An analysis of forces during three roller bending process (original) (raw)
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Forces and coefficient of friction during cylindrical three roller bending
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2018
Three roller bending process is one of the processes of forming cylindrical shells, for manufacturing drums, pressure vessels, windmill towers, etc. During the bending process, forces on the rollers must not exceed their bending capacity. Along with operational and material parameters, the forces exerted during bending and power consumption are affected by the coefficient of friction at the roller-plate interface. It is difficult to determine the coefficient of friction practically during three roller bending process. An attempt is made to determine the forces and friction coefficient at each roller-plate interface, through derived mathematical model, using experimental results. The variation of coefficient of friction under the higher loading conditions was also determined as a case study. With the present mathematical formulation along with the coefficient of friction, the forces at each roller-plate interface could be determined more precisely. The determination of forces and friction coefficient helps in deciding operational and design parameters of the bending machine, respectively. Keywords Three roller bending Á Coefficient of friction Á Bending forces Á Bending power Á Cylindrical bending Á Rolling friction Á Friction
World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, 2014
Conical sections and shells made from metal plates are widely used in various industrial applications. 3-roller conical bending process is preferably used to produce such conical sections and shells. Bending mechanics involved in the process is complex and little work is done in this area. In the present paper an analytical model is developed to predict bending force which will be acting during 3-roller conical bending process. To verify the developed model, conical bending experiments are performed. Analytical results and experimental results were compared. Force predicted by analytical model is in close proximity of the experimental results. The error in the prediction is ±10%. Hence the model gives quite satisfactory results. Present model is also compared with the previously published bending force prediction model and it is found that the present model gives better results. The developed model can be used to estimate the bending force during 3-roller bending process and can be ...
Bending force prediction for dynamic roll-bending during 3-roller conical bending process
Journal of Manufacturing Processes, 2014
Cylindrical as well as conical cross-section structural parts are widely used in industrial applications worldwide. Such parts are produced from metal plates using many manufacturing methods. 3-roller conical bending process is one such process. In this process first the metal plates in specified blank shapes are given static bending in the rollers. Then the rollers are driven using motors for bending of the blanks under dynamic condition. During bending reaction forces will be there on the rollers. Forces acting on the rollers during the process are transmitted to the machine frame at the roller supports. In the paper an analytical model is developed for the prediction of force during the stage of dynamic bending. The model consists of various parameters like material parameters and geometrical parameters. Experimentation is carried out and the developed model is validated with the experimental results. Effects of various material and geometrical parameters are studied in the present paper. The present work can give insight in the process and can be helpful to the designers as well as to the researchers working in the area of metal forming.
CASE STUDY & STRESS ANALYSIS OF A 3 ROLLER BAR BENDING MACHINE
TJPRC, 2013
The component that can be manufactured using 3-roller bar bending machine are circular washer having internal radius more than 150mm, circular collars, component used for balancing of wind tower assembly, high stiffness spiral spring, etc. For parametric specification of 3-point bar bending machine, it is necessary to analyze the stress induced in rollers and gear teeth radial force. Thus Finite element modeling is necessary and suitable software must be selected for analysis and observation.
CAD Modelling and Finite Element Analysis of Multistage Three Roller Pipe Bending Machine-Design
This paper deals with cad modelling and finite element analysis of multistage three roller pipe bending machine. This paper gives the cad model for existing and multistage three roller pipe bending machine. Cad modelling is helpful for safe designing a machine and also for further study. This cad model is then meshed in HYPERMESH for finite element modelling and analysis. The results of finite element analysis are very important part for designing the machine.
Modeling and computation of the three-roller bending process of steel sheets
Journal of Mechanical Science and Technology, 2012
Sheet metal bending processes are some of the most commonly used industrial manufacturing operations. The development and optimization of these processes are time consuming and costly. Therefore, finite element simulations may aid the design and quality assurance of sheet metal products. In the present study, a commercial finite element package was used to analyze the three-roller bending of a steel sheet. A two-dimensional finite element model of this process was built under the ABAQUS/Explicit environment based on the solution of several key techniques, such as contact boundary condition treatment, material property definition, meshing technique, and so on. Maps with desired curvature radii were established by varying the distance between the two bottom rollers and the position of the upper one. The developed maps made the rolling process easier and less time consuming. An industrial experiment using optimized numerical results was carried out to validate the numerical model. Residual stress and equivalent plastic strain distributions were also studied. The numerical spring back phenomenon was compared with analytical results. Fig. 1. Configuration of a pyramidal three-roller bending machine.
Analysis of elastic-plastic steel plates forming based on typical shipyard's roller bending machine
Ocean Engineering, 2019
Steel plates forming process, as an important component of the ship production process, is presented in this paper with the main intention to address the influence of different assumed stress-strain relationships to the analysis of the elastic-plastic forming process, particularly regarding bending moments, bending forces and energy required to achieve desired steel plate plastic deformations. Applicability of the simplified, one-dimensional analytical models and different stress-strain relationships is successfully verified against the experiment as well as by comparing the obtained results to more complex 2D plate theory in cases of four different steel grades (S235, S355, S420, S460) for the plate thicknesses up to 50 mm. Influence of bending radius, the distance between rollers and roller radius is analyzed further on and aspects of plate spring-back effects, i.e. residual stress, and permanent curvature, are addressed. Finally, the importance of the present research in cases of ship production and ship structural analysis and design is pointed out.
IJERT-Force Analysis of Metal Sheet in Bending Operation on Sheet Bending Machine
International Journal of Engineering Research and Technology (IJERT), 2015
https://www.ijert.org/force-analysis-of-metal-sheet-in-bending-operation-on-sheet-bending-machine https://www.ijert.org/research/force-analysis-of-metal-sheet-in-bending-operation-on-sheet-bending-machine-IJERTV4IS010115.pdf In the three roller bending machine, the three rollers rotate. Bending can be done in both sheet metal and bars of metal. For designing a three roller bending machine, it is required to calculate the exact force for bending. Based on this force, the machine parameters and motor power are decided. Various factors that should be considered while calculating this force are material properties, width, and thickness, number of passes, bending radius, force developing mechanism and link. To analyses the force and power for motor the designer takes the help of analysis software. The cost of software for analysis is high. So there is requirement to find simple formula. In this paper the various theories regarding bending are reviewed, formulae for force and power calculation are collected and finally a case study is taken where we have put together all the results of these formulae.
2016
Conical sections and shells of metal plates manufactured by 3-roller conical bending process are widely used in the industries. The process is completed by first bending the metal plates statically and then dynamic roller bending sequentially. It is required to have an analytical model to get maximum bending force, for optimum design of the machine, for static bending stage. Analytical models assuming various stress conditions are considered and these analytical models are compared considering various parameters and reported in this paper. It is concluded from the study that for higher bottom roller inclination, the shear stress affects greatly to the static bending force whereas for lower bottom roller inclination it can be neglected.