The Experts below are selected from a list of 38373 Experts worldwide ranked by ideXlab platform
Zhihong Liu - One of the best experts on this subject based on the ideXlab platform.
-
welding distortion control technology in cfetr Vacuum Vessel
Fusion Engineering and Design, 2020Co-Authors: Lei Xiu, Zhihong LiuAbstract:Abstract The Vacuum Vessel is very important component for China Fusion Engineering Test Reactor (CFETR), it is a double-layer shell structure with complex contour. The Vacuum Vessel is mainly formed by welding, which requires high precision of forming dimension. Welding distortion brings difficulties to the forming dimension control of Vacuum Vessel, so it is necessary to control the welding distortion in the progress of Vacuum Vessel welding. In this paper, many kinds of welding distortion control methods used in CFETR Vacuum Vessel manufacturing are introduced, and the application objects and key technology of each welding distortion control method are given. To accumulate experience for the formal CFETR Vacuum Vessel construction, and provide reference for other similar engineering construction.
-
analysis and control of welding deformation for cfetr Vacuum Vessel ps2
Fusion Engineering and Design, 2020Co-Authors: Zhihong Liu, Lei XiuAbstract:Abstract The large scaled Vacuum Vessel (VV) of CFETR is designed as a water-cooled, double-walled structure with a D-shaped poloidal cross-section. One sub-sector of VV contains four poloidal segments (PS) assembled by welding. Because of the large size of the VV, the distortion caused by welding will make the assembling difficult. Controlling the deformation during the welding process is a significant technological challenge. This article gives the analysis of the deformation of the component during the welding process, the optimization of the welding process and the design of the welding tooling and clamping positions firstly. Based on the inherent strain theory, the welding deformation analysis of the five different welding sequences of PS2 is performed, and the corresponding welding tooling and clamping positions are designed in accordance with the deformation results. The methods provide highly valuable information for the actual processing, and the welding deformation of PS2 in the actual production has been well controlled, all of which are within the tolerance requirements.
-
ng tig welding technology research on 1 8 sector of cfetr Vacuum Vessel
Fusion Engineering and Design, 2020Co-Authors: Zhihong LiuAbstract:Abstract With the development of the China Fusion Engineering Test Reactor (CFETR) engineering design, a 1/8 Vacuum Vessel (VV) sector prototype is conducted as one of the major R&D projects of CFETR. The welding structure between VV sectors in field assembly is modeled in this prototype, and narrow-gap tungsten inert gas (NG-TIG) welding, which has small welding deformation, high-quality welds, and excellent adaptability to this structure, is taken as an applicable welding strategy. All-position welding system solutions are provided in this paper, and the welding experiments, including flat, vertical, and over-head welding, are performed. Relevant test results, including nondestructive testing, mechanics performance testing, macro and micro weld detection, permeability testing, and the optimal process parameters, are obtained. Finite element analysis (FEA) by SYSWELD is executed, and the results are compared with the actual measurements. The NG-TIG welding system is used to perform the local VV double-wall structural welding experiment and the welding of four 1/32 sectors. These results show that the welding system and the process scheme are feasible.
-
phased array detection parameters for electron beam welds in cfetr Vacuum Vessel port stubs
IEEE Transactions on Plasma Science, 2020Co-Authors: Zhihong Liu, Rui Wang, Eiya JiangAbstract:The China Fusion Engineering Testing Reactor (CFETR) Vacuum Vessel (VV) port stub was formed by electron beam welding (EBW). In this article, the phased array ultrasonic testing (PAUT) method was introduced for testing the quality of the weld. First, the acoustic field simulation and analysis of the EBW of 316L austenitic stainless steel were carried out with different frequency probes, then the microstructure of electron beam welds were observed by microscopic metallographic to analyze the influence of the type and influence of probe, finally fabricating the reference test blocks according to the NB/T47013-2015 standard to conducting the PAUT experiment. The test results show that the type of probe has less influence on the signal-to-noise ratio (SNR) and localization of the detection of large-thickness austenitic stainless steel electron beam welds under low-frequency conditions. The SNR of EBW detection was gradually decreased as the frequency of the probe increases under the same type of probe. In the direction of depth of the EBW, with the increase in the depth, the weld microstructure size becomes finer, so the sector scan image of $\phi ~1$ -mm side drilled hole (SDH) near the upper weld was severely distorted, while the sector scan image of $\phi ~1$ -mm SDH near the lower EBW was relatively good.
