Abstarct: The fluid-structure interactions in water hammer phenomenon on pipe systems have always been considered. Because these effects are observed as vibration and an increase in the pressure and displacement of the pipe wall. . Regarding the properties of viscoelastic materials in damping and the effects of friction on energy depletion, the purpose of this study was to model the viscoelastic supports with axial and shear deformation mechanisms due to the (horizontal) forces applied to the supports and also the effect of friction on the supports during the water hammer phenomenon in straghit pipe systems (elastic and viscoelastic) with the viscoelastic sliding support approach to investigate their effects on FSI. In this thesis, poisson and junction coupling of FSI mechanisms are considered. Viscoelasticity behavior of the pipe wall and the supports is described with the generalized Kelvin-voigt mechanical model. Friction supports are modeled through the transition between stick and slip condition. By providing boundary conditions for modeling different types of viscoelastic supports at the valve and along the pipe, the governing equations are solved by the full MOC method in the time domain. Investigations showed that the use of simple viscoelastic supports (axial and shear deformation mechanism) with the appropriate specifications and number, in damping of the pressure and displacement of the pipe wall due to FSI, is effective. and the effects of friction due to slip support (in the viscoelastic sliding supports) depend on the amount of frictional force, so that in the initial cycles, by decreasing frictional force, the results (pressure and displacement) are close to free mode (without support) and by increasing that, the results (pressure and displacement) are close to the pipeline with the simple viscoelastic support (shear mechanism) mode. By increasing the amount of friction force in the viscoelastic support, over time, Decreasing and damping in the vibration of the pressure head and displacement of the pipe wall and the damping in the pressure head values, compared to the use of simple viscoelastic supports were observed, especially in the elastic pipe.