Concrete grandstands. Part II: numerical modelling Available to Purchase

This paper outlines the essential theoretical basis upon which a rigorous finite-element model comprising material non-linearities and failure criteria for both, concrete and steel reinforcement, is built. A numerical algorithm describing the analysis process, based on recent advances in numerical methods of reinforced concrete and a finite-element code were developed in parallel and summarised in a concise flowchart. It was concluded that the finite-element model captured successfully the non-linear flexural behaviour of the terrace units to failure, the formation of a ‘bowl’ at the centre, the lifting of the free tread ends and the rotation about a longitudinal axis. The results produced were rather sensitive to the modulus of elasticity assigned to concrete as well as the initial and, to a lesser extend, additional tangent moduli assigned to the reinforcement. The model was capable of predicting the introduction and propagation of flexural cracks formed around the midspan. More rigorous analytical and numerical work is under way, depicting both static and dynamic conditions, in an effort to establish suitable FE benchmarks, hence reducing uncertainties and increasing confidence of the performance of these structures during their working life.