VIRTUAL COMMISSIONING IN MACHINE TOOL MANUFACTURING: A SURVEY FROM INDUSTRY

Virtual commissioning has acquired a major interest with the introduction of Industry 4.0. It is demonstrated that virtual commissioning can significantly reduce the commissioning time, error rate and costs. However, industry is still experiencing difficulties with the integration of these new technologies. This paper is one of the first empirical surveys conducted in the industry that aims at understanding the challenges and current practices with respect to virtual commissioning, with special focus on the machine tool manufacturing sector. The survey contextualizes the practice of virtual commissioning and the digital twin in industry, and benchmarks the results with academia, in which main gaps are identified. Keywords: empirical survey, virtual commissioning, digital twin, machine tool manufacturing, testing

Experimental pressure drops during the water flow into porous materials realized via additive manufacturing

Open-cell foams offer several interesting possibilities in numerous technological fields. In fact, they present high surface area to volume ratio as well as enhanced flow mixing and attractive stiffness and strength. However, their complete and reliable characterization has not been completed yet. In fact, there is still no a comprehensive work that relates all the foam geometrical characteristics to their heat transfer and pressure drop features. This paper is the very first outcome of a larger study that aims at realizing open-cell foams via additive manufacturing, testing them, then generating a simulation model based on the real geometries to numerically optimize each parameter. The present manuscript presents the construction of the open-foam via 3D printing and the experimental pressure drop measurements when water flows through the foam.

Research on the Reliability Allocation Method of Smart Meters Based on DEA and DBN

Reliability allocation can reasonably determine the reliability index of each unit in the system to ensure product quality in design, manufacturing, testing and acceptance. In the design process of the smart meter, the preliminary reliability allocation results may be unreasonable, so in the middle and later stages of the design stage, the reliability needs to be reallocated. The traditional allocation method has some limitations, such as strong subjectivity, large amount of calculation and too much reliance on expert judgment. In order to solve these problems, this paper presents a multi-method fusion method of reliability allocation. First, this paper uses the goal-oriented methodology (GO methodology) to integrate dynamic Bayesian networks (DBNs) to predict the reliability of smart meters. Second, a data envelopment analysis (DEA) reliability allocation model is established, the posterior probability obtained by DBN reasoning together with the failure rate and structural complexity of each unit are used as the output indicators of this model. Finally, the reliability allocation weight is calculated by using the efficiency value obtained from the DEA reliability allocation model. The validity and accuracy of this method is verified by an accelerated life test. This provides a new idea for reliability reallocation of smart meters.

Preliminary Investigation of a Flax-Epoxy Composite Material for Orthopaedic Applications

In this dissertation, a preliminary experimental study was done on a flax-epoxy prepreg to determine its suitability as a composite material for making bone fixation plates. The research involved manufacturing, testing, data analysis, and design and optimizing. The material was found to have sufficient strength and mechanical characteristics similar to those of bone, and could be used for making bone fixation implants with proper design or in combination with other reinforcement fibres. The findings of this research are useful not only for using flax-epoxy composites in designing bone fixation plates but also for orthopaedic implants, such as joint replacement, in general.

Preliminary Investigation of a Flax-Epoxy Composite Material for Orthopaedic Applications

In this dissertation, a preliminary experimental study was done on a flax-epoxy prepreg to determine its suitability as a composite material for making bone fixation plates. The research involved manufacturing, testing, data analysis, and design and optimizing. The material was found to have sufficient strength and mechanical characteristics similar to those of bone, and could be used for making bone fixation implants with proper design or in combination with other reinforcement fibres. The findings of this research are useful not only for using flax-epoxy composites in designing bone fixation plates but also for orthopaedic implants, such as joint replacement, in general.

