| Aluminum-steel composite material is a commonly and widely used material with a variety of functions such as load bearing,corrosion resistance,friction resistance,heat resistance,light weight,etc.At present,the research mainly focuses on the fatigue life of the aluminum-steel composite,but neglects the interface cracks and the complex working environment in the actual engineering.Therefore,it has important sense to study the effect of interface cracks on the fatigue life of aluminum-steel composite wheels.The work and achievements of systematical studying the effects of the number and location of interfacial cracks on the fatigue life of aluminum-steel composite wheels mainly includes the following aspects:(1)Explaining the concept of random vibration and its statistical characteristics,and discussing the basic steps of calculating the fatigue life considering random vibration by using frequency domain analysis.Based on the frequency domain to determine the route of research and analysis.Combined with the theory of fatigue accumulation and S-N curve of the aluminum-steel composite material,and extended the three interval method of single material to aluminum-steel composite to predict the fatigue life of it with interface cracks.(2)In order to obtain the vibration characteristics of a wheel with an interface crack to lay the foundation for harmonic response analysis,random vibration fatigue analysis and fatigue life prediction,choosing the widely used aluminum-steel composite car wheel as research object.Through SolidWorks to build an accurate wheel analysis model and share to ANSYS,carried out the pre-treatment process such as prefabricating interface cracks for the hub model,based on the theory of finite element dynamics and the modal analysis of aluminum-steel composite hub with an interface crack was carried out.(3)Carried out the harmonic response analysis of the aluminum-steel composite hub with one interface crack and obtained its frequency response characteristics to predict the fatigue life.Based on the analysis results and considering the randomness of the load on the hub in practical application to carry out the random vibration fatigue analysis of the hub and then obtain the stress near the crack tip of the hub interface and the response stress spectral density curve at the dangerous position,at last,using the three interval method in frequency domain to predict the fatigue life.(4)Analyzed the situation of two adjacent interface cracks to clarify the number of interface cracks on the fatigue life of aluminum-steel composite hubs,two adjacent interface cracks was analyzed.The results show that the number of interface cracks has a great influence on the fatigue life of the hub.The fatigue life of two interface cracks is one-half of the fatigue life of the hub has one interface crack.Then,analyzed two non adjacent interface cracks to further study the fatigue life of the aluminum-steel composite hub with the location of the interface crack,the results show that the location of the interface crack has little effect on the fatigue life of the hub. |
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