Experimental and numerical modelling of nonlinear complex assembled structures

Nonlinearities often originate from different sources in an assembled engineering structure most especially in an industrial application, a large majority of these nonlinearities can be narrowed down to the nature of the joints, material properties, geometric and damping nonlinearities. Research on bolted connections and other types of joints have been proven to introduce large uncertainties in the stiffness and damping properties of a structure, Identifying and predicting the effects of bolted joints in structures is still an area with growing interest, hence this paper presents the nonlinear identification and numerical modelling of a complex assembled structure. Measured data was used to identify the nonlinearities in the assembly, the numerical model generated using Finite Element Method (FEM) provided valuable insight into the frequency response of the nonlinear FE model of the structure. Validation of the numerical model with experimental results was used to gain some awareness on the implications of the nonlinearities caused by the bolted joints.