Development of a Design Analysis Methodology for Bonded Structures.

A need has been identified for a joint analysis tool applicable to a wide variety of joint configurations and suitable for use by the designer rather than by the specialised stress analyst. The aim of this project was to create a prototype for such a tool, in the shape of a software program using as its basis a finite element method, along with guidelines for interpreting the results. A literature review was carried out to provide data on current joint design procedures. Testing of some of the software identified in the review was performed. The general conclusion was that while many analysis tools for specific joint types exist, there is none to satisfy the general case. A questionnaire was sent out to manufacturing companies using adhesive bonding. Its aim was to establish current practice in industry - the joint types, materials, and design methods employed. Results from the questionnaire confirmed the need for a tool such as the one proposed. Based in part on the results from the questionnaire, a specification for the software to be developed was drawn up. Central to the concept is a simplified system of meshing, using beam elements to represent the substrates in the joint and quadrilateral elements to model the adhesive. This method substantially reduces the number of elements in the model, allowing a faster analysis, without significantly compromising accuracy. This approach has been successfully validated in this work. Implementation of the software formed the major part of the project, and is described at some length. The final package presents an intuitive, mouse-driven interface for generating models, automatic rule-based meshing, a proprietary finite element analysis code, and postprocessing tools for the results. Related work in generating design allowables for use with the results developed guidelines that will allow joint strength prediction for static and fatigue loading. Detailed appendices furnish information on use of the finished package, and details of the program structure