Controlling Research of the Pre-Bending Deformation before Straightening and Residual Stresses after Straightening for 100-Meter

2012 ◽  
Vol 572 ◽  
pp. 296-301
Author(s):  
Jian Guo Wang ◽  
Lin Chen ◽  
Tong Qing Li ◽  
Ge Li ◽  
Hai Yan Cui ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Boundary Conditions ◽  
Cross Section ◽  
Hot Rolling ◽  
Fem Simulation ◽  
Cooling Process ◽  
Nonlinear Fem ◽  
Bending Deformation ◽  
Good Accordance ◽  
Heavy Rail

Of hot rolling 100-meter heavy rail, the shrinkage masses or swell increments are different in different positions of transverse sections during the cooling process by the reason of profiled cross-section, which resulted in alternating bend, and the flatness and residual stresses are directly affected by bending deformation before straightening during the cooling process. In this paper, By studying the heat boundary conditions in cooling process, the regularity of bending deformation of hot rolling heavy rail during cooling is observed, adopting 3-D transient nonlinear FEM simulation. By controlling the deformation value of bending before straightening and the value after straightening, the influence of residual stresses after straightening from pre-bending values before straightening is analyzed, drawing a conclusion of the regularity that residual stresses are affected by different chord heights at the same straightening rule, and the calculated results have a good accordance with the real values in field scene.

Numerical Analysis and Simulation of the Straightening Process of Heavy Rails on a Horizontal Roller-Straightening Machine

2019 ◽  
Vol 946 ◽  
pp. 775-781
Author(s):  
E.V. Timakov ◽  
F.S. Dubinskiy
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Hot Rolling ◽  
Input Data ◽  
Experimental Tests ◽  
Cooling Process ◽  
Horizontal Roller ◽  
Initial Camber ◽  
Heavy Rail

In this paper, the ABAQUS is adopted to carry on numerical simulation on straightening process of R65 heavy rail. The straightening process has been simulated here using the FE package of ABAQUS. All the input data were extracted from experimental tests according to tail manufacturing. Moreover, initial camber of the rail was measured after hot rolling and cooling process.

Bending Deformation of U75V Heavy Rail through Natural Cooling Process

2012 ◽  
Vol 190-191 ◽  
pp. 1244-1248
Author(s):  
Hua Song ◽  
Shan Hu Tong ◽  
Juan Juan Jiang ◽  
Hao Jia ◽  
Si Yu Yuan ◽  
...  
Keyword(s):  
High Speed ◽  
Theoretical Foundation ◽  
Reference Value ◽  
The Finite Element Method ◽  
Cooling Process ◽  
Bending Deformation ◽  
Technical Parameters ◽  
Chain Transmission ◽  
Heavy Rail ◽  
Cooling Model

The cooling process of heavy rail is the important step to the output, that the preflexed rail is cooled on the stepping-type cold bed which has been carried by the chain transmission device. We employed the finite element method to analyze the bending deformation of the U75V rail through natural cooling process, the effected factors including the rail side-laying on the cold bed, the latent heat of phase change, and the thermal radiation are considered in the analysis. In the paper, we discussed the establishment of the heavy rail cooling model, the cooling parameters and the boundary condition, and emphatically analyzed the rail bending deformation changes and its principles through the cooling process. The study of the hundred-meter high speed heavy rail can provide the theoretical foundation and reference value to the formulation of cooling technical parameters and preflex technical schedule.

ANALYSIS OF 100-METER RAIL TEMPERATURE FIELD DURING COOLING PROCESS BEFORE STRAIGHTENING BY FEM

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1203-1208 ◽  
Author(s):  
GE LI ◽  
HAIYAN CUI ◽  
LIN CHEN
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Solid State ◽  
Phase Change ◽  
Cross Section ◽  
Physical Parameters ◽  
Cooling Process ◽  
Bending Deformation

The straightness of the 100-meter rail after straightening is directly affected by the bending deformation during cooling before straightening, and the analysis of the temperature field in the cooling process is the basis of studying the bending deformation. By analyzing the heat boundary conditions in the cooling process, the temperature field was calculated and its variable law was analyzed by using the 3-D transient non-liner finite element method. The factors such as the solid-state phase change and the physical parameters with change of the temperature were considered, and the numerical results were coincident with the experimental data. The results show that the velocities of temperature changing at different positions of the rail's cross-section are different in the cooling progress, and the phase change and the irregular cross-section of rail are important influencing factors.

scholarly journals 3D-FEM Simulation of Hot Rolling Process and Characterization of the Resultant Microstructure of a Light-Weight Mn Steel