-
research on welding deformation of cfetr 1 16 Vacuum Vessel mockup
Fusion Engineering and Design, 2020Co-Authors: Xiaowei Xia, Zhihong LiuAbstract:Abstract The 1/16 prototype sector of China Fusion Engineering Test Reactor (CFETR) Vacuum Vessel is being manufactured by Institute of plasma physics, Chinese academy of sciences (ASIPP). Welding deformation assessment and reduction are the major issues which need to be resolved since they will directly affect the overall contour of the Vacuum Vessel. In this paper, welding deformation finite element method (FEM) analysis of the 1/16 Vacuum Vessel was performed with ABAQUS based on the inherent strain theory. The welding shrinkage was compensated by reserving welding allowance, while the angular deformation was decreased by adding the restraints near the welds, as per analysis results. The welding deformation was finally measured by the laser tracker with fixed fiducial points distributed around the 1/16 Vacuum Vessel. The measurement results met the technical requirements and validated the FEM analysis, which can provide useful engineering instructions and guidelines for series production of Vacuum Vessel.
K Ioki - One of the best experts on this subject based on the ideXlab platform.
-
structural analysis of the iter Vacuum Vessel regarding 2012 iter project level loads
Fusion Engineering and Design, 2014Co-Authors: J. M. Martínez, G Sannazzaro, C. Sborchia, C.h. Choi, K Ioki, C Portafai, M Cambaza, Ph Corti, K Pinori, S SfarniAbstract:Abstract A revision of the ITER Project-Level Load Specification (to be used for all systems of the ITER machine) was implemented in April 2012. This revision supports ITER's licensing by accommodating requests from the French regulator to maintain consistency with the plasma physics database and our present understanding of plasma transients and electro-magnetic (EM) loads, to investigate the possibility of removing unnecessary conservatism in the load requirements and to review the list and definition of incidental cases. The purpose of this paper is to present the impact of this 2012 revision of the ITER Project-Level Load Specification (LS) on the ITER Vacuum Vessel (VV) loads and the main structural margins required by the applicable French code, RCC-MR.
-
status of the iter Vacuum Vessel construction
Fusion Engineering and Design, 2014Co-Authors: C.h. Choi, J. M. Martínez, C. Sborchia, X. Wang, Y Uti, K Ioki, P Teissie, Le R Arbie, S Dani, V ArabashAbstract:Abstract The ITER Vacuum Vessel (VV) is under manufacturing by four domestic agencies after completion of engineering designs that have been approved by the Agreed Notified Body (ANB). Manufacturing designs of the VV have been being completed, component by component, by accommodating requirements of the RCC-MR 2007 edition. Manufacturing of the VV first sector has been started in February 2012 in Korea and in-wall shielding in May 2013 in India. EU will start manufacturing of its first sector from September 2013 and Russia the upper port by the end of 2013. All DAs have manufactured several mock-ups including real-size ones to justify/qualify and establish manufacturing techniques and procedures.
-
final design of iter Vacuum Vessel thermal shield
Fusion Engineering and Design, 2013Co-Authors: Chang Hyu Noh, C.h. Choi, Y Uti, W Chung, Kwanwoo Nam, Dong Kwo Kang, Kyung O Kang, C Hamlynharris, K IokiAbstract:Abstract The final design of ITER Vacuum Vessel thermal shield (VVTS), which is planned to be procured completely by Korea, has been implemented after the procurement arrangement was signed. In this paper, the design and the supporting analysis are described for the key components of the VVTS such as joint, panel, support, and stopper. The VVTS design is revised and finalized based on the manufacturing feasibility, interface requirement and assemble feasibility. The inboard and the outboard supports of VVTS are designed in detail considering structural rigidity and assemble feasibility. The shape of in-pit joint, which is installed every 40° sector in toroidal direction for compensation of possible misalignment during sector assembly, is determined. Three types of joints are developed in accordance with their locations and assemble feasibilities are checked through the R&D. Stopper design is developed in order to prevent direct contact against adjacent components such as Vacuum Vessel and magnets. Structural rigidity of the whole VVTS is also validated by finite element analysis under various kinds of operating conditions, such as deadweight, electro-magnetic load, seismic load and load combinations.
