Study On Mesh Stiffness And Mode Frequency Of A Gear Pair With Cracks

Gear drive is a kind of important drive mode which is widely used in the field of aerospace and mechanical engineering,and so on.Due to the effects of manufacture and motion transfer error,the cracks might be the main fault of gear drive.The exist of crack and its propagation,not only does impacts to the mesh stiffness of the gear pair,but also does changing to the vibration characteristic of the gear pair.On the basis of ABAQUS package,the crack propagation properties of a gear pair with multiple cracks,and its effect on the mesh stiffness and mode frequencies were studied deeply.The main works and contribution are as follows:First,based on the study of fundamental theory of crack propagation of tooth crack,a finite element model of a gear pair with cracks was set up by ABAQUS software.The reasonable of the analytical model was verified by comparing the theoretical contact stress with the calculated contact stress.Then,according to the model of a gear pair with cracks,the maximum principle stress and the stress intensity factor at crack tip was analyzed.Take a gear pair having cracks as study object,the ratio of crack depth in the root of tooth and that in the pitch circle was investigated.Thereafter,the definition of a time varying stiffness of a gear pair was defined by different method.Subsequently,a modelling method for cracked gear by ABAQUS was proposed.In addition,the multi-cracked gear pair with different crack modes was created by the study of crack growth of multi-cracked gear pair.The change law of mesh stiffness of a gear pair in one period was analyzed.The effects of crack modes on mesh stiffness were discussed.Finally,according to the analytical theory of mode and the finite element mode of a cracked gear pair,the mode frequencies of a gear pair having different cracks were investigated.And the effects of cracks on the mode frequencies of a gear pair were discussed in the end.