Finite Element Simulation of Fatigue Life Estimation and Crack Path Prediction of Two-dimensional Structures Components

Abstract

The main objective of this work is to analyse fatigue crack propagation of two-dimensional structures under constant amplitude loading using the developed adaptive mesh finite element. The finite element mesh is generated using the advancing front method. The adaptive remeshing process is carried out based on the posteriori stress error norm scheme. The stress intensity factors are estimated by employing the displacement extrapolation technique facilitated by construction of singular crack tip elements. The crack propagation is modelled by the splitting node approach and the trajectory follows the successive linear extensions of each crack increment. The propagation process is driven by linear elastic fracture mechanics approach. In the analysis, the resulted stress intensity factor range at each of crack increments is recorded. Fatigue life cycle can be predicted immediately after completion of the recording by integrating the generalised Paris' equation. The procedure is applied to the fatigue analysis of three different specimens namely modified compact tension, two internal non-colinear cracks specimen and PMMA beams specimen. Verification of the predicted fatigue life is conducted by comparing the results with the relevant experimental data and numerical results obtained by other researchers. The comparisons show that the developed programme is highly reliable in simulating fatigue crack propagation and predicting the fatigue life cycles.

2D and 3D numerical simulation of fatigue crack growth path and life predictions of a linear elastic

“…The step by step procedure of the developed program software is illustrated in Figure 3. The details of these steps are explained in the literature [29,45,[47][48][49][50]. The adaptive mesh refinement was explained in detail by Bashiri and Alshoaibi [45].…”

Adaptive Finite Element Model for Simulating Crack Growth in the Presence of Holes

“…Commercial software may also be used to model fracture propagation and fatigue life prediction; however, such software is highly expansive, and it is practically difficult to access the source code for further development. The proposed program's effectiveness was shown in a variety of scenarios with accurate results e.g., [18,[25][26][27][28].…”

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

“…It was noticed that too much mesh refinement in crack problems could significantly improve the accuracy of the calculation when increasing the computational time. The development of the present software began in 2004 and has continued to add a range of features from version to version for the simulation of two-dimensional fatigue crack growth with the under the LEFM assumptions [18][19][20][21][22][23][24][25]. LEFMs apply when the material's nonlinear deformation is limited to a small area at the tip of the crack, whereas Elastic Plastic Fracture Mechanics (EPFMs) is proposed to analyze the relatively large plastic zones and assumes isotropic and elastic-plastic materials.…”

“…Concerning knowledge, commercial software is not suitable for at least two reasons: first, it does not completely understand the basic algorithm that it uses, and second there is a complete lack of the state-of-the-art programming skills in its development. The efficiency of the proposed program was demonstrated in many cases such as a compact tension specimen under mixed-mode loading [3], specimen with a hole at its center and three interacting cracks [25], modified four-points bend specimen [22], modified compact tension specimen [6], two internal noncolinear cracks [18] and polymethyl methacrylate (PMMA) specimen with three holes [18].…”