Study on the cavity closure behavior of steel ingots during open die forging

Author(s):  
Yongchul Kwon ◽  
Sangsik Kim ◽  
Jonghun Kang

The manufacturing of sound forgings from large steel ingots requires that internal cavity defects generated during the steel ingot solidification process be compressed by open die forging. The forging ratio that is generally recommended to remove internal defects in large forged products is 3S (threefold); however, the practice lacks a theoretical basis. In this study, a forging experiment and a finite element analysis were performed to investigate the correlation between the forging ratio for large steel ingots (3S) and the cavity closure behavior. First, a hot compression experiment was performed by varying the temperature and strain rate, and the flow stress data observed in the experiment was applied to the finite element analysis. In the experiment for the cogging process, the forging ratio was applied to an actual non-compressive defect material. The finite element analysis was performed using the same forging path as the forging experiment. In the cogging experiment, cavity closure was found by ultrasonic inspection at the forging ratio of 2.9S. The finite element analysis showed that the size of the cavity was significantly decreased at the forging ratio of 2.9S. A finite element analysis was also performed to investigate effective strain and hydrostatic stress at the forging ratio of 2.9S. Finally, this article provides the theoretical basis for the limitation of the internal defect size in initial materials, the threshold effective strain, and the limiting forging ratio of forged products to ensure the internal soundness of large forged products.

2021 ◽  
Vol 2125 (1) ◽  
pp. 012047
Author(s):  
Xiaozhu Wang ◽  
Jian Zhang

Abstract In this paper, a new rotating standing wave ultrasonic motor with multiple driving teeth is proposed. Using the method of adding additional teeth, the correction of the B06 surface of the ultrasonic motor vibrator is expected, the design of the optimum position of the drive tooth is realized. At the same time, a method of reducing the stiffness of the rotor is proposed, and the flexibility is met, the integrated design of the rotor and the pressure device can be realized by removing the disc spring. The accuracy of the finite element analysis is verified by the vibration test of the prototype oscillator. The finite element analysis of the main structure parameters of the influence oscillator mode and natural frequency is carried out. It provides theoretical basis for the design and machining of vibration.


Author(s):  
Gao-Lian Liu

The untwist of rotating blades in turbomachines treated so far in the literatare simply as a pure elasticity problem is generalized and formulated rigorously as a problem of aeroelasticity by variational principles (VPs) and generalized VP (GVP). It takes into account not only the centrifugal force, but also the aeroelastic interaction between blades and the flow as well as the elastic distortion of the cross section shape of blades, assuming the material to be linearly elastic but nonisotropic. Thus, a new rigorous theoretical basis for the finite element analysis of blade untwist in turbomachine design is provided.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1591-1596 ◽  
Author(s):  
YO-HAN JI ◽  
JONG-JIN PARK ◽  
CHANG-HO MOON ◽  
MYUNG-SHIK CHUN ◽  
HAE-DOO PARK

Plastic deformation that occurs in a heavy slab during plane-strain rolling was investigated by the finite element analysis. A cylindrical pore was assumed to be located along the transverse direction of a slab. The effective strain was found to be the largest at the sub-surface layer and the smallest at the middle layer, where the shear strain developed the least. Pore closure was most difficult at the middle layer. This is where hydrostatic stress in addition to effective strain developed the least. Rolling torques, rolling forces and pressure distributions at the roll/slab interface were investigated as well, under various conditions.


2011 ◽  
Vol 347-353 ◽  
pp. 1276-1280
Author(s):  
Hong Liang Hu ◽  
Rui Jie Wang ◽  
Chun Ling Meng ◽  
Guo Feng Li

Abstract. Combining characteristic of the Wind Tturbines's rotary support, using finite element method, the paper probe the rotary support finite element analysis of static and modal analysis. Through the static analysis of the rotary support, receiving the deformation and stress-strain results; through modal analysis,receiving the 6-order natural frequency and vibration shape.Analyzing of the main failure forms and Dynamic performance ,the results provide a theoretical basis of improvement of the design and to finalize the program.


2011 ◽  
Vol 311-313 ◽  
pp. 1370-1374
Author(s):  
Ju An Zhang ◽  
Zhi Qiang Guo ◽  
Jin Fa Xie

Based on the tool of the ANSYS Workbench software, the modeling of three-dimensional Entity, meshing and dealing of loads and constraints has been done on the pipelayer’boom. According to the finite element analysis of pipelayer’boom in three basic conditions by the parameter of width, height and thickness, the material consumption of making boom is significantly reduced. All this is done in the premise of ensuring the safety of pipelayer’ boom with the objective of minimizing the quality by the finite element optimization. And the results will be the theoretical basis of the design and improvement of Pipelayer’ boom.


2015 ◽  
Vol 661 ◽  
pp. 62-68
Author(s):  
Dyi Cheng Chen ◽  
Ci Syong You ◽  
Chia An Tu ◽  
Chieh Hsin Ni

In this paper, construction of finite element analysis based on DEFORMTM 3D four-blade face milling cutter aluminum 6061 cutting, explore the finite element analysis of face milling cutter rotating in a circle cutting of aluminum alloy 6061.Tool types used WC milling cutters, cutting speed, feed rate as fixed process parameters. The study analyzed four rotations of the blade face milling chip formation, effective stress, effective strain and material changes in temperature and tool wear.


1985 ◽  
Vol 13 (3) ◽  
pp. 127-146 ◽  
Author(s):  
R. Prabhakaran

Abstract The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


2018 ◽  
Vol 55 (4) ◽  
pp. 666-675
Author(s):  
Mihaela Tanase ◽  
Dan Florin Nitoi ◽  
Marina Melescanu Imre ◽  
Dorin Ionescu ◽  
Laura Raducu ◽  
...  

The purpose of this study was to determinate , using the Finite Element Analysis Method, the mechanical stress in a solid body , temporary molar restored with the self-curing GC material. The originality of our study consisted in using an accurate structural model and applying a concentrated force and a uniformly distributed pressure. Molar structure was meshed in a Solid Type 45 and the output data were obtained using the ANSYS software. The practical predictions can be made about the behavior of different restorations materials.


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