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Road loads tire models are used in the automotive industry in full vehicle simulations to compute the loading from the road into the chassis encountered in proving ground durability events. Such events typically include Belgian Block events, bump events, potholes and others. Correctly capturing tire enveloping forces in such events has historically been challenging - several different approaches exist each with its own limitations. In this paper a model is presented which captures the first order tire dynamics (frequencies lower than 80 Hz) and associated enveloping loading without the need of an effective road profile. The theory behind this tire model is briefly introduced. Importantly, a comprehensive study of the validation of the tire model is given which shows correlation for full vehicle dynamic proving ground events. A Virtual Tire Lab (VTL) pre-processing tool is also presented which is used to compute tire model input parameters from a validated non-linear FEA tire model.

For powertrain mounts design and durability evaluation, directly measuring all the engine and transmission mount loads is a costly and time-consuming option. Analytical or semi-analytical approaches have been used for estimating maximum powertrain mount loads at the early design stage and also for calculating the dynamic loads when prototype test data is available. After reviewing various semi-analytical approaches or hybrid approaches using MATLAB® [1], this paper introduces a hybrid method using ADAMS® [2] with input of measured engine and transmission accelerations as well as drive shaft or half shaft loads. In this hybrid method the engine is modeled as a rigid body supported by the base structure (vehicle subframe, frame or body) through powertrain mounts with measured nonlinear properties. The method has been studied in various vehicle prototypes, in which the mount loads were measured for analysis and test correlation.