Estimation of air-spring life based on accelerated experiments

This paper presents a method for estimating the fatigue life of the air-spring, used in truck-cab suspension. Experimental fatigue data, together with finite element analysis data, was used to form the stress life (S–N) curve. Experimental data was obtained from several accelerated experiments using constant load amplitude. Finite element analysis was used to describe the stress–strain conditions in the air-spring’s bellows. Stress tensors gained by FE analysis were exported and used to calculate equivalent uni-axial stresses, using the critical plane approach. To calculate the fatigue life of the air-spring the Palmgren–Miner linear damage hypothesis was used. The same hypothesis was also used to transform linear loading spectrum to constant amplitude load spectrum.