Development and application of tail brush elastic test device.

The shield tail brush loss elasticity is the key reason for the failure of shield tail seal. However, due to the limitation of test equipment, there is little research on the elastic properties of tail brush. In this research, a tail brush elastic test device was developed. Through this device, the tail brush is tested for elasticity. In this test, the grease filling layer number, tail brush mass, tail clearance, pressing number and pressing time were taken as the influencing factors, and the elastic coefficient and resilience force were taken as the response values. Single-factor test was carried out for each factor, then based on the Plackett-Burmanf theory and Box-Behnken response surface design theory, the ANOVA method was used to find out the significant degree of each factor's influence on the quantitative index. The prediction model of elastic coefficient and resilience force was fitted based on RSM theory, and the verification group was added to verify the reliability of the prediction model. The results showed that the significance of influencing factors on the elasticity coefficient was ranked as follows: tail clearance > pressing number > pressing time > grease filling layer number. The significance of influencing factors on brush resilience F was ranked as follows: tailclearance > grease filling layer number > pressing time > pressing number. The accuracy of elastic coefficient regression model is 94.1%. The accuracy of the resilience force regression model is 99.56%, and the accuracy of the prediction model is high, which can be used to predict the elasticity coefficient and resilience force. Finally, the elastoplastic development mechanism of tail brush is discussed, and the safety standard of tail brush is proposed, which provides a basis for the selection of tail brush in practical construction.