Method for calculating thermoelastic instability phenomenon of disc brake

A technology of disc brakes, calculation methods, applied in the direction of calculation, instrumentation, special data processing applications, etc.

Inactive Publication Date: 2013-07-10
TONGJI UNIV
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  • Abstract
  • Description
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  • Application Information

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However, the value of the critical velocity obtained by

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  • Method for calculating thermoelastic instability phenomenon of disc brake
  • Method for calculating thermoelastic instability phenomenon of disc brake
  • Method for calculating thermoelastic instability phenomenon of disc brake

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Embodiment 1

[0125] Embodiment 1: In order to facilitate the description of the meaning and unit of each symbol in the specific embodiment, it is now unified, see the accompanying drawings.

[0126] (1) Establish the thermoelastic mathematical model of the disc brake

[0127] established as figure 2 The thermoelastic mathematical model shown, 1 represents the brake pad, 2 represents the brake disc, a 1 is the thickness of the brake pad, 2 a 2 is the thickness of the brake disc. Establish( x 1 , y 1 ), ( x 2, y 2 )with( x , y )3 coordinate systems, the coordinate system ( x 1 , y 1 )with( x 2 , y 2 ) are respectively fixed on the bottom surface of the brake pad and the middle surface of the brake disc and move together with the brake pad and the brake disc respectively. The coordinate system ( x , y ) moves with the disturbance. evenly distributed braking force P 0 Acts on the brake back of the brake pad. Assume that the moving speed of the brake disc and pad is...

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Abstract

The invention relates to a method for calculating a thermoelastic instability (TEI) phenomenon of a disc brake. The method comprises the following steps: establishing a thermoelastic mathematical model of the disc brake; evaluating the temperature field disturbance of a brake disc and a brake sheet respectively according to a transient heat conduction equation and a thermal boundary condition; respectively evaluating heat flow, absorbed by the brake disc and the brake sheet, on a sliding friction surface according to the temperature field disturbance; introducing a displacement potential function and a harmonic function so as to obtain the solution of a thermoelastic nonhomogeneous differential equation; representing displacement disturbance and stress disturbance, caused by friction heat, of the brake disc and the brake sheet by using the solution of the equation, and enabling to meet the thermal boundary condition; obtaining the initial contact pressure value between the brake disc and the brake sheet according to the boundary condition on the sliding friction surface; obtaining the expression formula of the required critical speed of the brake disc when the TEI phenomenon occurs by a heat flow balance equation: the total heat flow, absorbed by the brake disc and the brake sheet, on the friction surface should be equal to the product of the contact pressure and the friction coefficient between the brake sheet and the brake disc and the speed of the brake disc; and evaluating the critical speed and finding out the influence factor. By the method, after the brake is manufactured, the brake performance of the novel disc brake can be improved as much as possible through verification by a bench test.

Description

technical field [0001] The invention relates to the problem of thermoelastic instability of disc brakes during braking. In particular, the method is applicable to a calculation method of thermoelastic instability of a disc brake whose structure is axisymmetric to the circumference. Background technique [0002] When two objects are in contact and slide relative to each other, frictional heat is generated on the sliding surface. Frictional heat will cause thermal deformation of two objects at the contact surface. Thermal deformation in turn affects the contact pressure distribution between the friction surfaces. For a given coefficient of friction, there is a certain critical sliding velocity of the brake disc, above which the nominally evenly distributed contact pressure becomes unstable, creating pressure and friction in localized areas on the sliding surface Concentration of heat. When the temperature stress caused by friction heat is higher than the yield limit of the...

Claims

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Application Information

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IPC IPC(8): G06F17/50
Inventor 奚鹰夏德茂宋颖辉程宏朱美华陆佳伟张攀
Owner TONGJI UNIV
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