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 569
Author(s):  
Ana Claudia González-Castillo ◽  
José de Jesús Cruz-Rivera ◽  
Mitsuo Osvaldo Ramos-Azpeitia ◽  
Pedro Garnica-González ◽  
Carlos Gamaliel Garay-Reyes ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Thermomechanical Processing ◽  
Computational Simulation ◽  
Effective Strain ◽  
Fem Simulation ◽  
Rolling Process ◽  
3D Fem ◽  
Hot Rolling Process ◽  
Mn Steel

Computational simulation has become more important in the design of thermomechanical processing since it allows the optimization of associated parameters such as temperature, stresses, strains and phase transformations. This work presents the results of the three-dimensional Finite Element Method (FEM) simulation of the hot rolling process of a medium Mn steel using DEFORM-3D software. Temperature and effective strain distribution in the surface and center of the sheet were analyzed for different rolling passes; also the change in damage factor was evaluated. According to the hot rolling simulation results, experimental hot rolling parameters were established in order to obtain the desired microstructure avoiding the presence of ferrite precipitation during the process. The microstructural characterization of the hot rolled steel was carried out using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the phases present in the steel after hot rolling are austenite and α′-martensite. Additionally, to understand the mechanical behavior, tensile tests were performed and concluded that this new steel can be catalogued in the third automotive generation.

Fem Simulation of Micro-Rotating-Structures and Their Applications in Measurement of Residual Stresses in Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Xin Zhang ◽  
Tong-Yi Zhang ◽  
Yitshak Zohar
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Fem Simulation ◽  
Sensitivity Factor ◽  
Local Measurement ◽  
Micro Structure ◽  
Micro Raman Spectroscopy ◽  
Before And After ◽  
Polysilicon Films ◽  
Simulation Results

ABSTRACTFEM simulation of micro-rotating-structures was performed for local measurement of residual stresses in thin films. A sensitivity factor is introduced, studied and tabulated from the simulation results. The residual stress can be evaluated from the rotating deflection, the lengths of rotating and fixed beams, and the sensitivity factor. The micro-structure technique was applied to measure residual stresses in both silicon nitride and polysilicon thin films, before and after rapid thermal annealing (RTA), and further confirmed by wafer curvature method. Residual stresses in polysilicon films at different RTA stages were also characterized by micro-Raman spectroscopy (MRS). The experimental results indicate that micro-rotating-structures indeed have the ability to measure spatially and locally residual stresses in MEMS thin films with appropriate sensitivities.

Finite Element Simulation of Laser Beam Welding Induced Residual Stresses and Distortions in a T-Joint Configuration for Aeronautic Structures

2009 ◽  
Author(s):  
Muhammad Zain-ul-abdein ◽  
Daniel Ne´lias ◽  
Jean-Franc¸ois Jullien ◽  
Dominique Deloison
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Laser Beam ◽  
Boundary Conditions ◽  
Laser Beam Welding ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Small Scale ◽  
Joint Configuration ◽  
Simulation Results

Laser beam welding has found its application in the aircraft industry for the fabrication of fuselage panels in a T-joint configuration. However, the inconveniences like distortions and residual stresses are inevitable consequences of welding. The effort is made in this work to experimentally measure and numerically simulate the distortions induced by laser beam welding of a T-joint with industrially used thermal and mechanical boundary conditions on the thin sheets of aluminium 6056-T4. Several small scale experiments were carried out with various instrumentations to establish a database necessary to verify the simulation results. Finite element (FE) simulation is performed with Abaqus and the conical heat source is programmed in FORTRAN. Heat transfer analysis is performed to achieve the required weld pool geometry and temperature fields. Mechanical analysis is then performed with industrial loading and boundary conditions so as to predict the distortion and the residual stress pattern. A good agreement is found amongst the experimental and simulation results.

scholarly journals Validation of Welding Simulations Using Thermal Strains Measured with DIC

2011 ◽  
Vol 70 ◽  
pp. 129-134 ◽  
Author(s):  
Maarten De Strycker ◽  
Pascal Lava ◽  
Wim Van Paepegem ◽  
Luc Schueremans ◽  
Dimitri Debruyne
Keyword(s):  
Residual Stresses ◽  
Cross Section ◽  
Circular Cross Section ◽  
Welding Process ◽  
Weld Bead ◽  
Image Correlation ◽  
Steel Tubes ◽  
Element Analysis ◽  
Strain Evolution ◽  
The Cross

Residual stresses can affect the performance of steel tubes in many ways and as a result their magnitude and distribution is of particular interest to many applications. Residual stresses in cold-rolled steel tubes mainly originate from the rolling of a flat plate into a circular cross section (involving plastic deformations) and the weld bead that closes the cross section (involving non-uniform heating and cooling). Focus in this contribution is on the longitudinal weld bead that closes the cross section. To reveal the residual stresses in the tubes under consideration, a finite element analysis (FEA) of the welding step in the production process is made. The FEA of the welding process is validated with the temperature evolution of the thermal simulation and the strain evolution for the mechanical part of the analysis. Several methods for measuring the strain evolution are available and in this contribution it is investigated if the Digital Image Correlation (DIC) technique can record the strain evolution during welding. It is shown that the strain evolution obtained with DIC is in agreement with that found by electrical resistance strain gauges. The results of these experimental measuring methods are compared with numerical results from a FEA of the welding process.

