The Design Of Powertrain Mount Systems Inclusion Of Non-proportional Damping

Automotive powertrain mount system dynamic modeling is the key technology instudying the automotive ride comfort. This paper studies the method of torque roll axisdecoupling inclusion of non-proportional damping. The main research contents are list asfollows：1）Based on a lot of references, the developing history of decoupling methods ofautomotive powertrain mount system is reviewed. This paper analytically examines themulti-dimensional mounting schemes of an automotive engine gearbox system whenexcited by oscillating torques. In particular, the issue of torque roll axis decoupling isanalyzed in significant detail since it is poorly understood. New dynamic decouplingaxioms are presented and compared with the conventional elastic axis mounting andenergy methods. Only rigid body modes of the powertrain are considered and the chassiselements are assumed to be rigid. Torque roll axis method can completely decouple fornot only a symmetric engine mounting system but also for a asymmetric ones.2）This paper establishes the modeling of automotive powertrain system inclusionproportional damping or non-proportional damping. Also we analytically examines theeffects of non-proportional damping on the dynamics of a six degree of freedomautomotive powertrain system. The effect of coupling between powertrain motions is ofparticular interest and an emphasis is placed on the torque roll axis decoupling. Oneshortcoming of the existing theories and design methods is that they ignorenon-proportional viscous damping in their formulations. To overcome this deficiency，theanalytical problem for a non-proportionally damped linear system is first formulatedwhile recognizing that significant damping may be possible with mounts. Complex modemethod is employed and the torque roll axis decoupling paradigm is examined givenmount rate ratios，mount locations and orientation angles as key design parameters. Anecessary axiom for a mode in the torque roll axis direction is derived provided twoeigenvalue problems, in terms of stiffness and damping matrices, are concurrentlysatisfied.3) we carry out automotive ride comfort running test to the vehicle matching thepowertrain mounts designed by the method of torque roll axis decoupling consideringnon-proportional damping. Comparing the experiment data to the original automotive,we analysis the vibration signal to know the isolation characteristics of the samplevehicle. Through the design method and the experiment,we can improve the performanceof engine mounting system by tunning some parameters rationally.