Non-linear dynamic response of a reinforced concrete secondary containment shell subjected to seismic load

Abstract

The paper presents details of a non-linear dynamic analysis carried out at SERC, Madras on a reinforced concrete (RC) secondary containment shell subjected to seismic load, taking into account the non-linearities of reinforced concrete in the finite element modelling. A 20-noded, three-dimensional, solid isoparametric finite element is used for spatial discretisation. The concrete in compression is modelled using elasto-viscoplastic constitutive laws, which also include the strain-rate sensitivity and progressive strength degradation of concrete in compression. Cracked concrete is modelled by using a smeared approach and the tension-stiffening effect of concrete is considered by a strain-softening rule. The reinforcement is represented by a smeared approach and a classical elasto-viscoplastic material model is adopted for reinforcement steel. The non-linear response of the RC containment shell subjected to seismic loading was studied by considering appropriate values for the concrete's elastic limit and dynamic modulus of elasticity. The influence of these two parameters on the non-linear response and ultimate behaviour of the structure is discussed.