scholarly journals Theoretical Analysis of the Influence of Longitudinal Stress Changes on Band Dimensions During Continuous Rolling Process

2016 ◽  
Vol 61 (1) ◽  
pp. 183-188 ◽  
Author(s):  
P. Sygut ◽  
D. Klimecka–Tatar ◽  
S. Borkowski
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Rolling Direction ◽  
Rolling Process ◽  
Longitudinal Stress ◽  
Continuous Rolling ◽  
Nonuniform Temperature ◽  
Engineering Data ◽  
Stress Changes ◽  
Dimension Change

The paper presents the results of studies on the effect of nonuniform temperature distribution over the length of feedstock on the variation of longitudinal stresses in the rolling direction and band dimension change during the continuous rolling process. The studies were performed based on actual engineering data for a 160x160 mm square cross-section feedstock of steel S355J0. Numerical modelling of the rolling process was performed using Forge 2008®, a finite-element based computer program. Thermovision measurements and bars geometrical dimension changes were carried out in a domestic steelworks.

Research on the Color Difference on Surface of 3104 Aluminum Alloy Stripes during Cold Continuous Rolling Process

2012 ◽  
Vol 557-559 ◽  
pp. 1383-1386
Author(s):  
Jian Lin Sun ◽  
Guo Hong Ding ◽  
Lei Xia ◽  
Bing Yun ◽  
Ze Sheng Ji
Keyword(s):  
Aluminum Alloy ◽  
Rolling Direction ◽  
Surface Profile ◽  
Color Difference ◽  
Rolling Process ◽  
Aluminum Surface ◽  
Water Mixture ◽  
Continuous Rolling ◽  
Micro Cracks ◽  
Oil Water

Color difference on surface of aluminum alloy stripes when lubricated with oil-water mixtures in cold continuous rolling process was researched. The surface profile, 3D and micro morphology were observed by surface surface profiler, laser scanning confocal microscopeand scanning electron microscope. The chemical composition of aluminum surface was analyzed by X-ray energy dispersive spectrometer, and then the formation mechanism of color difference was studied. The results indicate that lubricated with oil-water mixture, oil and water can't mix sufficiently and lubrication failure was found in deformation zone because of lubrication oil shortage. Working roller and fresh surface of stripes contacted directly and leaded to adhesive, so lots of irregular shaped micro-cracks were found after rolling, the residual composition of oil-water mixture adsorbed in the micro-cracks and not easy to be cleaned up, so the organic matter of residue composition carbonized and manifested as color difference in the visible. The fringes of color difference are distributed approximately along the rolling direction and the average roughness was very nearly the same between different kinds of fringes.

scholarly journals Optimization design of curved outrigger structure based on buckling analysis and multi-island genetic algorithm

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110232
Author(s):  
Zhi-Hai Liu ◽  
Shao-Lu Tian ◽  
Qing-Liang Zeng ◽  
Kui-Dong Gao ◽  
Xin-Long Cui ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Optimization Design ◽  
Structural Parameters ◽  
Stiffened Plate ◽  
Element Analysis ◽  
Stress Changes ◽  
Element Method

In the present work, the working state of the crane leg is analyzed and discussed, and its structure is optimized. SolidWorks software is used for modeling; ANSYS software is used for finite element analysis. First of all, the constrained finite element method (CFEM) is used to analyze the linear eigenvalue buckling and geometric nonlinear buckling of outriggers with different cross-section shapes. Prove that the curved leg has certain advantages in buckling. At the same time, analyzing the leg along a different path of buckling condition and stress changes provide the basis for the design of the subsequent reinforcement. After selecting the best cross-section shape of the outrigger, the agent-based multi-island genetic algorithm is used to optimize the structural parameters of the outrigger under the transverse stiffened plate reinforced structure and the longitudinally stiffened plate reinforced structure respectively. It is proved that the outrigger with the transverse stiffened plate has a significant effect in improving the bearing capacity and in the lightweight of the structure. Finally, the gap between the movable leg and the fixed leg was changed, the stress of different gaps was analyzed by using the finite element method, and the appropriate gap value was selected according to the high-order fitting curve.

