State of the Art: Prototyping of the Roll Bending Machine

2013 ◽  
Vol 549 ◽  
pp. 76-83
Author(s):  
Jarmo Mäkikangas ◽  
Kari Kutuniva ◽  
Kari Mäntyjärvi
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Roll Forming ◽  
Modular Construction ◽  
Forming Process ◽  
Roll Bending ◽  
Short Run ◽  
New Type ◽  
Ultra High Strength Steels ◽  
Functional Components

This paper focuses on the development of a new type of roll bending machine. Our primary aim was to build a machine that could form ultra-high-strength steels (UHS) with smaller inner radii than those achieved by traditional bending methods. One of the main planning principles was modular construction, so a length of a bending line could be easily selected or changed later by the user without major changes to the basic construction of the machine. In contrast, in traditional roll forming, the blank does not move during the forming process, so the accuracy of the profile can be better controlled. Different kinds of cut to size-open profiles can be produced by this machine, which utilizes and combines bending and rolling techniques. In the initial stages of the project, the needs of smaller companies that do short-run productions are taken into account. First, the prototype is designed mainly for research use; moreover, it is important that the properties of the machine are multifunctional. In addition, forming can be done in several ways by this machine. In this paper, there is shown creation of a machine, designing of construction and manufacturing steps of the whole machine including assembling. Also detailed description of the various functional components and the operating principle is presented. The results of the forming tests are also presented.

Incremental Bending of Ultra-High-Strength Steels

2011 ◽  
Vol 473 ◽  
pp. 53-60 ◽  
Author(s):  
Antti Määttä ◽  
Kari Mäntyjärvi ◽  
Jussi A. Karjalainen
Keyword(s):  
Automotive Industry ◽  
Rolling Direction ◽  
High Strength Steels ◽  
High Strength ◽  
Roll Forming ◽  
Complex Phase ◽  
Bending Angle ◽  
Bending Radius ◽  
Ultra High Strength Steels ◽  
Traditional Manner

Utilisation of ultra-high-strength steels (UHS) has increased, particularly in the automotive industry. By using these materials vehicle structures can be lightened. However, one of the problems of UHS is weak formability. Materials fracture easily with small bending radii and the minimum bending radii are rather large. In this study, the tested materials were complex phase (CP) bainitic-martensitic UHS steels (YS/TS 960/1000 and 1100/1250). The steels were incrementally bent with a press brake in the rolling direction and perpendicular to it, and the final bending angle was 90 degrees. The incremental bending angles were 150°, 130°, 110° and 90°. The punch was unloaded after every incremental bending step. The test materials were bent with different bending radii. The aim was to find the minimum bending radius which produces an acceptable bend. Every incremental bend was compared with a bending performed in the traditional manner. The aim of this study was to examine how well the results of incremental bending compare to roll forming. In addition, clarification studies of when the bend started to fracture were made. It is well known that steels are more efficiently bent by roll forming compared with traditional bending. The results presented in this study demonstrate that incremental bending does not produce better results than traditional bending. Nevertheless, it has been shown that the examined steels can be bent incrementally against manufacturer’s recommendations.

Dissimilar Material Joint Strength and Structure for Friction Stir Forming Process

2014 ◽  
Author(s):  
Kenneth A. Ogata ◽  
Sladjan Lazarevic ◽  
Scott F. Miller
Keyword(s):  
Failure Modes ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Process ◽  
Experimental Conditions ◽  
Friction Stir ◽  
Automotive Body ◽  
Neck Fracture ◽  
Ultra High Strength Steels

Mass reduction of automotive body structures is a critical part of achieving reduced CO2 emissions in the automotive industry. There has been significant work on the application of ultra high strength steels and aluminum alloys. However, the next paradigm is the integrated use of both materials, which creates the need to join them together. Friction stir forming is a new environmentally benign manufacturing process for joining dissimilar materials. The concept of this process is stir heating one material and forming it into a mechanical interlocking joint with the second material. In this research the process was experimentally analyzed in a computer numerical controlled machining center between aluminum and steel work pieces. The significant process parameters were identified and their optimized settings for the current experimental conditions defined using a design of experiments methodology. Three failure modes were identified (neck fracture, aluminum sheet peeling, and bonding delamination i.e. braze fracture). The overall joint structure and grain microstructure were mapped along different stages of the friction stir forming process. Two layers were formed within the aluminum, the thermo-mechanical affected zone that had been deformed due to the contact pressure and angular momentum of the tool, and the heat affected deformation zone that deformed into the cavity.

