Using a probabilistic tool for making sensitivity analysis

Sensitivity analyses are often used in engineering practice to better understand a model or the reality. The method to conduct such an analysis is often to fix all the parameters at a certain value and then to make them varying deterministically one after the other one. Such an approach can then be long to conduct and difficult to interpret as soon as the variations of a large number of parameters are considered. In contrast, a methodology based on a probabilistic tool is proposed in this paper. This method has the advantage to detect quickly which are the most important parameters, to have a continuous approach and then to obtain diagrams easy to interpret. After a presentation of the method, its application to different problems such as the thermomechanical behaviour of a pressure vessel under severe accident or some sensitivity analyses on the isothermal hydration of an initially non saturated clay barrier is quickly illustrated.