For static loads the international design codes provide calculation methods to design equipment safely. In case of non static loads, such as cyclic temperature- and pressure changes, these calculation rules do not suffice for assessing the required operating life of pressure vessels. The design codes refer in those cases to Finite Element Analysis (FEA).
Hitard uses FEA and Fatigue life analysis when local stresses need to be calculated in complex structures or equipment with cyclic load (pressure, temperature, vibration) cases. With FEA a model is prepared to accurately define the structure and the appropriate boundary conditions, such as displacements and forces.
The calculation model of the construction or equipment is prepared with adequate computer hardware and modern software tools, such as: