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The paper describes simulation of frontal barrier impact of a car body shell structure for crashworthiness analysis using non linear explicit finite element package LS-DYNA3D. Predicted overall collapse modes of different structural component viz.apron, side rails etc. are in a good agreement with published results and also to some extent with experimental results. In this paper crash analysis of above car structure with crash guard is simulated using LS-DYNA3D and comparative analysis of crash behaviour of car structure in the presence of crashguard is shown to indicate its possible role on crash behaviour of a vehicle.

Three dimensional finite element analysis of mufflers has been carried out using ANSYS general purpose program. Analysis of simple expansion chamber muffler, extended tube muffler, tapered chamber muffler, offset chamber muffler and flow reversing chamber muffler has been carried out to predict the transmission loss. This three dimensional FEA technique has proved to be successful for the analysis of geometrically complicated mufflers where one dimensional theories can not be used. Parametric analysis of a simple expansion chamber muffler has been carried out to study the effect of expansion ratio, expansion chamber length, number of partitions within a chamber and unequal partitions. Analysis of acoustic cavity of a simple expansion chamber muffler has also been carried out to predict the natural frequencies and acoustic mode shapes.

Modal Analysis is a well established technique which defines the inherent dynamic properties of the structure. At the same time the experimental harmonic analysis by shaker method is also a very important tool in solving some of the engine induced vibration problems in the automotive structure. Computer simulation technique using finite element methodology has been very effective tool in simulating the problem. However the right combination of these techniques has been a tricky situation. The paper describes the methodology of using right combination of these techniques to reduce the motorcycle chassis vibration which are induced by engine and drive-line excitation in minimum time. The method involves the Finite Element Modelling with shell elements, experimental harmonic analysis with frequency sweep upto 600 Hz, validation of the FE model, animation techniques and find out correct modification to fine tune the structure to eliminate the engine induced vibrations in the frame.

Automotive crankshafts are subjected to fluctuating torques due to periodic explosions in the cylinders. Accurate three dimensional finite element modeling is often time consuming. The present research aims to reduce the pre-processing efforts by developing parametric software. A three-dimensional parametric finite element model of crankshaft is developed using brick and wedge elements. Crankshaft main journal bearings are modeled as linear springs and dashpots. The piston and reciprocating masses are lumped at the ends of the crank pins. Viscous damper as well as shaft material damping has been modeled. Results from the three-dimensional analysis have been compared with those obtained using beam element models to assess the capabilities and limitations of such simplified models. It has been demonstrated that the simplified beam element models result in significant errors and 3-dimensional finite element analysis is essential for accurate predictions.