bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Formula for Determining the Maximum Straight Length of a Buried Pipeline That Can Prevent Seismic Buckling
Authors: Onuki Shoma , Mitsuya Masaki 
Published: January 2021

Abstract
Buried pipelines must exhibit the appropriate seismic performance to be applied practically and securely. One major pipeline failure mode is buckling caused by seismic ground motion. Buckling typically occurs in straight pipeline sections because seismic axial loads mainly accumulate along straight lines. The design method for defining a maximum straight pipe length to decrease seismic axial loads is known to be effective in preventing buckling. Based on this previous knowledge, this study develops a theoretical formula for estimating the maximum straight length to prevent buckling. The proposed formula is derived using an analytical pipeline model with soil springs under seismic ground motion. Using this analytical model, the seismic loads which are applied to the straight pipe and the pipe connected to the straight pipe are calculated respectively. Then, the formula for the maximum straight length is derived by calculating the straight pipe length where the axial stress in the straight pipe is equal to the yield stress. The proposed formula is validated through finite element analysis. The maximum straight lengths obtained by the theoretical formula are in good agreement with FEM or shorter, thus providing a margin of safety. This work can be useful in designing buried pipelines to prevent buckling failures, thus enabling safer and more viable pipelines.
Effects of Slope Grade on Soil-Pipe Interaction: Full-Scale Experiments
Authors: Katebi Mohammad , Wijewickreme Dharma , Maghoul Pooneh , Roy Kshama 
Published: January 2021

Abstract
In the current industry practice guidelines, the soil restraints to assess the behaviour of pipelines subject to permanent ground displacements are numerically characterized using independent “soil springs”. These guidelines have been primarily generated by considering the typical configurations of buried pipelines in level ground. The assumption of level ground does not always hold true when assessing pipelines located on sloping ground in mountainous areas and riverbanks. This research presents the outcomes from a set of full-scale physical model tests conducted on a pipe buried in slopes. The results highlight the significance of the slope grade effects on soil-pipe interaction. The results are useful as input to modify soil springs accounting for the ground surface inclination.
Joint Strength and its Improvement of Friction Welded Joint Between Ductile Cast Iron and 5052 Al Alloy
Authors: Kimura Masaaki , Yoneda Akira , Kusaka Masahiro , Kaizu Koichi , Hayashida Kazuhiro , Takahashi Tsuyoshi 
Published: January 2021

Abstract
To obtain dissimilar joint for easily making multi-material structures, the characteristics of friction welded joint between ductile cast iron (FCD400) and 5052 Al alloy (A5052) was investigated. The relatively high tensile strength of joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa, respectively. However, this joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. Although the weld interface had no intermetallic compound layer, the fractured surface at the A5052 side had some graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particles were reduced from the weld faying surface at the FCD400 side by decarburization treatment. The joint had approximately 96% in the tensile strength of the A5052 base metal and that was fractured between the A5052 side and the weld interface. The joint with high tensile strength as well as the possibility improving the fractured point of that were obtained when those were made with opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.
Proposal of High-Quality Laser Hardening System for Shaft Parts Using Cylindrical Mirror and Ring-Beam Shaped by High-Speed Laser Scan System
Authors: Tanabe Hirotaka , Ogawa Keiji , Nakagawa Heisaburo , Tsukada Hirohito , Goto Yuki 
Published: January 2021

Abstract
Shaft parts are important parts used in almost all machines including automobiles. In addition, extremely high reliability is required since a shaft failure is directly linked to a fatal machine trouble. Therefore, a hardening process is usually conducted to improve strength and wear resistance. In this study, we propose a new laser heat treatment method to produce high-quality and high-accuracy shafts with high efficiency, low cost and low environmental impact. We will also develop a technique to derive the appropriate laser irradiation conditions quickly and systematically for shafts with various shapes and dimensions. There are the other hardening techniques including the electric furnace method and the induction method. These methods require post-processing for deformation correction, whereas the proposed method uses a laser to achieve thermal deformation-free hardening, eliminating the need for the post-processing. As a result, an improvement in yield can be expected due to a reduction of the products that cannot be corrected after heat treatment, which had to be waste disposed with conventional methods. By using our method, the entire circumference of the shaft was hardened by using a ring-shaped laser beam and a cylindrical inner mirror. Here, the ring-shaped laser beam was formed by high-speed scanning of a spot shapelaser. In the present paper, the details of this system were introduced and some experimental results were described.
Developing a Human-Cognition-Based Reverse Engineering Approach
Authors: Tashi  , Ullah A. M. M. Sharif , Kubo Akihiko 
Published: January 2021

