【作者】 张攀登；

【导师】 陈旭；

【作者基本信息】 重庆大学 ， 车辆工程， 2007， 硕士

【摘要】 为了减小噪声污染对社会的危害,与国际接轨,我国不断修订针对汽车产品噪声新的限制法规。汽车噪声限值法规日趋严格,GB1495-2002《汽车加速行驶车外噪声限值及测量方法》规定2005年1月1日后各类车型的噪声限值标准又严格2～4分贝。在汽车噪声中,作为汽车主要噪声源的发动机的噪声问题显得日益重要。要对汽车发动机噪声进行控制,就少不了对发动机表面辐射噪声的分析研究,作为发动机表面主要辐射噪声源的壳体零件(如油底壳、曲轴箱盖等)的振动噪声的控制就成为一个需要解决的问题。本文通过JS400ATV噪声源识别实验,确认某400ATV车的发动机表面主要噪声辐射源是几种壳体零件—气缸头部、曲轴箱盖等,针对曲轴箱盖,在UG软件中建立了实体模型,ANSYS中建立了有限元模型并进行模态分析,结果与实验模态基本一致,这表明所建立的有限元模型能有效反映壳体零件的结构动态特性,再利用LS-DYNA对壳体零件进行了振动环境下的瞬态响应分析。重点研究了壳体零件的结构参数、结构形式和壳体振动模态之间的关系。在此基础上,对曲轴箱零件提出了抑制振动响应的结构修改方案。本文还运用振动速度法预测了修改后该壳体零件辐射的噪声。更多还原

【Abstract】 In order to reduce the harmness of noise to the society and link to international practice,our country amend the legislation from time to time.More stringent legislations of vehicle noise appeared,and GB1495-2002《Limits and measurement methods for noise emitted by accelerating motor vehicles》prescribe that the noise limit of vehicle after January 1, 2005 will be striken by 2~4dB. Ameng the noise of vehicle the noise of engine seem to be more important.To control the noise of vehicle,the analyse and study of engine surface is absolutely necessary. The shell such as Oil pan or crankcase are serious problems and must be controlled.Through investigation of the noise source of JS ATV 400,we know that the main noise sourses of the engine are several shells,such as the cylinder head and the right crankcase cover plate etc.As for the crankcase cover plate,The full-scale mock-up by using UG and the fea model in ansys are established,then do the modal analysis. The result is consistent with the experimental result.It show that the fea model builted can reflect the dynamic characterics in effect.Then Ls-DYNA is use to do the transient response analysis in vibration environment,mainly studying the relationship ameng the structural parameter,structural style and structure mode.Base on it,a scheme to restrain the vibration and noise radiation of the crankcase is presented,and then the noise power of the shell after modified is forecasted using vibration and noise method.更多还原