Prefacedoi: 10.1088/1757-899X/831/1/011001pmid: N/A
The proceedings contain the scholarly papers presented in two reputable joint conferences, the 7th International Conference on Mechanical, Automotive and Materials Engineering (CMAME 2019) with its workshop the 2nd International Conference on Progress in Mechanical and Aerospace Engineering (PMAE 2019). Both conferences have been held in different parts of the world for some years, as indicated by the number sequence. This year (2019), the conferences are held in Melbourne, Australia.The conferences have invited keynote speakers who are professors from renowned universities in Australia, England and China. Together with the assistance of the International Technical Committee (members from universities and research organisations around the world), the conference attracted many submissions of high quality papers. Hence, the papers in these proceedings have passed the vigorous review process and amended to the satisfaction of reviewers and have undergone critiques in a face-to-face presentation with expert audience. It is on this basis that these proceedings are good references to future research investigations and publications.The proceedings have four sections. Section 1 (Engineering Material Design and Analysis) has papers on different treatment of materials or related processes. Study of materials properties is essential to develop efficient machining and formation processes for cost effective manufacturing. The papers are good reflection of the ultimate goals of materials engineering research.Section 2 (Mechanical Engineering and Intelligent Robots) papers focus on robotics and kinematics. Applications range from inspection to localisation and sensors. The broad application areas of robots in industry are highlighted in the short conference version of the papers. It is interesting to note that authors of this section come from countries such as Australia, China and South Korea.Section 3 (Applied Mechanics and Engineering) papers are related to more fundamental treatment of fluid mechanics, mechanical design, drive systems and residual strain problems. These studies have no immediate industry applications but the theoretical knowledge outcomes form the more foundation level research will contribute to future development of products requiring these technologies.Section 4 (Advanced Manufacturing Systems and Technologies) papers are more application oriented investigating real-life industry problems in ship building, machining discrepancies, automotive crash, product life cycle analysis, energy consumption and non-linear control systems. These applications are researched in universities from 4 countries around the world, illustrating the benefits of a face-to-face conference allowing exchange of ideas and latest research findings.The variety of research topics presented in the conference and novelty exhibited in the papers published in these proceedings once again demonstrated the value of the two conferences jointly organised enabling researchers of different nationalities and different engineering fields to participate in a live research conversation. I would like to thank the conference committee, the conference secretariat, keynote speakers and all participants for their hard work making this conference a success as well as publishing a valuable knowledge literature contributing to state-of-the-art developments in mechanical, automotive, materials and aerospace engineering.
Peer review statementdoi: 10.1088/1757-899X/831/1/011003pmid: N/A
All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.
A Kind of Triple-negative Elastic MetamaterialWang, X; Wan, S
doi: 10.1088/1757-899X/831/1/012001pmid: N/A
In this paper, a kind of triple-negative elastic metamaterial (EMM) is proposed, which means it possesses negative equivalent mass density, negative equivalent bulk modulus, negative equivalent shear modulus in the same frequency range simultaneously, and can realize negative refraction of both transverse and longitudinal waves. Furthermore, the influence of rectangular oscillators and semi elliptical oscillators on the band structure is analysed, and we find that the unit cell with semi elliptical oscillators has a much wider band gap, which has a potential in supressing vibration at a wide frequency range.
Interaction Effect of Machining Parameters on Material Removal Rate in the Machining of AA6061–T6 Using Minimum Quantity Lubrication ConditionsNajiha, M.S.; Rahman, M.M.; Kadirgama, K.; Ramasamy, D.
doi: 10.1088/1757-899X/831/1/012002pmid: N/A
The objectives of this study are to investigate the interaction effect of machining parameters on material removal rate in end milling of aluminium alloy AA6061-T6 with conventional MQL techniques. Uncoated tungsten carbide (WC-Co 6.0%) and PVD TiAlN and TiAlN+TiN coated carbide cutting tools are considered using 23.4-54.0 ml/hr flow rate of commercial mineral oil for MQL machining with different combinations of input cutting parameters. Response surface methodology with central composite design approach is used for the design of experiments. Second-order mathematical models are developed for machining performance measures with different cooling conditions and validated statistically. The developed models show good agreement (< 5 % error) with the experimental results. The metal cutting performance of the TiAlN coated tools relative to uncoated and TiN coated inserts is better at all combinations of input cutting parameters. Hence the superior performance of TiAlN coating makes it more suitable for use with MQL. In case of material removal rate, all the tools show similar behaviour in all the measurements with the depth of cut as the most significant parameter followed by feed rate. Interaction of feed rate and depth of cut is most effective.
