Heterogeneous ageing on laminated rubber bearings under combined compression and cyclic shear loadings: Experiments and simulations
Résumé
Laminated rubber bearings are commonly used for the seismic isolation of civil engineering structures. During earthquake, the rubber material is supposed to undergo static compressive loading combined with cyclic shear loading. During long term service, the mechanical properties, mainly shear and bulk moduli, can evolve due to environmental conditions such as temperature, humidity, oxygen... This evolution can be related to the reorganization of the rubber network due to the chemo-mechanical interaction [1]. In order to highlight this network evolution, an important experimental investigation will be replicated on rubber samples submitted to oxidative thermal ageing.
When it comes to modelling, rubber is generally assumed to have homogeneous mechanical properties. Nevertheless, in the laminated geometry of bearings, exhibiting a high shape factor [2], taking into account the heterogeneous ageing is of prime importance. In this contribution an attempt is made to investigate the effects of the heterogeneous shear and dilatational responses in laminated rubber bearings. The experimental results will be used to enhance the simulation model by offering a closer look at the ageing effects on the rubber mechanical properties.
[1] L. Steinke, J. Spreckels, M. Flamm, and M. Celina. Model for heterogeneous aging of rubber products. Plastics, Rubber and Composites, 40(4):175–179, 2011.
[2] A. Dorfmann, K.N.G. Fuller, and R.W. Ogden. Shear, compressive and dilatational response of rubberlike solids subject to cavitation damage. International Journal of Solids and Structures, 39:1845–1861, 2002.