| 摘要 |
The invention provides a method for tightening threaded fasteners in a flange joint or the like, which comprises initially tightening each fastener to a predetermined initial load or stress, measuring the final load, stress, strain or elongation of each fastener after all fasteners have been tightened, and calculating interaction coefficients from the experimental data thus obtained. The interaction coefficients are representative of elastic interactions occurring between each fastener in the system, and enable an initial fastener strain value or load to be predicted for each fastener in the system. Using the predicted initial strain, stress or load values and the interaction coefficients for each fastener and applying an initial stress to each bolt in a second test in accordance with these calculations, allows updating of the interaction coefficient values along with the predictions of initial loads so as to enable calculation of preloads on each bolt which will yield essentially uniform bolt stress. The method compensates for elastic interactions between fasteners in the system and is self-correcting to reduce effects of flange surface misalignment.
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