-
progress of iter Vacuum Vessel
Fusion Engineering and Design, 2013Co-Authors: K Ioki, Y Gribov, C.h. Choi, E. Daly, C Kim, Angel Ayo, C Hamlynharris, S Dani, J Davis, E KuzmiAbstract:Abstract Design modifications were implemented in the Vacuum Vessel (VV) baseline design in 2011–2012 for finalization. The modifications are mostly due to interface components, such as support rails and feedthroughs for the in-Vessel coils (IVC). Manufacturing designs are being developed at the domestic agencies (DAs) based on the baseline design. The VV support design was also finalized and tests on scale mock-ups are under preparation. Design of the in-wall shielding (IWS) has progressed, considering the assembly methods and the required tolerances. Further modifications are required to be consistent with the DAs’ manufacturing designs. Dynamic tests on the inter-modular and stub keys to support the blanket modules are being performed to measure the dynamic amplification factor (DAF). An in-service inspection (ISI) plan has been developed and R&D was launched for ISI. Conceptual design of the VV instrumentation has been developed. The VV baseline design was approved by the agreed notified body (ANB) in accordance with the French Nuclear Pressure Equipment Order procedure.
-
Final design and start of manufacture of the ITER Vacuum Vessel ports
2013 IEEE 25th Symposium on Fusion Engineering (SOFE), 2013Co-Authors: Yu Utin, A. Alekseev, V Barabash, C. Sborchia, B. Giraud, J Davis, C. Choi, S. Fabritsiev, F. Geli, K IokiAbstract:The ITER Vacuum Vessel (VV) features upper, equatorial and lower ports. Although the port design has been overall completed in the past, the design of some remaining interfaces was still in progress and has been finalized now. As the ITER construction phase has started, the procurement of the VV ports has been launched. The VV upper ports will be procured by the Russian Federation DA, while the equatorial and lower ports will be procured by the Korean DA. The main industrial suppliers were selected and development of the manufacturing design is in progress now. Since the VV is classified at nuclear level N2, design and manufacture of its components are to be compliant with the French code RCC-MR and regulations of nuclear pressure equipment in France. These regulations make a strong impact to the port design and manufacturing process, which is in progress now.
L Jones - One of the best experts on this subject based on the ideXlab platform.
-
weld distortion prediction of the iter Vacuum Vessel using finite element simulations
Fusion Engineering and Design, 2013Co-Authors: Joa Caixas, L Jones, Andres Dans, Angel Ayo, J Guirao, Jean Francois Arbogas, Andrea Arbensi, Aldo Facca, Elena Fernandez, Jose Garcia M FernandezAbstract:Abstract The as-welded surfaces of the ITER Vacuum Vessel sectors need to be within a very tight tolerance, without a full-scale prototype. In order to predict welding distortion and optimize the manufacturing sequence, the industrial contract includes extensive computational simulations of the weld processes which can rapidly assess different sequences. The accurate shape prediction, after each manufacturing phase, enables actual distortions to be compared with the welding simulations to generate modified procedures and pre-compensate distortions. While previous mock-ups used heavy welded-on jigs to try to restrain the distortions, this method allows the use of lightweight jigs and yields important cost and rework savings. In order to enable the optimization of different alternative welding sequences, the simulation methodology is improved using condensed computation techniques with ANSYS in order to reduce computational resources. For each welding process, the models are calibrated with the results of coupons and mock-ups. The calibration is used to construct representative models of each segment and sector. This paper describes the application to the construction of the Vacuum Vessel sector of the enhanced simulation methodology with condensed Finite Element computation techniques and results of the calibration on several test pieces for different types of welds.
