Fatigue Life Analysis Of Sub - Frame Of Concrete Mixer

The subframe is the chief bearing component of the concrete-mixer truck as the connection carrier between the vehicle chassis and the stirring tank. When the vehicle is running, loading and unloading, the load of top parts is almost transmitted to the vehicle chassis via the subframe. Meanwhile random dynamic loads caused by vibrations transfer to the subframe through the vehicle chassis, so the subframe withstands two types of the loads. Under the two loads, the subframe stress is changeable and easy to damage due to the lack of strength. Or because of fatigue damage caused by the lack of fatigue life, it is seriously affecting the driving safety and life of the mixer. Therefore, the actual fatigue life can be known through the structural strength and fatigue analysis of the subframe, and it can improve the driving safety and life of the concrete mixer truck.Taking a subframe of concrete mixer truck as the research object, there is a comprehensive analysis of the subframe structure and properties based on the finite element technology and test technology. The finite element analysis model of a subframe was built and the finite element static strength and modal analysis were carried out. The modal test system of a subframe was established and the modal parameters were obtained, which verified the correctness of the finite element modal calculation. Based on the strain testing technology, the dynamic stress of the subframe key points exposed to the city roads is collected. And the random loads were analyzed used by rainflow counting method to obtain the Weibull distribution function of subframe load spectrum. The subframe fatigue life analysis of concrete mixer truck was carried out using the software nCode DesignLife, which used the load spectrum of the subframe resulting from the acquisition analysis.The result of this paper offers the reference basis for improving and designing the structure of the subframe. And it has important practical value for improving the safety and life of the concrete mixer truck.