197,688 research outputs found
Mapping customer needs to engineering characteristics: an aerospace perspective for conceptual design
No full textDesigning complex engineering systems, such as an aircraft or an aero-engine, is immensely challenging. Formal Systems Engineering (SE) practices are widely used in the aerospace industry throughout the overall design process to minimise the overall design effort, corrective re-work, and ultimately overall development and manufacturing costs. Incorporating the needs and requirements from customers and other stakeholders into the conceptual and early design process is vital for the success and viability of any development programme. This paper presents a formal methodology, the Value-Driven Design (VDD) methodology that has been developed for collaborative and iterative use in the Extended Enterprise (EE) within the aerospace industry, and that has been applied using the Concept Design Analysis (CODA) method to map captured Customer Needs (CNs) into Engineering Characteristics (ECs) and to model an overall ‘design merit’ metric to be used in design assessments, sensitivity analyses, and engineering design optimisation studies. Two different case studies with increasing complexity are presented to elucidate the application areas of the CODA method in the context of the VDD methodology for the EE within the aerospace secto
An aerospace component cost modelling study for value driven design
No full textDemand is increasing in aero-engine products for better efficiency and environmental performance whilst keeping the cost low. Unlike performance, the physics behind cost is least understood. This paper presents a proposed unit cost modelling methodology applied to a Rolls-Royce aero-engine fan blade. An objective of the cost model is the allow engineers to understand the breakdown of cost. A value driven design concept is outlined and presents an opportunity to conduct design optimisation
A generic operational simulation for early design civil unmanned aerial vehicles
No full textContemporary aerospace programmes often suffer from large cost overruns, delivery delays and inferior product quality. This is caused in part by poor predictive quality of the early design phase processes with regards to the operational environment of a product. This paper develops the idea of a generic operational simulation that can help designers to rigorously analyse and test their early product concepts. The simulation focusses on civil Unmanned Air Vehicle products and missions to keep the scope of work tractable. The research agenda is introduced along with ideas, initial results and future work. Designers specify details about their product, its environment and anticipated operational procedures. The simulation returns information that can help to estimate the value of the product using the value-driven design approach. Information will include recurring and non-recurring mission cost items. The research aim is to show that an operational simulation can improve early design concepts, thereby reducing delays and cost overruns. Moreover, a trade-off between mission fidelity and model generality is sought along with a generic ontology of civil Unmanned Air Vehicle missions and guidelines about capturing operational informatio
Timothy (Tim) Scanlan
No full textBIOGRAPHICAL INFORMATION: Timothy (Tim) Scanlan is a Caucasian male born on September 15, 1946. He is the third out of seven kids. Both of his parents worked. He grew up Catholic. SUBJECTS DISCUSSED: Scanlan starts by describing how he came from a big family, and talks about how they were all close knit, as well as what family pets they had. He mentions how it seemed like they were financially getting by, but that his parents probably had a depression-era mentality when it came to conversations about money. He briefly discusses his religious upbringing, and how it was important in their family. He goes on to describe his experience with growing up in the neighborhood, and how everyone knew each other and would have huge neighborhood nights. Scanlan mentions the value of loyalty. Afterwards, he touches on the television shows that he watched when he was growing up, as well as how schooling was very positive. He ends the interview by describing the local issues affecting the neighborhood, such as how they grew up in a time of economic boom, the Vietnam war, Kennedy’s, and Martin Luther King Jr.\u27s assassination, and growing up with people that were different from him.https://digitalcommons.csp.edu/tc-ohp_interviews_stp/1012/thumbnail.jp
My heart's in County Clare [music] /
No full text"Dedicated to my father".; "Broadcast and featured by Danny Malone".; Also available online http://nla.gov.au/nla.mus-vn1406108; MUS: N, MUS/344
On axisymmetric adhesive joints with graded interface stiffness
No full textAn improved analytical model is presented for the stress analysis of interface stiffness graded axisymmetric adhesive joints. The governing integro-differential equation of the problem is obtained through a variational method which minimizes the complementary energy of the bonded assembly. The joint is composed of similar or dissimilar polar anisotropic and/or isotropic adherends and a functionally modulus graded bondline (FMGB) adhesive. The elastic modulus of the adhesive is functionally graded along the bondlength by assuming smooth modulus profiles which reflect the behavior of practically producible graded bondline. Influence of non-zero radial stresses in the bonded system on shear and normal stresses is evaluated. The stress distribution predicted by this refined model is compared with that of mono-modulus bondline (MMB) model for the same axial tensile load in order to estimate reduction in shear and normal stress peaks in the bondline and the adherends. A systematic parametric study indicates that an optimum joint strength can be achieved by employing a stiffness graded bondline with an appropriate combination of geometrical and material properties of the adherends. This model can also be applied to examine the effects of loss of interface stiffness due to an existing defect and/or damage in the bondlin
Modeling of modulus graded axisymmetric adhesive joints
