This study is to simulate the self-excited oscillation taking place in a flow of the collapsible tube such as a venular vessel or a natural rubber tube. In order to understand the mechanism, one dimensional model is used to formulate the strong interaction between fluid and tube. In flow region, it is assumed that one dimensional incompressible flow with varying widths of tube is considered. The stabilized Galerkin method combined with the predictor multi-corrector algorithms is implemented. In structure region, the beam element is used for longitudinal deformation of the tube and the experimental formula, tube law, been employed to evaluate the circumferential stiffiness. The tube is subjected to very large deformation and unstable, bucking, characteristic. Then, we tried to introduce incremental theory of virtual work principle. The HHT-α method is also used in the time integration schemes. By introducing the incremental formulation, significant improvement is obtained. The mechanism and the relationship between pressure and deformation of the self-excited oscillation were shown in these computations of simple model.
