scholarly journals Estimating of Bending Force and Curvature of the Bending Plate in a Three-Roller Bending System Using Finite Element Simulation and Analytical Modeling

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1204
Author(s):  
Ionel Gavrilescu ◽  
Doina Boazu ◽  
Felicia Stan
Keyword(s):  
Finite Element ◽  
Plastic Hinge ◽  
Plate Thickness ◽  
Practical Importance ◽  
Vertical Displacement ◽  
Curvature Radius ◽  
Bending Force ◽  
Wide Range ◽  
Bending Process ◽  
Analytical Expressions

Many industries such as shipbuilding require steel bending plates in a wide range of radii, thus bending machines are often designed and produced on a custom basis in shipyards. From a design perspective, however, the bending force and the radius of the bending plate as a function of vertical displacement of the upper roller must be known. In this paper, a hybrid numerical–analytical approach is proposed to investigate the three-roller bending process for two plates of steel used in the naval industry. Firstly, the bending process is modeled using the finite element (FE) method and regression models for the bending force as a function of plate thickness and vertical displacement of the upper roller were constructed. Then, based on the findings from FE analysis, using the bent bar theory, two analytical expressions for the bending force were derived. Using geometric and deformation compatibilities, analytical expressions for the vertical displacement of the upper roller as a function of the curvature of the bending plate were also developed. The FE results suggest that the cross section of the plate is practically a plastic hinge in the tangent area of the upper roller and that the deformation compatibilities must be considered in order to estimate the curvature radius of the bending plate using analytical formulations. These results are of practical importance in designing rolling machines to estimate the setting parameters.

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

2008 ◽  
Author(s):  
A. H. Gandhi ◽  
H. V. Gajjar ◽  
H. K. Raval
Keyword(s):  
Finite Element ◽  
Plate Thickness ◽  
Thick Layer ◽  
Structural Element ◽  
Element Analysis ◽  
Maximum Width ◽  
Shell Diameter ◽  
Bending Load ◽  
Bending Process ◽  
Mn Steel

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.

scholarly journals Analysis and Control of Twist Defects of Aluminum Profiles with Large Z-Section in Roll Bending Process

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31 ◽  
Author(s):  
Anheng Wang ◽  
Hongqian Xue ◽  
Emin Bayraktar ◽  
Yanli Yang ◽  
Shah Saud ◽  
...  
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Element Model ◽  
Effective Control ◽  
Curvature Radius ◽  
3D Fem ◽  
Fe Method ◽  
Element Analysis ◽  
Roll Bending ◽  
Bending Process

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.

Novel U-bending designed setups for investigating the spring-back/spring-go of two-layer aluminum/copper sheets through experimental tests and finite element simulations

2020 ◽  
Vol 234 (8) ◽  
pp. 1142-1153 ◽  
Author(s):  
Ehsan Etemadi ◽  
Abbas Naseri ◽  
Mohsen Valinezhad
Keyword(s):  
Finite Element ◽  
Experimental Tests ◽  
Finite Element Simulations ◽  
Curvature Radius ◽  
Stacking Sequence ◽  
Spring Back ◽  
Effective Parameters ◽  
Bending Process ◽  
Copper Aluminum ◽  
Good Agreement

This paper presents novel U-bending setups in order to investigate the effects of the curvatures created on the punch, die, or both on the spring-back/spring-go of the two-layer aluminum/copper sheets. Comparison of the new U-bending setups with the regular ones showed that the curvatures had important roles in reducing the spring-back/spring-go in the U-bending process. The results further indicated the good agreement between spring-back/spring-go and finite element simulations. Moreover, through finite element simulations, the effects of three effective parameters on reducing the spring-back/spring-go, including the curvature radius ( r) of the punch, the distance between curvature center and the fillet center ( d) in the punch, and the curvature radius at the end of the die ( R) were investigated. In achieving the desired state (90°), the results showed that the distance of curvature center from the fillet center ( d) was a more important parameter compared with the curvature radius at the end of the punch ( r) and the curvature radius at the end of the die ( R). This paper also focuses on the thicknesses of copper and aluminum as well as the stacking sequence of layers. Concerning the thicknesses of the implemented copper and aluminum change, the minimum angle of the spring-back/spring-go relative to the desired state was 75% Al/25% Cu thickness. Furthermore, the spring-back of aluminum/copper was lower than the copper/aluminum layer sheet. The effects of both thickness changing and stacking sequence of aluminum/copper layers on the spring-back/spring-go amounts of different sheets were due to the relocation of the neutral axis.

