Abstract: The interest of the present work which is firstly the mastery of mechanical behavior of plastic and metallic material to improve and optimize the mechanical characteristics of the different materials(ABS material, PVC material, PR material and P265GH steel material), another characterization approach was considered in this paper; it is a statistical study of Student that allows the selection of the most reliable results with a risk threshold of 10% for the both types of materials. On the other hand, a Weibull statistical study is carried out to extract the Weibull elements and subsequently define the reliability theory and damage of Weibull.

Keywords: Mechanics, material, weibull, science, releability.