A cyclic stress softening model for the Mullins effect

Transversely isotropic cyclic stress-softening model for the Mullins effect

This paper models stress softening during cyclic loading and unloading of an elastomer. The paper begins by remodelling the primary loading curve to include a softening function and goes on to derive non-linear transversely isotropic constitutive equations for the elastic response, stress relaxation, residual strain and creep of residual strain. These ideas are combined with a transversely isotropic version of the Arruda-Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during cyclic stress-softening for a transversely isot…

Modeling of the equilibrium component of the stress tensor of filled elastomeric materials with taking into account the Mullins softening effect

Elastomers are viscoelastic materials and their properties significantly depend on the loading rate. The actual stress experienced by these materials is the sum of equilibrium and dissipative (inelastic) terms. At very low loading rates we can eliminate the significant influence of time effects and model the material as hyperelastic. In this paper, the features of the experimental determination and subsequent mathematical description of equilibrium stresses are considered. Verification of the proposed equations has been carried out for a series of experiments - cyclic uniaxial tests of samples…

Modelling Mullins Effect Induced by Chain Delamination and Reattachment

We propose a continuum theory to model the Mullins effect, which is ubiquitously observed in polymer composites. In the theory, the softening of the materials during the stretching process is accounted for by considering the delamination of polymer chains from nano-/micro-sized fillers, and the recovery effect during the de-stretching process is due to the reattachment of the polymer chains to nano-/micro-sized fillers. By incorporating the chain entanglements, Log-Normal distribution of the mesh size in the network, etc., we can obtain a good agreement between our numerical calculation result…

The Mullins effect in the wrinkling behavior of highly stretched thin films

Recent work demonstrates that finite-deformation nonlinear elasticity is essential in the accurate modeling of wrinkling in highly stretched thin films. Geometrically exact models predict an isola-center bifurcation, indicating that for a bounded interval of aspect ratios only, stable wrinkles appear and then disappear as the macroscopic strain is increased. This phenomenon has been verified in experiments. In addition, recent experiments revealed the following striking phenomenon: For certain aspect ratios for which no wrinkling occurred upon the first loading, wrinkles appeared during the fi…

Multicyclic modelling of softening in biological tissue

In this paper we derive a model to describe the important inelastic features associated with the cyclic softening, often referred to as stress-softening, of soft biological tissue. The model developed here includes the notion of multiple stress-strain cycles with increasing values of the maximum strain. The model draws upon the similarities between the cyclic softening associated with carbon-filled rubber vulcanizates and soft biological tissue. We give non-linear transversely isotropic models for the elastic response, stress relaxation, residual strain and creep of residual strain. These idea…

强非线性粘弹性软材料中的应力软化损伤：一种具有时间-温度耦合的物理信息数据驱动本构模型

Stress Softening Damage in Strongly Nonlinear Viscoelastic Soft Materials A Physics Informed Data Driven Constitutive Model with Time Temperature Coupling

本文提出一种物理信息数据驱动本构模型，通过嵌入Clausius-Duhem不等式约束损伤变量并结合时间卷积网络，统一描述强非线性粘弹性软材料在时间-温度耦合下的应力软化与Mullins效应，并经Abaqus/Explicit验证有效。