scholarly journals The Multi-Breakage Phenomenon in Air Bending Process

2014 ◽  
Vol 611-612 ◽  
pp. 1047-1053 ◽  
Author(s):  
Vitalii Vorkov ◽  
Richard Aerens ◽  
Dirk Vandepitte ◽  
Joost R. Duflou
Keyword(s):  
Finite Element ◽  
High Strength ◽  
Large Radius ◽  
Element Analysis ◽  
Bending Force ◽  
Bending Process ◽  
The Difference ◽  
The Moment ◽  
Force Calculation ◽  
Three Phases

In this work, the multi-breakage effect has been studied by means of an experimental campaign and finite element analysis. We suggest that large radius bending (XL-bending) consists of three phases that are distinguishable according to the type of contact of the plate with the tool: 1-point, surface and 2-points. In the experimental investigation the high-strength steel Weldox 1300 and a 40 mm radius punch were used. The authors created a camera setup to film the multi-breakage effect. Additionally, finite-element calculations were performed to confirm the hypothesis of the three phases of the bending process. For the springback and the bending force evaluation, the difference in the moment distribution for each phase has been calculated in the case of a beam. It shows that the multi-breakage effect must be taken into account to obtain a good accuracy for the springback and the bending force calculation.

scholarly journals Numerical Sensing of Plastic Hinge Regions in Concrete Beams with Hybrid (FRP and Steel) Bars

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3255 ◽  
Author(s):  
Fang Yuan ◽  
Mengcheng Chen
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Plastic Hinge ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Concrete Members ◽  
Steel Bars ◽  
Hybrid Reinforcement ◽  
Steel Hardening

Fibre-reinforced polymer (FRP)-reinforced concrete members exhibit low ductility due to the linear-elastic behaviour of FRP materials. Concrete members reinforced by hybrid FRP–steel bars can improve strength and ductility simultaneously. In this study, the plastic hinge problem of hybrid FRP–steel reinforced concrete beams was numerically assessed through finite element analysis (FEA). Firstly, a finite element model was proposed to validate the numerical method by comparing the simulation results with the test results. Then, three plastic hinge regions—the rebar yielding zone, concrete crushing zone, and curvature localisation zone—of the hybrid reinforced concrete beams were analysed in detail. Finally, the effects of the main parameters, including the beam aspect ratio, concrete grade, steel yield strength, steel reinforcement ratio, steel hardening modulus, and FRP elastic modulus on the lengths of the three plastic zones, were systematically evaluated through parametric studies. It is determined that the hybrid reinforcement ratio exerts a significant effect on the plastic hinge lengths. The larger the hybrid reinforcement ratio, the larger is the extent of the rebar yielding zone and curvature localisation zone. It is also determined that the beam aspect ratio, concrete compressive strength, and steel hardening ratio exert significant positive effects on the length of the rebar yielding zone.

Nonlinear dynamic behaviour of guy cables in turbulent winds

2001 ◽  
Vol 28 (1) ◽  
pp. 98-110 ◽  
Author(s):  
Bruce F Sparling ◽  
Alan G Davenport
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Aerodynamic Drag ◽  
Numerical Study ◽  
Horizontal Displacement ◽  
Wind Loading ◽  
Second Phase ◽  
Nonlinear Coupling ◽  
Wide Range ◽  
Cable Vibrations

Large amplitude cable vibrations are difficult to predict using linear theory due to the presence of sag in the suspended profile. A numerical study was therefore undertaken to investigate the dynamic behaviour of inclined cables excited by imposed displacements. To model the nonlinear nature of cable response, a time domain finite element approach was adopted using nonlinear catenary cable elements. Two types of horizontal displacement patterns were enforced at the upper end of the guy. In the first phase of the study, harmonic displacement histories with a wide range of forcing frequencies were considered. In the second phase, random enforced displacements were used to simulate the motion of a guyed mast in gusty winds. The influence of aerodynamic drag and damping forces was investigated by performing analyses under still air, steady wind, and turbulent wind conditions. It was found that nonlinear coupling of related harmonic response components was significant at certain critical frequencies, particular when the excitation was harmonic and acted in the plane of the guy. Positive aerodynamic damping was shown to effectively suppress resonant and nonlinear coupling response.Key words: cables, structural dynamics, wind loading, finite element method, nonlinear analysis, guyed towers.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

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.