-
manufacturing preparations for the european Vacuum Vessel sector for iter
Fusion Engineering and Design, 2012Co-Authors: L Jones, Angel Ayo, Joa Caixas, Jean Francois Arbogas, Aldo Facca, A Ianchi, Gianbattista Fachi, Jose L Fernandez, Marcello Losasso, Thorste LoweAbstract:Abstract The contract for the seven European Sectors of the ITER Vacuum Vessel, which has very tight tolerances and high density of welding, was placed at the end of 2010 with AMW, a consortium of three companies. The start-up of the engineering, including R&D, design and analysis activities of this large and complex contract, one of the largest placed by F4E, the European Domestic Agency for ITER, is described. The statutory and regulatory requirements of ITER Organization and the French Nuclear Safety regulations have made the design development subject to rigorous controls. AMW was able to make use of the previous extensive R&D and prototype work carried out during the past 9 years, especially in relation to advanced welding and inspection techniques. The paper describes the manufacturing methodology with the focus on controlling distortion with predictions by analysis, avoiding use of welded-on jigs, and making use of low heat input narrow-gap welding with electron beam welding as far as possible and narrow-gap TIG when not. Further R&D and more than ten significant mock-ups are described. All these preparations will help to assure the successful manufacture of this critical path item of ITER.
-
a study of the influence of electron beam welding sequences on the iter Vacuum Vessel prototype vats
Fusion Engineering and Design, 2011Co-Authors: J Guirao, Angel Ayo, E Rodriguez, J L Cortizo, L JonesAbstract:Abstract This paper presents a detailed finite element simulation of the welds of the prototype Vessel Advanced Technology Segment (VATS) by electron-beam welding. The flexible support housings are reinforcing cylinders of the pressure boundary of the ITER Vacuum Vessel. They connect inner and outer shells. Eight different simulation sequences were carried out to explain the different mechanisms that drive the distortion process during welding and to lead to an optimum sequence which minimizes the final distortions. The simulations were used to guide the manufacture of the final sequence of the VATS.
-
design finalization and material qualification towards procurement of the iter Vacuum Vessel
Journal of Nuclear Materials, 2011Co-Authors: K Ioki, Y Gribov, G Johnso, C.h. Choi, V Arabash, J J Cordie, C Achma, P Chappuis, Ph Heitzenroede, L JonesAbstract:Abstract Procurement arrangements for ITER key components including the Vacuum Vessel (VV) have been signed and the ITER activities are now fully devoted towards construction. Final design reviews have been carried out for the main Vessel and ports. One of the design review topics is the selection of materials, material procurement, and assessment of material performance during operation. The width of the inner shell splice plates was increased from 120 mm to 160 mm to minimize risk during the assembly of the Thermal shields and the VV. Instead of facet shaping, 3D shaping was introduced for the outboard inner shell. The material qualification procedures have been started for VV structural materials such as 316L(N) IG for licensing as a nuclear pressure equipment component. In accordance with the regulatory requirements and quality requirements for operation, common material specifications have been prepared in collaboration with the domestic agencies.
-
iter Vacuum Vessel design and construction
Fusion Engineering and Design, 2010Co-Authors: K Ioki, Y Gribov, G Johnso, C.h. Choi, V Arabash, J J Cordie, C Achma, P Chappuis, Ph Heitzenroede, L JonesAbstract:Abstract After implementing a few design modifications (referred to as the “Modified Reference Design”) in 2009, the Vacuum Vessel (VV) design had been stabilized. The VV design is being finalized, including interface components such as support rails and feedthroughs for the in-Vessel coils. It is necessary to make adjustments to the locations of the blanket supports and manifolds to accommodate design modifications to the in-Vessel coils. The VV support design is also being finalized considering a structural simplification. Design of the in-wall shielding (IWS) has progressed, considering the assembly methods and the required tolerances. The detailed layout of ferritic steel plates and borated steel plates was optimized based on the toroidal field ripple analysis. A dynamic test on the inter-modular key to support the blanket modules was performed to measure the dynamic amplification factor (DAF). An R&D program has started to select and qualify the welding and cutting processes for the port flange lip seal. The ITER VV material 316 L(N) IG was already qualified and the Modified Reference Design was approved by the Agreed Notified Body (ANB) in accordance with the Nuclear Pressure Equipment Order procedure.
Xiaowei Xia - One of the best experts on this subject based on the ideXlab platform.
-
research on welding deformation of cfetr 1 16 Vacuum Vessel mockup
Fusion Engineering and Design, 2020Co-Authors: Xiaowei Xia, Zhihong LiuAbstract:Abstract The 1/16 prototype sector of China Fusion Engineering Test Reactor (CFETR) Vacuum Vessel is being manufactured by Institute of plasma physics, Chinese academy of sciences (ASIPP). Welding deformation assessment and reduction are the major issues which need to be resolved since they will directly affect the overall contour of the Vacuum Vessel. In this paper, welding deformation finite element method (FEM) analysis of the 1/16 Vacuum Vessel was performed with ABAQUS based on the inherent strain theory. The welding shrinkage was compensated by reserving welding allowance, while the angular deformation was decreased by adding the restraints near the welds, as per analysis results. The welding deformation was finally measured by the laser tracker with fixed fiducial points distributed around the 1/16 Vacuum Vessel. The measurement results met the technical requirements and validated the FEM analysis, which can provide useful engineering instructions and guidelines for series production of Vacuum Vessel.
