Introduction and PDF File

The tutorial thoroughly explains the theoretical foundations needed to understand fracture mechanics, as well as how to implement related problems using the available models in Abaqus. As a result, not only will you be able to solve fracture mechanics problems in Abaqus, but you’ll also gain a solid understanding of the underlying theory and relevant equations.

Moreover, in this tutorial, delamination propagation simulation in low-cycle fatigue analyses using VCCT method and Paris law is taught in full detail. The geometric model used in this study is based on finite element models of the Mixed-Mode Bending (MMB) specimen.
Moreover, The project is designed to enhance participants’ understanding how to accurately simulate the fatigue crack growth model using the virtual crack closure technique (VCCT) and Paris law. This method was implemented by editing the keywords.

Theoretical and Base Relations

According to the main topic of this tutorial, it’s important to review the fundamental concepts related to fracture and the principles of linear elastic fracture mechanics. After that, as we have a workshop on fatigue crack growth, how to simulate fatigue crack growth using the VCCT Method and Paris Law is taught in full detail.

Workshop 1: 2D Crack Propagation with XFEM

This session focuses on simulating 2D crack growth in a rectangular steel model using the Extended Finite Element Method (XFEM).

Workshop 2: Classic Method Crack Simulation

Here, you’ll explore crack simulation using the classic method on a 2D rectangular steel model. This workshop also demonstrates the application of the contour integral criterion.

Workshop 3: 3D XFEM Crack Growth

This workshop delves into simulating XFEM crack growth in a 3D cylindrical steel model. The maximum principal stress criterion is used to simulate crack growth in this scenario.

Workshop 4: 3D Crack Simulation in a Tube

In this example, you’ll observe crack growth effects in a 3D steel tube model. The XFEM method is employed to simulate the crack’s behavior.

Workshop 5: crack growth Simulation in bolt connection

In this workshop, we modeled crack growth in a bolted connection using XFEM in Abaqus, aiming to cover a more realistic and complex example. To simplify the model and reduce computational cost, the connection was simulated in 2D. The damage criterion applied is the maximum stress type, and the material used is steel. CPE4 elements were used for the modeling.

Workshop 6: A step-by-step guide on the simulation of delamination propagation in low-cycle fatigue analyses using the VCCT method and Paris Law

The workshop provides a full step-by-step guide through a video to simplify the simulation of fatigue crack growth using the VCCT method and Paris Law. In the video, how to model, edit keywords, submit the job and extract the results are shown in full detail.

Geometry: This example includes a rigid loading arm and two Lagrangian specimens. The upper specimen is subjected to periodic tension by this arm. The schematic design of problem is shown in Figure 1. 

The material properties used in this example is presented in an Excel file named “Material Properties”. The load or displacement applied to the loading arm is multiplied by a periodic amplitude.

Figure 1: The schematic designs of the problem

Workshop 7: Crack Simulation in a Pressurized Tank

This workshop covers crack simulation in a tank under internal and external pressure. It utilizes the DLOAD subroutine and the contour integral criterion. You’ll also be able to see the J-integral value at the end of the workshop.

Workshop 8 (New): Extracting Crack Length and Other Post-Processing Tasks in 2D Fracture Mechanics Simulation Using the XFEM Method

In this workshop, unlike the previous ones, our goal is not to model fracture mechanics problems in Abaqus. Instead, we focus on teaching you how to extract specific results after the analysis is complete.

For example, we provide a Python script that, when run in Abaqus, automatically extracts the crack length over time and saves it to a CSV file. We also demonstrate how to extract the force–crack mouth opening displacement (CMOD) curve and how to plot the external work as a function of crack length.

Since the main focus of this workshop is post-processing, no new problem is modeled. We use the same model from Workshop 1 and apply the post-processing procedures to it.

To help you understand how the crack length extraction script works and the logic behind it, we’ve also included a block-by-block explanation of the code in a PDF document.