Strain measuring method based on Moire fringe phase analysis

Abstract

The invention discloses a strain measuring method based on Moire fringe phase analysis. The method includes the steps: generating the mechanism of a Moire fringe structure by means of a grating structure, converting the strain of an object structure into a morphologic change of Moire fringes, and determining the strain of the object structure through a phase analysis mode. During a strain measuring process, parallel light vertically enters an object grating mark G1, a grating is imaged on the surface of the object structure through a left dual-telecentric system (1), a right dual-telecentric system (2) enables the grating image on the surface of the object structure to be imaged again in a detection grating mark G2 position, and the two grating marks are overlapped after space imaging to form Moire fringe distribution. The strain of an object causes the phase shift of Moire fringes, so the strain of the object is calculated through a phase analysis algorithm. The characteristics are that the method is contact-free, is high in measuring precision and high in technical adaptability, is highly practical, etc.

Description

technical field [0001] The invention relates to the above-mentioned strain measurement method based on the phase analysis of Moiré fringes, and belongs to the application field of optical principle technology in mechanical engineering. Background technique [0002] With the rapid development of modern industrial products, the three-dimensional size measurement of products is also more important, and there is also a demand for the measurement of micro-nano structure products. Strain measurement is a basic task in the mechanical performance testing of materials and structures. It is the basis for understanding the deformation, damage and failure behavior of materials under the action of factors such as mechanical loads. It is also important for determining the design allowable value of structures. significance. The usual electrical measurement methods include resistance, capacitance, and inductance testing methods. Although they have high sensitivity and precision, they can o...

AI Technical Summary

Problems solved by technology

The method of measuring strain by the strain measuring device has high measurement accuracy, but it is contact type, and the cost is relatively high

At the same time, foreign countries also have optical strain measurement methods through white light interferometry, which have high precision, but have high requirements for the working environment and long measurement time.

[0004] Because most of the optical interference principle is used to test the strain of objects at home and abroad, the principle of the interference method is relatively complicated and the measurement cost is high.

Images