Numerical and Experimental Analysis of the Base of a Composite Hydraulic Cylinder Made of PET

Abstract

The paper presents the process of designing a base made of PET that will be used as an element of a hydraulic cylinder made of composite materials. The requirements for the designed element include the possibility of working with mechanical and thermal loads comparable to conventional cylinders. The choice of material based on the set criteria and assigned weights, experimental research of its real properties, numerical calculations of the element as well as experimental verification on the real object were presented. The material’s non-linearity and the change of its parameters as a function of working temperature were taken into account.

In order to obtain real values of tensile strength and Young’s modulus, static tensile tests were carried out in accordance with ISO 527–2. The obtained results allowed to include non-linear material properties in the numerical calculations. To know the glass transition temperature and at the same time make sure that the elements made of PET material can be used at temperatures up to 80stC, measurements were carried out using the DMA (Dynamic Mechanical Analysis) method in the temperature range from −120 °C to 250 °C.

Numerical calculations were made using Ansys Mechanical 19.0 software. After the design stage was completed, a base prototype was made that was subjected to static tests in the pressure range up to 25 MPa. Element strains were recorded using strain gauges, which allowed validation of the numerical model.