Mathematical Modelling and Finite Element Simulation of Pre-Bending Stage of Three-Roller Plate Bending Process

Author(s):  
A. H. Gandhi ◽  
H. V. Gajjar ◽  
H. K. Raval

Continuous three roller bending process is widely used in practice to bend the plates into cylinders. Bending load for plate material under bending is affected by plate thickness, width and shell diameter combinations. Maximum top roller load is encountered during the edge pre-bending stage as top roller is set at an offset distance from its mid position. Shell diameter, thickness and material for cylindrical structural element to be produced are fixed by design. Width of the plate for roller bending decides number of cylindrical segments required to achieve the designed shell length. Maximum pre-bending width depends on maximum top roller load imparting capacity. Looking to the above considerations, maximum width which can be pre-bend at limiting top roller load (for designed shell diameter, thickness and material combinations) specifies the capacity. Presented work aims at developing the mathematical model of top roller load for pre-bending. Top roller offset for pre-bending were calculated based on practical top roller pre-bending load data, for different grades of C-Mn steel plates (as per ASME sec II part-A). Based on these top roller offsets, finite element analysis (FEA) of pre-bending stage were performed using Hyperform LS-DYNA. Effect of co-efficient of friction at roller plate interfaces was analyzed. FE simulation of pre-bending of cladded plate (54 mm thick C-Mn steel plate of material grade SA-387Gr11Cl2 having 3 mm thick layer of stain less steel material grade SS-308) was performed. FEA load results were found in good agreement with the practical load results and can be used for capacity assessment and analysis of roller bending machines.

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.


1983 ◽  
Vol 105 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Hua-Ping Li ◽  
F. Ellyin

A plate weakened by an oblique penetration of a circular cylindrical hole has been investigated. The stress concentration around the hole is determined by a finite-element method. The results are compared with experimental data and other analytical works. Parametric studies of effects of angle of inclination, plate thickness, and width are performed. The maximum stress concentration factor (SCF) obtained from the finite-element analysis is higher than experimental results, and this deviation increases with the increase of angle of skewness. The major reason for this difference is attributed to the shear-action between layers parallel to the plate surface which cannot be directly included in the two-dimensional elements. An empirical formula is derived which accounts for the shear-action and renders the finite-element predictions in line with experimentally observed data.


2020 ◽  
pp. 109963622092465 ◽  
Author(s):  
Chong Li ◽  
Hui-Shen Shen ◽  
Hai Wang

This paper investigates the nonlinear bending behavior of sandwich plates with functionally graded auxetic 3D lattice core. First and foremost, an auxetic 3D lattice metamaterial with negative effective Poisson’s ratio (EPR) is designed and examined via theoretical and finite element methods with experimental verifications using specimens fabricated by 3D printing. Furthermore, three functionally graded configurations of the auxetic 3D lattice core through the plate thickness direction are proposed and compared with the uniform distribution case. Full-scale finite element modeling and nonlinear thermal-mechanical analysis are performed for the sandwich plates, with the temperature-dependent material properties of both core and face sheets taken into account. Numerical results revealed that the auxetic core can remarkably reduce the lateral deflections, with comparison to their non-auxetic counterpart with positive EPR. Parametric studies are further carried out to demonstrate the effects of functionally graded configurations, temperature rises, facesheet-to-core thickness ratios, boundary conditions, and strut radii on the nonlinear bending load-deflection curves, along with EPR-deflection curves in the large deflection region.


Author(s):  
Shivdayal Patel ◽  
B. P. Patel ◽  
Suhail Ahmad

Welding is one of the most used joining methods in the ship industry. However, residual stresses are induced in the welded joints due to the rapid heating and cooling leading to inhomogenously distributed dimensional changes and non-uniform plastic and thermal strains. A number of factors, such as welding speed, boundary conditions, weld geometry, weld thickness, welding current/voltage, number of weld passes, pre-/post-heating etc, influence the residual stress distribution. The main aim of this work is to estimate the residual stresses in welded joints through finite element analysis and to investigate the effects of boundary conditions, welding speed and plate thickness on through the thickness/surface distributions of residual stresses. The welding process is simulated using 3D Finite element model in ABAQUS FE software in two steps: 1. Transient thermal analysis and 2. Quasi-static thermo-elasto-plastic analysis. The normal residual stresses along and across the weld in the weld tow region are found to be significant with nonlinear distribution. The residual stresses increase with the increase in the thickness of the plates being welded. The nature of the normal residual stress along the weld is found to be tensile-compressive-tensile and the nature of normal residual stress across the weld is found to be tensile along the thickness direction.


Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31 ◽  
Author(s):  
Anheng Wang ◽  
Hongqian Xue ◽  
Emin Bayraktar ◽  
Yanli Yang ◽  
Shah Saud ◽  
...  

This paper focuses on the twist defects and the control strategy in the process of four-roll bending for aluminum alloy Z-section profiles with large cross-section. A 3D finite element model (3D-FEM) of roll bending process has been developed, on the premise of the curvature radius of the profile, the particularly pronounced twist defects characteristic of 7075-O aluminum alloy Z-section profiles were studied by FE method. The simulation results showed that the effective control of the twist defects of the profile could be realized by adjusting the side roller so that the exit guide roll was higher than the entrance one (the side rolls presented an asymmetric loading mode with respect to the main rolls) and increasing the radius of upper roll. Corresponding experimental tests were carried out to verify the accuracy of the numerical analysis. The experimental results indicated that control strategies based on finite element analysis (FEA) had a significant inhibitory function on twist defects in the actual roll bending process.


2013 ◽  
Vol 671-674 ◽  
pp. 417-423
Author(s):  
Ji Xiong Liu ◽  
Shao Bin Dai ◽  
Yao Peng ◽  
Jun Huang

3 extended-end-plate joints of T-shaped concrete-filled rectangular composite tubular column with H-shaped beam were designed. The experimental research and ANSYS nonlinear finite element analysis on the earthquake resistance behaviors of the joints were conducted under low cyclic loading. The results indicate that the shapes of hysteresis curve of each specimen is full and presents spindle, all the specimens possess good energy dissipation capacity. The end-plate thickness and high-strength bolt diameter have a great influence on the bearing capacity of the joints. Increasing the thickness of end-plate and the diameter of high-strength bolt, the displacement ductility factors of the joints decrease slightly, but their ultimate bearing capacities obviously enhance. The stress distributions and the finite element failure characteristics of the joints are basically consistent with the test phenomena, yield bearing capacity and ultimate bearing capacity of the finite element calculations can agree well with the experimental results.


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