Abstract
Conventional reverse engineering uses 3D scanning or image processing technologies to extract the shape information of a given object in terms of point clouds before creating its virtual and real models. It requires complex and user-intensive geometric modeling processes such as noise removal and surface reconstruction. In order to avoid all these complex processes, this paper presents a scanning-free reverse engineering approach defined as a human-cognition-based reverse engineering. The approach consists of four spaces. The first space is defined as a human cognition space wherein the information of a given object is represented using some predefined linguistic expressions. The second space is defined as a point cloud creation space wherein the predefined linguistic expressions are translated to a point cloud model. The third space is defined as a virtual model creation space wherein the point cloud model is converted into a virtual model using a commercially available CAD system. The last space is defined as a real model creation space wherein the virtual model is converted into a real model using 3D printing technology. The efficacy of the proposed approach is demonstrated by performing a case study. The findings will help those who want to simplify the current practices regarding reverse engineering.
Fabrication of an Antireflective Structure on a Lenticular Lens
Authors: Yatagawa Katsuyuki , Nakamura Masato , Ono Masaki , Taniguchi Jun , Hiwasa Shin 
Published: January 2021

Abstract
In our previous study, various lenses with antireflective structures (ARSs) were fabricated by ultraviolet nanoimprint lithography (UV-NIL) and a thin flexible replica mold, which had ARSs. However, in the case of a lens with a large uneven surface such a lenticular lens, it is difficult to transfer an ARS. In this paper, the improvement of the transfer process for a lenticular lens with an ARS is investigated.
A master mold of ARSs was fabricated by irradiating glassy carbon with an oxygen ion beam. A flexible replica mold with ARSs was transferred from the ARS master mold by UV-NIL. In this case, the thickness of the flexible replica mold was 210 μm. A lenticular lens with the reverse shape was also transferred from the original lenticular lens by UV-NIL. To add an ARS to the lenticular lens with the reverse shape, it was covered with a flexible replica mold coated with a UV-curable resin. In addition, the lenticular lens was placed on the back side of the flexible replica mold to contact the lens curve properly. Afterwards, the setting samples were pressed with a roll press and simultaneously UV-cured. After this roll press method was carried out, a lenticular lens with the reverse shape and an ARS was obtained. Using this mold, a lenticular lens with an ARS was replicated by UV-NIL and the reverse-shape mold with an ARS.
Study on Wire Electrochemical Machining of Nickel Base Alloy Using Fine Wire Electrode
Authors: Sasaki Wataru , Natsu Wataru , Xing Huachen 
Published: January 2021

Abstract
Nickel-based alloys represented by Inconel are materials with excellent high-temperature characteristics, and are widely used in the aerospace industry, such as aircraft and rocket engine parts. On the other hand, it is known as a typical difficult-to-cut material. Furthermore, in machining and electric discharge machining (EDM), the machining speed is slow and tool or electrode wear is a big problem. Meanwhile, electrochemical machining (ECM) using electrochemical reaction is not affected by the hardness of the material, does not generate a heat-affected layer on the workpiece surface, and has no tool wear. So, it is considered that ECM is suitable for machining difficult-to-cut materials. Therefore, in this study, focusing on the nickel-based alloy Inconel718 (Alloy718), we conducted a machining experiment using NaNO3 aqueous solution by wire ECM using a thin wire (mainly tungsten) as a tool electrode, and investigated the ECM characteristics. Wire ECM can be machined like wire EDM, and high-efficiency machining is possible by using a pulse power supply. As a result, it was found that increasing the voltage, electrolyte concentration, electrolyte supply pressure, and diameter of wire increases the current flowing between the electrodes and has the effect of promoting machining. In addition to simple cutting, the possibility of being effective not only for grooving but also for cutting complex shapes was shown.
Cutting Characteristics of Hard-Brittle Materials Under Nano/Micro Groove Cutting Using a V-Shape Tool
Authors: Masahiko Yoshino , Hao Shen , Nakagawa Yuki , Abdelkawy Abdallah 
Published: January 2021

Abstract
The cutting characteristics and the critical depth of cut in nano/micro cutting of hard/brittle materials were investigated. A V-shaped single crystal diamond tool with a negative rake angle was used as the tool, and a cutting experiment was conducted by means of the inclined cutting test technique.
The effect of rake angle on specific cutting force was also compared with V-groove cutting model based on simple shear plane. It was found that the cutting force increased and the burrs height increased as the rake angle became negative. and it was considered that the plastic flow influenced on the cutting force. It was also found that the critical cutting depth decreases with the decrease of the rake angle. The result of this experiment showed the opposite tendency to previous studies on the critical depth of cut. This is attributed to that, in the V-type tool cutting, the crack growth by increasing plastic flow is more effective than the suppress of cracks growth by increase of hydrostatic pressure.
Strength Characterization of Adhesive Joint Surface-Modified by Large-Area EB Irradiation
Authors: Omiya Yuya , Toyota Kenji , Nakanishi Ryota , Okada Akira , Shinonaga Togo , Fujii Masahiro 
Published: January 2021