Testing and Modeling of Roll Levelling Process

2014 ◽  
Vol 611-612 ◽  
pp. 1753-1762 ◽  
Author(s):  
Elena Silvestre ◽  
Eneko Sáenz de Argandoña ◽  
Lander Galdos ◽  
Joseba Mendiguren
Keyword(s):  
Finite Element ◽  
High Strength Steels ◽  
Beam Theory ◽  
High Strength ◽  
Theoretical Models ◽  
Element Model ◽  
Forming Process ◽  
Element Analysis ◽  
Design Engineers ◽  
Ultra High Strength Steels

Roll levelling is a forming process used to remove the residual stresses and imperfections of metal strips by means of plastic deformations. During the process the metal fibres are subjected to cyclic tension-compression deformations leading to achieve flat product. The process is especially important to avoid final geometrical errors when coils are cold formed or when thick plates are cut by laser. In the last years, and due to the appearance of high strength materials such as Ultra High Strength Steels, machine design engineers are demanding a reliable tool for the dimensioning of the levelling facilities. In response to this demand, Finite Element Analysis and Analytical methods are becoming an important technique able to lead engineers towards facilities optimization through a deeper understanding of the process. Aiming to this study two different models have been developed to analyze the roll levelling operations: an analytical model and a finite element model. The FE-analysis was done using 2D-modelling assuming plane strain conditions. Differing settings, leveller configuration and materials were investigated. The one-dimensional analytical levelling model is based on classical beam theory to calculate the induced strain distribution through the strip, and hence the evolving elastic/plastic stress distribution. Both models provide a useful guide to process-sensitivities and are able to identify causes of poor leveller performance. The theoretical models have been verified by a levelling experimental prototype with 13 rolls at laboratory.

scholarly journals Overview on the digitized production of welded steel structures

2022 ◽  
Author(s):  
Tuomas Skriko ◽  
Antti Ahola ◽  
Timo Björk
Keyword(s):  
High Strength Steels ◽  
Steel Structures ◽  
High Strength ◽  
Production Quality ◽  
Robotic Welding ◽  
Human Errors ◽  
Welded Steel ◽  
Short Run ◽  
Ultra High Strength Steels ◽  
Cost Efficient

Abstract This paper presents a concept and practical topics involved in digitized production. The term “production” denotes the design, fabrication, and service life of a product, which in this case elaborates on welded steel structures. This includes the required information for guiding all the process stages of the chosen material back to its re-melting, following the material flow in a fully digitized form. This concept enables an increase in production quality at a higher level while minimizing the risk of human errors. Automation of the short-run production of steel structures for demanding applications is also a key goal, together with securing a cost-efficient process. Typically, such structures are fabricated from high- or ultra-high-strength steels. Though challenging, reaching these aims seems to be realistic by applying advanced fatigue design methods, using high-quality robotic welding and receiving information about the real loading of the structure.

scholarly journals Prototyping of Straight Section Components Using Incremental Shape Rolling

2022 ◽  
Author(s):  
Abdelrahman Essa ◽  
Buddhika Abeyrathna ◽  
Bernard Rolfe ◽  
Matthias Weiss
Keyword(s):  
Numerical Model ◽  
High Strength Steels ◽  
High Strength ◽  
Variable Cross Section ◽  
Roll Forming ◽  
Variable Cross ◽  
Straight Section ◽  
Forming Process ◽  
Shape Rolling ◽  
Residual Strains

Abstract Flexible Roll Forming (FRF) allows the forming of components with a variable cross-section along the length of the component. However, the process has only limited application in the automotive industry due to wrinkling in the flange which currently prevents the forming of high strength steels and limits the part shape complexity. This paper presents a new forming technology, Incremental Shape Rolling (ISR), where a pre-cut blank is clamped between two dies and then a single forming roll is used to incrementally form the material to the desired shape. The new process is similar to some Incremental Sheet Forming (ISF) approaches but with the difference that Incremental Shape Rolling (ISR) allows the manufacture of longitudinal components from high strength metal sheets. In this work, a numerical model of the ISR of a straight section is developed. Experimental prototyping trials are performed and are used to validate the numerical model which is then applied to analyse the new forming process. The results show that in ISR, tensile residual strains are developed in the flange. Flange wrinkling is observed and directly linked to the number of forming passes that are used in the process.

