Characteristics of high-density polyethylene and its properties simulation with use of finite element method

Abstract

It the paper, an analysis of strength characteristics of polyethylene products, obtained by different methods of processing was presented, to obtain definite input data for numerical analysis with the use of finite element method (FEM). The dependence of variations of stress and deformation values on the conditions of tests was analyzed using as examples the samples of high-density polyethylene obtained in the technological processes, subjected to the uniaxial tension at a testing machine. Crystallity degree was determined for the samples obtained from extruded or injected products. The changes of internal characteristics of the products were tested in chosen areas of testing samples under influence of external load increasing in time. The results of laboratory tests formed the basis for development of the characteristics of material and values of parameters for numerical models were determined, dependently on the method applied for polymer sample production. The numerical simulations were conducted in linear formulation, being the simplified analysis in the scope of Hooke's law being in force, and also in physically non-linear range, taking into account the real characteristics of plastic during the process of sample loading. The numerical investigations allowed to define the state of strain and stress in the whole sample analyzed dependently on the processing conditions.