Research On Vibration Reliability Enhancement Test Technology Of Composite Sensor

As a key information acquisition component of the on-board fault diagnosis system,a new type of composite sensor is used to monitor the temperature,vibration and shock signals of the bearings and gears in the train.It is generally installed under the vehicle and bears various quite harsh environmental stresses.At the same time,it is high reliability and long life required.If the traditional reliability growth test technology is applied to the new type of composite sensor,the test time is very long and the cost is very high,they are unacceptable.In recent years,the reliability-enhanced test technology has developed rapidly,and it has become more and more widely used because of its low cost and high efficiency.In this paper,the reliability enhancement test technology is applied to the new type of composite sensor,and the following research work is carried out:Firstly,based on the analysis of the basic composition and principle of the new type of composite sensor,the fault mode and impact analysis are carried out.According to the statistical data of field use faults of other similar products,the failure mechanism and the distribution of sensitive stress are analyzed.Investigating the main factors affecting the reliability of composite sensors,it is found that most of the failures of similar composite sensors are related to vibration stress.Determining vibration stress is the main sensitive stress that causes the failure of composite sensors.The analyses provide reference for carrying out vibration reliability enhancement test.Secondly,using the traditional vibration-enhanced test equipment pneumatic vibrating table and the characteristics of the new electric vibrating table non-Gaussian vibration controller with spectrum and kurtosis control,three sets of vibration reliability strengthening tests are carried out for the new type of composite sensor.The first set of test is a vibration strengthening test based on the super Gaussian vibration excitation of a pneumatic vibrating table,and the second set of test is a vibration strengthening test based on the super-Gaussian vibration excitation of the electric vibrating table to change the power spectral density level,and the third set of test is based on electric The vibration enhancement test of the bandwidth and kurtosis values of the super-Gaussian vibration excitation of the vibrating table.The comparative analysis of the above test results shows that: First,the super-Gaussian vibration strengthening test of the electric vibrating table stimulates a failure mode different from the super-Gaussian vibration strengthening test of the pneumatic vibration table,which takes less time to excite potential failures.It shows that these two vibration excitation environments can effectively stimulate different potential defects of the composite sensor.The two complement each other can more fully stimulate the failure mode of the composite sensor.Second,the electric vibration table super Gaussian vibration strengthening test It can be changed by changing the power spectral density,bandwidth and kurtosis of the vibration excitation,and can adapt to various products with different frequency characteristics,which is more flexible than the pneumatic vibration table;and the greater the power spectral density of the super Gaussian vibration excitation The smaller the bandwidth and the greater the kurtosis,the higher the excitation efficiency of potential defects of the product,so the super Gaussian vibration excitation with controllable spectrum and kurtosis has significant advantages in stimulating product failure.