VCCT method to simulate the crack in Abaqus

Description

Before explaining the VCCT crack model, let’s learn more about crack in metals.

What is the crack in metals?

Cracks are surface or subsurface fissures that develop in a material. Propagation energy derived from mechanical, thermal, chemical, and metallurgical effects, or a combination of these may influence crack initiation and growth. Various types of cracks exist in metals and can be categorized as cooling, solidification, centreline, crater, grinding, pickling, heat treatment, machining tears, plating, fatigue, creep, stress corrosion and hydrogen cracks. Cracks can grow and lead to complete fracture of the component posing significant threats to component life and may lead to serious injuries or loss of life. Brittle fracture in metals occurs with little or no visible warning. The discovery of any cracks warrants immediate interventions to arrest the cracks before they propagate to the point of fracture.

Simulating the crack

Evaluating the behaviour of metals during crack propagation requires expensive and time-consuming experiments. This makes the FEA method a great tool for a comprehensive study. Since the model requires  prediction of the complex behaviour of the material during propagation, researchers propose various types of simulations. Each method has a specific benefit which makes it an appropriate technique for each purpose or material.

The virtual crack closure technique (VCCT)

The Virtual Crack Closure Technique (VCCT) criterion uses the principles of linear elastic fracture mechanics (LEFM) and, therefore, is appropriate for problems in which brittle crack propagation occurs along predefined surfaces. VCCT is based on the assumption that the strain energy released when a crack is extended by a certain amount is the same as the energy required to close the crack by the same amount.

(Abaqus documentation)

More details about VCCT in Abaqus

You can include a VCCT crack in a static or quasi-static analysis procedure. Alternatively, you can include a VCCT crack in an implicit dynamic analysis procedure to simulate the fracture and failure in a structure under high-speed impact loading. VCCT is available only for Abaqus/Standard (three-dimensional solid and shell and two-dimensional planar and axisymmetric models). You can use VCCT to study a crack in parts containing geometry, orphan mesh elements, or a combination of the two. You define a VCCT crack in the Interaction module and specify the location of the surfaces that are initially bonded.

(Abaqus documentation)

Tutorial Video

In this video, you will learn how to create a simple model to study crack propagation through a part. VCCT is among popular methods to analyze the behaviour of crack during a process. In addition, this method is very fast and appropriate for creating large models. The video is short so you can learn this in less than 10 minutes and you will have the output and Abaqus CAE file.

 In this video, we avoid giving too many details so you can easily use the product. Here you can find the following files:

Abaqus files: CAE, ODB, INP, and JNL

Video files: How to create this model.

PowerPoint and Solidworks files

For more information please send me an Email:

rezatangestani@hyperlyceum.com