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With strict government requirements for automobile fuel economy and global climate warming concerns, powertrain design becomes ever more challenging and complicated. New technologies come out daily, and each component, small or large, is scrutinized for weight, cost, performance, etc. To meet these ever demanding requirements, Computer Aided Engineering (CAE) becomes very critical in the product development process. It not only saves tremendous developing time and cost, but also helps discover new and innovative ideas very quickly. Digital product development process is an industrial norm nowadays. Parts are modeled in 3D in a Computer Aided Design (CAD) system, and then they are passed to and modeled in a Finite Elements Analysis (FEA) software package for analysis. If the analysis results do not meet the requirements, engineers either modify the FEA models or 3D CAD geometry for re-analysis.

Large axial displacement at the edge of a flywheel causes a clutch to fail to disengage in high-speed rotation. To find out the root cause, a numerical procedure is proposed to investigate the vibration source and to understand dynamic behavior of the crank-train system. A simulation of the whole engine system including block, crankshaft, piston, and connecting rod was performed with AVL/Excite. The resulting CAE baseline model had good correlation with measurements. A comprehensive study was conducted for a set of flywheel and crankshaft models with different materials and unbalanced masses. The contribution to flywheel wobbling of each vibration order was carefully investigated, and an optimal design was presented.

Exhaust manifold design is one of the more challenging tasks for the engine engineer due to the harsh thermal and severe vibration environment. Extremely high exhaust gas temperatures and dynamic loading combine to subject the manifold to high cyclic stress when the material has reduced fatigue strength due to the high temperature. A long service life before a fatigue failure is the objective in exhaust manifold design. Accumulation of fatigue damage can occur from dynamic loading and thermal loading combined. Thermal mechanical fatigue (TMF) is a primary mechanism for accumulating fatigue damage. TMF typically occurs when a vehicle driving cycle has operating conditions that repeatedly change the exhaust gas temperature between hot and cold. Another way to experience temperature cycling is through splash quenching. Splash quenching was analyzed and found to rapidly accumulate fatigue damage.