Multiple Fixture Design Of HF Fatigue Testing Machine And Its Dynamic Characteristics Research

High frequency fatigue testing machine is used to test the resisting fatigue rupture capability of all kinds of metal material and nonmetal material, and makes a fatigue life curve(S-N), which is widely applied to aviation, spaceflight, metallurgy, universities, scientific research and education as well as all departments of industry producing.There are some fixtures, which is used to test fatigue life of different parts, associated with High frequency fatigue testing machine. But each one can only fix a part only in a test. Some parts are so small that it will cause the low frequency. In this case, they won’t be tested in the High frequency fatigue testing machine. In order to avoid this problem; it designs two special fixtures which help to improve whole frequency. Because of the high frequency, the testing efficiency also improves as well.Based on the principle of High frequency fatigue testing machine and the rule of fixture designing, the paper designs multipoint fixtures for column and board. With the help of PRO/E three-dimensional software, it draws models. Then, it analyzes the static force and mode of these two fixtures through ANSYS Workbench software. Static force analysis shows that the slight change of fixtures is within the limit of experiment. Mode analysis shows that whole frequency can be applied in the testing machine.The requirement for the allowable load of the testing machine would be much higher if loads on multiple smooth specimens with bigger force. We analyze the model of the V-shape notched circular cross section specimens and U-shape notched rectangle section specimens, we find that if the loading fore is small, then the requirement would not be that high. Through the analysis, it shows that the frequency and mode of vibration of the smooth specimens is almost the same with notched ones, we can proceed the experiment. Finally, according to the condition of fixtures, it processes the data simply. At the same time, it derives parent distribution with sample distribution.