]. The structures and components are fractured in many fields of engineering due to the accumulation of fatigue failure. The finite element method (FEM) research has been shown to offer a reliable justification for experimental dynamic crack propagation in two-dimensional situations. The SIFs depend on many parameters which are the applied loading of the component, the crack geometry or Metals 2020, 10, 1316; doi:10.3390/met10101316 www.mdpi.com/journal/metals

Objectives

Methods

Results

Conclusion