From the non-linear state of the first loading compression curve, it can be determined that a certain amount of plastic deformation has been generated in the gasket at this time; whether in the state of loading or unloading, the springback response of the elastic washer lags slightly behind the frictional force. The change of the load causes the rebound curve at this time to have a certain degree of nonlinear characteristics. The compression rebound curve of the elastic washer is composed of an elastic section and a nonlinear section. For the gasket, the axial load is below 100 kN for elasticity ( Linear) segment. The compression-rebound curve of the elastic washer is shown in Figure 5 when friction is not considered. It can be seen that the first loading compression curve is basically the same as when there is friction, but the first unloading of the rebound curve, the loading of the compression curve again, and the reloading of the rebound curve again have linear elastic characteristics. When the load is repeatedly applied and unloaded, the rebound curves of the elastic washers coincide with each other, that is, have the same rebound stiffness, and in the elastic section, the compression stiffness is approximately equal to the rebound stiffness.

In the elastic section of the loading and unloading, the compression stiffness and the rebound stiffness of the gasket with friction are slightly lower than those without friction. Retraction curve Due to the actual situation, there must be friction between the nut, the washer and the flange. In order to discuss the compression and rebound stiffness of the elastic washer when there is friction, it is necessary to analyze the rebound curve of the washer under different loads. The compression-rebound curve of the elastic washer under different loads. The curves are all rebound lines except the one shown as the compression curve. It can be seen that the elastic washers with an axial load of less than 200kN can basically maintain the linear elastic characteristics of the structure regardless of the compression or rebound process, and the compression and rebound stiffness are basically the same. Generally, the application range of the elastic washer should be in the elastic section, so from a conservative point of view, the slope of the A line in the figure can be approximated to replace the compression and rebound stiffness of the elastic washer, that is, SY=KDY, SC=KDC.

The design of the stiffness of the elastic washer is calculated. The stiffness of the elastic washer is designed to calculate the stiffness of the bolt flange connection system caused by the working load and the creep of the bolt and gasket material under a certain preload load. Solve the separation of the program flow chart of the SG to ensure that there is enough residual working pressure on the gasket to ensure the seal is effective. Elastomeric Washer Bolt Flange gasket connection is a pre-stressed static indeterminate system with high stress levels at preload. Under operating conditions, the medium pressure creates axial static pressure at the flange joint, and the effect of high temperature causes the bolt to stretch, the flange to deflect, the elastic washer to rebound and the pressing surface to tend to separate, and the gasket to generate creep and stress. Slack, but these changes are compatible and conform to the deformation coordination conditions of the connected system.

Escalator Modernization

While the escalator truss can last for the lifetime of the building, mechanical components can wear out or become outdated. Safety regulations, as well as electrical and monitoring systems, have changed considerably in the last 10 or 20 years. And aesthetics can change as quickly as trends in interior design.