Strategic Approach to Develop Solutions for Shaping Complex Workpieces of Exotic MaterialsAlmeida, Sergio; Mo, John; Bil, Cees; Ding, Songlin; Wang, Xiangzhi
doi: 10.1088/1757-899X/831/1/012003pmid: N/A
Exotic materials such as hardened steel and tungsten carbide tool steel have unique resistance and properties that make them hard-to-cut. Thus, research to find better ways to process such materials requires an innovative approach and new ideas. Therefore, the present study investigates the design of a novel WDEM combined with robotic machining to overcome limitations of traditional robotic machining. Wire EDM (WEDM) stands out as a non-traditional machining process able to cut complex profiles of hard-to-cut materials, achieving high dimensional accuracy and superior surface finishing. Unfortunately, WEDM is designed in rigid bed-based CNC machines which restrict design freedom in terms of size, shape and features due to machining envelope constraint. On the other hand, traditional machining processes such as drilling and milling using six-axis industrial robots have been investigated and some applications have successfully delivered cost efficiency, improved envelope and high flexibility. However, due to the structure and strength of the robot arm, accuracy, repeatability and finishing are not comparable to CNC machining outcomes. These researches are also restricted by the power of the robot arm holding the machining tool. This paper explores, identifies and selects suitable configurations and define research actions that must be taken to achieve a highly flexible, accurate machining system for exotic materials.
Low Frequency Vibration Isolation Performance of the Plate with Periodic Cylindrical OscillatorsZhou, Peng; Wan, Shui
doi: 10.1088/1757-899X/831/1/012005pmid: N/A
The paper is devoted to the vibration reduction and isolation performance of a periodic structure with cylindrical vibrators. A plate with periodic oscillators was investigated using finite element technic. In the finite element analysis, test specimens were modelled with finite element software. With appropriate geometric and material parameters, the structure can obtain elastic wave band gaps, where vibrations are prohibited. So, the structure can be regarded as a kind of vibration isolation material. The dispersion curve and transmission spectrum of the structure were calculated to find the range of the band gaps. Both the longitudinal vibration and flexural vibration of the plate are studied. The results show that the designed plate with proper parameters has a low frequency range of band gaps. It has a wide application prospect in the field of low frequency vibration isolation.
Experimental Investigation of Heterogeneous Strain Fields Created in Metallic MaterialsShariat, Bashir S
doi: 10.1088/1757-899X/831/1/012006pmid: N/A
This study reports experimental evaluation of inhomogeneous strain fields created in NiTi structures during stress-induced martensitic transformation. A superelastic NiTi thin plate was used to create samples with uniform and non-uniform geometries. Digital image correlation technique was employed to measure the local strain variation in the NiTi samples under mechanical loading. Clear Lüders band formation and propagation were observed during experiments. The local strain contours revealed that the deformation was localised and spatially inhomogeneous in all samples. In the geometrically non-uniform sample, the transformation initiation and propagation were controlled by geometrical gradient. Also, the global deformation behaviour exhibited stress-gradient during forward and reverse transformations because of geometrical non-uniformity.
A Numerical Investigation into the Impact of Icing on the Aerodynamic Performance of AerofoilsBhatia, Dinesh; Wahaibi, Al Yaqadan Shaaban al
doi: 10.1088/1757-899X/831/1/012007pmid: N/A
Aircraft wings and wind turbine blades are often subjected to harsh and cold climatic conditions. Icing is often observed on wing and blade surfaces in these cold climatic conditions. Wind turbine blades, in particular, are severely impacted by ice accretion which greatly hampers their performance and energy generation efficiency. Ice-accretion patterns are observed to vary with changes in temperature. As the temperature changes, the thickness of the ice accretion, the shape and location of ice-accretion vary greatly. In this paper, three different ice accretion patterns and their impact on the aerofoil efficiency have been investigated using the SST k – ω model in ANSYS CFD. An analysis of the impact of ice-accretion through a comparison of lift and drag coefficients for all three ice accretion patterns indicate that the accretion of ice on an aerofoil can reduce lift generation by 75.3% and increase drag by 280% thereby severely impacting the performance of the aerofoil. The loss in aerodynamic performance is greatly dependent on the ridge height, the extent of ice accretion and the thickness of this ice. The loss in aerodynamic performance has no fixed correlation to the drop in temperature.