Design and development of a portable moire interferometer.

摘要

Moire interferometry is an optical technique for full-field high-resolution in-plane and out-of-plane displacement measurements. However, to this date, most of the moire interferometry tests are conducted in a research laboratory environment, with a bulky optical setup mounted on an optical breadboard.; In this research, a user-friendly portable moire interferometer with well-defined specifications was designed and assembled. The key features of this design were u-, v- and w-displacements measurement, linear and rotational axes movement, motorized in-plane rotation, built-in reference laser for easy alignment, compactness, lightweight and portability. Solidworks CAD software was used to perform the design.; Mechanical components of the design were manufactured, while assembly of optical and mechanical components resulted in prototype development. An assembly process manual was developed establishing the procedure to perform the assembly. The prototype was calibrated and validated for its specifications through testing and study of a three-point-bending fatigue pre-cracked IN 783 Superalloy specimen. A test setup and procedure manual was also developed.; Fringe pattern of the three-point-bending test at 250lb, 400lb, and 600lb were analyzed. The u and v displacement fields around the crack tip region were compared to 3D finite element analysis results. The comparison revealed good agreement between experimental and FEA results. The shape and size of the crack-tip elastic-plastic zone were also studied and found in agreement with past numerical studies.