Analysis And Control Of High Frequency Double Steel Road Roller Cab Structure Noise

With the competition of engineering machinery industry becoming increasingly intensified, the technical requirements for products have become more and more high,and vibration and noise performance of construction machinery has become one of important index to evaluate the quality of the products. The problem on how to enhance the effect of compaction and ensure comfort of the driver at the same time is always the key problem in research and development of products. This paper takes a section of double steel wheel roller as the research object, analyze the characteristics of structure and acoustic about the roller cab by method of finite element, boundary element, acoustic on CAE, support vector machine(SVM), particle swarm optimization(PSO) and other methods. According to the results of the analysis,we put forward optimization scheme of structural to reduce road roller structural noise and improve the acoustics environment of road roller cab at the design stage.The main works are list as follows:(1) The structure finite element model and acoustics finite element model of the road roller cab are built. Then structural modal and acoustics modal was conducted to understand the inherent characteristics of body structure and acoustic.The rationality of the cab structure for the new cab was analysis. The acoustic-structure coupling model was built. Based on the theory of modal frequency response, pressure response about the cab of reference point were calculated and acoustics characteristics of coupled acoustic field were forecast when each a white noise excitation was applied in the mounting point.(2) The theory on acoustic contribution of panel was applied to analysis the amount of panel contribution when the peak of sound pressure response for the cab’s reference point and the main operating frequency. In allusion to contribution amount larger panel, the scheme of structure optimization was put forward and the feasibility of improved scheme is validated. And the level of structure noise of low frequency is improved.(3) A series of design process based on SVM and PSO were applied to command structure noise of the cab. The level of structure noise of the cab has been reduced dueto modify parameter of the bridge’s main panel. A high fitting accuracy of support vector machine model that replace the finite element model was established due to the parameters of SVM was optimized by using improved particle swarm optimization(IPSO). Thickness parameter of the model was optimized by IPSO. A set of optimal parameters of thickness makes the reference point(Location of the driver’s right ear)of SPL(Sound Pressure Level) is minimal. Thought of structure optimization for the design phase of the road roller was provided. Structure noise was reduced in the design phase of the product.(4) The new design of road roller were tested, we found that the SPL of driver’s ear and sound power level outside the car meet national mandatory standard noise and exceed sound level of international products.