Stress Distribution in Soft Polymer Laminates

Abstract

The influence of the mechanical properties of the adhesive on the stress distribution in the polyurethane film laminated
leather layers was investigated. The finite elements method was used for the 3-D model evaluation. Laminate models
consisted of three layers: split leather, adhesive film and polyurethane film. The elastic modulus of adhesive layer was
varied from 40 MPa up to 110 MPa. The models were loaded in two different ways, i.e. constant strain of 3 % and
constant force of 100 N. The relationships of adhesive elastic modulus and principal stress in the layers of the laminate
on the loading condition of constant strain or constant force were obtained. The results showed that the increase of
adhesive elastic modulus increases stress only in the adhesive layer of laminate. In the case of loading by constant force
it was obtained that the increase of adhesive elastic modulus increases stresses in its layer and insignificantly decreases
stresses of split leather and microporous polyurethane layers. Layers orientation also influences the deformability and
stress distribution of the laminate. The highest deformability was reached as each split leather or PU film were orientated
in the direction of the lowest elastic modulus