Experimental study of dynamic response of structures with gaps excited by random white noise: Flexible impact support

摘要

In the dynamic design of the structures with gaps, the interaction between the oscillating structure and the impact support is usually evaluated under the condition that the impact force modelling is the derivative of the elastic energy of the system only. This approximate dynamic model is frequently used for practical analysis to predict the response of dynamic structures such as piping having a clearance with the supporting device, mechanical equipment subjected to impact disturbance with the basements, and so on. Moreover, with a random excitation, the simulated response and the stationary Fokker-planck equation solution are frequently obtained by using this modelling. Nevertheless, the computation results have never been confronted to the experimental ones. This observation has motivated our research. Therefore, we have installed a dynamic experimental model thanks to which we could achieve the above mentioned comparison. In the first part of this study, we describe the methodology numerical modelling. The second part deals with the description of the experiment equipment and the necessary adjustment tests. In the last part, the stochastic non-linear experimental results are given and compared with the modelled ones. This study is based on the determination of the probabilistic characteristics (mean, standard deviation, probability law and spectral density) of the dynamic motion of both systems (principal structure and stopper).