Determination of thermal fatigue characteristics of thin plates

With the development of technology, engineers try to design more safe, light and less costly structures to meet people's needs. Engineers also need to consider the difficult working conditions of the design of structures in industries such as aviation. The materials used in the aviation industry are subjected to continuous and cyclic temperature changes due to their operating conditions. The thermal loads occur between the subzero and temperatures above the zero degrees. In this thesis, it is aimed to search the thermal fatigue characteristics of materials under various boundary conditions and load cases. This investigation was performed numerically using an improved algorithm. The algorithm has the opportunity to examine the behavior of materials subjected to cyclic thermal loads. Many parts of the aircraft including outer surface are exposed these cyclic thermal loads. So, consideration of effects of thermal fatigue during the design of structures used in these parts is necessary. 7075 T6, 6061 T6, 2024 T4, and 2014 T6 aluminum alloys are used in this thesis. Thermal fatigue resistance of these materials is compared using the safety factor distribution of plates under the thermal fatigue and thermal fatigue with cyclic mechanic loads. Also effects of different cutouts (to see the effects of nonlinearities) and location of these cutouts on the plate are investigated. The results of different cases are compared to each other.