ABSTRACT
This chapter describes a simple approach to form a Haigh-diagram which is suitable for damage calculations on stochastically loaded rubber parts. In this approach the Haigh-diagram is divided into four areas by the load ratio. The two major areas can be treated with Miner's rule and a formulation from spatial analytical geometry. For the remaining areas conservative estimations can be made. In comparison to a Woehler-curve the number of necessary tests needed to characterize this behavior of the lifetime is much higher. Because of the time consuming test procedure, the question which tests should be performed to obtain a Haigh-diagram with a sufficient accuracy and a minimum number of tests plays an important role. If the direction of the maximum principal stresses in the critical point of a test specimen changes only slightly under pure tension and pure compression loads, the area of the alternating loads in the Haigh-diagram can be described with Miner's rule.
