Experimental Study on Mechanical Properties of Polyethylene HDPE in Conditions of Hydraulic Impact Simulation

Experimental research on mechanical properties of hardened polyethylene HDPE, is developed in the paper. The conditions of hydraulic impact simulation, caused by sudden opening or closing of the valve or by working pomp were adopted in the model. The created in such conditions shock wave moves at a high speed causing additional dangerous dynamic loadings, which lead to faster pipe wear process. The aim of this study is to determine Young's modulus of the pipe material in the cyclic load conditions. The assumed amplitude and frequency of the applied load relates to variation of the impact wave pressure also the speed of the disturbances propagation are taken from experimental measurement of the real water hammer. The measured Young's modulus is higher than that obtained from a static tensile test. The presented study arises from the need to verify the actual value of pipe material mechanical properties, i.e. longitudinal stiffness, for designing of hydraulic pipes under conditions of water hammer.