Advances in High-Performance Mechanical Fastening

This paper discusses the advances in mechanical fastening made over the last decade. More detailed analyses of the bolted joint have led to a better understanding of the relationships between the working loads imposed on the bolted joint and the stresses felt by the bolt. The induced preload (tension) in the fastener is shown to be the critical factor involved in the static and dynamic reliability of the bolted assembly. The need for more accurate assembly methods to insure good control of fastener tension has resulted in the development of special electronic controls which are being used on the assembly line. Preload loss mechanisms which occur in service were studied, and new fastener locking methods are being evaluated by means of transverse vibration tests. The designer facing the challenge of greater reliability and fuel efficiency has the recently developed fastening technology at his disposal. Using this technology, the designer avoids costly design fixes, product liability, weight penalties and thus can meet the needs of today’s more stringent designs.