Detection of Crack and Prediction of Fatigue Life of Components Against Proportional Fluctuating Loading
In refrigeration and air-conditioning products, components such as fan bracket of outdoor unit, suction and discharge tubes of system fail due to fluctuating loads that cause crack initiation in components. There are various techniques to observe the fatigue crack growth on components. The detection of crack initiation is of great importance for fatigue behavior of components or structures. In this paper, life of component before crack initiation is calculated using strain gauges. During crack generation in components, the strain acting on the component changes significantly. Fatigue life of components is calculated based on the time required for rapid changes in the strain values. Reversible displacement with constant frequency is used for this study. Rectangular steel plates with holes and copper tubes are considered for the analysis. The finite element simulations are carried out using ANSYS Mechanical for locating high-stress areas and finding number of cycles required for failure. It is found that the simulations and experimental results are in good agreement.