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Online Deformation Measurement of Laser Repair Substrate Based on Orthogonal Sampling Moiré. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12115469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As an important branch of metal additive manufacturing, laser repair has broad application potential in the aerospace, automobile and ship building industries. In the process of laser repair, metal powder is introduced into the laser action area and heated to a molten state to form a molten pool, which moves on the component surface according to the preset scanning path. Additionally, the temperature of the repaired component changes dynamically with the movement of the molten pool, leading to the time-evolution of stress and deformation. Therefore, online deformation measurement for the repair process is essential for understanding the evolution mechanism of stress and deformation in laser repair. However, extreme environments such as ultra-high temperature, strong laser radiation and metal powder splashing exist during the laser repair, which bring great challenges for dynamic optical measurement. In this paper, an online deformation measurement system based on orthogonal sampling moiré for laser repair environment is developed, which is applied to measure the deformation field of the metal substrate during laser repair. In the measurement, laser repair is performed on a cantilever beam substrate and orthogonal grating is prepared on the side surface of the cantilever beam. The real-time grating images are recorded by an optical imaging system, in which a group of filter components are used to obtain optical images with high signal-to-noise ratio. Finally, the deformation field of the substrate during laser repair is calculated with the orthogonal sampling moiré method. The results show that the scanning path in the repair process has a significant influence on the distribution of residual deformation, which offers reference for optimizing parameters of laser repair.
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Lionetto F. Carbon Fiber Reinforced Polymers. MATERIALS (BASEL, SWITZERLAND) 2021; 14:5545. [PMID: 34639938 PMCID: PMC8509335 DOI: 10.3390/ma14195545] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/22/2021] [Indexed: 12/12/2022]
Abstract
The current demand for lightweight and high-performance structures leads to increasing applications of carbon fiber reinforced polymers, which is also made possible by novel production methods, automation with repeatable quality, the reduced cost of carbon fibers, out of autoclave processes such as resin transfer molding and resin infusion technologies, the re-use of waste fibers, development in preform technology, high-performance, fast-curing resins, etc [...].
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Affiliation(s)
- Francesca Lionetto
- Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce, Italy
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Nanashima A, Komi M, Imamura N, Yazaki S, Hiyoshi M, Hamada T, Yano K, Nishida T, Enzaki M, Sakae T. Novel analysis using magnetic resonance cholangiography for patients with pancreaticobiliary maljunction. Surg Today 2021; 52:385-394. [PMID: 34324090 DOI: 10.1007/s00595-021-02349-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/01/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE We used a novel diagnostic Fourier transform (FT) algorithm of the entire extrahepatic bile duct (EHBD) measured by magnetic resonance cholangiography (MRC) to evaluate subtle deformation of bile duct lumen, indicating the malignant potential of EHBD, in patients with pancreaticobiliary maljunction (PBMJ) and in a comparative group of controls without PBMJ. METHODS From the workstation, the EHBD lumen was traced automatically and a 2D diagram cross section was measured at 0.5 mm-longitudinal intervals. The FT-based integrated power spectral density function value (FTPSDI) of the diameter or area (mm2 or mm4/Hz) and the phase value distribution entropy (PVDE) were also measured. RESULTS There were 16 patients with undilated PBMJ and 7 with dilated PBMJ. The control group comprised 10 patients with a normal bile duct, 20 with bile duct carcinoma (BDC), and 1 with primary sclerosing cholangitis. Both the diameter and area of the dilated bile ducts and the ducts with early- or advanced-stage BDC were significantly greater than those of the normal duct (p < 0.05). The undilated type of PBMJ tended to have a larger FTPSDI diameter than a normal bile duct, which had a smaller diameter than the dilated type of PBMJ or BDC. BDC had a significantly larger FTPSDI diameter (p < 0.05) and the cutoff value for accuracy was 168 mm2 Hz-1. CONCLUSION The novel mathematical FTPSDI is a promising indicator of whether preventive EHBD resection is necessary for patients with PBMJ, which can be widely applied in the early diagnosis of other biliary diseases.
