Modal and Fatigue Analysis of the Stratotimer

Abstract: Fatigue analysis of the printed circuit boards (PCBs) of an avionic instrument has been analyzed. The natural frequency and transmissibility has been estimated through analytical approach and finite element approach with Solid- Works and experimentally. Fatigue analysis damage has been obtained with three methods: Steinberg Stress approach, Steinberg Relative Displacement approach and Dirlik method. The analysis indicates that the solder that holds the CPU on the control unit is critical for the fatigue life. The results show that each method is far from the critical CDI value of 0:7 and therefore the design could be optimized.