The effect of temperature on the compressive behavior of epoxy compound EPY®
M. Urbaniak, K. Grudziński Politechnika Szczecińska, Wydział Mechaniczny, Katedra Mechaniki i Podstaw Konstrukcji Maszyn al. Piastów 19, 70-310 Szczecin
Quarterly No. 1, 2006 pages 20-25
DOI:
keywords: epoxy compound, mechanical properties, compressive strain rate, temperature effects
abstract The object of the investigations described in this article was a special epoxy material, known under its trade name EPY®, which is applied to foundation chocks of ships’ machinery and installations, and also in many other heavy land-based machines. Casting of foundation chocks from this material on the spot, directly under an installed object (e.g. a ship’s main engine) considerably simplifies the assembling technology of heavy machines and gives a lot of technical, economic and maintenance advantages. However, it must be taken into account that mechanical properties of foundation chocks obtained in this way depend not only on the chemical composition of the polymer but also on the production technology and operating conditions of the chocks - and particularly on the temperature and the strain rate. The aim of the studies presented in the article was to investigate the postcuring process for the EPY® material and the effect of the temperature and strain rate on the mechanical properties of this material too. The postcuring process of the EPY® material was investigated by DSC method. The obtained DSC thermograms are shown in Figure 1. The mechanical characteristics and the values of some selected compressive strength parameters for the EPY® material subjected to load at various temperatures (from 22 to 160°C) and various strain rates (from 0.0208 to 20.8 min– 1) were determined by means of a computerized testing machine INSTRON. The results of these investigations are shown in Figures 2 to 5. The results of the tests showed their good fit to the Eyring equation (2). Consequently, the compressive strength of the postcured EPY® material increases lineally together with the logarithm of strain rate (Fig. 6). However, elevated test temperatures (in the range from 22 to 100°C) of the material led to a decrease of its sensitivity to strain rate changes (Fig. 6). The results of the tests proved to be in good fit with the results calculated using the Lesser empirical equation (4) which allows compressive strength forecasting of the postcured EPY® material depending on the temperature of measurement (Fig. 7). The performed investigations make it possible to carry out a more comprehensive evaluation of the essential mechanical properties of the EPY® material treated as a structural material used for assembling of heavy machines and installations which work in various thermal and loading conditions.