Stress Distribution in a Uniformly Rotating Equilateral Triangular Shaft

1955 ◽  
Vol 22 (2) ◽  
pp. 255-259
Author(s):  
H. T. Johnson
Keyword(s):  
Approximate Solution ◽  
Stress Distribution ◽  
Boundary Conditions ◽  
Plane Strain ◽  
Cross Section ◽  
Plane Stress ◽  
Biharmonic Equation ◽  
Approximate Solutions ◽  
Distribution Of Stresses ◽  
General Method

Abstract An approximate solution for the distribution of stresses in a rotating prismatic shaft, of triangular cross section, is presented in this paper. A general method is employed which may be applied in obtaining approximate solutions for the stress distribution for rotating prismatic shapes, for the cases of either generalized plane stress or plane strain. Polynomials are used which exactly satisfy the biharmonic equation and the symmetry conditions, and which approximately satisfy the boundary conditions.

Optimization of Flexible Pipes Dynamic Analysis Using Artificial Neural Networks

2016 ◽  
Author(s):  
Victor Chaves ◽  
Luis V. S. Sagrilo ◽  
Vinícius Ribeiro Machado da Silva
Keyword(s):  
Dynamic Analysis ◽  
Fem Simulation ◽  
Training Data ◽  
Local Analysis ◽  
Flexible Pipe ◽  
Nonlinear Fem ◽  
Irregular Wave ◽  
Flexible Pipes ◽  
Artificial Neural ◽  
Hybrid Methodology

Irregular wave dynamic analysis is an extremely computational expensive process on flexible pipes design. One emerging method that aims to reduce these computational costs is the hybrid methodology that combines Finite Element Analyses (FEA) and Artificial Neural Network (ANN). The proposed hybrid methodology aims to predict flexible pipe tension and curvatures in the bend stiffener region. Firstly using short FEA simulations to train the ANN, and then using only the ANN and the prescribed floater motions to get the rest of the response histories. Two approaches are developed with respect to the training data. One uses an ANN for each sea state in the wave scatter diagram and the other develops an ANN for each wave incidence direction. In order to evaluate the accuracy of the proposed approaches, a local analysis is applied, based on the predicted tension and curvatures, to calculate stresses in tension armour wires and the corresponding flexible pipe fatigue lifes. The results are compared to those from full nonlinear FEM simulation.

scholarly journals The effect of surface plastic hardening technology, residual stresses and boundary conditions on the buckling of a beam

2020 ◽  
pp. 87-98
Author(s):  
V P Radchenko ◽  
O S Afanaseva ◽  
V E Glebov
Keyword(s):  
Residual Stresses ◽  
Boundary Conditions ◽  
Hardened Layer ◽  
Surface Plastic ◽  
Straight Line ◽  
Calculated Profile ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Plastic Hardening ◽  
Initial Strains

The complex influence of the surface plastic hardening technology, residual stresses, and boundary conditions on the bending of a hardened beam of EP742 alloy was performed. A phenomenological method of restoring the fields of residual stress and plastic deformations performed by its experimental verification in the particular case of ultrasonic hardening is given. The correspondence of the calculated and experimental data for the residual stresses is observed. For assess the influence of the formed residual stresses on convex cylinders, the calculation methods are used for initial strains based on using analogies between the initial (residual) plastic strains and temperature strains in an inhomogeneous temperature field. This allowed us to reduce the consideration of the problem to the problem of thermoelasticity, which was further solved by numerical methods. The effect of four types of boundary conditions for fixing the ends of the beams (rigid fastening and articulation of the ends and ribs in various combinations, cantilever) on the shape and size of the bending of the beam 10×10×100 mm after ultrasonic hardening is studied in detail. It was found that the minimum deflection is observed with a hard seal of both ends of the beam. The effect of the thickness of the beam, which varied from 2 to 10 mm, on their buckling under the same distribution of residual stresses in the hardened layer was studied, and the nonlinear nature of the increase in the deflection boom with decreasing thickness for all types of boundary conditions was established. It is shown that under all boundary conditions, the curvature along the length of the beam practically does not change, therefore it can be considered constant. The consequence of this is the preservation of the hypothesis of flat sections after the hardening procedure, which is confirmed by the calculated profile of the beam section in plane symmetry, close to a straight line. The influence of the anisotropy of surface plastic hardening on the buckling of the beam was found to be significant, which can serve as the basis for choosing the optimal hardening procedure. The performed parametric analysis of the task is presented in the form of graphical and tabular information on the results of the calculations.

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