The Fatigue Life Evaluation Of Construction Crane Based On The Fracture Mechanics

With the development of modern economy, the working intensity of construction crane is getting heavier day by day. The accidents that structural failure caused repeat occurrence. People pay more attention to the safety quality of construction cranes. When designing construction crane, people pay more attention to the quality and stiffness of the whole crane. The working conditions and factors that affected fatigue life are very complicated. The fatigue life evaluation of crane is a question at all times. So, research on the fatigue life evaluation of construction crane is meaningful to the safety manufacture.In this paper the method of predicting fatigue and the situation of fatigue life evaluation of crane is introduced. By analyzing the structure and fatigue failure characteristic of construction crane, the fatigue life of construction crane is evaluated based on the fracture mechanics.The flows and steps of evaluating the fatigue life in construction crane are summed up. It provides a new thread of evaluating the fatigue life of construction crane.The fatigue dangerous position is determined by the finite element method and fatigue damage statistics. Based on the previous dynamics research of cranes, the load spectrum is compiled by the working statistics. It provides important basis for fatigue life evaluation.Taking a50t crawler crane for example, the fatigue life of the crane is evaluated by the flows summed up. The boom is very important for the crane. According to the surface crack growth style of the structure, the stress intensity factor is calculated by the ANSYS’s stress intensity factor module. The fatigue life of boom including surface crack or buried crack is computed. It can provide a basis for equipment maintenance and scrap based on the critical condition got. The rationality of the flows is verified through the assessment of the crane.The paper is not only theoretical meaningful to the fatigue life evaluation of construction crane, but also applied to the fatigue life evaluation of other machinery products.