INFLUENCE OF THE VOLUME FRACTION OF THE CARBONYL IRON PARTICLES ON THE MECHANICAL PROPERTIES OF THE MAGNETORHEOLOGICAL ELASTOMERS

Magnetorheological materials belong to the group of the so called intelligent materials. Their rheological properties can be changed in a large range using an external magnetic field. That is why they find ever growing application in modern technical equipment, among others in controlled dampers, clutches, sensors etc. In the paper, a numerical strength analysis of a magnetorheological material was presented. The influence of the volume fraction of carbonyl iron particles (the share of the carbonyl iron particles varied from 1.5 to 33.0 vol. %.) on the mechanical properties of the material were investigated, in particular on the Young’s modulus variation. Experimental tests were carried out for specimens made of pur e PU 70/30 elastomer with iron particles. They included uniaxial compression tests. In the former case, specimens were in a shape of a cylinder with a diameter of 20 mm and a height of 25-30 mm. The results of experimental tests carried out in order to determine the parameters necessary to build the numerical model were included in the paper. In the paper, an algorithm developed for determining the parameters for modelling the structure was presented. A fragm ent of the structure, containing several particles of iron and some quantity of elastomer, corresponding to the assumed volume fractions, was subjected to numerical analysis