Research on forming precision of flexible rolling method for three-dimensional surface parts through simulation

2014 ◽  
Vol 71 (9-12) ◽  
pp. 1717-1727 ◽  
Author(s):  
Daming Wang ◽  
Mingzhe Li ◽  
Zhongyi Cai
Keyword(s):  
Three Dimensional ◽  
Flexible Rolling ◽  
Forming Precision ◽  
Rolling Method ◽  
Dimensional Surface

Development of Flexible Rolling Device for 3D Plate

2012 ◽  
Vol 271-272 ◽  
pp. 852-857
Author(s):  
Ren Jun Li ◽  
Ming Zhe Li ◽  
Ning Jia Qiu
Keyword(s):  
Research And Development ◽  
Sheet Metal ◽  
Three Dimensional ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flexible Rolling ◽  
Design Scheme ◽  
Working Principle ◽  
Conventional Rolling ◽  
Dimensional Surface

To effectively form three-dimensional sheet metal parts with various curvatures produced in small quantities, flexible rolling forming, a new flexible forming method is being developed. Firstly, concept of the flexible rolling forming is introduced and its characteristics and working principle are analyzed by the combination of conventional rolling and multi-point forming. Secondly, the equipment design scheme of flexible rolling forming is put forward and the relevant device is developed. Thirdly, the feasibility and practicality of flexible rolling forming are verified by rolling several typical three-dimensional surface parts such as spherical and saddle surface parts by self-developed device. Finally, verifies the reasonableness of the device and at the same time possesses the important guiding significance to the research and development of practical flexible rolling forming equipment.

Enhancement of Heat Transfer Performance in Nuclear Fuel Rod Using Nanofluids and Surface Roughness Technique

2015 ◽  
Author(s):  
Kang Liu ◽  
Titan C. Paul ◽  
Leo A. Carrilho ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Nuclear Fuel ◽  
Three Dimensional ◽  
Pressurized Water ◽  
Bulk Fluid ◽  
Fuel Rod ◽  
Dimensional Surface

The experimental investigations were carried out of a pressurized water nuclear reactor (PWR) with enhanced surface using different concentration (0.5 and 2.0 vol%) of ZnO/DI-water based nanofluids as a coolant. The experimental setup consisted of a flow loop with a nuclear fuel rod section that was heated by electrical current. The fuel rod surfaces were termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (diamond shaped blocks). The variation in temperature of nuclear fuel rod was measured along the length of a specified section. Heat transfer coefficient was calculated by measuring heat flux and temperature differences between surface and bulk fluid. The experimental results of nanofluids were compared with the coolant as a DI-water data. The maximum heat transfer coefficient enhancement was achieved 33% at Re = 1.15 × 105 for fuel rod with three-dimensional surface roughness using 2.0 vol% nanofluids compared to DI-water.

scholarly journals DISCRETE AND CONTINUUM APPROACHES TO THREE-DIMENSIONAL QUANTUM GRAVITY

1991 ◽  
Vol 06 (39) ◽  
pp. 3591-3600 ◽  
Author(s):  
HIROSI OOGURI ◽  
NAOKI SASAKURA
Keyword(s):  
Gauge Theory ◽  
Moduli Space ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Analogue Model ◽  
Gauge Invariant ◽  
Invariant Functions ◽  
Dimensional Lattice ◽  
Chern Simons ◽  
Dimensional Surface

It is shown that, in the three-dimensional lattice gravity defined by Ponzano and Regge, the space of physical states is isomorphic to the space of gauge-invariant functions on the moduli space of flat SU(2) connections over a two-dimensional surface, which gives physical states in the ISO(3) Chern–Simons gauge theory. To prove this, we employ the q-analogue of this model defined by Turaev and Viro as a regularization to sum over states. A recent work by Turaev suggests that the q-analogue model itself may be related to an Euclidean gravity with a cosmological constant proportional to 1/k2, where q=e2πi/(k+2).

scholarly journals Exceptional Mechanical Properties and Heat Resistance of Photocurable Bismaleimide Ink for 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1708
Author(s):  
Wenqiang Hua ◽  
Qilang Lin ◽  
Bo Qu ◽  
Yanyu Zheng ◽  
Xiaoying Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Heat Resistance ◽  
Three Dimensional ◽  
Mechanical And Thermal Properties ◽  
Amino Group ◽  
Building Models ◽  
Fast Processing ◽  
Forming Precision ◽  
Complex Structural

Photosensitive resins used in three-dimensional (3D) printing are characterized by high forming precision and fast processing speed; however, they often possess poor mechanical properties and heat resistance. In this study, we report a photocurable bismaleimide ink with excellent comprehensive performance for stereolithography (SLA) 3D printing. First, the main chain of bismaleimide with an amino group (BDM) was synthesized, and then, the glycidyl methacrylate was grafted to the amino group to obtain the bismaleimide oligomer with an unsaturated double bond. The oligomers were combined with reaction diluents and photo-initiators to form photocurable inks that can be used for SLA 3D printing. The viscosity and curing behavior of the inks were studied, and the mechanical properties and heat resistance were tested. The tensile strength of 3D-printed samples based on BDM inks could reach 72.6 MPa (166% of that of commercial inks), glass transition temperature could reach 155 °C (205% of that of commercial inks), and energy storage modulus was 3625 MPa at 35 °C (327% of that of commercial inks). The maximum values of T-5%, T-50%, and Tmax of the 3D samples printed by BDM inks reached 351.5, 449.6, and 451.9 °C, respectively. These photocured BDM inks can be used to produce complex structural components and models with excellent mechanical and thermal properties, such as car parts, building models, and pipes.

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