-
welding technology development for the fabrication of Vacuum Vessel for cfetr
Fusion Engineering and Design, 2019Co-Authors: Zhihong Liu, Xiaowei Xia, Zhenfei Liu, Xu SheAbstract:Abstract The Vacuum Vessel (VV) is an important component in the Chinese Fusion Engineering Test Reactor (CFETR). Various welding methods have been applied in manufacturing of the VV. The electron beam welding (EBW) technique was applied in the fabrication of the port stubs of VV taking advantages of low welding deformation and capable of manufacturing full penetration welds of complex geometry with heavy thickness by a single pass. While narrow gap tungsten inert gas (NG-TIG) welding featuring wide application scope and high welding quality have been applied in the welding of 1/32 V V. Microstructure and mechanical properties of EB welded and NG-TIG welded 50-mm-thick 316 L are investigated. The EBW weld microstructure characterized by columnar and equiaxed ferrite in austenite while NG-TIG weld consisted of typical single austenite phase and a little δ-ferrite. Different solidification behaviour lead to different microstructures. Tensile tests, in line with microhardness results, demonstrated that higher strength in NG-TIG weld than base metal (BM). However, the impact absorbed energy in both EB and NG-TIG welded joints were lower than the BM. Besides, both welds exhibited excellent bending properties.
-
reverse engineering of cfetr Vacuum Vessel mockup
IEEE Transactions on Plasma Science, 2018Co-Authors: Zhihong Liu, Xiaowei XiaAbstract:The 1/32 subsector of China Fusion Engineering Test Reactor Vacuum Vessel mockup is fully penetration welded together with four poloidal segments (PSs) which are made by forming and welding, so that each PS needs to machine the welding grooves. However, the measurement results show that there are dimensional errors between the design model and each PS which has been made. This means that the welding grooves cannot be machined directly according to the design model. So, the method of reverse engineering is used to achieve the 3-D model of each PS which has been made. Based on this 3-D model, the model for CNC machining can be designed. At the same time, the machining equipment for PS is a three-coordinate CNC floor-type milling and boring machine which needs a datum plane when it is milling. Considering each PS has a complex surface profile, 3-D datum transformation is used for solving the problem of lacking the machining benchmark. At present, based on these two methods, the machining work of welding grooves for eight PSs has been completed which has met the requirements of assembly and welding.
-
weld distortion prediction of the cfetr Vacuum Vessel by inherent strain theory
Fusion Engineering and Design, 2017Co-Authors: Lei Xiu, Zhihong Liu, Xiaowei XiaAbstract:Abstract The CFETR (China Fusion Engineering Test Reactor) Vacuum Vessel sectors have high density welded joint, and as-welded size of the Vacuum Vessel is within a very tight tolerance, prediction of weld distortion is critical to allow the final assembly with the other components. Based on inherent strain theory, the weld distortion of the Vacuum Vessel can be predicted using the computer package ABAQUS. In this paper, calculation and application method of inherent strain on various welded joints is proposed. Six possible welding sequence schemes of the PS3 segment are provided within the actual processing condition, weld distortion of Vacuum Vessel on six welding sequence schemes is studied without external constraints condition, then according to the distortion value and distortion tendency without external constraints condition, the external constraints condition are provided. The optimal welding sequence can be obtained by the simulation result with external constraints condition, which can provide data support and theoretical guidance for the actual processing of the CFETR Vacuum Vessel.
Yuntao Song - One of the best experts on this subject based on the ideXlab platform.
-
design and analysis of lifting lugs and supporting platform for cfetr 1 8 Vacuum Vessel mock up
Fusion Science and Technology, 2020Co-Authors: Qingfeng Wang, Zhihong Liu, Sumei Liu, Peng Liu, Xi Mao, Yang Zhang, Che Liu, Jing Wei, Guang She, Yuntao SongAbstract:AbstractThe China Fusion Engineering Test Reactor (CFETR) is a new superconducting magnet tokamak. The Vacuum Vessel (VV) is one of the core components of the CFETR device, and it will provide a hi...
