Study Of Stress Mitigation And Failure Map Of Bolted Joint In Glass Fibre Reinforced Epoxy Composite Structure
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Date
2014-02
Authors
Jadee, Khudhayer J.
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Bolted joints are vastly used in many applications and constitute an integral part of structural components. Understanding the stress distribution around the bolt-hole and mitigation of these stresses represents the crucial task in determining the failure load, failure mode and bearing strength of the composite bolted joint. Several attempts have been done to reduce the stresses by increasing the composite thickness, laminating inserts or steering fibres around the bolt-hole. This study investigated the effect of introducing auxiliary hole (relief hole) near the bolt-hole (main hole) to mitigate the stresses around the bolt-hole. This technique known as the Defence Hole System (DHS) and it has been utilized in the past for mitigation the stress concentration around the main hole in plates subjected to tension, compression, or shear stress. Both experimental and finite element analysis were performed to investigate the effect of a range of width and edge distance to bolt-hole ratios on the performance of fibre reinforced composite single bolt double lap joint. Results showed that the defence hole system is able to mitigate the stress concentration around the bolt-hole and hence contribute in improving the load carrying capacity of the joint. The maximum stress mitigation was achieved for the laminate with W/D=3 and E/D=5 which was -18.7% for laminate with DHS of DHD=0.625D at a distance DS=2.5D, which also produce a maximum failure load increment of 34.8%. The failure map of the composite bolted joint has also been derived based on the geometric parameters (W/D and E/D) and the stresses around the bolt-hole, to clarify the specific failure modes of the joint.
Description
Keywords
Stress Mitigation , Glass Fibre