Recently, a rapid determination method of fatigue limit based on dissipated energy measurement using infrared thermography has been getting an increasing interest in industries. The applicability of this method to the specific materials such as carbon steels and stainless steels has been investigated well by many researchers. On the other hand, the applicability of this method to aluminum alloys is different in case by case. In this study, the relationship between dissipated energy and fatigue strength for aluminum alloy A6061-T6 was investigated. As a result, the relationship between dissipated energy and plastic strain energy was confirmed for A6061-T6. In addition, the dissipated energy values measured during the staircase-like stress amplitude testing were well correlated to the number of cycles to failure obtained from the constant stress amplitude testing. Therefore, the possibility to be able to evaluate the fatigue life for A6061-T6 by measuring the dissipated energy was clarified.
