Abaqus橡胶本构模型选择

A Comprehensive Overview of Rubber Constitutive Model Selection within Abaqus: Approaching the Intricacies of MultiParameter Nonlinear Behavior

Abstract

The application of rubber in diverse sectors including medical devices, industry, construction, and defense highlights its versatility and functional importance. However, the constitutive behavior of rubber, driven by complex deformation, large displacements, and significant sensitivity to environmental factors and loading rates, poses significant challenges to modeling and simulation efforts. This paper delves into the methodologies used to select and apply suitable constitutive models for rubber within Abaqus, a powerful finite element analysis software, enabling more precise and reliable simulations.

1. Introduction to Rubber Constitutive Complexity

Contrary to traditional mechanical materials, rubber materials exhibit a nonlinear behavior, characterized by their ability to undergo large deformations and displacements under load. This complexity is further amplified by rubber’s inherent inability to change volume during deformation, combined with its variability in response to environmental conditions, loading history, and the rate of loading. Such properties necessitate detailed and sophisticated mathematical modeling for accurate representation.

2. Selection of Rubber Constitutive Models in Abaqus




In Abaqus, the process for setting up rubber constitutive models encompasses multiple steps which are crucial for achieving accurate mechanical analysis. Below are the primary steps involved in this selection process:

Step 1: Creation of Model Parameters

Initially, within the appropriate module, users must create model parameters such as density, strain capability, and hyperelasticity, as depicted in Figures 13. This step sets the stage for incorporating the foundational aspects of rubber material behavior.

Step 2: Data Import and Selection of Constitutive Models

Following the creation of base parameters, data import for properties like stressstrain curves from singleaxis tests must be prepared (refer to Figures 4 and 5 for an illustration of this preparatory step). Upon data import, the software conducts a test of potentially relevant constitutive models (Figure 6), allowing users to visualize and compare the fit of these models to the experimental data, subsequently selecting the most promising model through a series of comparisons (see Figure 7).

Step 3: Validation of Model Selection

After identifying the potential models, the validation step compares the outcomes from these models to the experimental data (refer to Figures 8, 9, and 10). The results showcased in Figure 8 outline a direct comparison between the experimental data curve and the curve predicted by different constituent models, enabling clear evaluation of each model’s compatibility with the experimental data. Figure 9 and Figure 10 offer an additional perspective, providing a direct comparison between different models and highlighting the most appropriate model based on the graphical outcomes. Following this validation, the selected model can be adjusted within the strain energy potential parameters in Abaqus (returning to Figure 4).

3. Additional Considerations for Rubber Constitutive Modeling

To enhance the accuracy and applicability of rubber modeling, it is essential to address specific considerations:

Irreducible Models for Incompressible Materials: In cases where the material’s behavior is characterized by a Poisson ratio of exactly 0.5 or close to this value, traditional finite element models may fail to accurately predict the stress and strain within the material. For materials approaching incompressibility under the loading condition of plane stress, the reliability of stress predictions becomes questionable.

Response to Uniform Hydrostatic Pressure: Under the influence of a uniform hydrostatic pressure (Figure 11), incompressible materials, including rubber, maintain their volume. This scenario introduces a challenge for predicting the internal deformation within the material, as both the progress of strain and the distribution of stress are uncertain, impeding the connection between nodal displacements and force.

ApplicationSpecific Model Selection: For materials with incompressible properties, such as rubber, the selection of appropriate computational models becomes critical. A hybrid element, like the C3D8RH element, which offers direct determination of the pressure within the element, becomes necessary. This approach allows for the separation of strain energy contributions through displacement and pressure components, enabling more precise mechanical analysis.

By addressing the complexities inherent in modeling rubber’s nonlinear behavior, engineers and analysts can achieve more accurate simulations, further enhancing the development and application of rubber in various industries through precise numerical predictions and optimized designs.