OPTIMAL SENSOR PLACEMENT FOR MODAL PARAMETERS TEST OF LARGE SPAN SPATIAL STEEL STRUCTURAL

In order to select the modal order effectively, to make the value of angle among the modal shape vectors and the kinetic energy of measurement point be as large as possible at the same time, a multi-objectives method based on modal energy and adaptive genetic algorithm is proposed. The modal shape order for optimal sensor placement is the order of significant modals selected by the modal strain energy. Optimal sensor placement is done by the adaptive genetic algorithm (AGA), whose fitness function is a new function based on the kinetic energy and the modal assurance criterion (MAC) matrix. Taking the steel structural of National Aquatic Center as a case, the acceleration sensors in modal parameter testing are optimized by the proposed method. The results show that: the proposed method is suit for optimal sensor placement for the modal parameter test of a large span spatial steel structure under ambient excitations.