Abdulaziz M. El-Tamimi

Optimization of Process Parameters of Rotary Ultrasonic Machining Based on Taguchis Method

In this Research, Taguchi optimization methodology is used to optimize Rotary Ultrasonic Machining (RUM) parameters for face milling of zirconia ceramic. The influence of the RUM parameters such as vibration frequency, vibration amplitude, spindle speed, feed rate, and depth of cut on cutting force and material removal rate (MRR) is studied. A three-level orthogonal array table is used to determine the signal-to-noise (S/N) ratios based on Taguchis design of experiments. Furthermore, analysis of variance (ANOVA) has been performed to study the relative significance of the different factors on cutting force and MRR of zirconia ceramic. Finally, verification tests were carried out to compare the predicted values of the outputs with their experimental values in order to confirm the effectiveness of the Taguchi Optimization.

Parameters Optimization of Rotary Ultrasonic Machining of Zirconia Ceramic for Surface Roughness Using Statistical Taguchi’s Experimental Design

Taguchi optimization methodology is used to optimize Rotary Ultrasonic Machining (RUM) parameters for the milling of zirconia ceramic. The influence of the RUM parameters such as vibration frequency, vibration amplitude, spindle speed, feed rate, and depth of cut on the surface roughness is studied. A three-level orthogonal array table is used to determine the signal-to-noise (S/N) ratios based on Taguchi’s design of experiments. Furthermore, analysis of variance (ANOVA) has been performed to study the relative significance of the different factors on the surface roughness of zirconia ceramic. Finally, verification tests were carried out to compare the predicted values of the surface roughness with their experimental values in order to confirm the effectiveness of the Taguchi Optimization.

Development and Evaluation of a Virtual Assembly Trainer

This paper discusses the development and evaluation of a virtual assembly training system for the first Saudi Arabian car prototype (Gazal-1) fender assembly. An evaluation study was conducted to compare 3 training scenarios: Traditional Engineering (TE), Computer Aided Design Environment (CADE), and immersive virtual reality (IVR). 15 students from King Saud University were randomly assigned to the different training conditions. After that, transfer of training to the actual assembly was evaluated. Performance measures used to assess transfer of training include time to complete task and number of frustration points during task. The results of the evaluation study suggest that the participants of IVR training condition performed better than the other two conditions. Therefore, virtual assembly simulation using virtual reality systems might be useful for training operators who will be conducting assembly operations.

Confusion avoidance for discrete event systems by P/E constraints and supervisory control

Xiaoliang Chen School of Mathematics and Computer Engineering, Xihua University, Chengdu 610039, P. R. China and School of Electro-Mechanical Engineering, Xidian University, Xi’an 710071, P. R. China Zhiwu Li∗ and Naiqi Wu Institute of Systems Engineering, Macau University of Science and Technology, Taipa, Macau, P. R. China and School of Electro-Mechanical Engineering, Xidian University, Xi’an 710071, P. R. China ∗Corresponding author: zhwli@xidian.edu.cn

Assessment and comparison of immersive virtual assembly training system

This paper presents the assessment and comparison of a virtual assembly training system for the first Saudi Arabian car prototype fender assembly. An assessment study was conducted to compare three training scenarios: Traditional Engineering, Computer Aided Design Environment, and Immersive Virtual Reality (IVR). Fifteen students from King Saud University were randomly assigned to the different training conditions. After that transfer of training to the actual assembly was evaluated. Performance measures used to assess transfer of training include time to complete task and number of frustration points during task. Furthermore, experiments were conducted to evaluate the effect of number of trainings in IVR environment on user’s performance while performing the virtual assembly. The results of study suggest that the participants of IVR training condition performed better than the other two conditions. Also, it was seen that the participants with more number of training within IVR performed better while doing virtual assembly.

Investigation of Micro-EDM input Parameters on Various Outputs in Machining Ni-Ti Shape Memory Alloy Using Full Factorial Design

Micro Electric Discharge Machining (μ-EDM) is a non-traditional machining process which is used for drilling micro holes in a high strength-to-weight ratio advanced engineering materials like shape memory alloys that have many applications in the field of aerospace and medical sciences. However, in order to achieve the desired output responses the process control parameters of the machine have to be set at an optimal setting. In this research work, an investigation has been made to study the influence of the input parameters (such as capacitance, discharge voltage and electrode material) on the micro-EDM process output responses (such as MRR, TWR, Ra and circularity of the micro-holes) while drilling the micro-holes on Ni-Ti shape memory alloy. The full factorial design based study resulted in a set of recommended values for input variables to obtain the desired output. Mathematical predictive models have also been developed, which predict good values for the output responses.

