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How to evaluate the fastener's anti-loosening performance

2018-05-01 17:36:24

For how to evaluate the anti-loosening performance of fasteners, two standard test methods are generally used at present. The first is the fastener accelerated vibration test method (ISO standard or GJB715.3-89), the second is the fastener lateral vibration test method (GB/T10431-1989). Both are test methods to accelerate fastener connection loosening, they have their own characteristics, the first method is currently mainly used in aerospace systems, while other systems use the second method.

Tools/Materials

Fasteners.

Steps/methods
1

This information is taken from experience without authorization

2

Test method for transverse vibration of fasteners (GB/T10431-1989). This method is a direct force on the bolt (or screw), so it can make the fastener connection loose in a shorter time, and the test efficiency is higher. Another feature of the second method is that it can accurately measure the variable of the preloading force in the vibration test process of the fastener connection, describe the change process of the preloading force in the test, give the relationship curve between the preloading force and the number (or time) of vibration, and use the variable of the expected decline of the tightening force as the criterion for measuring the loosening of the fastener connection. This is more intuitive and accurate than the first method, and also easier to operate.

Matters needing attention

The transverse vibration test method of fasteners can accurately evaluate the effect of the torsion-tension relationship of fasteners on the anti-loosening performance, which provides a more effective test way for further research and design of various new anti-loosening firmware.

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