A fatigue analysis is used to predict the lifespan of a material or structure under repeated loading and unloading, which can cause cracks and failures. It helps engineers and designers determine the factor of safety needed to ensure the structural integrity and safety of a product.
The factor of safety is a ratio of the maximum stress a material can withstand to the applied stress in the design. In fatigue analysis, the factor of safety accounts for the uncertainties and variations in the loading conditions and material properties.
The factor of safety is determined by dividing the ultimate strength of the material by the maximum stress applied in the design. The ultimate strength can be determined through laboratory testing or by using material properties from literature.
Static analysis only considers the maximum stress applied to a material, while fatigue analysis takes into account the repeated loading and unloading, which can cause fatigue failure over time. Additionally, fatigue analysis requires more complex calculations and considerations for different loading scenarios.
Several factors can affect the accuracy of fatigue analysis, including the quality and variability of material properties, the type and magnitude of loading, the design and manufacturing processes, and the environmental conditions in which the product will be used. It is crucial to consider all these factors and use appropriate safety factors in the analysis to ensure accurate results.