The Failure Analysis Of The Air Nailer’s Needle Assembly Based On Ansys

The failure of an air nailer is often started from the rupture of the needle assembly which withstands impulse force directly as air nailer in working state. So the life of an air nailer is determined by the needle assembly’s strength and ability against the failure. Then analyzing the key parameters which influence the failure of an air nailer becomes the focal point when an air nailer is designed. But there are some difficulties when failure analysis is being done, such as the needle assembly suffering complex force, contact problem among the accessories and the rupture of the assembly caused by fatigue. By virtue of the ongoing technology of FEA, Failure analysis being done to improve the life of the needle assembly is meaningful.In this paper, an air nailer produced by a domestic enterprise is studied. Based on the universal FEA software ANSYS, according to the force obtained by experimentation when air nailer is working, contact analysis for the air nailer’s needle assembly is done. And following with the fatigue analysis testing of the needle assembly’s life fatigue analysis is done to validate result of the FEA. The main tasks and achievements are presented as below:1. The force suffered by the needle assembly in working state is analyzed on grading method. The working process is predigested. By means of experimentation being designed to test the force when the needle assembly is working, proper load is obtained for finite element analysis.2. The accurate FEM model of the needle assembly is established. Using the powerful function of nonlinear analysis to solve the contact problems in ANSYS, static analysis of structure is done, by which the key parameters affecting the stress value and distributing is discovered. 3. The factors which influence the fatigue life of the needle assembly are obtained with the help of ANSYS fatigue model.4. The result after FEA is proved reasonable through the experimentation which testes the real fatigue life of the needle assembly in working state.In conclusion, with systematic analysis and research, towards the needle assembly, the method of the nonlinear analysis to solve the contact problems and the fatigue analysis in ANSYS is given. Key factors influencing the stress and life of the needle assembly is obtained. It is certified that FEA has good value and practical application prospects.