Analysis About Noise Of Motorcycle Frame And Its Design Optimization

The motorcycle industry of our country obtains to advance by leaps and bounds of development, the motorcycle yield and retention quantity presents index number class a growth. But, the increment of the motorcycle yield and retention quantity also bring the social problem such as some safeties and pollution of the environment, the Noise pollution of motorcycle would be one of them. The motorcycle usually drives the street area which hustles at the residents and leave pedestrian and residence very near, so the Noise endanger opposite be getting more serious, one of the main reasons which even becomes some cities to forbid Motor and limits Motor of the Noise of motorcycle. Because the environmental protection request of continuously raise, our country motorcycle Noise the standard be gradually strict, motorcycle noise's management of the voice also continuously the facing norm turn and systemize with the country mark turn a direction development.In the process of the motorcycle development, speed and qualities of the product development are the main factors that the business enterprises actively seek, in the market compete vigorous today, to any business enterprise shorten a product development a period possibly to capture a market as soon as possible by attain is count for much.Ask for help of a FEA theories, apply technique and CAE technique of the modern test combine together of the method passed some motorcycle the voice source of Noise to carry on analysis, and pass by means of modal analysis get modal analysis of correspond the Pin segment to flap a type, indicated a Noise the position of the source, experiment a certificate, that method is fast efficiently, and for further the structure was excellent to turn a design to provide a direction.This literary grace uses the vibration noise of LMS company a voice a test analysis system, according to GBT 4569-2000 motorcycle Noise limit value and test the method carried on to the test of Noise, analyze the Noise Pin segment which mainly distributes, then carry on a FEA modal analysis to the car, the Test. Lab system which makes use of a LMS company carried on a modal analysis test, and carry on a ratio as a result with calculation to, proved the accuracy of model, for next move of analytical the calculation provided foundation. Analytical carried on analysis as a result to the modal analysis in confirming the foundation of model exactitude. According to the result of passing noise, the noise looked for a noise source. For confirm above of analytical result, did a simple experiment a verification, the whole car place in experiment indoor, carried on vehicle fixation a vibration noise test to the whole motorcycle frame . Empty colander and handle knob conjunction are the main reason which influences the whole motorcycle frame to pass a Noise a creation. By analytical to apply to the motorcycle modal analysis of the frame means and CAE technique of the modern test combine together of the method is in the process of lowering to pass a Noise in of important meaning.The application forerunner's structure is excellent to turn software in making sure a Noise the foundation of the source position, motorcycle car carry on structure excellent analyze a certificate. Because of behind handle stage and structure excellent turn to apply same software, not only carry on a FEA analysis to the product, but also and directly check to calculate hint in the software intelligence under carry on a design improvement, after handle with design excellent turn to synchronously combine, make product develop the process carried out leap of quality in the speed and the quality and consumedly raised a product a design a development of speed, shorten development period, and design the product of development to have excellent quality.The types of the structure optimization include the topology optimization, the appearance optimization, the shape optimization and the size optimization, all the types of structure optimization may be combined. In this present paper, the topology optimization has been mainly used. The topology optimization is essentially in the design space assigned, and achieves the best material distribution of structural element; The appearance optimization is a kind method in the structure assigned, the stiffener layout is determined to be optimized, it is mainly applied on the shell unit, its difference with the topology optimization is that, it does not remove the material, and produce stiffener in the design region based on the transportable nodes in order to make the structure strengthen, and enhance the rigidity and the frequency of the structure; The shape and size optimizations enable the structural partial region to achieve the best shape and the size aiming at the optimized questions assigned. The goal of the structure optimization is causing the radiant noise capacity smallest from the structure surface, and achieves the best acoustics effect under condition given.The structural design process may be regarded as a kind of optimization process, the process is that the people seek the structure and the structure composition to reduce the cost, and enhance the performance and the outward appearance of the structure process. Generally speaking, the design process includes the following constitution: Conceptual design, design, confirmation and optimization. The conceptual design stage is acting a foundational role, and relating to the progress of the entire process. The topology optimization is a kind of important design tool in the conceptual design stage. It is taking the result of the optimized computation as the foundation, but not depending on the estimation. Introducing to the topology optimization, it can make the result obtained in the computation analysis process as the foundation of the design input content in the reference design stage, thus obtain the structural concept model, and avoid changing the conceptual design model in the experimental design stage. Then on the foundation of the conceptual design, obtaining finite element model of the conceptual model, then carrying on analysis and processing in the finite element analysis software, the result of finite element analysis is usually determining the direction of structure improvement, then optimizing the details of the structure, by the time the best structural design is achieved, it is a process in an orderly way.This text design of completion is currently more advanced follow of the means of the design and an usage of the method, apply the forerunner's software, under support that FEA theories and modal analytical theories, applied modern test means and CAE technique combine together of method, break past product development mode of design, develop in the product time and quality tops all kept advantage, to the product of the future design development and Noise the structure of the product be excellent to turn to all have importance instruction meaning.