# Elastomers

## Yeoh Model Parameter

Greetings,

I'm conducting a simple shear test (single lap joint) between aluminum bonded with 3M adhesive.

Adhesive material is 3M VHB 4930 adhesive (acrylic)

Result obtains =

Load vs Displacement Curve

True Stress vs Stretch Ratio

From the literature, mostly they used Yeoh model for 3M adhesive (Modeling and simulation of dielectric elastomer actuators,M.Wissler 2005).

The material constant for C10, C20, C30 I get from the curve fitting equation from the True Stress vs Stretch Ratio.

## Cohesive Elements and Soft Materials

I am working on a model in which i have a soft layer of material bonded between to rigid layers of material via cohesive elements following a linear separation-traction law based on a critical fracture energy value I determined from experimental and numerical work. I have the interlayer and cohesive elements as one part with a partitioned face and connected to the two adherends via surface-to-surface ties. I have found that my model runs successfully only if the soft interlayer material is made very stiff.

## elastomers

Why the elastomers are giving large actuation,what is the reason behind it

## Pressure over closure function for Polyurethane or (nearly) incompressible materials in general

Hi,

Is anyone aware of a pressure-overcosure function for (nearly) incompressible materials.

I am aware of functions for PE and articular cartilage but they do not work with v=0.5.   I have been trying to find similar functions for elastomers, but can't seem to find anything.

I am grateful for any input.

Andreas