The Paton Welding Journal, 2013, №05



2013 №05 (08)

2013 №05 (01)

---

The Paton Welding Journal, 2013, #5, 61-64 pages  

METHOD FOR MEASUREMENT OF DYNAMIC STRAINS IN EXPLOSION WELDING

L.D. DOBRUSHIN, E.D. PEKAR, A.G. BRYZGALIN and S.Yu. ILLARIONOV

E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
 
 
Abstract
The method is suggested for measurement of dynamic strains by using resistance strain gauges. The working power is supplied by the generator of DC pulses with a voltage of 23 V and duration of 14 ms. The short-time supply of the power allows increasing the working current from 25-50 to 200-250 mA, this leading to almost an order of magnitude increase in sensitivity of the method. The measurement system comprises the DC pulse generator and the digital oscillograph connected to a computer. Calibration tests were carried out, and performance of the measurement system was investigated in a range of elastic and elasto-plastic strains. It is shown that the dynamic strains due to explosion loading of metal structures can be measured at a satisfactory accuracy within -0.6-0.6 % in a time interval of 0-14 ms. In addition, the system makes it possible to fix residual strains of metal of a structure after the dynamic impact. 6 Ref., 1 Table, 8 Figures.
 
 
Keywords: dynamic load, strains, resistance strain gauge, measurement, bridge circuit, pulse generator, sensitivity of method
 
 
Received:                13.02.13
Published:               28.05.13
 
 
References
1. Nedoseka, A.Ya. (2001) Principles of calculation and diagnostics of welded structures. Kiev: INDPROM.
2. Kolodyazhny, A.V., Sevryukov, V.I. (1986) Impact and pulse actions on structures and materials. Kiev: Naukova Dumka.
3. TU3.06 Ukraine 7710-0001-93: Resistance strain gauges. Purpose and field of application.
4. Vorobiov, Yu.S., Kolodyazhny, A.V., Sevryukov, V.I. et al. (1989) Rapid deformation of structural elements. Kiev: Naukova Dumka.
5. Dobrushin, L.D., Bryzgalin, A.G., Pekar, E.D. et al. (2012) On the possibility of application of pulse current generator for measurement of dynamic strains in metal structures. Izvestiya Volgograd. Gos. Tekhn. Un-ta. Series Explosion welding and properties of welded joints. 5(14), 78-82.
6. Kuchling, H. (1985) Reference book on physics. 2nd ed. Moscow: Mir.

---