-
a feasibility study of cfetr 1 8 sector Vacuum Vessel mock up
Fusion Science and Technology, 2019Co-Authors: Yang Zhang, Zhihong Liu, Sumei Liu, Che Liu, Jing Wei, Guang She, Yuntao SongAbstract:AbstractThe Vacuum Vessel (VV), one of the important components for the Chinese Fusion Engineering Test Reactor (CFETR) superconducting magnet tokamak, can provide an ultrahigh Vacuum and clean environment for plasma operation. The CFETR VV was preliminarily designed to be a torus with a D-shaped cross section, eight upper vertical ports, eight equatorial ports, and eight lower ports. In order to verify the design and key technologies to be used in the future, a 1/8 VV sector mock-up has been designed and fabricated at the Institute of Plasma Physics, Chinese Academy of Sciences (abbreviated ASIPP). In this paper, the mock-up is used to demonstrate thick austenitic stainless steel plate hot forming, welding, cutting, part segment assembly, and other technologies and developments. The design considerations and criteria of the 1/8 sector mock-up are discussed in detail. Based on these considerations, the main design parameters and characteristics of the 1/8 VV sector mock-up are described, including the inn...
-
analytical analysis of the electromagnetic response for the Vacuum Vessel of east
Journal of Fusion Energy, 2016Co-Authors: Xufeng Liu, J P Zheng, Yuntao SongAbstract:During plasma disruptions and vertical displacement events (VDEs), time-varying eddy currents are induced on Vacuum Vessel (VV) and Plasma Facing Components (PFCs) of Tokamak. In this paper, we calculate eddy currents induced forces on VV and inner limiter (one of the PFC) during plasma disruption in Experimental Advanced Superconducting Tokamak (EAST). Various plasma transients—VDEs and major disruptions (MDs) are considered. And the study includes assessments of integral values (net vertical, hoop forces), time evolution, peaks of the force distribution. It is shown that the distribution pattern of the eddy currents for different scenarios differ greatly, therefore the resulting EMFs and torques cause different mechanical response.
-
structural modification and elastic analysis and limit analysis extrapolation in irregular sector 2 of global iter Vacuum Vessel
Journal of Fusion Energy, 2014Co-Authors: Zhire Luo, J. M. Martínez, X. Wang, Yuntao Song, S W Zhang, Yao YaoAbstract:The Vacuum Vessel is a vital component of the ITER facility, serving as a plasma Vacuum and safety barrier. Several structural modifications have been worked out to facilitate the manufacture and assembly, yet the structural strength needs to be assessed. By means of the finite element method theory, elastic analyses are performed to verify the modified design and compared to the one of previous design. Besides, an extrapolation of limit analysis is worked out to assist the verification. Based on the criterion of RCC-MR, the evaluated result demonstrates that the modified design satisfies the strength requirement and it is appropriate.
-
numerical analysis of md events and preliminary thermal calculation for ktx Vacuum Vessel
Fusion Engineering and Design, 2013Co-Authors: Shanshuang Shi, Yuntao Song, Qingxi Yang, Zhongwei Wang, Wandong Liu, W X Ding, Zhire Luo, J P ZhengAbstract:Abstract KTX is a new reversed field pinch (RFP) magnetic confinement device which is under design in ASIPP and USTC. Major disruption (MD) events may occur in future operating process, which is simulated with the finite element (FE) method. The results present that the peaks of eddy currents on Vessel and conductor shell are respectively 11.791 kA and 68.637 kA with maximum stress 67.1 MPa due to high transient electromagnetic (EM) force. It is confirmed that the structure is still strong enough to bear the electromagnetic loads even if the worst case. Besides, as KTX Vacuum Vessel will take the method of natural cooling for heat dissipation during plasma discharge (0.5–1.0 MA), a preliminary thermal calculation was implemented in normal condition to decide suitable time parameters such as duration and interval. It is suggested that the discharge interval should be no less than 5 min for the complete 1 MA plasma with 100 ms duration, which can guarantee the temperature of Vacuum Vessel below 200 °C.
