Multidisciplinary Optimization of Geometric Variation and Modal Behaviour for Squeak and Rattle Prevention
Typ
Examensarbete för masterexamen
Program
Product development (MPPDE), MSc
Publicerad
2019
Författare
Thanga Ratnam, Dharun Velmani
Kulkarni, Saiprasad
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Squeak and Rattle are two undesired phenomenon that occurs when adjacent parts
come into contact with each other either by sliding or impacting. The Squeak and
Rattle directly affects the end user’s perception towards the quality of the car which
is not desirable for any automotive company. One of the main reason for the generation
of Squeak and Rattle in a car is geometric variations which happen due to
manufacturing tolerances, temperature etc. With modification in attachment points
in an assembly, many other attributes like modal behaviour of the component are
affected. This thesis aims to combine the design optimization process for geometric
variation and modal behaviour for Squeak and Rattle prevention.
The study is carried out on a passenger car door and deco panel-IP assembly. Geometric
variation analysis is performed in CAT software package of RD&T whereas
the modal behaviour of an assembly is determined by doing FEM analysis. To couple
the optimization process for two different disciplines, modeFRONTIER is used
which is an integration platform for multi-objective and Multi Disciplinary Optimization
(MDO). Initially, single discipline is framed in the optimization workflow
to understand the optimum or best attachment points in an assembly. Further,
MDO workflow is created and the results were compared with deco upled optimization
to analyze its effects on the selection of optimum attachment points.
Multi Objective Genetic Algorithm (MOGA-II) is used as the optimization algorithm
to find the best optimal positions within an assembly. The results show that
the two objectives from MDO optimization workflow are conflicting with each other
wherein the best solutions lie on a Pareto front. The MDO methodology can be
applied for different types of geometries and attachment schemes. No experimental
validation was done and could be considered as future scope of work.
Beskrivning
Ämne/nyckelord
Squeak and Rattle, Multidisciplinary optimization, Modal behaviour analysis , Geometric variation, Tolerances, Resonance, MOGA-II