An Example For a Damage Explicit Model (2)

Description

There are two types of process simulations in Abaqus 1- Implicit 2-Explicit model. Implicit models help simulate a process close to a steady-state. On the other hand, Explicit models are good to simulate fast models with element deletion. The damage model is an explicit model. Damage models are common in simulating part failure and are only possible with the explicit method.

Explicit Vs Implicite models:

Implicit models:

Implicit models have large time increment size and are capable of larger time step modelling. The advantage of using implicit models is creating models that take a longer time in the real process. This is because of the element formulations used in this technique. The most common examples of implicit models are rolling processes, low deformation processes and satellite movements in space. However, there are problems which make it impossible to use implicit models for some processes. Models that suddenly change and are deformed dramatically require smaller time increment size. Since the required time to solve each increment is large in implicit models, it is not possible to create models with numerous increments. Consequently, implicit models are not good for explosions simulations and such.

Explicit models:

Explicit models have smaller time increment size compared to implicit models. In fact, explicit models are the combination of lots of static models used to minimize the effect of acceleration in simulation. The time increment are small enough to ignore the effect of acceleration in each increment. However, the effect of acceleration excites in the whole process. Since the time increments are small it is possible to create models with large deformations and sudden changes. The most common examples of explicit models are explosion, large deformation processes, and models with complex surface contacts.

Damage models

Abaqus provides various types of damage models to simulate a part failure. Based on material properties,  different types of models can be considered. In fact, the damaged property for brittle and ductile material are different. For some models, it is necessary to choose elements with deletion property to show the part failure graphically. In order to show element deletion in the process, it is necessary to consider specific field output.

More details about this product:

There are many kinds of processes that require the use of explicit models to be solved. Based on the process the model can be time-consuming or complex to simulate. Thus, the best way to start is to create a straightforward and interesting model. A damage model is the second step to learning explicit models. If you are an absolute beginner, you can start with the following product:

A damage model for a bullet penetration (Second approach)

This model is between beginner to intermediate level. With this model you can start learning more complex explicit models. Bullet penetration is a very interesting case for studying the effect of bullet and plate material properties. Furthermore, in more complex models it is possible to predict field temperature after penetration. Here we are going to cover one of the many approaches of penetration simulation. If you are interested in learnin more approaches, use the following product:

In this example, we try to teach how to use an Explice method to simulate the bullet crushing a plate. We also define damage in this model so when the elements exceed the limit they will be deactivated and the stiffness matrix becomes infinitesimal. Unlike the first approach, you don’t need to use the Abaqus keyword to define any material properties. Because of the element deletion option, this approach is straightforward and offers better graphical results.

In this product, we only give an example to help you use the damage property for your model. We avoid giving too many details so you can easily use the products and learn how to use this option in Abaqus to simulate super large deformation processes. In this product, you can find the following files:

Abaqus files: CAE, ODB, INP, and JNL

Solidwork model

Powerpoint files that contain more details.

Video files: How to create this model, Powerpoint presentation.

For more information please send me an Email:

rezatangestani@hyperlyceum.com