The AutoFEM Fatigue Analysis module is used in conjunction with AutoFEM Static Analysis and allows one to evaluate the strength of a structure, which is subjected to cyclic loading. This type of loading is usual in mechanical and structural engineering. The problem is that,when the load is constant, the strength of the structure load may prove to be sufficient. But if this load alternates frequently fatigue of the material occurs and the structure can be damaged or even crushed despite static analysis shows acceptable safety factor. The AutoFEM Fatigue Analysis module allows you to calculate the safety factor depending on the number of loading cycles and on the law of variation of the load's amplitude . First, it is necessary to solve static study assuming that the loads are constant. Then the user can define cyclic loading parameters in dedicated dialog box of Fatigue Analysis Study. These parameters determine the type of loading (variation law) and number of cycles. Before running Fatigue Analysis an S-N Curve for the material of the design should be determined. The special S-N Curve Editor is used for this purpose.