Computation of magnetic field in an actuator

Design and optimization of an actuators based on magnetostrictive technology requires computation of the magnetic field. The “MS”-technology offers an attractive controllability with high power density. The magnetostriction is a reversible feature which can be used in various actuator layouts. The actuator performance depends on driving magnetic field and the particular magnetic properties of used materials. Good understanding of specific design constrains is required to define and to optimized a magnetostrictive actuator. The non-linear computation of the magnetic field using FEM software is vital for the finale experimental design of a low-frequency actuator. This paper presents results of magnetic field simulation with FEMM software package and experimental measurements of the magnetic flux density. Good correlation between the simulation results and experimental measurements has been achieved

Engineering programme structure requirements for Bologna compliance

In 1999 twenty nine European countries have signed the Bologna Declaration to establish a common European higher education system as for the year 2010. Engineering Ireland has decided that the education standard for the title of CEng and MIEI should be raised to Master Degree in engineering accredited by Engineers Ireland with effect from programmes completed in 2013”. This paper focuses on engineering programme structure in our school. Further discussions will be carried out to present the current engineering programmes in our school and the future vision to compliance with Bologna treaty

Design of experiment study of the parameters that affect performance of three flow plate configurations of a proton exchange membrane fuel cell

Low temperature hydrogen fuel cells are electrochemical devices which offer a promising alternative to traditional power sources. Fuel cells produce electricity with a reaction of the fuel (hydrogen) and air. Fuel cells have the advantage of being clean; only producing water and heat as by products. The efficiency of a fuel cell varies depending on the type; SOFC with CHP for example, can have a system efficiency of up to 65%. What the Authors present here is a comparison between three different configurations of flow plates of a proton exchange membrane fuel cell, the manufacturer’s serpentine flow plate and two new configurations; the maze flow plate and the parallel flow plate. A study of the input parameters affecting output responses of voltage, current, power and efficiency of a fuel cell is performed through experimentation. The results were taken from direct readings of the fuel cell and from polarisation curves produced. This information was then analysed through a design of experiment to investigate the effects of the changing parameters on different configurations of the fuel cell’s flow plates. The results indicate that, in relation to current and voltage response of the polarisation curve and the corresponding graphs produced from the DOE, the serpentine flow plate design is a much more effective design than the maze or parallel flow plate design. It was noted that the parallel flow plate performed reasonably well at higher pressures but over all statically the serpentine flow plate performed better

Effect of process parameters and optimization of CO2 laser cutting of ultra high performance polyethylene

The aim of this work is to relate the cutting edge quality parameters (responses) namely: upper kerf, lower kerf, ratio of the upper kerf to lower kerf and cut edge roughness to the process parameters considered in this research and to find out the optimal cutting conditions. The process factors implemented in this research are: laser power, cutting speed and focal point position. Design of experiment (DoE) was used by implementing Box-Behnken design to achieve better cut qualities within existing resources. Mathematical models were developed to establish the relationship between the process parameters and the edge quality parameters. Also, the effects of process parameters on each response were determine. Then, a numerical optimization was performed to find out the optimal process setting at which the quality features are at their desired values. The effect of each factor on the responses was established and the optimal cutting conditions were found

Optimising the laser-welded butt-joints of medium carbon steel using RSM

The optimization capabilities in design-expert software were used to optimise the keyhole parameters (i.e. maximize penetration (P) and minimise the heat input, width of welded zone, (W) and width of heat affected zone (WHAZ)) in CW CO2 laser butt-welding of medium carbon steel. The previous developed mathematical models to predict the keyhole parameters in terms of the process factors namely; laser power (LP), welding speed (S) and focused position (F) were used to optimize the welding process. The goal was to set the process factors at optimum values to reach the desirable weld bead quality and to increase the production rate. Numerical and graphical optimization techniques were used. In fact, two optimization criteria were taken into account. In this investigation optimal solutions were found that would improve the weld quality, increase the productivity and minimize the total operation cost. In addition to that, superimposing the contours for the various response surfaces produced overlay plots

Design of a magnetostrictive (MS) actuator

Several advanced technologies are introduced in automotive applications. Higher energy density and dynamic performance are demanding new and cost effective actuator structures. Magnetostriction (MS), change in shape of materials under the influence of an external magnetic field, is one of these advanced technologies. Good understanding of specific design constrains is required to define and optimized a magnetostrictive actuator. This paper presents parametrical analysis with magnetic simulation of a magnetostrictive actuator. Proposed actuator has been designed, and the performance has been evaluated on experimental rig. Strain, elongation of the shaft, of 1000ppm at 10Amp and a blocked force over 4500N has been achieved with shaft of 8mm diameter, made of Terfenol-D. Furthermore, the effect of pre-stress of the Terfenol-D shaft has been evaluated experimentally. The study shows that excellent features can be obtained by magnetostrictive materials for many advanced applications

Multi-response optimization of CO2 laser welding process of austenitic stainless steel

Recently, laser welding of austenitic stainless steel has received great attention in industry, due to its wide spread application in petroleum refinement stations, power plant, pharmaceutical industry and households. Therefore, mechanical properties should be controlled to obtain good welded joints. The welding process should be optimized by the proper mathematical models. In this research, the tensile strength and impact strength along with the joint operating cost of laser welded butt joints made of AISI304 was investigated. Design-expert software was used to establish the design matrix and to analyze the experimental data. The relationships between the laser welding parameters (laser power, welding speed and focal point position) and the three responses (tensile strength, impact strength and joint operating cost) were established. Also, the optimization capabilities in design-expert software were used to optimise the welding process. The developed mathematical models were tested for adequacy using analysis of variance and other adequacy measures. In this investigation the optimal welding conditions were identified in order to increase the productivity and minimize the total operating cost. Overlay graphs were plotted by superimposing the contours for the various response surfaces. The process parameters effect was determined and the optimal welding combinations were tabulated

Feedrate planning for machining with industrial six-axis robots

The authors want to thank Stäubli for providing the necessary information of the controller, Dynalog for its contribution to the experimental validations and X. Helle for its material contributions.Nowadays, the adaptation of industrial robots to carry out high-speed machining operations is strongly required by the manufacturing industry. This new technology machining process demands the improvement of the overall performances of robots to achieve an accuracy level close to that realized by machine-tools. This paper presents a method of trajectory planning adapted for continuous machining by robot. The methodology used is based on a parametric interpolation of the geometry in the operational space. FIR filters properties are exploited to generate the tool feedrate with limited jerk. This planning method is validated experimentally on an industrial robot

Using Taguchi method to optimize welding pool of dissimilar laser welded components

In the present work CO2 continuous laser welding process was successfully applied and optimized for joining a dissimilar AISI 316 stainless steel and AISI 1009 low carbon steel plates. Laser power, welding speed, and defocusing distance combinations were carefully selected with the objective of producing welded joint with complete penetration, minimum fusion zone size and acceptable welding profile. Fusion zone area and shape of dissimilar austenitic stainless steel with ferritic low carbon steel were evaluated as a function of the selected laser welding parameters. Taguchi approach was used as statistical design of experiment (DOE) technique for optimizing the selected welding parameters in terms of minimizing the fusion zone. Mathematical models were developed to describe the influence of the selected parameters on the fusion zone area and shape, to predict its value within the limits of the variables being studied. The result indicates that the developed models can predict the responses satisfactorily