Theses and Dissertations

Issuing Body

Mississippi State University


Rais-Rohani, Masoud

Committee Member

Lacy, Thomas E.

Committee Member

Motoyama, Keiichi

Date of Degree


Document Type

Graduate Thesis - Open Access


Aerospace Engineering

Degree Name

Master of Science


James Worth Bagley College of Engineering


Department of Aerospace Engineering


A computationally efficient multilevel decomposition and optimization framework is developed for application to automotive structures. A full scale finite element (FE) model of a passenger car along with a dummy and occupant restraint system (ORS) is used to analyze crashworthiness and occupant safety criteria in two crash scenarios. The vehicle and ORS models are incorporated into a decomposed multilevel framework and optimized with mass and occupant injury criteria as objectives. A surrogate modeling technique is used to approximate the computationally expensive nonlinear FE responses. A multilevel target matching optimization problem is formulated to obtain a design satisfying system level performance targets. A balance is sought between crashworthiness and structural rigidity while minimizing overall mass of the vehicle. Two separate design problems involving crash and crash+vibration are considered. A major finding of this study is that, it is possible to achieve greater weight savings by including dummy-based responses in optimization problem.



crashworthiness||optimization||surrogate models||occupant restraint system