Strength and durability of steel to composite joints for marine application

This thesis deals with the assessment of the strength and durability of steel to composite<br/>joints for composite superstructures on ships where reduced weight is a design driver. The<br/>purpose of the work is to understand the long-term performance characteristics of hybrid<br/>connections to allow for improvements to the design of hybrid structures. Two joints were<br/>investigated in the present research. The first was a full-scale connection suitable for<br/>application in superstructures of marine vehicles, specifically a helicopter hanger on a naval<br/>vessel. The second was a generic steel/composite connection for testing performance after<br/>hygrothermal ageing.<br/><br/>The strength and durability of the full-scale connection were examined in compression, the<br/>loading scenario representative of in-service conditions. The results indicated that the static<br/>and fatigue performance were in excess of the realistic in-service loading conditions.<br/>Failure for both static and fatigue tests were comparable and therefore good confidence in<br/>the prediction of the joint’s failure was achieved. The generic hybrid connection was<br/>artificially aged through immersion in water. The results indicated that there was no<br/>significant reduction in the performance of the joint in either static tension or bending.<br/><br/>The numerical modelling highlighted a number of issues. Due to the geometry of the joint<br/>high stress concentration factors were observed in some locations. It is in these areas that<br/>failure of the joint was predicted in the numerical modelling. Similar results were obtained<br/>experimentally and this gave confidence in the modelling of the joint. Numerical<br/>parametric and optimisation studies were conducted to assess the influence of the joint<br/>geometry on performance characteristics obtained from both the experimental and<br/>numerical studies. This highlighted that improvements to the performance of the joint<br/>could be obtained through geometric changes alone.

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Southampton

Year dc:date.issued

2006

Author dc:creator

• Boyd, Stephen William

Advisors dc:contributor.advisor

• Shenoi, Ajit
• Blake, James