The analyses were performed for five loading levels corresponding to the loading levels in experimental investigation and continued up to failure or maximum 10,000 cycles. For example, forthe load level of 0.65sy, the analysis was performed up to 3500 cycles. Fig. 6 shows the images of the microstructure model after 3245 loading cycles. According to Fig. 7, the beginning of failureand, in fact, the lifetime of foam for this specimen is about 3245 cycles and it happened at strain of about 0.03.