Nonlinear F.E. analysis of Montreal Olympic Stadium roof under natural loading conditions

The roof over the Montreal Stadium is composed of a pre-tensioned membrane combined with an eccentric cable-stayed system, i.e. the structure is non-symmetric, which leads to a non-uniform structural response under variable static loads. The Montreal Stadium roof is modelled by finite element method as a three-dimensional structure, accounting for geometrically non linear behaviour. The paper begins by analyzing the free vibrations of the structure, then goes on to consider the static as well as the dynamic effects of wind and snow. The loads induced by wind are simulated as deformation-dependent forces, i.e. follower loads. These analyses enable the structural mechanisms that caused the failure of the roof membrane to be described and better understood. In particular, the paper deals with the first failure, which occurred in an apparently unexceptional condition of wind velocity.