Stress Analysis
The engineering discipline of stress analysis seeks to determine the effect and extent that forces have on materials. Stress analysis is an integral part of the structural design of almost any article or structure. State of the art structural analysis tools and finite element analysis packages are used to perform stress analysis.
Structural components that have failed are usually subjected to a failure analysis. During this process, the operational forces that act on the component are used as input for a detailed stress analysis in order to determine the reason for failure. Frequently, cyclic loadings may result in failures and a detailed fatigue analysis (usually including finite element analysis) will show where the component lacked the necessary preventative design to avoid the failure.
The aim of stress analysis is to design a component so that it will be able to withstand all stresses and forces that act upon it without suffering fatigue and subsequently failing. In order to comply with this requirement, the limits of fatigue strength (including tensile and compressive strength) of the component's construction material(s) should be known, and the required safety factor must be designed-in. This means that the component must be over-designed to not only withstand the stresses, but to withstand them for its entire operating life.
This margin of safety is a known value that can be calculated for every material and component. When a component undergoes a stress analysis, the required margin of safety is a firm value whereby the stress analyst starts his or her test. The component is tested according to the known standard and should meet or exceed it.
Stress analysis may not only be applied to physical objects. Virtual stress analysis is applied to structures in the design stage. Advanced computer software can accurately calculate potential stresses on components before they exist. For example, a bridge design can be virtually tested for resistance against wind shear, so that the correct methods, materials and safety parameters may be determined before the bridge is built.