Research Seminar : Mechanical Design and Machine Construction of Metallic and Composite Materials

Abstract: In the design of mechanical components the identification of the failure mechanisms is crucial to build up a reliable design procedure. The experimental evidences acquired through the characterization of materials and components represent the basis for the development of reliable numerical and analytical models to be adopted in the design phase. Depending on the material and the service conditions the failure mechanisms involved are different and thus the design approach (in terms of either the most appropriate analytical model or numerical model implementation) needs to be tailored to the particular application. To make this scenario even more complicated a reliable design needs to take in account the presence of defects. Defects that can be of different types as for example:

• In metals defects might be due to the nucleation and propagation under fatigue load;

• They might be related to the puncturing produced by the impact of a structure with non-uniform stiffness against a small obstacle;

• They can be represented by a delamination and/or an interlaminar and intralaminar damage produced by low velocity impact on composite plate;

• They can be associated with the random variation in the lateral and vertical resistance of the ballast surrounding the railway track.