Rancang Bangun Dan Evaluasi Media Pengenalan Hewan Serangga Dengan Teknologi Augmented Reality

<p>Abstrak :</p><p>Usia dini merupakan salah satu masa penting bagi seorang anak dalam mengembangkan bakat dan potensinya. Dalam Pendidikan Anak Usia Dini juga diajari untuk mengenal tentang berbagai macam hewan contohnya serangga. Anak-anak mulai diperkenalkan pembelajaran tentang berbagai macam hewan serangga seperti belalang, kepik, wangwung, lalat, nyamuk dan sebagainya. Guru mengenalkan berbagai macam serangga tersebut dengan menggunakan media buku bergambar. Buku bergambar memiliki keterbatasan, yaitu hanya menampilkan gambar dan teks. Teknologi <em>Augmented Reality </em>dapat dimanfaatkan sebagai media bantu pembelajaran mengenalkan berbagai macam serangga dengan menambahkan objek 3 dimensi di atas media buku tersebut. Metode penelitian mengadopsi metode <em>Multimedia Development Life Cycle</em> (MDLC). MDLC terdiri dari enam tahap yaitu pengonsepan, perancangan, pengumpulan materi, pembuatan, pengujian , dan pendistribusian. Hasil penelitian berupa aplikasi pembelajaran tentang pengenalan aneka macam serangga dalam aplikasi android. Aplikasi AR SERANGGA ini dibuat secara interaktif dengan menggunakan alat bantu <em>marker </em>untuk menampilkan obyek dalam bentuk 3 dimensi dan informasi yang ditampilkan agar anak usia dini tertarik atau antusias dalam kegiatan belajar mengajar yang dibuktikan dengan 70% responden memberikan nilai setuju atas aplikasi ini.</p><p>_____________________________</p><p>Abstract : </p><p><em>Early childhood is one of the important times for a child to develop his talents and potential. In Early Childhood Education, it is also taught to get to know various kinds of animals, for example insects. Children were introduced to learning about various kinds of insects such as grasshoppers, ladybugs, wangwung, flies, mosquitoes and so on. The teacher introduces the various kinds of insects using picture books as media. Picture books have limitations, which only display pictures and text. Augmented Reality technology can be used as a learning aid to introduce various kinds of insects by adding 3-dimensional objects on top of the book media. The research method adopted the Multimedia Development Life Cycle (MDLC) method. The MDLC consists of six stages, namely drafting, designing, gathering materials, manufacturing, testing, and distributing. The results of the research are in the form of a learning application about the introduction of various kinds of insects in an android application. The AR SERANGGA application is made interactively by using marker tools to display objects in 3-dimensional form and the information displayed so that early childhood is interested or enthusiastic in teaching and learning activities as evidenced by 70% of respondents giving agreed scores on this application.</em></p>

Analisis Pemanfaatan Panas Mesin Kendaraan Menjadi Sumber Energi Listrik Pada Kendaraan Bermotor Dengan Menggunakan Efek Seeback Pada Thermoelektrik Generator

This study discusses the analysis of the heat utilization of vehicle engines into electrical energy using the seeback effect on the thermoelectric generator. This type of research is a level 3 development research with several stages, namely: potential and problems, product design, system validation, design revision, product manufacturing, testing product trials, product revisions, usage trials, product revisions. Based on the research conducted, several things can be concluded, namely. First, the use of the level 3 development research method can be applied in research on analyzing the use of vehicle engine heat into electrical energy using the seeback effect on the thermoelectric generator. Second, when testing the thermoelectric generator, it is carried out 2 times, so that the electrical energy is obtained from a temperature difference of 70.1 ° C of 2.98 volts. Penelitian ini membahas mengenai analisis pemanfaatan panas mesin kendaraan menjadi energi listrik dengan menggunakan efek seeback pada thermoelektrik generator. Jenis penelitian ini adalah penelitian pengembangan level 3 dengan beberapa tahap, yakni: potensi dan masalah, desain produk, validasi sistem, ,revisi desain, pembuatan produk, uji coba produk, revisi produk, uji coba pemakaian, revisi produk.Berdasarkan penelitian yang dilakukan dapat disimpulkan beberapa hal, yaitu. Pertama penggunaan metode penelitian pengembangan level 3 dapat diterapkan dalam penelitian analisis pemanfaatan panas mesin kendaraan menjadi energi listrik dengan menggunakan efek seeback pada thermoelektrik generator. Kedua pada saat melakukan pengujian terhadap thermoelektrik generator dilakukan sebanyak 2 kali, sehingga didapatkanlah energi listrik yang dihasilkan dari perbedaan temperatur 70.1 °C sebesar 2,98 Volt.

