Advanced Materials Research Vols. 875-877

Abstract: In this work, machining test was carried out in various machining conditions using ultrasonical vibration capable CNC machine. For work material, alumina ceramic (Al2O3) was used while for tool material diamond electroplated grinding wheel was used. To evaluate ultrasonical vibration effect, grinding test was performed with and without ultrasonic vibration in same machining condition. In ultrasonic mode, ultrasonic vibration of 20kHz was generated by HSK 63 ultrasonic actuator. On the other hand, grinding forces were measured by KISTLER dynamometer. And an optimal sampling rate for grinding force measurement was obtained by a signal processing and frequency analysis. The surface roughness of the ceramic was also measured using stylus type surface roughness instrument and atomic force microscope (AFM). Besides, the scanning electron microscope (SEM) was used for observation of surface integrarity.

Abstract: Based on the computational fluid dynamics (CFD) simulation software and its parallel techniques, the standard k-ε turbulent flow equations with additional buoyancy-modified, the PDF(Probability Density Function) non-premixed combustion model, and the discrete ordinates (DO) radiation model were used to simulate the kerosene pool fire scenarios of various pool diameters in stagnant air and in a cross-wind. Based on these simulations, the relationships between the pool size and the flame height and flame temperature were obtained, as well as the effective law of the wind speed change on the fire tilt angle. The results presented in this paper are of great significance in the hazard evaluation of the thermal radiation of the pool fire.

Abstract: In this paper, the problems of state feedback control for a class of switched singular linear systems are investigated. By constructing a novel switched Lyapunov functional and convex combinations techniques, a sufficient condition established in terms of strict linear matrix inequalities (LMIs) is presented such that the system is asymptotically stable and satisfies performance. An explicit expression for the state feedback stabilization sub-controller and switching rule are designed. The merits of the proposed criteria lie in their less conservativeness and relative simplicity, in which the closed-loop system satisfies performance at each point in whole state-space through switching, although each sub-system doesn’t satisfy the performance and even is not asymptotically stable. A numerical example is provided to illustrate the validity of the proposed methods.

Abstract: Freeform architecture places a high demand on its accomplishment. With today's technology a lot of individual and manual work is needed. By means of serial-production some challenges such as high costs and compliance of small tolerances can be handled. This results not only in issues in the field of manufacturing technology but also in the field of geometry.In order to simplify the manufacturing process a tool library with a defined minimum count of moulds is developed to map groups of surface elements on each mould. The Aim is to map any freeform surface with a clearly defined tool set based on an approximated curvature description.

Abstract: The aim of this work is to build software which enables us to set up an active smart materials data base especially the piezoelectric ones. This is done using two approaches: firstly, by mean of literature, allow the different characteristics we select piezoelectric materials. The second approach consists of selecting the appropriate material according to its usage either as a sensor or as an actuator. The purpose is to provide users an easier way to combine use versus characteristics in an automatic manner. Therefore according to a given application we can overcome the selection difficulties by knowing much more about the materials through their integrated functions when actuating as sensors or actuators. This tool remains also based on an open chart that will permit to the user or developer to update it in concordance with future knowledge of material developments. This work presents the developed software (called ExTooPIEZ’s), its main features and first feed backs gained after first usage.

Abstract: Electric vehicle (EV) motor and common traction motor are operation in different states, the insulation aging model based fixed working conditions are no longer applicable. The secondary development of motor system is carried in ADVISOR to get a new motor thermal model with which to analysis the lifetime of winding insulation. In addition, SIMULINK model is established to decouple motor currents in ADVISOR. ANSYS is carried to simulate the motor temperature rise using the obtained decouple currents, two results of models are in good agreement which verifies the validity of the redevelopment thermal model. Combined with the electric ageing model of winding insulation, the electro-thermal aging model in the EV motor is proposed based actual operation states, and insulation lifetime is calculated which provides theory basis for the analysis of electro-thermal aging model in EV motors.

Abstract: In this article the computational algorithm and solution technique of the problem of identifying temperature field as well as strain and stress components throughout the rod length exposed to heat flows supplied to cross section areas of both ends and heat exchange in its lateral surface on the basis of heat quantity variation law are developed. Herewith the tested rod physical and mechanical properties are taken into account. The solutions so acquired are presented in a graphical form. Certain dependencies between temperature pivotal values and capacities of the set heat flows are found.

Abstract: An automated warehousing system often consists of storage modules, storage and retrieval mechanism, lifting equipment and conveyor systems. These facilities are used to overcome some disadvantages of manually operated warehousing systems which often lead to a high frequency of human errors, high labour cost and low efficiency. The usage of these automated facilities may also be helpful to maximise utilisation of shop floor space and improve efficiency of warehousing operations. On the other hand, at this age of information technology that the access to the internet is just at the fingertip, it has been seen a rising trend for online shopping in the past decade. Thus, manufacturers, suppliers or distributors have been seeking for even more efficient and effective new methods to store and distribute their goods. A number of studies through a literature review suggest that future generation warehouses may be designed and implemented as more centralised and distributed warehousing systems in which customers place their orders on-line and goods will then be dispatched directly to their door steps from these centralised distribution centres. This paper presents a proposal for designing and implementing future generation warehousing systems using fast-growing IT technologies such as radio frequency identification (RFID), wireless sensors and networks. The overall purpose of this study is to develop a conceptual design of an integrated system for future generation automated warehouses by incorporating a new design of storage and retrieval modules with the applications of these IT technologies used for automation activities. The presentation of this paper only highlights the part of this work including a design of a core mechanism for automated storage module namely the cantilever storage racks, which have the feature of scalability and reconfigurability.

Abstract: This paper work presents results from the application of maintenance management system in a transformer station. In this area of asset management, it is necessary to use the asset management (AM) methods to build a single structure, taking into account the principle of best investment value. Thus, this paper presents the results obtained from a LabView simulation for such a structure. The research has been made on the base of economic aspects, technical characteristics of the equipment and the parameters characterizing their operation.

Abstract: In this work, a vibration based damage identification technique (VBDIT) is used to determine the presence of damages in metallic structures, using the undamaged structure information as reference. A complex structure is used in order to contrast the results obtained with those reported for techniques previously employed specially on single beam simulated structures. A finite element model of the structure is developed and validated as a support tool for the study. Theoretical and experimental modal analysis techniques were used as the main tool for damage identification.