Large Tonnage Of Performance Analysis And Study The Impact Of Fatigue Testing Machine

Automatic machine guns are repeated impact loads at work, an important factor affecting their failure is the impact of fatigue. Due to the theory of impact of fatigue has not perfect, it can not give good predictions about the parts which suffered complex fatigue failure, so we need to get through the test means, to predict the failure behavior under the impact of fatigue and fatigue life about an important component. In order to meet this demand for impact fatigue test on automatic machine guns, we need to study for theoretical and experimental on a large tonnage impact fatigue testing machine.This paper's main tasks are as follows:(1) established a virtual prototype simulation model of large tonnage impact fatigue testing machine, which supplies a loading mechanism with conjugate cam, this model can be used to analyze the kinematic characteristics and impact force characteristics, obtain the affect of parameters from them; (2) proposed a half-sine force pulse generator design, hedge head configuration of different materials and combinations of the stiffness of the conditioning block, with the finite element simulation software for numerical analysis results show that changing the stiffness of punch can achieve the impact of pulse width, it also can be adjusted in a small area; (3) used finite element analysis of C-type openings fuselage modal analysis and transient modal dynamic analysis, determined the testing machine frame vibration characteristics and dynamic response analysis of the impact of vibration on the frame. To ensure adequate stiffness under the premise of the frame, optimized the target thickness of frame size, improved the first-order natural frequency; (4) debugged and tested the large-tonnage impact fatigue testing machine prototype, determined the test machine performance through experimental data analysis, verified the correctness of this simulation analysis. This study provides a scientific basis for the development and improvement of large-tonnage impact fatigue testing machine.