Abstract
With recent improvement in adhesive performance, adhesive joints are used more in various industrial fields. Despite their advantage in connecting dissimilar adherends, adhesive joints are considered not suitable for key components of mechanical structures due to their large scatter in joint strengths. There are many factors that affect the strength of adhesive joint. However, the general bonding factors are (1) mechanical bond, (2) physical bonding, (3) chemical bonding. The adhesion mechanism is complex because these theories occur at same time. Thus, it is necessary to consider the factors separately. And it is important to understand the bonding mechanism on interfaces in adhesive joint and to improve the reliability of the joint strength more. In this study, the tensile strength of single lap joint was measured in order to investigate the influence of various surface treatments and strength characterization of adhesive. Specimens consist of aluminum alloy plates (A6061). Large-area electron beam (EB) and plasma were used for surface treatment. Each one of specimens were examined from the view of wettability, roughness parameter. Compared with unirradiated specimens, other joints improved the wettability and tensile strength. The inference of large-area EB irradiation on adhesive mechanism was discussed.
Investigation of Laser Hardening Forming Method for Thin Steel Plate From a View of Origami Engineering
Authors: Manabe Yuki , Nishida Hiromichi , Onishi Hirokazu , Hirogaki Toshiki , Aoyama Eiichi 
Published: January 2021

Abstract
In recent years, products have been miniaturized and multi-functionalized, and the importance of integration in compact machine tools has increased. In this study, we propose integration via laser hardening forming which combines laser hardening and laser forming on a compact machine toolfor thin steel sheets. For the processing, the deformation and quenching were considered during repeated laser scanning repeated at the same location. In addition, to apply laser quenching forming to origami engineering, a test piece with resilience was prototyped. As a result, problems in repeated laser scanning were clarified, and the tool’s applicability to origami engineering was demonstrated.
Diamond Fly Cutting Applied to Improve Curved Surface Machining by In-Process Measurement and Control on an Ordinary Milling Machine
Authors: Otsubo Tatsuki , Yazawa Takanori , Wang Jinhui , Kato Tomonori 
Published: January 2021

Abstract
To improve the accuracy of the machined surface produced by an ordinary milling machine, a system called workpiece-referred form accuracy control (WORFAC) was developed and confirmed in diamond turning. However, non-rotational symmetric surface structures, such as V-grooves, pyramid structures, F-theta lenses, and other free form surface cannot be machined by diamond turning. We proposed to improve the form accuracy of a machined surface produced by an ordinary milling machine by diamond fly cutting using controlled cutting with reference surface (CCRS), an in-process measurement and control method. Fly cutting is usually used to manufacture ultra-precision microstructures with nanometric surface roughness and submicrometric form accuracy, without the need for subsequent polishing. Nevertheless, a high level of accuracy has only recently been achieved on ultra-precision milling machines. In this study, we verified the effectiveness of fly cutting with CCRS on an ordinary milling machine. CCRS improves machined surface accuracy by controlling the relative displacement between the tool and workpiece. Diamond fly cutting using CCRS was demonstrated to reduce the table motion error on an ordinary milling machine. The experiments of curved surface machining by uncontrolled machining and control machining were conducted, and the effectiveness of improving the circular are machining accuracy of the general-purpose milling machine was confirmed.
High Efficiency Molding by Real-Time Control of Distance Between Nozzle and Melt Pool in Directed Energy Deposition Process
Authors: Aizawa Kengo , Ueda Masahiro , Shimada Teppei , Aoyama Hideki , Yamazaki Kazuo 
Published: January 2021

