Composite Fatigue Simulation with Subroutine in ABAQUS (unidirectional) for 3D Element
Fatigue in composites refers to the weakening of a material caused by repeatedly applied loads or stress cycles over time. When a composite material is subjected to cyclic loading, small cracks or microdamage can form within the material, which may grow and lead to failure after a certain number of loading cycles. This is a significant consideration in the design and analysis of composite structures, especially in applications subjected to repeated stress, such as in aerospace, automotive, or civil engineering.
In one of our other packages, we have used the UMAT subroutine in Abaqus to simulate fatigue in composites in two-dimensional space. The current project is more comprehensive, as it addresses composite fatigue in both 2D and 3D spaces. So you can use it for the simulation of both shells and solids. In this project, you will first become familiar with simulating composite fatigue in 3D space using the Abaqus UMAT subroutine. Then, we will provide a complete UMAT code along with Abaqus files for extending the simulation to 3D space, enabling the 3D simulation of composite fatigue in Abaqus.
Simulation of the Generalized Maxwell Viscoelastic Model using UMAT Subroutine
This research presents a precise three-dimensional mechanical response of viscoelastic materials, such as polymers and elastomers, using the generalized rheological Maxwell viscoelastic model (considering the five Maxwell elements). That is to say, we implement the Maxwell model of viscoelasticity using the UMAT subroutine for the Abaqus standard solver. To clarify, using the concepts in this tutorial, you can implement the model for any N-Maxwell elements, using the viscoelastic Maxwell model.
The Maxwell viscoelastic model is appropriate for qualitative and conceptual analysis, but the single Maxwell element is not sufficient to describe the behavior of elastomers and polymers. For a more precise definition of these materials, the generalized Maxwell viscoelastic model is used. In the generalized Maxwell viscoelastic model, N piece of Maxwell elements and a single spring (the Hooke-element) are assembled in parallel. This tutorial, by customizing the UMAT subroutine to simulate flexible samples behavior, contributes to the advancement of viscoelastic materials design and analysis.