Two-part supporting type flange connecting structure and designing method thereof

Abstract

The invention discloses a two-part supporting type flange connecting structure which is a flange connecting structure capable of decreasing the bolt peak stress and increasing the bolt strength allowance. The designing process of the flange connecting structure comprises the following steps that firstly, the compression amount and the springback amount of a seal ring are determined according to the sealing requirements or relevant standards, and then the height difference between two supporting parts is calculated; secondly, the number and specification of bolts are primarily determined according to separating force borne by a flange and the drift diameter of the flange; thirdly, the flange shape can be primarily determined by experience, and parameters such as the flange shape, the bolt specification and the pretightening force are optimized by conducting finite element analysis; lastly, the bolt pretightening force is converted into a control parameter for engineering use. According to the two-part supporting type flange connecting structure, bending moment peak values borne by the bolts in the whole working cycle can be effectively decreased, then a bolt stress peak value is decreased, the strength safety allowance of the bolts is increased, then the flange stiffness requirements are lowered, and the overall weight of the flange connecting structure is decreased.

Description

technical field [0001] The invention relates to a flange connection structure and a design method thereof. Background technique [0002] The rocket engine has strict requirements on the structural weight, and the reduction of the structural weight of the engine means the increase of the payload weight of the rocket. A large number of liquid rocket engines use flange connection structures. According to the different supporting parts of the two flanges, the current flange connection structures can be roughly divided into two categories: 1) Large-area contact flange connection structures, such as figure 1 As shown in (a); 2) Only the sealing structure is in contact - a single position supporting flange connection structure, such as figure 1 (b) shown. [0003] The sealing ring is located on the medium side. For the large-area contact flange connection structure, the bolts are basically not subject to bending moments in the assembled state (not filled with medium) (due to the ...

AI Technical Summary

Problems solved by technology

The action of bending moment will make the stress distribution of the bolt along its circumferential direction uneven. Under the condition of the same axial force, the uneven stress distribution will cause the peak value of the stress to increase and the safety margin of the bolt will decrease.

For the single-position supported flange connection structure, the bolts are subject to a large bending moment in the assembled state, and the bending moment on the bolts will further increase in the working state. Under the same axial force of the bolts, The safety margin of the bolt is low

[0004] In order to reduce the bending moment on the bolts, the method of increasing the thickness of the flange is generally used to increase the stiffness of the flange, which leads to an increase in the weight of the flange connection structure

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