Nonlinear pressure wave analysis by concentrated mass model (4th report, modeling of elastic pipe element)

A pressure wave propagating in a tube often changes to a shock wave because of the nonlinear effects in the propagation medium. The purpose of this study is to establish a practical analytical model to analyze this phenomenon. In the first report, a concentrated mass model was proposed to analyze a nonlinear pressure wave phenomenon in a rigid straight cylindrical tube. In this paper, we apply the model to an elastic pipe. The model in the elastic pipe consists of masses, nonlinear connecting springs, base support dampers, base support springs, and connecting dampers. The effect that the cross-sectional area of the elastic pipe changes is considered by the nonlinear connecting spring. To confirm the validity of the proposed elastic pipe model, we perform experiments on a silicone tube, and the experimental results are compared with the numerical results obtained by the concentrated mass model. The numerical computational results agree well with the experimental results. Therefore, it is concluded that the proposed elastic pipe model is valid for the numerical analysis of nonlinear pressure wave problem in an elastic pipe.