Micro Vibration Testing And Damage Identification On Sliding Electrical Contact Component

Electrical contact is the key structure of the equipment in automatic device, remote control machinery, communication device and other mechanical equipment and is the very important component, its quality and contact element life directly affects the reliability of equipment operation. For electrical contact process, the electrical contact component inevitably have interaction, lead to local vibration of the structure, and electrical contact structure appeared different degree of damage will affect force or the size of the direction, so it is necessary to detect vibration damage analysis and the analysis of system dynamic response. In order to study the vibration of the sliding electrical contact elements and find out the key factors influencing the vibration, test method of the transient vibration was studied in this paper, the vibration test system was established, experimental study were carried out with sliding electrical contact tester, Dynamic effect of the contact element was studied by finite element techniques.First of all, self- mixing technology has the advantages of high precision, fast dynamic response, large measuring range, non-contact measurement and resistance to electromagnetic interference, A phase extraction method based on the EMD algorithm is proposed in this paper. The displacement measurement based on EMD has been tested by computer simulation under different optical feedback conditions to ensure that the proposed method works well in the actual signal. The experiment system is established, and the algorithm based on EMD was applied to the test setup self-mixing signals with an accuracy of 30 nm. The results for the testing signals exhibit great consistency in the simulative results and demonstrate the effectiveness of this proposed method.Secondly, Due to mix the interference method is applied to high-speed sliding, and the limitation of high frequency vibration, high frequency, high speed limit), the more suitable method to be further studied, considering the development of piezoelectric acceleration sensor is relatively mature, the impact of vibration signal acquisition effect is good. So the transient sliding contact rail vibration test method was studied and the vibration test system is designed based on the piezoelectric acceleration sensor. The system adopts the high-speed data acquisition equipment that it used to measure, display and storage vibration data by using Lab VIEW.Finally, this paper studies the feature algorithm based on NExt/STD to determine whether have damage, the NEx T/STD method was used to calculated the first two order natural frequency, and then through the power spectral density differences between the undamaged and damaged one to locate the damage. Compared to natural frequencies before and after damage, the change of PSD and the actual damage location, we can found the correlation and consistency. Compared with modal analysis, this method is more convenient. At the same time, it avoid the loss of useful information, which can realize real-time online monitoring.