CMS methods in complete NVH analysis

Nowadays in engineering problems the use of finite element models is a common rule and the use of analysis tools in predicting the dynamic behavior of a structure is a common practice. Specifically, in the automotive industry the level of details included in a full model has been increased constantly followed by the need for higher computational power capable in order to handle such huge models and to keep the simulation time on a reasonable level. To fight this trend many di↵erent techniques exist in order to fill the need for detailed dynamic analysis and short analysis time. In this thesis the Dynamic Substructuring (DS) approach will be proposed with a focus on noise and vi-bration analysis within the automotive engineering field. Dynamic subtracting is based on the principle of dividing our large model in smaller subsystems, easier to study and analyze. Then the total structure dynamics is calculated assembling all the small components dynamics. Since this topic is very broad, the thesis will focus on one theory of Component Mode Synthesys (CMS), one of the many techniques within the DS. The thesis in divided into three main parts: firstly, the theory behind the DS is covered. From the analysis of linear dynamic systems to the two CMS reduction methods (Craig-Bampton and Craig-Cang methods) that are compared in the next parts. Secondly a dynamic substructuring analysis is performed on a simple model