ホログラフィ干渉法を利用した熱変形計測 (第1報)

補正台による干渉じま補償法を応用した熱変形計測装置の開発

抄録

This paper describes a development of an apparatus for highly accurate measurement of a thermal deformation of a mechanical part. The apparatus makes possible a real time monitoring a microscopic change of the thermal deformation pattern by using real-time holographic interferometry. One of the most important problems to be solved on a measurement of thermal deformation is how to fix a measuring object. When environmental temperature changes, the spurious interferometric fringes are happened by an unnecessary slip between contact surfaces of the measuring object and its holder, due to thermal expansion differences between them. An adjustable correcting stand utilizing piezoelectric elements is developed for a real time compensation of the spurious fringes. The effectiveness of the correcting stand for a precise and real time measurement of the thermal deformation pattern was confirmed experimentally. An air bath that has an optically stable window for observation of the deformation from outside is used for highly accurate control of the temperature of the measuring object. The interferometric fringes are recorded on a thermoplastic plate for real time monitoring of the changing process of the thermal deformation pattern.