On the Design and Life Prediction of Transmission Belts Made of Elastomer Composites

Doktorsavhandling, 1988

Next to gear transmissions, belt transmissions are the most important mechanical transmissions. Today, belt design and development is based on extensive application tests of belts in the product development process. There is a need for theory development and design support systems. This would enable simulation for prediction and optimization of fatigue life.

The aim of this work is to study certain parts of the belt in detail when the belt is running under loaded conditions. The areas of special interest are those which can be related to failure mechanisms. Thus the model can be used for calculations to predict service life. Here, the attention is focused on V-belts. A fully three-dimensional finite strain constitutive model has been developed for the anisotropic elastomer composites used in V-belts and the constitutive model has been implemented into FEM-software. This makes it possible to do general stress and strain analysis of machine elements designed of elastomer composites. Several different failure modes can be identified in V-belt fatigue. Here it is shown that the failure modes thus defined occur for such test conditions that long life can be associated with radial cracks, medium life with separation, and cord break with short life. In order to monitor the stress-strain state at any location in the belt, while simulating a running belt, “the parametric belt segment model” has been developed. Correlation with V-belt fatigue data for 11 different load cases has been made.

Our conclusion is that both failure mode and fatigue life can be predicted using computer simulations. Friction and wear of materials in a V-belt drive have also been studied.