Morphology Change of Extrusion Molded Crystalline Polymer by Rolling Process

2011 ◽  
Vol 391-392 ◽  
pp. 595-599 ◽  
Author(s):  
Takuya Murata ◽  
Jian Hui Qiu ◽  
Eiichi Sakai ◽  
Xue Li Wu ◽  
Makoto Kudo
Keyword(s):  
Internal Structure ◽  
Cross Section ◽  
Molecular Orientation ◽  
Rolling Direction ◽  
Crystalline Polymer ◽  
Dimensional Change ◽  
Rolling Process ◽  
Spring Back ◽  
Structure And Morphology ◽  
High Reduction

In this work, the spring back, dimensional change, internal structure and morphology of extruded polypropylene were investigated in order to consider the rolling characteristic. It was found that the internal structure, molecular orientation and crystallinity were changed a little by high spring back under low reduction in thickness. Crystal structure was extended along the rolling direction with high reduction in thickness due to the increase of plastic deformation. As a result, molecular orientation increased and crystallinity decreased at over 30% of reduction in thickness. Crystalline structure of surface was similar to the center part in cross-section at 70% reduction in thickness, and molecular orientation was constant.

Controlled Residual Stress Research of H-Beam

2014 ◽  
Vol 898 ◽  
pp. 237-240
Author(s):  
Jin Hong Ma ◽  
Xiao Han Yao ◽  
Bin Tao ◽  
Shuo Li
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Temperature Difference ◽  
Uniform Elongation ◽  
Rolling Process ◽  
Controlled Rolling ◽  
Continuous Rolling ◽  
Element Analysis ◽  
Finite Element Software ◽  
H Beam

Because of the residual stress of H-beam after hot rolling, the service performance of H-beam is seriously impacted. it is necessary to reduce the residual stress by controlled rolling and cooling process. In this paper, a continuous rolling model of finish product of H200 x 200 x 8 x 12 is set up. The continuous rolling process of H-beam was simulated using the large finite element software ANSYS/LS-DYNA. The effect of non-uniform elongation of web with flange and section temperature difference on the residual stress are analyzed. Through metallographic observations, the vary microstructure of rolling piece with residual stress and with no residual stress is analyzed. As can be seen from the finite element analysis and the experimental results, reasonable elongation of flange and web and controlling cooling speed to decrease the sectional temperature difference can reduce the residual stress of H-beam.

First and Second Order Elastoplastic Analyses of Thin-Walled Metal Members using Generalized Beam Theory

2018 ◽  
Author(s):  
Miguel Abambres
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Cross Section ◽  
Beam Theory ◽  
Second Order ◽  
Flow Rule ◽  
Non Linear ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalized Beam Theory

Original Generalized Beam Theory (GBT) formulations for elastoplastic first and second order (postbuckling) analyses of thin-walled members are proposed, based on the J2 theory with associated flow rule, and valid for (i) arbitrary residual stress and geometric imperfection distributions, (ii) non-linear isotropic materials (e.g., carbon/stainless steel), and (iii) arbitrary deformation patterns (e.g., global, local, distortional, shear). The cross-section analysis is based on the formulation by Silva (2013), but adopts five types of nodal degrees of freedom (d.o.f.) – one of them (warping rotation) is an innovation of present work and allows the use of cubic polynomials (instead of linear functions) to approximate the warping profiles in each sub-plate. The formulations are validated by presenting various illustrative examples involving beams and columns characterized by several cross-section types (open, closed, (un) branched), materials (bi-linear or non-linear – e.g., stainless steel) and boundary conditions. The GBT results (equilibrium paths, stress/displacement distributions and collapse mechanisms) are validated by comparison with those obtained from shell finite element analyses. It is observed that the results are globally very similar with only 9% and 21% (1st and 2nd order) of the d.o.f. numbers required by the shell finite element models. Moreover, the GBT unique modal nature is highlighted by means of modal participation diagrams and amplitude functions, as well as analyses based on different deformation mode sets, providing an in-depth insight on the member behavioural mechanics in both elastic and inelastic regimes.

Determination of collapse moment of different angled pipe bends with initial geometric imperfection subjected to in-plane bending moments

2021 ◽  
pp. 095440622199640
Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Circular Cross Section ◽  
Initial Imperfection ◽  
Bend Angle ◽  
Bending Moments ◽  
Element Analysis ◽  
Geometric Imperfection ◽  
Initial Geometric Imperfection

From the recent literature, it is revealed that pipe bend geometry deviates from the circular cross-section due to pipe bending process for any bend angle, and this deviation in the cross-section is defined as the initial geometric imperfection. This paper focuses on the determination of collapse moment of different angled pipe bends incorporated with initial geometric imperfection subjected to in-plane closing and opening bending moments. The three-dimensional finite element analysis is accounted for geometric as well as material nonlinearities. Python scripting is implemented for modeling the pipe bends with initial geometry imperfection. The twice-elastic-slope method is adopted to determine the collapse moments. From the results, it is observed that initial imperfection has significant impact on the collapse moment of pipe bends. It can be concluded that the effect of initial imperfection decreases with the decrease in bend angle from 150∘ to 45∘. Based on the finite element results, a simple collapse moment equation is proposed to predict the collapse moment for more accurate cross-section of the different angled pipe bends.

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