Loading device for accurately controlling rivet preload of riveting member

Abstract

The invention relates to a loading device for accurately controlling rivet preload of a riveting member. The device is composed of a bolt (1), a ring clamp (2), a strain gauge (6) attached to the outside of the ring clamp, a pin (3) and a press block (7). The strain gauge is in the vertical direction. The tightening load of the bolt is applied to the pin (3). A test method includes the steps of pressing the press block (7) by tightening the bolt (1), measuring the strain of the preload exerted by the bolt through a static strain indicator connected to the strain gauge attached to ring clamp (2) and accurately calculating the preload required by a test according to a corresponding preload formula. The loading device for accurately controlling rivet preload of the riveting member is reliable in method principle, uniform in loading force, high in test accuracy, accurate in data recording and result analysis, capable of avoiding negative factors on a riveting fretting fatigue test under the premise of not knowing how much the preload is and especially suitable for the research of the influence of riveting structure preload on the fatigue life.

Description

technical field [0001] The invention relates to a test method, in particular to a loading device for precisely controlling the pretightening force of rivets in a riveted structure. Background technique [0002] Fretting fatigue widely exists in various mechanical components, especially the connection with rivets, bolts, pins and other interference methods. Due to the characteristics of reliable connection, light weight and low cost, riveting is widely used in the connection of structures. The fatigue performance of riveted components is affected by many factors such as riveting process, structural material, external load and so on. In the riveting process, the rivet pressure force has a great influence on the fretting fatigue damage of the riveted structure: large pressure riveting force will lead to large rivet pre-tightening force, and fretting fatigue cracks will initiate at the edge of the rivet head; small pressure riveting force will cause rivet pre-tightening force ...

AI Technical Summary

Problems solved by technology

However, none of the above methods can effectively measure the pre-tightening force of the riveting fretting fatigue test.

For example, using reasonably designed bolts to simulate the method of riveting fretting fatigue test, although this method can measure the pre-tightening force through the wrench torque, but with the continuous change of the test load and times, it is impossible to understand and master the riveting in time The pre-tightening force of the fretting fatigue test will have a great change in the test results, so that the accurate test data and results cannot be obtained; while the test method of directly riveting the rivet is in the process of riveting the rivet It will produce a large plastic deformation, so it is impossible to know the accurate preload of the test

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