仪表板横梁结构参数对振动特性的影响规律

The effects of structural parameters on the vibration performance of cross car beam

仪表板横梁总成的振动性能是整车NVH性能的一个重要评价参数。采用有限元软件Optistruct对等径二维弯管仪表板横梁总成进行模态分析,得出横梁系统的模态参数;基于有限元分析模型,通过正交试验,分析仪表板横梁圆管梁厚度和外径、前上支架厚度等结构参数对振动特性的影响规律。结果表明,圆管梁厚度是最关键的结构参数,前上支架与车身连接点位置以及前上支架厚度和H型支架厚度对横梁总成振动性能也有明显的影响。根据分析所得的影响规律,以横梁三个零件厚度为设计变量,在Optistruct中建立数学模型并对横梁总成进行结构优化,使得仪表板横梁系统重量、固有频率和刚度之间达到了较好的平衡,改善了仪表板横梁总成振动特性。

The vibration performance of Cross Car Beam （CCB） assembly is an important evaluation parameter in the NVH per- formance of complete vehicle. Modal parameters of constant-diameter bend cross car beam system were calculated via the finite el- ement software Optistruct. The effects of tube thickness, tube diameter and front body bracket thickness etc on the CCB vibration performance are investigated by orthogonal test method based on finite element model. The results show that the tube thickness is the key structure parameters. The position of connection point between the front body bracket and body, front body bracket thick- ness and the thickness of H-type bracket also have a significant impact on the CCB vibration performance. According to the analy- sis results, select the thickness of three parts on the CCB as the design variables. Then mathematical model is established in Opti- struct and the CCB structure is optimized,which obtains a better balance among the whole mass and natural frequency and stiff- ness, improving the natural vibration characteristics of cross car beam assembly.