Developing modular product family using GeMoCURE within an SME

Companies adopt the strategy of producing variety of products to be competitive and responsive to market. Product variation is becoming an important factor in companies' ability to accurately meet customer requirements. Ever increasing consumer options mean that customers have more choices than ever before which put commercial pressures on companies to continue to diversify. This can be a particular problem within Small to Medium Enterprises (SMEs) who do not always have the level of resources to meet these requirements. As such, methods are required that provide means for companies to be able to produce a wide range of products at the lowest cost and shortest time. This paper details a new modular product design methodology that provides a focus on developing modular product families. The methodology's function is described and a case study detailed of how it was used within an SME to define the company's product portfolio and create a new Generic Product Function Structure from which a new family of product variants can be developed. The methodology lends itself to modular re-use which has the potential to support rapid development and configuration of product variants

Application of context knowledge in supporting conceptual design decision making

Conceptual design is the most important phase of the product life cycle as the decisions taken at conceptual design stage affect the downstream phases (manufacture, assembly, use, maintenance, and disposal) in terms of cost, quality and function performed by the product. This research takes a holistic view by incorporating the knowledge related to the whole context (from the viewpoint of product, user, product's life cycle and environment in which the product operates) of a design problem for the consideration of the designer to make an informed decision making at the conceptual design stage. The design context knowledge comprising knowledge from these different viewpoints is formalised and a new model and corresponding computational framework is proposed to support conceptual design decision making using this formalised context knowledge. Using a case study, this paper shows the proof of the concept by selecting one concept among different design alternatives using design context knowledge thereby proactively supporting conceptual design decision making for an informed and effective decision making

Integrated product relationships management : a model to enable concurrent product design and assembly sequence planning

The paper describes a novel approach to product relationships management in the context of concurrent engineering and product lifecycle management (PLM). Current industrial practices in product data management and manufacturing process management systems require better efficiency, flexibility, and sensitivity in managing product information at various levels of abstraction throughout its lifecycle. The aim of the proposed work is to manage vital yet complex and inherent product relationship information to enable concurrent product design and assembly sequence planning. Indeed, the definition of the product with its assembly sequence requires the management and the understanding of the numerous product relationships, ensuring consistency between the product and its components. This main objective stresses the relational design paradigm by focusing on product relationships along its lifecycle. This paper gives the detailed description of the background and models which highlight the need for a more efficient PLM approach. The proposed theoretical approach is then described in detail. A separate paper will focus on the implementation of the proposed approach in a PLM-based application, and an in-depth case study to evaluate the implementation of the novel approach will also be given

Helicity hardens the gas

A screw generally works better than a nail, or a complicated rope knot better than a simple one, in fastening solid matter, but a gas is more tameless. However, a flow itself has a physical quantity, helicity, measuring the screwing strength of the velocity field and the degree of the knottedness of the vorticity ropes. It is shown that helicity favors the partition of energy to the vortical modes, compared to others such as the dilatation and pressure modes of turbulence; that is, helicity stiffens the flow, with nontrivial implications for aerodynamics, such as aeroacoustics, and conducting fluids, among others

Study on lubrication effect on motorbike chain transmissions

This paper examines motorbike's chain transmission, focusing on chain lubrication and its effect on the temperature, efficiency and vibrations of the transmission. Purpose of the paper is to compare transmission's performances under three different lubrication conditions: (i) chain not lubricated at all, (ii) chain lubricated with a spray PTFE addicted lube, and (ii) chain lubricated with a mineral oil at every minute of the test. An experimental campaign has been performed running a chain under the three above lube conditions at different speeds with the purposes of: (A) measuring the effect that each lube conditions has on temperature, on vibrations and on the efficiency of the transmission, and (B) identify the best conditions for practical use. A test rig has been designed and manufactured for the purpose, and temperature, transmission's efficiency and vibrations have been recorded during the tests by using a thermocamera, a dynamometer and an accelerometer respectively. Results showed that a proper lubrication is desirable. Additionally using a continuous lubrication with a mineral oil lubricant leads to better transmission compared to the use of the spray PTFE from the efficiency and thermal points of view. This work presents an experimental investigation on the effect of two different kind of lubrication form motorbike chain on transmission’s efficiency. The findings are still valid for different applications of chain transmission in dirty environments. Novelty of the paper is following highlighted: 1.this is the first work scientifically facing the important topic of lubrication of chain in dirty environments, particularly of motorbike chain; 2.a complete analysis of thermal and mechanical effect due to presence of lubricant has never been shown; 3.different kind of lubricant have been used and their effect has been separately highlighted

Aroyl phosphates : The Mechanism of Isomerization

The transfer of energy and its conversion from one form to another are very important in biological systems. Mammals use energy to control their environment, i.e. keeping warm and physical activity, whereas bacteria use energy primarily in chemical synthesis for their very existence as a life form depends upon rapid reproduction. There are two original sources of energy: light and oxygen, Oz. Photosynthesis and oxidative metabolism convert these energy sources via photosynthetic phosphorylation and oxidative phosphorylation into ATP (Adenine Triphosphate), which is in effect the molecular repository of energy. Thus, high energy phosphates (compounds which hydrolyze with a large negative free energy) are very important to biological systems. Acyl phosphates are mixed anhydrides of carboxylic acids and phosphoric acids. They are very important members of the group of high energy phosphate compounds found in biological system. They act as mediators in the transfer of energy and. are important biological acylating and phosphorylating agents. A study of the chemistry of this group of compounds is important if we are to understand how cells create and use energy

Graphical modelling of modular machines

This research is aimed at advancing machine design through specifying and implementing (in "proof of concept" form) a set of tools which graphically model modular machines. The tools allow mechanical building elements (or machine modules) to be selected and configured together in a highly flexible manner so that operation of the chosen configuration can be simulated and performance properties evaluated. Implementation of the tools has involved an extension in capability of a proprietary robot simulation system. This research has resulted in a general approach to graphically modelling manufacturing machines built from modular elements. A focus of study has been on a decomposition of machine functionality leading to the establishment of a library of modular machine primitives. This provides a useful source of commonly required machine building elements for use by machine designers. Study has also focussed on the generation of machine configuration tools which facilitate the construction of a simulation model and ultimately the physical machine itself. Simulation aspects of machine control are also considered which depict methods of manipulating a machine model in the simulation phase. In addition methods of achieving machine programming have been considered which specify the machine and its operational tasks. Means of adopting common information data structures are also considered which can facilitate interfacing with other systems, including the physical machine system constructed as an issue of the simulation phase. Each of these study areas is addressed in its own context, but collectively they provide a means of creating a complete modular machine design environment which can provide significant assistance to machine designers. Part of the methodology employed in the study is based on the use of the discrete event simulation technique. To easily and effectively describe a modular machine and its activity in a simulation model, a hierarchical ring and tree data structure has been designed and implemented. The modularity and reconfigurability are accommodated by the data structure, and homogeneous transformations are adopted to determine the spatial location and orientation of each of the machine elements. A three-level machine task programming approach is used to describe the machine's activities. A common data format method is used to interface the machine design environment with the physical machine and other building blocks of manufacturing systems (such as CAD systems) where systems integration approaches can lead to enhanced product realisation. The study concludes that a modular machine design environment can be created by employing the graphical simulation approach together with a set of comprehensive configuration. tools. A generic framework has been derived which outlines the way in which machine design environments can be constructed and suggestions are made as to how the proof of concept design environment implemented in this study can be advanced