OPTIMIZATION OF THE POWERTRAIN MOUNTING SYSTEM VIA DOE METHOD Authors: Wang Yang*, Wang Hui*, Xu Yong* * NVH Section, Brilliance-Auto Engineering Research Institute, Shenyang, China, 110141 Key Words: NVH; DOE; Powertrain Mounting System; Analysis of Variance Research and/or Engineering Questions/Objective The vibration isolation performance of vehicle powertrain mounting system is mostly determined by the three-directional stiffnesses of each mount block. Because of the manufacturing tolerance and the coupling effect, the stiffnesses of mounts cannot be maintained stable. The purpose of this study was to find out the way to optimize the stiffnesses of mounts via the design of experiments (DOE). Methodology According to the DOE process, a full factorial design was implemented. The z-direction stiffnesses of three mount blocks in the mounting system were selected as the three analysis factors. The maximum and the minimum stiffnesses of each mount block within the manufacturing tolerance were selected as the two levels. The measured vibration level of vehicle body under certain loading case was selected as the response factor. After eight times of experiment, the DOE parameters were analyzed with statistical methods. Results The final DOE results showed that the vibration level of vehicle could be expressed by a linear equation, the parameters in which are the stiffnesses of mount blocks. And the analysis of variance indicated that the vibration level of vehicle is mostly affected by the stiffness of engine mount block. Limitations of this study Considering the time consumption and the number of experiments, the main limitation of this research was that not all of the related factors were applied in the DOE analysis. Another limitation was that the levels of the factors were restricted within the manufacturing tolerance. What does the paper offer that is new in the field including in comparison to other work by the authors? It was an innovative attempt that the DOE method was applied in the powertrain mounting system optimization. The relationship between the vehicle vibration and the stiffnesses of mount blocks could be expressed with a linear equation. Conclusions A DOE based optimization method was developed in this work. With the DOE result, the vibration of vehicle was directly related to the stiffnesses of mount blocks. And the most effective facotr that affects the vehicle vibration was determined.