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Method for calculating and evaluating pre-tightening relaxation law of composite material interference connection structure

A composite material and connection structure technology, which is applied in the direction of connection components, calculation, thin plate connection, etc., can solve the problems of the effect of pre-tightening relaxation, difficult relaxation mechanism, and the pre-tightening mechanism is more complicated than gap connection.

Pending Publication Date: 2020-10-09
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The interference connection structure to be studied in the present invention, due to the interference fit between the bolt and the composite material connection hole, friction and extrusion with the hole wall will inevitably occur during the bolt installation process, and its pre-tightening mechanism is more complex than that of the gap connection. complex, and this friction effect will also affect the pre-tightening relaxation of the later connection structure when it is in service, making it difficult to obtain the relaxation mechanism by analogy from existing research
Therefore, in order to ensure the safe service of the structure, it is necessary to conduct further in-depth research on the pretension mechanism and relaxation law of the composite interference connection structure. At present, the force and deformation analysis, deformation calculation method, The research on the mathematical model of axial force changing with temperature and the attenuation coefficient of preload force is still blank

Method used

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  • Method for calculating and evaluating pre-tightening relaxation law of composite material interference connection structure
  • Method for calculating and evaluating pre-tightening relaxation law of composite material interference connection structure
  • Method for calculating and evaluating pre-tightening relaxation law of composite material interference connection structure

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specific Embodiment 1

[0119] combine figure 1 , the present invention describes a pretension relaxation modeling and calculation method for composite interference connection structures. Considering the influence of temperature and time in service environment, the linear elastic model and viscoelastic model are used to describe the composite material in the process of pretension and relaxation respectively. Immediate response behavior and delayed response behavior, and the model parameters are calibrated by the experimental data, and the parameter model with intuitive physical meaning is used to reflect the pretension mechanism and relaxation decay law of the composite material interference connection structure. The purpose of the present invention is to make up for the deficiencies in the existing research, and to provide a modeling and calculation method for the pretension relaxation of the composite material interference connection structure, which can accurately quantify the pretension mechanism ...

specific Embodiment 2

[0211] The present invention will be further described in detail below in conjunction with diagrams, implementation methods, and implementation examples.

[0212] (1) Composite material interference connection structure specification

[0213] The single-layer thickness of the composite laminate is 0.2mm, the overall thickness after curing is 4.8mm, and the stack thickness is 9.6mm. The shape is a square with a side length of 70mm and a connection hole in the center. . Titanium alloy bolt diameter is 8mm. Composite material interference connection structure specifications such as Figure 5 shown.

[0214] (2) Experimental calibration of the pretension relaxation characterization process of the composite material interference connection structure

[0215] a. Nail insertion experiment of composite material interference connection structure

[0216] The head of the bolt transformed into a sensor has a collection line protruding from the extensometer, and the indenter of the t...

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Abstract

The invention discloses a method for calculating and evaluating a pre-tightening relaxation law of a composite material interference connection structure. The method comprises the following steps: considering the influence of temperature and time in a service environment; respectively describing an instant response behavior and a delayed response behavior of a composite material in the pre-tightening and loosening processes by using a linear elastic model and a viscoelastic model; constructing corresponding pre-tightening and relaxation models; calibrating model parameters according to experimental data; and using a parameter model with visual physical significance to reflect the pre-tightening action mechanism and relaxation attenuation law of the composite material interference connection structure. The pre-tightening action mechanism and the relaxation attenuation law of the composite material interference connection structure can be accurately quantified, a foundation is laid for researching interference connection damage and structural strength, and guidance is provided for optimization design of interference fit connection of the composite material structure.

Description

technical field [0001] The invention relates to the technical field of composite material structure processing and assembly, in particular to a method for calculating and evaluating the pre-tightening relaxation law of a composite material interference connection structure, which is used to analyze the bolts in the process of inserting, pre-tightening and relaxation of a composite material interference connection structure The interaction between composite materials and the precise quantification of the preload mechanism and relaxation attenuation law of composite interference connection structures. Background technique [0002] Advanced composite materials have been widely used in the aerospace field due to their high specific strength, high specific stiffness, good fatigue resistance and designability. Bearing structure. With the development of technology, a large number of composite material structures have appeared in the aircraft body, among which Carbon Fiber Reinforc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F30/20F16B5/02G01L5/00G01M13/00G01N3/22G06F113/26G06F119/14
CPCG06F30/20F16B5/02G01M13/00G01N3/22G01L5/0042G01L5/0028G06F2113/26G06F2119/14G01N2203/0021G01N2203/0075G01N2203/0676G01N2203/0224G01N2203/0212Y02T90/00
Inventor 胡俊山张胜平田威周越
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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