Local Hydrostatic Pressure Test for Cylindrical Vessels

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
H. Al-Gahtani ◽  
A. Khathlan ◽  
M. Sunar ◽  
M. Naffa'a
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hydrostatic Pressure ◽  
Cylindrical Vessel ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Wide Range ◽  
Pressure Test ◽  
Local Test ◽  
Alternative Test

The juncture of a small cylindrical nozzle to a large cylindrical vessel is very common in the pressure vessel industry. Upon fabrication, it is required that the whole structure is subjected to pressure testing. The test can be expensive as it necessitates pressurizing the whole structure typically having a large volume. Hence, it is proposed to make a “local test,” which is considerably simpler as it involves capping the small nozzle and testing only a relatively small portion of the structure. This paper investigates the accuracy and reliability of such an alternative test, using the finite-element method. Two different finite-element types are used in the study, specifically a shell-based element and a solid-based element. The verification of the finite-element results for two different cases shows that the models used in the study are valid. It also proves that the two element types yield very similar stress results. In addition, the study includes a numerical investigation of more than 40 different nozzle-to-vessel junctures with a wide range of parameters for the nozzle and vessel. The results indicate that the use of cylindrical caps that are slightly larger than the nozzle is not recommended as it produces stresses that are significantly different from those for the original required pressure test. As such, the study provides an estimate of the smallest size of the cap that may be used in the local test to generate stresses that agree with the full test. For most practical geometries, it is shown that the size of the cap needs to be at least 2–30 times larger than that of the nozzle, depending on the geometrical parameters of the juncture.

NOVEL COUPLING CONSTRAINT TECHNIQUE FOR EXPLICIT FINITE ELEMENT ANALYSIS

2004 ◽  
Vol 01 (02) ◽  
pp. 309-328
Author(s):  
R. J. HO ◽  
S. A. MEGUID ◽  
R. G. SAUVÉ
Keyword(s):  
Finite Element ◽  
Current Method ◽  
Explicit Integration ◽  
Rotation Tensor ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Wide Range ◽  
Large Rotations ◽  
Generalized Constraint

This paper presents a unified novel technique for enforcing nonlinear beam-to-shell, beam-to-solid, and shell-to-solid constraints in explicit finite element formulations. The limitations of classical multi-point constraint approaches are examined at length, particularly in the context of explicit solution schemes. Novel formulation of a generalized constraint method that ensures proper element coupling is then presented, and its computer implementation in explicit integration algorithms is discussed. Crucial in this regard is the accurate and efficient representation of finite rotations, accomplished using an incremental rotation tensor. The results of some illustrative test cases show the accuracy and robustness of the newly developed algorithm for a wide range of deformation, including that in which large rotations are encountered. When compared to existing works, the salient features of the current method are in evidence.

Dynamic Characteristic Analysis of Irregularity under Turnout by Vehicle-Turnout Rigid-Flexible Coupling Model

2014 ◽  
Vol 945-949 ◽  
pp. 591-595 ◽  
Author(s):  
Meng Chen ◽  
Yan Yun Luo ◽  
Bin Zhang
Keyword(s):  
Finite Element ◽  
Longitudinal Direction ◽  
Element Model ◽  
Vertical Displacement ◽  
Coupling Model ◽  
Interaction Force ◽  
Vertical Acceleration ◽  
Characteristic Analysis ◽  
Flexible Coupling ◽  
Multi Body

Finite element model of track in frog zone is built by vehicle-turnout system dynamics. Considering variation of rail section and elastic support, bending deformation of turnout sleeper, spacer block and sharing pad effects, the track integral rigidity distribution in longitudinal direction is calculated in the model. Vehicle-turnout rigid-flexible coupling model is built by finite element method (FEM), multi-body system (MBS) dynamics and Hertz contact theory. With the regularity solution that different stiffness is applied for rubber pad under sharing pad of different turnout sleeper zone, analysis the variation of vertical acceleration of bogie and wheelset, rail vertical displacement and wheel-rail interaction force, this paper proves that setting reasonable rubber pad stiffness is an efficient method to solve rigidity irregularity problem.

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