Boundary element analysis of spherical and radome shells

This study presents the application of the Boundary Element Method (BEM) to spherical and radome geometries. The boundary of the solution domain was discretized by using both linear and quadratic elements and the validity of the results were compared against other analytical and numerical methods.Several improvements to the BEM have been presented. These include the efficient evaluation of the singular integrals where new methods have been implemented and compared with other schemes. Improvement is also shown by the implementation of the semi-continuous elements to solve the well known limitation of the Corner Problems present in the BEM. Exhaustive numerical experimentation is carried out to establish the optimum collocation point for the semi-continuous elements and to link this to the quadrature rule used for the integration of that element. The present study also includes the limitations of the BEM in applications involving geometries of long and thin sections. The study shows in detail the circumstances under which accurate results can be expected in the BEM. In this case, the emphasis is placed on the element size and the section thickness. A relationship linking these two parameters in the control of the accuracy of the BEM results is also established. For the surface stresses and strains of the domain, a detailed implementation of a natural cubic spline is illustrated which greatly improved these surface results

Product design as a vehicle to integrate arts and sciences in design education

In many parts of the world, Higher Education has often considered arts and sciences as an odd combination and many institutions have avoided this particular mix. Historically, this has been the accepted view; however, this view is changing. This paper provides a detailed account of curriculum development and strategies for enabling arts and science disciplines to blend in an effective way. It shows how strong alliances can be built in line with industry and general design practice expectations through “Live Projects”, that is projects sponsored by industry or other clients. The case studies provided in the paper are based on work conducted in the Product Design and Engineering Department at Middlesex University. The paper further demonstrates the importance of industry involvement, and how industrial collaborations can be managed to ensure that the academic provision is both relevant to the sector as well as responding to the needs of students. The paper was presented at the International Association of Societies of Design Research (IASDR07), held at the Hong Kong Polytechnic University. The papers for the conference were reviewed in a double blind review process, and the conference was attended by an audience of over 400 delegates, focusing on emerging trends in design researc

Design and development of an automatic tool changer for an articulated robot arm

In the creative industries, the length of time between the ideation stage and the making of physical objects is decreasing due to the use of CAD/CAM systems and adicitive manufacturing. Natural anisotropic materials, such as solid wood can also be transformed using CAD/CAM systems, but only with subtractive processes such as machining with CNC routers. Whilst some 3 axis CNC routing machines are affordable to buy and widely available, more flexible 5 axis routing machines still present themselves as a too big investment for small companies. Small refurbished articulated robots can be a cheaper alternative but they require a light end-effector. This paper presents a new lightweight tool changer that converts a small 3kg payload 6 DOF robot into a robot apprentice able to machine wood and similar soft materials

Blending arts and sciences: gimmick or necessity?

The shortage of degree qualified engineers in the UK is well documented. On the other hand the surplus of art and design graduates is growing. Whilst acknowledging the shortage in engineering graduates, there is also the need to recognise the breadth and increased skill level that engineering graduates require. Is it therefore possible to convert some of the excess graduates in art and design to careers in design and development engineering? The success of many engineering businesses depends not only on technical excellence but also on understanding of the market needs and the speed of response to this demand. To make this task even harder, businesses are also expected to compete in markets that are open to global competition and are also faced with much more sophisticated consumers. Businesses that are engaged in the manufacture of goods now require a new breed of engineer. These are not only technically competent individuals, but also possess what is known as “soft” or “creative” skills traditionally found in graduates of art and design disciplines. This paper details an innovative curriculum model offered at postgraduate level to address the 21 st century needs of engineering businesses. The paper also details rigorous recruitment tools developed and used for selecting students exclusively from the art and design discipline

Development of a design probe to reveal customer touch points in the sale of mass customised products

As mass customisation (MC) increases in both popularity and accessibility, it raises questions as to the nature and notion of the customer co-design experience; what is a ‘co-design experience’, and how can this be best designed for? This paper posits that by its very nature, a co-design experience consists of activities that relate to the co-design of the product via the product configurator (physical store, online store etc), but also that a co-design experience is broader than that, comprising both tangible and intangible elements, and encompassing the entire purchasing experience from the beginning of co-design activity through to the receipt of the customised product and beyond. Traditional research methods will often fail to capture the entirety of this experience. This paper highlights the need for empathic research methods which go beyond current research within the field of MC, and discusses the development of a design probe used to gain insight into co-design experiences

