RESUMO
In this work, the contact force model and experiment methods were used to study the dynamic response and impact wear behavior of TP316H steel. The Flore model and the classic Hertz model were selected for comparison with the experimental results, and the model was revised according to the section parameters of the TP316H tube. The results show that there is a large difference between the models without considering the effect of structural stiffness on the impact system and the test results, whereas the revised model has a good agreement. With the rise in impact mass, the coefficient of restitution increases from 0.65 to 0.78, whereas the energy dissipation and wear volume decrease. Spalling, delamination, plastic deformation, and oxidative wear are the main impact wear mechanism of TP316H steel.
RESUMO
Cam mechanism is widely applied in industry because it can help achieve various complex motions of the follower via the cam contour design. However, its performance is significantly affected by the wear condition. This study proposes a load distribution measurement instrument to assist the study on friction and wear regularities of oscillating follower cam mechanisms through obtaining the normal pressure (F) and friction force (Ff) distributions along the cam profile. In the instrument, F and Ff are automatically calculated via a MATLAB program based on the geometry and the measured rotary resistance torque and rotary angle of the cam. The latter two parameters are obtained through a static torque sensor and a rotary encoder built in servo motor in real time, respectively. An experimental test was conducted and the cam morphology after service was observed using scanning electron microscopy. Results show that the wear condition of the cam is significantly related to the corresponding F and Ff. Complex load parameters of oscillating follower cam mechanisms can be provided by this instrument, which is crucial in understanding the friction and wear behaviors of cams and finding the vulnerable position.