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Nowadays, studying the human body response in a seated position has attracted a lot of attention as environmental vibrations are transferred to the human body through floor and seat. This research has constructed a multi-body biodynamic human model with 17 degrees of freedom (DOF), including the backrest support and the interaction between feet and ground. Three types of human biodynamic models are taken into consideration: the first model doesn't include the interaction between the feet and floor, the second considers the feet and floor interaction by using a high stiffness spring, the third one includes the interaction by using a soft spring. Based on the whole vehicle model, the excitation to human body through feet and back can be obtained by ride simulation. The simulation results indicate that the interaction between feet and ground exerts non-negligible effect upon the performance of the whole body vibration by comparing the three cases.

A simulation model of the single cone synchronizer is presented using the dynamic implicit algorithm with commercial Finite Element Analysis (FEA) software Abaqus. The meshing components include sleeve gear, blocking ring and clutch gear, which are all considered as deformation body. The processes mainly contain the contact between sleeve teeth and blocking teeth, meshing period and the impact of sleeve teeth and clutch gear teeth, and these nonlinear contact steps are realized with Abaqus. In addition, a shift force derives from experiment is applied to the sleeve ring, and a moment is added to the clutch gear to realize the relative rotational speed. Based on the FEA model, the effect of the varied frictional coefficients between the cone surfaces of blocking ring and clutch gear on the synchronizer time and contact stress is discussed. Variation of stresses and contact force with respect to time are evaluated from this analysis.

Powertrain mounting system (PMS) often operates with some degrees of uncertainty. These uncertainties may result from poorly known or variable parameters such as mount stiffness, or from uncertain inputs. For realistic predictions of the system behavior, the PMS models have to account for these uncertainties. To this end, the Chebyshev interval method is applied to study the uncertain characteristics of PMS. In the PMS, the location and orientation of each mount are off-design variables due to the space limitation of the powertrain. The stiffness coefficients of the mounts are considered as interval variables. The lower bounds and upper bounds of natural frequencies and the mode kinetic energy distributions of PMS are obtained using the Chebyshev interval analysis method. As a comparison, the scanning method is used to validate the interval method. The overall conclusion is that the Chebyshev interval method is a powerful approach for the simulation of PMS with interval parameters.