ErwanVerron's blog

This is the preprint of an article that will appear in the International Journal of Non-linear Mechanics

Energy release rate of small cracks in hyperelastic materials by M. Ait-Bachir, W. V. Mars, and E. Verron

We recently published two papers that present an optimization method to design multi-layer composites with damping properties. The method consists in adding elastomeric layers in the composite. In this way, a multi-criteria optimization tool has been developed to determine the best geometrical and material properties of the composite: position of the elastomeric layers, layers thickness, ...

Dear all,

Infinity asked me for posting more information about one of our papers. It was published in 2006 in Rubber Chemistry and Technology and proposes a comparison and a ranking of 20 different hyperelastic constitutive models for rubber (from the Mooney model (1940) to the micro-sphere model (2004)) in the incompressible case.

Marckmann G. et Verron E., Comparison of hyperelastic models for rubberlike materials, Rubber Chemistry and Technology, 79(5), 835-858, 2006.

Here are some of my recent papers about mechanics of rubber material. They concern constitutive modelling, fatigue and fracture.

If you are interested by the mechanics of elastomers, there is a dedicated conference for you : ECCMR 5, which will be held in Paris, France, 4-7 September 2007.

It is the fifth edition of the European Conference on Constitutive Models for Rubber Conference. The call for paper is now closed, but registration is still open.

See the conference web page: http://eccmr.egim-mrs.fr/

The simple extension tear test-piece also referred to as the trousers sample is widely used to study crack propagation in rubber. The corresponding energy release rate, called tearing energy for rubber materials, was first established by Rivlin and Thomas (Rupture of rubber. I. Characteristic energy for tearing. J. Polym. Sci., 10:291–318, 1953); a second derivation was proposed later by Eshelby (The calculation of energy release rates. In G. C. Sih, H. C. van Elst, and D. Broek, editors, Prospects of Fracture Mechanics, 69–84, Leyden, Noordhoff, 1975).

From an engineering point of view, prediction of fatigue crack nucleation in automotive rubber parts is an essential prerequisite for the design of new components. We have derived a new predictor for fatigue crack nucleation in rubber. It is motivated by microscopic mechanisms induced by fatigue and developed in the framework of Configurational Mechanics. As the occurrence of macroscopic fatigue cracks is the consequence of the growth of pre-existing microscopic defects, the energy release rate of these flaws need to be quantified. It is shown that this microstructural evolution is governed by the smallest eigenvalue of the configurational (Eshelby) stress tensor. Indeed, this quantity appears to be a relevant multiaxial fatigue predictor under proportional loading conditions. Then, its generalization to non-proportional multiaxial fatigue problems is derived. Results show that the present predictor, which covers the previously published predictors, is capable to unify multiaxial fatigue data.