Implementation of Cohesive by interaction & element based methods in ABAQUS

Cohesive element and surface Abaqus training package:

Cohesive behavior describes how one or multiple materials respond when their elements begin to separate. It simulates the material’s resistance to fracture by introducing a traction force (force per unit area) that opposes this separation. As the separation exceeds a critical limit, this traction decreases and eventually drops to zero—representing complete failure or fracture.

To better visualize this, imagine glue between two surfaces. As you pull them apart:

1. The glue resists the separation (traction).
2. The resistance increases until it reaches a maximum value (peak cohesive strength).
3. It then gradually weakens until it can no longer hold the surfaces together (fracture).

Definition of the Cohesive behavior in simulation software

In simulation software, cohesive behavior is defined using a traction-separation law (TSL), which governs the relationship between traction (normal or shear stress across an interface) and the relative displacement between the two surfaces. A simple example of TSL is the linear softening law. In this model, traction increases linearly with displacement up to a peak value (maximum strength). Beyond this point, traction decreases linearly until it reaches zero at a critical separation. The area under the traction-separation curve represents the fracture energy. Other commonly used TSL variants include:

• Bilinear
• Trapezoidal
• Exponential

Classical continuum mechanics assumes a homogeneous material and often fails to capture the initiation and growth of discrete cracks. In such cases, cohesive zone models (CZMs) offer a more accurate and physically meaningful way to simulate fracture phenomena such as delamination, debonding, and interfacial failure. Cohesive behavior is not a material property itself, but a modeling approach, especially useful when traditional stress-based failure criteria are inadequate.

Cohesive modeling is commonly applied in:

• Polymers and adhesives (e.g., glue joints)
• Composites (e.g., fiber-matrix debonding)
• Concrete (e.g., aggregate-matrix separation, crack propagation)
• Geological materials (e.g., rock fractures under loading)
• Metals (e.g., grain boundary/interface separation)
• Wood (e.g., inter-fiber failure)
• Ceramics (e.g., thermal/mechanical cracking)
• Biological tissues (e.g., tissue rupture, bone cracking)

Cohesive modeling in Abaqus

Abaqus is one of the most powerful software tools for simulating cohesive models accurately and robustly. There are two main approaches in Abaqus:

• Element-based
• Surface-based

Both methods are discussed in detail in this package. To enhance your understanding, we’ve also reviewed three practical workshops, and the corresponding Abaqus model files are included.

What topics are covered in this training?

In this package, tips will be given on how to choose the right adhesive element for the problem, how to apply these elements to engineering problems, define the basic geometry of the adhesive elements, and how to define the mechanical behavior of these elements in ABAQUS.

This training package comprehensively examines the cohesive element ABAQUS and cohesive surface Abaqus. The focus of this training package is on modeling by the traction-separation method. Two methods of element-based and surface-based modeling are used to simulate the adhesive, each of which has advantages and disadvantages. The theories used in this package include all adhesive behaviors, including the elastic zone, damage initiation, progressive damage, and element removal.  All equations, damage initiation criteria, and adhesive damage progression are also fully described in this package. In this training package, various examples for each of these methods have been used. Also, note that the use of a solver is effective in how to use these two methods. It should be noted that like other issues, if you use an implicit solver, sometimes there is a problem in convergence, and in this package, solutions to the divergence problem are also presented. Cohesive contact Abaqus in the interaction module and traction-separation law in Abaqus are also explained well in this course.

Lesson Overview

The lesson begins with a basic introduction to cohesive behavior and progresses to modeling strategies in Abaqus. Covered topics include:

1. Applications of cohesive behavior
2. Methods to simulate cohesive behavior
3. Traction-separation laws, damage initiation, and progressive damage evolution
4. Element-based vs surface-based methods for cohesive simulation
5. Detailed comparison of the two methods

Workshops Overview

While the workshops simulate specific problems in Abaqus, they’re designed to equip you with transferable techniques. Topics covered include:

1. Defining traction-separation behavior for cohesive elements
2. Modeling procedures for the element-based approach
3. Assembling cohesive parts and configuring modules
4. Plotting damage initiation vs time for critical elements
5. Addressing convergence issues in the implicit solver
6. Simulating cohesive behavior between bricks and a masonry wall
7. Defining Concrete Damage Plasticity (CDP) behavior
8. Using mass scaling in Abaqus Explicit
9. Output settings for cohesive surface behavior
10. Defining surface-based cohesive behavior in the Explicit solver
11. Defining surface-based cohesive behavior in the Implicit solver

This list represents only part of the content in this package. By now, you’ve likely realized how comprehensive and practical this training can be. The following sections provide further insight into cohesive behavior modeling in Abaqus.

It would be useful to see Abaqus Documentation to understand how it would be hard to start an Abaqus simulation without any Abaqus tutorial.

    It will guide you going from the basics up to complex simulation techniques, and it is very fluid and comprehensive, and every single detail is explained.

   Every lesson goes straight to the point, without any worthless piece of content. You will learn what you need at every stage, and you will be putting it into practice from the very first day.

In a word, being complete and having support in this course is the essential value of this course.

       Most importantly, we support you as you learn in this course. You can contact our experts to ask your questions and enjoy our modelling and simulations step-by-step support for Abaqus software for civil engineering.

       This is just the beginning for you. If you want to become a professional in Abaqus and simulation, you can use our advanced packages and become a professional in advanced Abacus coding.

Read More: abaqus fracture

Click on the chapters of each lesson on the right section of this tab to know the details of the tips and issues presented in this very comprehensive and useful  ABAQUS training package.