AN EXPLORATION TO THE PRELOAD OF THREADED FASTENER CONTROLLED DIRECTLY BY LASER

摘要

In order to ensure the reliability of threaded fasteners, the preload of threaded fastener must be controlled as accurately and rapidly as possible. One of the proper methods for it is to avoid the friction between the bolt and the connectng parts so as to control directly the tension which is produced in the bolt while the bolt is tightened. In this paper, an optical method for preload control by means of measuring the strain of an appointed surface of a bolt or a nut, after a bolt is tightened, is proposed. It is a rapid and accurate measurement and is likely to be widely adopted in the future since the instruments to be used are quite ordinary and cheap.