Abstract
Laser metal deposition (LMD) is an additive manufacturing technique, whose performance can be influenced by a considerable number of factors and parameters. Typically, a powder is carried by an inert gas and sprayed by a nozzle, with a coaxial laser beam passing through the nozzle and overlapping the powder flow, thereby generating a molten material pool on a substrate. Monitoring the evolution of this process allows for a better comprehension and control of the process, thereby enhancing the deposition quality. As the metal additive manufacturing mechanism has not yet been elucidated, it is not clear how process parameters affect material properties, molding accuracy, and molding efficiency. When cladding is performed under uncertain conditions, a molded part with poor material properties and dimensional accuracy is created. In this paper, we propose a method for high efficiency molding by controlling the distance between the head nozzle and the molten pool in real time. The distance is identified by an originally developed sensor based on a triangulation method. According to the distance, the head nozzle is automatically controlled into the optimum position. As a result, an ideal molding process can be generated, so that high efficiency molding and high-quality material properties can be obtained. Experimental results show that continuing deposition at the optimum distance assists in achieving deposition efficiency and dimensional accuracy. According to the specific experimental results of this method, the modeling efficiency was increased by 27% compared to the method without correction, and the modeling was successful with an error within 1 mm.
Development of Friction Stabilization Control Using Genetic Algorithm and Contact Point Control Method
Authors: Yamada Takazumi , Murashima Motoyuki , Umehara Noritsugu , Tokoroyama Takayuki 
Published: January 2021

Abstract
Currently, there are many tribological components that require long life. In the case of unique machines such as satellites and wind turbines, parts replacement and maintenance require huge costs. Generally, machine surfaces get damaged (e.g. wear scar) during operations, which impedes stable sliding [1,2]. We establish a new surface which can avoid the damaged part in order that maintenance-free or energy-efficient mechanical components can be realized. The previous researchers have developed a method which actively controls friction by using a morphing surface. The morphing surface consists of morphing diaphragms and some supportive parts. Inspired by previous research, this study established a new friction stabilization method that controls the contact position when partial damage occurs on the counter surface. We applied genetic algorithm (GA), one of the artificial intelligence technology, to realize efficient contact point control. In order to stabilize friction, we searched for an optimum pattern of contact points that could avoid the damaged parts by applying GA. By repeating this searching method, a contact point pattern that avoids the damaged parts can be found. As results of experiments, we have succeeded in stabilizing friction by searching for contact point patterns that automatically avoid damage in the friction test using GA. However, even if the search is performed efficiently using GA, the calculation times is necessary about 10–20 times. Therefore, it is necessary to shorten the time before the damage is avoided. We report on a method to shorten the search time for the optimal contact point pattern using GA as the latest progress. In this method, some simple contact point patterns are used to roughly identify the locations where damage might be present during some rotations. At the section of creating the 50 contact patterns, this probability of damage existence is used to create the 50 contact patterns that are more likely to avoid the damaged parts. By adding this process before the friction test using GA, we succeeded in reducing the number of calculations from 10–20 times to 2 times.
Molecular Dynamics Study on the Machining of Titanium
Authors: Bhattacharya Ayan , Zhang Xueping , Shivpuri Rajiv 
Published: January 2021

Abstract
Titanium is a popular metal with good strength-weight ratio, high resistance to corrosion and can withstand higher temperatures. Titanium and its alloys are widely used in the aerospace industries. As the experimental tests for titanium are costly and Finite Element Method analysis do not permit observation of deformation defects occurring at the atomistic scale, at shorter time scales, Molecular Dynamics analysis tool has been used to study the machining process at the atomistic scale. The small dimension of workpiece, reduced depth of cut and cutting speed bring up several issues that may not play any significant role in conventional machining but are of significant importance in micro and nano-level cutting process. During Machining, an increase in dislocation density occurs at the machined surface, due to this plastic deformation on these upper layers of the machined surface. Previous work on machining at the nano-scale has been performed for Copper, Aluminum and Silicon with a focus on different potential energy functions, tool life, tool geometry and effect of cutting forces. In this present work, a molecular dynamics simulation study has been performed to investigate evidence of deformation on the machined surface and subsurface layers during machining of monocrystalline titanium workpiece with a rigid diamond tool at nanometric scale using different cutting speeds. The distribution of deformation factors including stress, strain, strain rate, the temperature in the machined surface and sub-surfaces are analyzed at various cutting speeds given the same other conditions.
Detection Scheme of Volume of Repair of Engineering Equipment Based on Line Structured Light
Authors: Liu Bowen , Lu Hong , Wu Zidong , Li Shuo , Liu Qiong 
Published: January 2021

Abstract
When the body, main support and other large metal parts are damaged, welding or surfacing is generally used as the repair method. Measuring volume of repair is a key step before welding repair, because former provides relevant parameters for latter. Line structured light detection is a fast and convenient machine vision detection method, which is suitable for detection tasks in various complex environments and satisfies the requirements of volume of repair of engineering equipment detection. This paper designs a scheme based on line structured light. In this scheme, the parameters of welding repair are obtained by several steps, such as scanning, image processing, light strip center extraction and trend points extraction. Compared with other common methods, this scheme has the advantages of fast detection, easy operation, high cost-performance ratio and easy expansion. especially in combination with welding robots, it can greatly improve the level of automation and reduce the maintenance time.