Fastener stress state evaluation method and detection device

A stress state, fastener technology, applied in measuring devices, force/torque/work measuring instruments, torque/torsional force measurement during tightening, etc., can solve problems such as inaccurate residual stress evaluation

Active Publication Date: 2020-06-19
SHANGHAI ELECTRIC POWER GENERATION EQUIPMENT CO LTD
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a fastener stress state evaluation method and detection device, which solves the problem of inaccurate evaluation of the residual stress of fasteners in the prior art

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Fastener stress state evaluation method and detection device
  • Fastener stress state evaluation method and detection device
  • Fastener stress state evaluation method and detection device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0052] Please also refer to Figure 1 to Figure 7 As shown, the present invention is a method for evaluating the stress state of fasteners, which at least includes the following steps:

[0053] Please also refer to Figure 1 to Figure 7As shown, in steps S1 and S2, the target material is subjected to a relaxation fatigue interaction test with different strain amplitude ε control at the preset temperature, that is, the service temperature. The collected data is as ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a fastener stress state evaluation method and device, and relates to the technical field of fastener maintenance and detection. The evaluation method comprises the following steps: carrying out a relaxation fatigue interaction test on a fastener material at a preset temperature; collecting stress values of the fastener material corresponding to different fastening times under the conditions of different strain amplitudes and different retention time; obtaining a stress relaxation curve cluster according to the stress value collected by the data collector; fitting the stress relaxation curve cluster to obtain a first stress relaxation fitting curve; obtaining a residual stress value at the preset temperature according to the first stress relaxation fitting curve; andcomparing the residual stress value with a preset residual stress threshold value, and evaluating the stress state of the fastener under the condition of the residual stress value. The technical problem that in the prior art, only a pure high-temperature relaxation curve is used for evaluating the residual stress of repeated fastening inaccurately is solved.

Description

technical field [0001] The invention belongs to the technical field of fastener maintenance and detection, and in particular relates to a fastener stress state evaluation method and a detection device. Background technique [0002] In some special fields, fasteners usually need to serve at high temperatures, such as in the fields of steam turbine cylinder valves, boiler pipe flanges, etc. The phenomenon of stress relaxation is prone to occur, that is, the residual stress will continue to decrease. When the residual stress decreases to less than the minimum sealing stress, it will cause the seal to fail and cause leakage. In the process of repeated fastening, the residual stress of the fastener is difficult to accurately evaluate due to multiple re-tightening, which will cause the fastening force loaded on the fastener to exceed the loading limit and cause the fastener to break, causing catastrophic accident. [0003] At present, the relaxation stress curve obtained by hig...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01L5/00G01L5/24
CPCG01L5/0047G01L5/24
Inventor 吴海利
Owner SHANGHAI ELECTRIC POWER GENERATION EQUIPMENT CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap