Realization of the true 3D printing using multi directional wire and arc additive manufacturing

Robotic wire and arc based additive manufacturing has been used in fabricating of metallic parts owing to its advantages of lower capital investment, higher deposition rates, and better material properties. Although many achievements have been made, the build direction of Wire Arc Additive Manufacturing (WAAM) is still limited in the vertical up direction, resulting in extra supporting structure usage while fabricating metallic parts with overhanging features. Thus, the current WAAM technology should be also called 2.5D printing rather than 3D printing. In order to simplify the deposition set up and increase the flexibility of the WAAM process, it is necessary to find an alternative approach for the deposition of ‘overhangs’ in a true 3D space. This dissertation attempts to realize true 3D printing by developing a novel multi directional WAAM system using robotic Gas Metal Arc Welding (GMAW) to additively manufacture metal components in multiple directions. Several key steps including process development, welding defect investigation and avoidance, and robot path generation are presented in this study

Knowledge-based automatic tolerance analysis system

Tolerance measure is an important part of engineering, however, to date the system of applying this important technology has been left to the assessment of the engineer using appropriate guidelines. This work offers a major departure from the trial and error or random number generation techniques that have been used previously by using a knowledge-based system to ensure the intelligent optimisation within the manufacturing system. A system to optimise manufacturing tolerance allocation to a part known as Knowledge-based Automatic Tolerance Analysis (KATA) has been developed. KATA is a knowledge-based system shell built within AutoCAD. It has the ability for geometry creation in CAD and the capability to optimise the tolerance heuristically as an expert system. Besides the worst-case tolerancing equation to optimise the tolerance allocation, KATA's algorithm is supported by actual production information such as machine capability, types of cutting tools, materials, process capabilities etc. KATA's prototype is currently able to analyse a cylindrical shape workpiece and a simple prismatic part. Analyses of tolerance include dimensional tolerance and geometrical tolerance. KATA is also able to do angular cuts such as tapers and chamfers. The investigation has also led to the significant development of the single tolerance reference technique. This method departs from the common practice of multiple tolerance referencing technique to optimise tolerance allocation. Utilisation of this new technique has eradicated the error of tolerance stackup. The retests have been undertaken, two of which are cylindrical parts meant to test dimensional tolerance and an angular cut. The third is a simple prismatic part to experiment with the geometrical tolerance analysis. The ability to optimise tolerance allocation is based on real production data and not imaginary or random number generation and has improved the accuracy of the expected result after manufacturing. Any failure caused by machining parameters is cautioned at an early stage before an actual production run has commenced. Thus, the manufacturer is assured that the product manufactured will be within the required tolerance limits. Being the central database for all production capability information enables KATA to opt for several approaches and techniques of processing. Hence, giving the user flexibility of selecting the process plan best suited for any required situation

Application of Reverse Engineering and Rapid Prototyping to Casting

The automotive industry has an increasing need for the re manufacturing of spare parts through reverse engineering. In this thesis we will review the techniques used in Fused Deposition Modeling system for the reverse engineering of vintage automotive parts. The objective of the project is to be able to generate part-to-CAD and CAD-to-part reconstruction of the original part for future usage. These newly created 3D models will be added to the 3D Part Database. The integration of reverse engineering and rapid prototyping is being used for getting product to the market quickly by resolving a long-standing conflict between design and manufacturing. Rapid prototyping (RP) technology has undoubtedly had a major impact on the manufacturing industry throughout the world. RP technology has developed as a result of the requirements of manufacturing industry. There are a number of application areas where RP has been used to good effect and one of these is Metal Casting. This thesis describes work carried out to investigate potential applications for metal casting, as well as an attempt to explore the limits of the technology. It will go on to discuss how the technology may be developed to better serve the requirements of the manufacturing industr

ReSCon '12, Research Student Conference: Book of Abstracts

The fifth SED Research Student Conference (ReSCon2012) was hosted over three days, 18-20 June 2012, in the Hamilton Centre at Brunel University. The conference consisted of 130 oral and 70 poster presentations, based on the high quality and diverse research being conducted within the School of Engineering and Design by postgraduate research students. The conference is held annually, and ReSCon plays a key role in contributing to research and innovations within the School