Rotary ultrasonic drilling of Ti6Al4V: Effects of machining parameters and tool diameter

This article presents the use of the rotary ultrasonic machining process for drilling holes in Ti6Al4V alloy which is regarded as a difficult-to-cut material due to its high-temperature strength and low thermal conductivity. This research presents an experimental investigation on the effect of the key rotary ultrasonic machining input parameters including ultrasonic power, spindle speed, feed rate, and the tool diameter on the main output responses including cutting force, hole cylindricity and overcut errors, and tool wear. No previous reports were found in literature to experimentally investigate the effect of the rotary ultrasonic machining parameters and the tool diameter on tool wear, surface integrity, and the accuracy of the drilled holes in Ti6Al4V alloy. The results showed that the rotary ultrasonic machining input parameters within the current ranges can significantly affect the quality of the drilled holes. Through proper selection of input parameters, holes could be drilled in Ti6Al4V alloy with smoothed surface morphology, low tool wear (0.7 mg) and very low cylindricity (2 µm) and overcut (120 µm) errors. Moreover, it was found that the selected level of any input parameter has the ability to significantly affect the influence of the other input parameters on the output responses.

A study on the effect of main process parameters of rotary ultrasonic machining for drilling BK7 glass

BK7 glass is an important engineering material with extensive applications in high-quality and precision transmissive optical components. However, BK7 glass is considered to be a difficult-to-cut material due to its high brittleness and nonconductivity. This article presents the use of rotary ultrasonic machining process for drilling holes in BK7 glass. No previous reports have been found in the literature to experimentally investigate the response of the BK7 glass to rotary ultrasonic drilling. The experimental investigations take into account the effect of the key rotary ultrasonic machining input parameters including the ultrasonic power, spindle speed and feed rate on the output responses of cutting force, exit chipping, surface roughness, hole cylindricity and overcut errors, and surface integrity. The results show that the input parameters within the current ranges can significantly affect the quality of the drilled holes. Moreover, the selected level of any input parameter has the ability to significantly affect the influence of the other input parameters on the output responses. Through proper selection of input parameters, holes could be drilled in BK7 glass with less fractured topography, low surface roughness (1.32 µm), low exit chipping size (0.85), and very low cylindricity (3 µm) and overcut (73.6 µm) errors.

Development and Evaluation of the Virtual Prototype of the First Saudi Arabian-Designed Car

Prototyping and evaluation are imperative phases of the present product design and development process. Although digital modeling and analysis methods are widely employed at various product development stages, still, building a physical prototype makes the present typical process expensive and time consuming. Therefore, it is necessary to implement new technologies, such as virtual prototyping, which can enable industry to have a rapid and more controlled decision making process. Virtual prototyping has come a long way in recent years, where current environments enable stereoscopic visuals, surround sound and ample interaction with the generated models. It is also important to evaluate how representative the developed virtual prototype is when compared to the real-world counterpart and the sense of presence reported by users of the virtual prototype. This paper describes the systematic procedure to develop a virtual prototype of Gazal-1 (i.e., the first car prototype designed by Saudi engineers) in a semi-immersive virtual environment. The steps to develop a virtual prototype from CAD (computer-aided design) models are explained in detail. Various issues involved in the different phases for the development of the virtual prototype are also discussed comprehensively. The paper further describes the results of the subjective assessment of a developed virtual prototype of a Saudi Arabian-designed automobile. User’s feedback is recorded using a presence questionnaire. Based on the user-based study, it is revealed that the virtual prototype is representative of the real Saudi Arabian car and offers a flexible environment to analyze design features when compared against its physical prototype. The capabilities of the virtual environment are validated with the application of the car prototype. Finally, vital requirements and directions for future research are also presented.

Microchannels Fabrication in Alumina Ceramic Using Direct Nd:YAG Laser Writing

Ceramic microchannels have important applications in different microscale systems like microreactors, microfluidic devices and microchemical systems. However, ceramics are considered difficult to manufacture owing to their wear and heat resistance capabilities. In this study, microchannels are developed in alumina ceramic using direct Nd:YAG laser writing. The laser beam with a characteristic pulse width of 10 µs and a beam spot diameter of 30 µm is used to make 200 µm width microchannels with different depths. The effects of laser beam intensity and pulse overlaps on dimensional accuracy and material removal rate have been investigated using different scanning patterns. It is found that beam intensity has a major influence on dimensional accuracy and material removal rate. Optimum parameter settings are found using grey relational grade analysis. It is concluded that low intensity and low to medium pulse overlap should be used for better dimensional accuracy. This study facilitates further understanding of laser material interaction for different process parameters and presents optimum laser process parameters for the fabrication of microchannel in alumina ceramic.