扭力梁式后悬架模态与疲劳实验研究

扭力梁式后悬架是汽车行驶系统中重要的承重构件,在不同的行驶工况下,会受到不同幅值和不同频率的激励。在激励频率和扭力梁式后悬架固有频率接近或相同时,会产生共振,进而发生疲劳断裂。通过对扭力梁式后悬架进行模态实验,获得该结构的固有频率和模态振型。对同一型号的扭力梁式后悬架进行弯曲、扭转疲劳实验,得到其疲劳破坏的具体形式。对产生破坏的扭力梁式后悬架进行模态实验,对未损坏和损坏的扭力梁式后悬架各自的固有频率和模态振型进行对比分析,发现产生疲劳破损的扭力梁式后悬架在某一阶频率下的模态振型有较大变化,结构的固有频率值和固有频率分布的变化并不很大。

Experimental Study on Modals and Fatigue of Torsional Beam Rear Suspensions

Torsion beam rear suspension is an important load-bearing component in automobile driving system. Under different driving conditions, it is excited by different amplitude and different frequency of excitation. When the excitation frequency and the natural frequency of the torsion beam rear suspension are similar or equal, the torsion beam rear suspension resonates, and then the fatigue fracture occurs. In this paper, the modal test method was used to test the torque of the torsion beam rear suspension and find out the natural frequencies and modal shapes. The same types of torque beam were carried out on bending and torsional fatigue tests to get the specific forms of damage to their failures. Finally, the modal experiments were carried out on the torsion beam rear suspension with the damage. The natural frequencies and modal shapes of the torsion beam rear suspension with no damage and the ones with damage were compared and analyzed. It is found that the torsion beam rear suspension with fatigue damage has a great change in the mode formation, the frequencies and the frequency distribution are little different.