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A method is presented to evaluate diesel engine structure borne noise differences caused by component design changes of the engine assembly. A flexible multi-body dynamics model is used to develop loads on the engine due to combustion, piston-liner interactions, and interactions at the main bearings. These loads are applied to an engine finite element model for frequency response analysis. The frequency response analysis is then varied by changing the component design of the engine assembly. Surface velocities and modal participation factors are determined from the frequency response. The participation factors are then used in a modal acoustic transfer analysis to compute the sound power. Comparisons are made between assemblies and to experimental data.

Analytical methods have been developed to determine equivalent material properties of brake dampers for their inclusion in a system model. A multi-layered model of a damper is reduced to a single layer model. The material properties for this single layer model are determined from a simulation of a bench-top, damper/shoe/lining impact modal test. Two different dampers are considered. The damper's response is confirmed by experimental results. A complex-eigenvalue analysis is then presented to show the effect the two brake dampers have on the braking system. Conditions of the eigenvalue analysis were set to match noise events in a squeal rig test. The eigenvalue analysis shows a stabilization of the braking system with the equivalent damper models. The results are confirmed with dynamometer testing.

In this paper, a brake damper is modeled with the finite element method to predict its response in a free-free impact modal test. A multi-layer representation of a brake shim is described which captures the dynamic characteristics of a damper, bonded to a brake shoe and lining. Calculations of damping values and natural frequencies are compared to impact modal test results over a wide temperature range. It was found that the finite element model accurately predicts the results from the experiment. A discussion is also given on how the model may be used to develop a material database and automation of the modeling process to analyze any layered brake damper.

This paper will outline the analytical procedure of designing automotive dash panels with laminated metal. A laminated dash is analyzed to determine its proper gauge to maintain the stiffness of the sheet metal original. A custom preprocessor is used to generate a finite element mesh of a laminated design. A static analysis determines the laminate displacement for some given worst case scenario. Displacements are determined for several loading conditions. The laminate skin thickness is then varied to achieve the same displacement as that of the original sheet metal design. A modal test is then simulated on the laminated dash to demonstrate its NVH characteristics. A natural frequency extraction is done to visualize the vibration profile of the part. Damping is seen with a frequency response calculation due to an impact load on the part. The frequency response clearly shows the reduced vibrations associated with the laminated dash.