Strain accumulation of the components in power-plants and large industries, which causes physical and human costs, has been interested of many researchers in last decades, because of unexpected collapse of these components under periodic loads and internal pressure. In this study, the effect of four basic factors of piping elbow material, frequency of periodic loading (typically below 10 Hz), internal pressure of pipe and periodic dynamic moments on the amount strains accumulation of piping elbows have been considered. Also, the effect of factors variation listed above, on the amount of strains accumulation has been studied. Analyses done in this study, shows that increase in loading frequency, internal pressure and dynamic moments at the end of piping elbow, increases the amount of strains accumulation. Behavior of strain accumulation of two kinds of materials (carbon steel and stainless steel) was investigated in same condition. Studies showed that the strain accumulation in carbon steel are more than stainless steel due to differences in hardness behavior of these materials. The results showed that, stainless steel piping elbow has better performance compared to carbon steel.