基于有限元分析及实验的轿车铝合金防撞梁模态研究

Modal research on car aluminum alloy bumper beam based on finite element analysis and experiment

为研究不同结构轿车铝合金防撞梁的模态特性,建立了两种型号铝合金防撞梁的有限元分析模型,对其进行有限元自由模态分析,得到了其弹性模态的前六阶固有频率及相应振型,并通过模态实验进行验证。结果表明:有限元模态分析结果与模态实验分析结果基本一致,最大误差为13.4%;铝合金防撞梁的低阶模态固有频率大于外部激励频率,不会产生共振;结构复杂程度以及材料厚度越大,其一阶自由模态频率越高,各阶频率差值越大,越不易产生共振。

To study the modal characteristics of aluminum alloy bumper beams with different structures,a finite element analysis model of two types of aluminum alloy bumper beams is established,and the finite element free modal analysis is carried out to obtain the frequency of the first six inherent elastic modes and corresponding vibration shape.And it is verified by modal experiment.The comparative analysis showed that the results of finite element modal analysis and modal experiment analysis are consistent,with the maximum error of 13.4%.The low-order modal natural frequency of the aluminum alloy bumper beam is greater than the external excitation frequency.There would be no resonance.And the more complex the structure and the greater the material thickness,the higher the first-order free mode frequency,and the greater the difference between the frequencies of each order,the less likely it is to generate resonance.