Učinci vremena izlaganja i temperature na zakretne momente uvrtanja vijaka u toplinski obrađeno drvo anadolskoga crnog bora i hrasta kitnjaka

This study aimed to investigate the characteristics of screw driving torques in heat-treated Anatolian black pine and sessile oak wood. The wood samples were subjected to heat under atmospheric pressure at three different temperatures (130, 180 and 230 °C) and two different exposure time levels (2 and 8 h). Screw driving torques of seating and stripping torque (SET and STT) was performed on all samples. The process of screw driving had two main torques, one of which was the seating torque defined as the torque required to clamp parts and the other one was the stripping torque defined as the maximum torque right before the screw strips in the material and the torque drops suddenly because of the formed screw threads being stripped in wood material. Results show that, in both wood species, the SET and STT values decreased due to the increase in heat treatment temperature and exposure time compared to the control groups.Cilj ovog istraživanja bilo je ispitivanje svojstava zakretnih momenata zavrtanja vijaka u toplinski obrađeno drvo anadolskoga crnog bora i hrasta kitnjaka. Uzorci drva izloženi su toplini u atmosferskom tlaku pri trima različitim temperaturama (130, 180 i 230 °C) i tijekom dva različita vremena izlaganja (2 i 8 h). Na svim su uzorcima određeni zakretni momenti uvrtanja i odvrtanja vijaka (SET i STT). Riječ je o dvama glavnim zakretnim momentima u procesu spajanja vijcima, od kojih je jedan zakretni moment zatezanja, a drugi je zakretni moment odvrtanja, definiran kao maksimalni zakretni moment neposredno prije nego što se vijak izvuče iz materijala i moment se naglo smanji zbog guljenja navoja formiranih u drvnome materijalu. Rezultati pokazuju da se vrijednosti SET i STT za obje vrste drva smanjuju s povećanjem temperature toplinske obrade i produljenjem vremena izlaganja u usporedbi s kontrolnim skupinama

Investigating the mobility of unmanned ground vehicles.

Unmanned Vehicles have to be as capable if not more capable than a human in the same situation, especially when used by the military to serve as an extension of the soldiers capability on the battlefield. All unmanned systems types have obstacles and encounter difficulties when trying to complete their missions, but none more so than the Unmanned Ground Vehicle (UGV). This is because UGV’s have to operate in environments with a large amount of variables which includes a range of different obstacles, and terrain types; making the simple task of driving from A to B very hard. This highlights the fact that a UGV’s capability is predominantly dependant on its mobility and is seen as one of the most important factors in their development, because the more capable of traversing over all types of terrain the vehicle is, then the less likely it will become stuck and need human assistance. This paper investigates current military UGV’s, their mobility capabilities and the future of UGV development

Blending arts and sciences: gimmick or necessity?

The shortage of degree qualified engineers in the UK is well documented. On the other hand the surplus of art and design graduates is growing. Whilst acknowledging the shortage in engineering graduates, there is also the need to recognise the breadth and increased skill level that engineering graduates require. Is it therefore possible to convert some of the excess graduates in art and design to careers in design and development engineering? The success of many engineering businesses depends not only on technical excellence but also on understanding of the market needs and the speed of response to this demand. To make this task even harder, businesses are also expected to compete in markets that are open to global competition and are also faced with much more sophisticated consumers. Businesses that are engaged in the manufacture of goods now require a new breed of engineer. These are not only technically competent individuals, but also possess what is known as “soft” or “creative” skills traditionally found in graduates of art and design disciplines. This paper details an innovative curriculum model offered at postgraduate level to address the 21 st century needs of engineering businesses. The paper also details rigorous recruitment tools developed and used for selecting students exclusively from the art and design disciplines

Control of Ship capsize in stern quartering seas.

A non-linear mathematical model for the roll-yaw behaviour of a ship is used to predict capsize of a small tanker which sank in the North Sea some years ago. This capsize problem was initially simulated on an analogue computer by the Danish Maritime Authorities as well as being tank tested. The problem was simulated using the digital package SIMULINK, which produced comparable results indicating instability in waves of just less than 3 m in height. Validation of the results is attempted and a discussion of possible improvements to the model is given. Simulated responses of the tanker with simple hydrodynamic fin stabilisers show that capsize could have been prevented by this means in waves up to 7 m in height. Active PID control using a simple full span elevon is used to show a factor of ten reduction in roll angle to much greater waves. This work is of use to ship designers illustrating that stability can be enhanced for a fraction of the cost of major redesign of the ship hull and can be tailored to load conditions