No full textThis study presents a refined theoretical framework for the stress analysis of modulus graded axisymmetric adhesive joints which takes into account the radial stresses in the bonded assembly. This semi-analytical is based on a variational method which minimizes the complementary energy of the bonded system. The joint consists of similar or dissimilar polar anisotropic composite adherends or metallic adherends and a functionally modulus graded bondline (FMGB) adhesive. The elastic modulus of the adhesive is functionally graded along the bondlength by assuming smooth modulus profiles which reflect the behavior of practically producible graded bondline. The stress distribution predicted by this refined model is compared with that of MMB model which also accounts for in the bonded system to estimate reduction in shear and peel stress peaks in the bondline. The axisymmetric stress analysis reveals that the peel and shear stress peaks in the FMGB are much smaller and the stress distribution is more uniform along its length than those of mono-modulus bondline (MMB) adhesive joints under the same axial tensile load. A systematic parametric study has been conducted by selectively perturbing the material and geometrical properties of the joint in order to study their influence onstress distribution in the bondline. Furthermore, the results suggest that the peel and shear strengths can be optimized by spatially controlling the modulus of theadhesive
Evaluating design decisions in real-time using operations modelling
No full textContemporary design processes of large aerospace products are rigidly focused on customer specifications in order to meet their expectations. Life cycle costs, design space exploration and value engineering are neglected, often leading to substantial cost overruns and delivery delays. Moreover, customer specifications are not scrutinized and design decisions are made ignoring potential operational knowledge. Value-driven design suggests a new approach using flexible customer specifications in order to find optimal designs by exploring the solution space. One aspect of this optimization is the simulation of the anticipated operational life of a product in order to gain operational knowledge and analyse customer specifications. This paper suggests that an operational simulation can be used actively or reactively by designers during the design process to improve a product. It is investigated how an operational simulation can act as a design decision support tool and how it can react to customer specifications. Answers are presented by means of a simulation model recreating the operational life of a Search-and-Rescue Unmanned Air Vehicle developed in parallel at the University of Southampton. The simulation's ability for acting as a decision support tool is explored by conducting a fuel tank size optimization. Reactive capabilities are explored by calculating the surplus value of using UAVs. This exemplifies the derivation of product specifications as the simulation reveals the value and hence usefulness of given customer specifications. It is shown that operational simulations benefit designers and overall product value by analysing product specifications and guiding designers to more informed design decision
Design and flight test of a civil unmanned aerial vehicle for maritime patrol: the use of 3D-printed structural components
No full textThis paper describes the design of the “Spotter” unmanned aerial vehicle, developed by the University of Southampton as part of the 2SEAS-3i European Interreg project. Spotter is a twin engine, 4m wing span, fixed-wing aircraft which has been designed to perform long-endurance, all-weather patrol missions in coastal and maritime environments. Reliability and safety have been among the strongest design drivers of this project; Spotter is able to survive the failure of one engine and of any single control surface. A modular approach has been adopted for the payload unit in order to allow the users to rapidly interchange the sensors required to perform different missions.One of the most innovative aspects of Spotter is the extensive use of the Selective Laser Sintering (SLS) technology (also known as 3D printing) for many of the components of its airframe. By eliminating tooling and manual labour, the 3D printing technology allows the designer to produce complex and high-performance structures at a relatively low cost and within hours of the completion of the design. Spotter and a sub-20kg version, codenamed 2SEAS-20, have undergone an extensive flight test campaign, totalling hundreds of autonomous flights (including autonomous take-off and landings) and many flight hours. This has provided the opportunity to test the reliability and robustness of the system and to gain a deeper insight into the opportunities and problems presented by the use of 3D printed structures for large airframe components
Fragments of bacterial endoglycosidase S and immunoglobulin G reveal subdomains of each that contribute to deglycosylation
No full textEndoglycosidase S (EndoS) is a glycoside-hydrolase secreted by the bacterium Streptococcus pyogenes. EndoS preferentially hydrolyzes the N-linked glycans from the Fc region of IgG during infection. This hydrolysis impedes Fc functionality and contributes to the immune evasion strategy of S. pyogenes. Here, we investigate the mechanism of human serum IgG deactivation by EndoS. We expressed fragments of IgG1 and demonstrated that EndoS was catalytically active against all of them including the isolated CH2 domain of the Fc domain. Similarly, we sought to investigate which domains within EndoS could contribute to activity. Bioinformatics analysis of the domain organization of EndoS confirmed the previous predictions of a chitinase domain and leucine-rich repeat but also revealed a putative carbohydrate binding module (CBM) followed by a C-terminal region. Using expressed fragments of EndoS, circular dichroism of the isolated CBM, and a CBM-C-terminal region fusion revealed folded domains dominated by β sheet and α helical structure, respectively. Nuclear magnetic resonance analysis of the CBM with monosaccharides was suggestive of carbohydrate binding functionality. Functional analysis of truncations of EndoS revealed that, whereas the C-terminal of EndoS is dispensable for activity, its deletion impedes the hydrolysis of IgG glycans
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