A Fastener Analysis Addressing Various Types of Misfit and an Innovative Simple Design Solution - Part-II Monitoring the Joints for a Crack 2011-01-2715

The fastener analysis for an airframe panels under random cyclic loading conditions were analyzed with various elaborate solutions. But here a simple technique is proposed to analyze the problem. The fastener system in any structure could develop crack at the edges of the hole or at the fastener head rim location and propagate further between bolts. The sub- layer crack and micro cracks are hard to locate visually. Here a solution method is presented to detect the crack for various types of fastener conditions such as the fully contacted fastening, partial contact and no-contact condition. This is one of the useful tools to check the health of the fastening systems. Part I of this paper shows the necessity for a fix that arise in the initial misfit conditions. They also show the fastening efficiency for all the different condition. Here we would like to address the detection of a crack in any of the above fastening conditions. The analysis results in this paper does show the necessity for a fix of the partial fastener (model 3) which behaves like a cracked model by itself.