Abstract
In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of carrier fringes of moiré interferometry. A cross-line grating with frequency of 1200 lp/mm is replicated on the specimen surface, and the strain can be deduced from the changes in carrier fringes before and after the deformation of an object. Four coherent laser beams are used to obtain the carrier fringe patterns of field U and V. Both theoretical analysis and numerical simulation indicate that the ideal accuracy of strain can be controlled within a range of ±1με. Case study of a plane extension experiment shows that the measurement accuracy of strain can be controlled within the range of ±10με. The average strain values of every row of field U and every column of field V can be obtained by using this method, and approximated strain of every pixel in the whole-field can be further acquired, and thus it is possible to measure tiny strains occurred in a micro-field. The technology in this paper can provide comprehensive information for analyzing related mechanical content in the field of MEMS.
Similar content being viewed by others
References
Post D., Han B., Ifju P.: High Sensitivity Moiré Experimental Analysis for Mechanics and Materials. Springer, New York (1994)
Fang D.N., Liu Z.W., Xie H.M. et al.: Study on fracture-behavior of ferroelectric ceramics under combined electromechanical loading by using a moiré interferometry technique. Acta Mech. Sin. 20(3), 263–269 (2004)
Kimber M., Blotter J.: A novel technique to determine difference contours between digital and physical objects for projection moiré interferometry. Opt. Lasers Eng. 44(1), 25–40 (2006)
Liu Y.W., Fang Q.H., Jiang C.P.: Electroelastic interaction between a piezoelectric screw dislocation and a circular coated inclusion with interfacial cracks. Chin. J. Theoret. Appl. Mech. 38(2), 185–191 (2006)
Min Y., Hong M., Xi Z. et al.: Determination of residual-stress by use of phase-shifting moiré interferometry and Hole-drilling method. Opt. Lasers Eng. 44(1), 68–79 (2006)
Qiu W., Kang Y.L., Qin Q.H. et al.: Regional identification, partition, and integral phase unwrapping method for processing moire interferometry images. Appl. Opt. 45(25), 6551–6559 (2006)
Salbut L.: Automated laser extensometer for full-field and local in-plane displacements and strains measurement. Proc. SPIE 4900, 1254–1261 (2002)
Wang S.B., Tong J.W., Yue C. et al.: New method on experimental damage study of AS4/PEEK composite laminates. Proc. SPIE 4704, 69–73 (2002)
Xie H.M., Chen P.W., Shi H. et al.: An experimental study on creep deformation of PBX with laser moiré interferometry method. Key Eng. Mater. 306, 1037–1042 (2006)
Samsonov V.P., Samsonova I.V.A.: Moiré interference technique for studying vortex flame structures. Tech. Phys. Lett. 31(2), 157–158 (2005)
Author information
Authors and Affiliations
Corresponding author
Additional information
The project was supported by the Basal Research Funds of National Defence Science and Technology. The English text was polished by Yunming Chen.
Rights and permissions
About this article
Cite this article
Cao, Y., Wang, S., Qi, S. et al. Carrier fringe method of moiré interferometry for tiny strain measurements in micro-field. Acta Mech Sin 25, 101–106 (2009). https://doi.org/10.1007/s10409-008-0205-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10409-008-0205-7