Residual Stress Measurement by the Hole-Drilling Method Residual Stress Measurement by the Hole-Drilling Method | HBM

MTS3000 - 殘餘應力測試系統

殘餘應力存在於物體內部,外部沒有任何徵兆,但是會影響其力學性能,因此,測量物體內部的殘餘應力是必不可少的。採用快速鑽孔方式,1.6 mm 的孔深入到物體內部,這樣任何的應變變化將會被應變計測量到.

現在,SINT Technology提供整個的測量鏈讓應力測量過程更加容易。鑽孔機以300 000 revs./min運轉產生鑽孔。隨著步進電機的逐步推進,應力的變化將會被專為此設計的應變花檢測到.

整個的信號處理都是通過數位方式進行的,包括控制功能以及4種運算方程。

所有的測量過程都是通過PC控制的,這可以保證測量的高精度和重複性.

SINT Technology

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Integral Method

This method, proposed by G. S. Schajer, provides a separate residual stress analysis at every hole-drilling depth increment. In this method, the contributions to the total measured strain relaxations of the stresses at all depths are considered simultaneously giving a higher spatial resolution than the other methods.

To simplify the problem of residual stress evaluation, Schajer proposed that the stress field could be described by means of step-wise functions whose value is constant through the partial hole depths. Using this hypothesis, Schajer established the numerical coefficients that are used for the calculation. The maximum depth that the method can be used for is 0.5 times the mean radius of the strain rosette used for the test.

The integral method should be chosen when residual stresses are expected to vary significantly with depth; however, it also has the highest sensitivity to test errors.

Flyer Residual Stress Measurements