Finite Element Analysis Of The Dynamic Simulation And Fatigue Life Of DTH Hammer Piston

In recent years, the investment of Chinese government in infrastructure co nstruction strength is also very big, driving the rapid development of DTH related technology and equipment. Piston is one of important components of DTH hammer, the life and the quality of the products largely depends on the quality and service life of the piston. At present, most manufacturers are relying on experience to design and manufacture the piston, and this is no scientific basis. At the same time, in the process of practical engineering application, DTH hammer piston often fractures, and the problem is not only caused huge economic losses to the engineering application, structure parameters and manufacturers are also necessary for optimization of DTH hammer piston to improve its performance. Therefore, to research the problem of piston fracture of DTH percussion is having very important real senseThis article is through to the fracture of DTH impacter piston physical and chemical experiments, dynamic analysis module of finite element software ANSYS Is-dyna to simulate dynamic simulation, the piston is obtained of the most dangerous place and the situation of the stress intensity factor, and combining the theory of fracture mechanics and fatigue life of Paris formula to predict the fatigue life of DTH impacter piston.1. The physical and chemical experiments, in view of the fracture of the piston fracture analysis, chemical composition analysis.Detection, toughness and hardness testing, metallographic analysis of physical and chemical experiments, to determine fracture belongs to fatigue fracture of the piston.2. No crack body finite element dynamic simulation. Using ANSYS Is-dyna to dynamic simulation for the piston, the analysis results show that the fillet in piston path there is an obvious stress concentration phenomenon, it is a very dangerous place.3. The finite element dynamic simulation of crack in body. Combined with the analysis of the1and2, in the path of the fillet out the most likely source of crack, so in here to establish a body of crack, the division of the singular element method, stress intensity factor is obtained, and it is concluded that under the condition of without the rule of stress intensity factor4. The prediction for the fatigue life of the piston. Combined with manual of stress intensity factor and the fatigue life of Paris, the correction formula for the piston of the initial crack length and crack length and crack extension threshold, thus predicting fatigue life under different conditions of piston.