National freight transport planning: towards a Strategic Planning Extranet Decision Support System (SPEDSS)

This thesis provides a `proof-of-concept' prototype and a design architecture for a Object Oriented (00) database towards the development of a Decision Support System (DSS) for the national freight transport planning problem. Both governments and industry require a Strategic Planning Extranet Decision Support System (SPEDSS) for their effective management of the national Freight Transport Networks (FTN). This thesis addresses the three key problems for the development of a SPEDSS to facilitate national strategic freight planning: 1) scope and scale of data available and required; 2) scope and scale of existing models; and 3) construction of the software. The research approach taken embodies systems thinking and includes the use of: Object Oriented Analysis and Design (OOA/D) for problem encapsulation and database design; artificial neural network (and proposed rule extraction) for knowledge acquisition of the United States FTN data set; and an iterative Object Oriented (00) software design for the development of a `proof-of-concept' prototype. The research findings demonstrate that an 00 approach along with the use of 00 methodologies and technologies coupled with artificial neural networks (ANNs) offers a robust and flexible methodology for the analysis of the FTN problem domain and the design architecture of an Extranet based SPEDSS. The objectives of this research were to: 1) identify and analyse current problems and proposed solutions facing industry and governments in strategic transportation planning; 2) determine the functional requirements of an FTN SPEDSS; 3) perform a feasibility analysis for building a FTN SPEDSS `proof-of-concept' prototype and (00) database design; 4) develop a methodology for a national `internet-enabled' SPEDSS model and database; 5) construct a `proof-of-concept' prototype for a SPEDSS encapsulating identified user requirements; 6) develop a methodology to resolve the issue of the scale of data and data knowledge acquisition which would act as the `intelligence' within a SPDSS; 7) implement the data methodology using Artificial Neural Networks (ANNs) towards the validation of it; and 8) make recommendations for national freight transportation strategic planning and further research required to fulfil the needs of governments and industry. This thesis includes: an 00 database design for encapsulation of the FTN; an `internet-enabled' Dynamic Modelling Methodology (DMM) for the virtual modelling of the FTNs; a Unified Modelling Language (UML) `proof-of-concept' prototype; and conclusions and recommendations for further collaborative research are identified

Investigation into the Effect of Bonding Methods for 3D Printed Titanium in Scarf Ribbon Repairs with a Composite Parent

As material technology has continued improving, creating materials that are lighter, stronger, and more resistant to environmental conditions, their prevalence in all industries has also increased. This is no truer than in aviation which has gradually transitioned to polymer composites in order to minimise weight and consequently create some of the most advance transportation and weapons systems ever seen. The use of these materials is not without drawbacks, these mainly being cost, and the complex nature of failure and subsequent repair required. Because of these major factors, research into repair methods has come to the forefront of the industry with emphasis placed on the minimisation of costs associated with the repair processes as well as down-time experienced by the aircraft. The most dominant method used in such repair methods are scarf repair joints which are prepared in an autoclave system. In order to explore more portable and fast paced solutions, out-of-autoclave processes have become the main focus of repair techniques for research. The aim of this study was to identify associated effects and subsequent quality of bond created using the single vacuum bag debulking variant of out-of-autoclave processes utilising a set of basic testing criteria and comparable data taken from the literature. Using appropriate sample preparation techniques, cure cycle selection and pre-experiment inspection, initial bond quality predictions were established based on visible porosity content and bond line observations. It was observed that cure cycle selection was definitively adequate for the double adhesive thickness samples while the results provide no clear indication of the adequacy for single adhesive samples. The double film adhesive honeycomb lattice scarf performed to the highest standard mechanically producing tensile strengths of 161.8 +/- 15.0 MPa, however displayed high levels of porosity (between 3% - 4%) which is not conducive to bond consolidation. Upon comparison to double vacuum bag debulking techniques, evidence suggested the quality of bond produced by the SVD system was of lower quality with regard to both porosity and resulting failure strength. The final observation was the thermal effect on the failure behaviour evident in the DIC videos taken of the failure event. These observations suggested evidence of a discontinuity caused by a mismatch in thermal properties of the materials. Further studies into the reduction of porosity utilising DVD systems for dissimilar materials is required in order to establish a clear trend between porosity and resulting repair strength. An investigation into the catering of cure cycle for specific adhesive thicknesses as well as further mechanical testing would benefit the development of repair procedures specifically utilising SVD systems and offer insight into their suitability within the wider industry