Prevention of Offshore Wind Power Cable Incidents by Employing Offshore Oil/Gas Common Practices

It has been observed that, although submarine power cables have a critical role to wind power arrays and power export to shore, they are often overlooked at early stages of projects and oversimplified during late stages. This leads to lack of attention given during cable design and planning, as well as pressured schedules during manufacturing, testing and installation. The significant number of incidents attributed to offshore submarine cables during construction has increased overall project risk, lowered system average power availability and increased insurance costs. Lack of proper routing can also result in an inability to maintain asset integrity for the project design life. Despite the attention that submarine power cables have received over the past few years, the number and cost of incidents does not appear to be decreasing. A comparison can be made between offshore HVAC and HVDC cables used for wind power and offshore umbilicals and MV cables used in the oil and gas sector. These umbilicals are often similar in weight, size and bending stiffness, and have similar design, manufacturing, routing and installation challenges, but with a fraction of the incidents observed with offshore wind array and export cables. An additional caveat is that the offshore oil and gas sector has achieved a reliable track record while installing and maintaining these umbilicals and cables in fully dynamic conditions (ultra-deep water) as well static conditions. One primary difference between how the oil and gas sector executes these systems are design, planning and specification from an early stage of the project. Significant attention is given at an early stage to quality control, including offshore routing and umbilical testing specifically to avoid incidents resulting in umbilical damage due to the tension and crushing forces during installation as well as ambient seawater and seabed interaction. Management of these risks are documented, and optimal mitigation strategies are implemented early in the design phase. This paper will discuss the types of incidents which have been observed during construction and installation of submarine HVAC/HVDC cables in the wind power sector and how they could have been prevented by normal practices of the offshore oil/gas sector from early design and planning all the way to installation and commissioning.

Developing of the optimal shape and reinforcement structure of the specimen for adequate determination of the tensile strength in unidirectional composites

Unidirectional composites exhibit the highest strength when stretched along the fibers. However, the proper determination of the strength faces great methodological difficulties. The main problems of tensile testing of polymer composites consisted in developing of the specimen shape and the method of specimen fixation which ensure the minimum impact of the stress concentration near the grips on the strength measurements. A conventional shape of the specimen with fillets is unsuitable for unidirectional polymers due to the splitting occurred in the fillet zones upon loading. Therefore, the specimens are usually standardized in the form of rectangular strips fixed using pads or special grips which provide constant transverse forces. However, with such a specimen shape, a significant stress concentration inevitably occurs at the edge of grips and the lower the ratio of the interlayer shear modulus to the longitudinal Young’s modulus, the greater the stress concentration impact. For the purpose of the most correct determination of the strength we propose to use specimens with smoothly varying dimensions at the same cross-sectional area which ensures keeping the total number of unbroken fibers in each section. The specimen thickness decreases when moving from the working part of the specimen to the gripping part, whereas the width (while maintaining the section area) grows to prevent the specimen collapsing resulting from transverse forces in standard self-tightening grips. Analytical and FEM modeling is performed to select a rational contour shape. Technological equipment has been developed and a procedure of manufacturing testing specimens has been worked out. The tensile test of specially manufactured curvilinear reinforced specimens showed higher strength values compared to standard rectangular strips or specimens with semicircular fillets.