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Affiliation(s)
- Atsushi Nanashima
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
| | - Masanori Komi
- Division of Radiology, Miyazaki University Hospital, Miyazaki, Japan
| | - Naoya Imamura
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan
| | - Shigetoshi Yazaki
- Department of Mathematics, School of Science and Technology, Meiji University, Kanagawa, Japan
| | - Masahide Hiyoshi
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan
| | - Takeomi Hamada
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan
| | - Koichi Yano
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan
| | - Takahiro Nishida
- Division of Hepato-Biliary-Pancreas Surgery, Department of Surgery, University of Miyazaki Faculty of Medicine, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan
| | - Masahiro Enzaki
- Division of Radiology, Miyazaki University Hospital, Miyazaki, Japan
| | - Tatefumi Sakae
- Department of Radiology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
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A Binocular Vision-Based 3D Sampling Moiré Method for Complex Shape Measurement. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11115175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As a promising method for moiré processing, sampling moiré has attracted significant interest for binocular vision-based 3D measurement, which is widely used in many fields of science and engineering. However, one key problem of its 3D shape measurement is that the visual angle difference between the left and right cameras causes inconsistency of the fringe image carrier fields, resulting in the phase mismatch of sampling moiré. In this paper, we developed a phase correction method to solve this problem. After epipolar rectification and carrier phase introduction and correction, the absolute phase of the fringe images was obtained. A more universal 3D sampling moiré measurement can be achieved based on the phase match and binocular vision model. Our numerical simulation and experiment showed the high robustness and anti-noise ability of this new 3D sampling moiré method for high-precision 3D shape measurement. As an application, cantilever beams are fabricated by directed energy deposition (DED) using different process parameters, and their 3D deformation caused by residual stresses is measured, showing great potential for residual stress analyses during additive manufacturing.
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Kefer S, Sauer T, Hessler S, Kaloudis M, Schmauss B, Hellmann R. Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites. Polymers (Basel) 2020; 12:polym12030715. [PMID: 32210150 PMCID: PMC7183260 DOI: 10.3390/polym12030715] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 11/17/2022] Open
Abstract
This contribution demonstrates the functionality of polymer planar Bragg grating (PPBG) sensors integrated into commercial-grade carbon fiber reinforced polymer (CFRP) components. Multiple CFRP specimens are generated by curing a stack of pre-impregnated fibers inside of a heated mechanical press, exposing the polymer sensor to a pressure of 7 bar and a temperature of 120 °C for 2 h. After integration, the sensor still exhibits a strong and evaluable signal. Subsequent flexural experiments reveal a linear response of the integrated sensor’s Bragg wavelength to the CFRP specimen’s maximum deflection. Additional findings demonstrate that the embedded PPBG can be used to detect plastic deformations of a CFRP workpiece, whereas a linear correlation of plastic deformation to the resulting Bragg signal offset is determined. A plausibility check of the obtained results is delivered by a comparison of three-point flexural experiments on bulk CFRP workpieces, without integrated sensors and additional specimens featuring external optical sensors affixed to their surface. It is found that PPBGs based on cyclic olefin copolymers are able to overcome the temperature-related limitations of traditional polymer-based optical sensors and can thus be directly integrated into commercial-grade composites during production.
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Affiliation(s)
- Stefan Kefer
- Applied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, Germany
- Correspondence:
| | - Theresia Sauer
- Laboratory for Packaging and Interconnection Technology, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, Germany
| | - Steffen Hessler
- Applied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, Germany
| | - Michael Kaloudis
- Laboratory for Packaging and Interconnection Technology, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, Germany
| | - Bernhard Schmauss
- Institute of Microwaves and Photonics, University of Erlangen-Nuremberg, Cauerstrasse 9, 91058 Erlangen, Germany
| | - Ralf Hellmann
- Applied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, Germany
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