Springback Investigation in Roll Forming of a V-Section

2014 ◽  
Vol 553 ◽  
pp. 643-648 ◽  
Author(s):  
Akbar Abvabi ◽  
Joseba Mendiguren ◽  
Bernard F. Rolfe ◽  
Matthias Weiss
Keyword(s):  
Elastic Modulus ◽  
Continuous Process ◽  
High Strength Steels ◽  
Shell Element ◽  
High Strength ◽  
Material Model ◽  
The Body ◽  
Roll Forming ◽  
Forming Process ◽  
Advanced High Strength Steels

To have fuel efficient vehicles with a lightweight structure, the use of High Strength Steels (HSS) and Advanced High Strength Steels (AHSS) in the body of automobiles is increasing. Roll forming is used widely to form AHSS materials. Roll forming is a continuous process in which a flat strip is shaped to the desired profile by passing through numerous sets of rolls. Formability and springback are two major concerns in the roll forming of AHSS materials. Previous studies have shown that the elastic modulus (Young’s modulus) of AHSS materials can change when the material undergoes plastic deformation and the main goal of this study is to numerically investigate the effect of a change in elastic modulus during forming on springback in roll forming. Experimental loading-unloading tests have been performed to obtain the material properties of TRIP 700 steel and incorporate those in the material model used in the numerical simulation of the roll forming process. The finite element simulations were carried out using MSC-Marc and two different element types, a shell element and a solid-shell element, were investigated. The results show that the elastic modulus diminution due to plastic strain increases the springback angle by about 60% in the simple V-section roll forming analyzed in this study.

Study of Formability of Steel Thick Plates for Offshore Structures

2014 ◽  
Vol 622-623 ◽  
pp. 322-329
Author(s):  
Kwang Soo Park ◽  
Sook Hwan Kim ◽  
Dong Kyu Kim
Keyword(s):  
Process Analysis ◽  
High Strength Steels ◽  
High Strength ◽  
Offshore Structures ◽  
Roll Forming ◽  
Offshore Structure ◽  
Forming Process ◽  
Sea Bed ◽  
Jack Up ◽  
Roll Forming Process

A jack-up rig or a self-elevating unit is a type of mobile platform that consists of a buoyant hull fitted with a number of movable legs, capable of raising its hull over the surface of the sea. The buoyant hull enables transportation of the unit and all attached machinery to a desired location. Once on location the hull is raised to the required elevation above the sea surface on its legs supported by the sea bed. The legs of such units may be designed to penetrate the sea bed, may be fitted with enlarged sections or footings, or may be attached to a bottom mat. Generally Jack up rigs are not self-propelled and rely on tugs or heavy lift shipsfor transportation. Formability problems in offshore structure construction where particularly high-strength steels are used for chords and racks. Attainment of mechanical properties is not usually difficult, although procedural trials are advisable. Fatigue cracking is probably the major cause of service failure of jack-up rigs, and the use of high-strength steels, which permits higher static stress limits, can exacerbate this problem. Roll forming process is one of the most widely used processes in the world for forming metals. It can manufacture goods of the uniform cross section throughout the continuous processing. However, process analysis is very difficult because of the inherent complexity. Therefore, it is time-consuming and much money is needed for manufacturing goods. In order to overcome this difficulty, a new computational method based on the rigid-plastic finite element method is developed for the analysis of roll forming process.

Friction Coefficient Identification in Roll Forming Processes

2014 ◽  
Vol 611-612 ◽  
pp. 425-435 ◽  
Author(s):  
Lander Galdos ◽  
Unai Ulibarri ◽  
Imanol Gil ◽  
Rafael Ortubay ◽  
Eneko Sáenz de Argandoña
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Roll Forming ◽  
High Yield ◽  
High Yield Strength ◽  
Forming Process ◽  
Advanced High Strength Steels ◽  
High Production Rate ◽  
High Production ◽  
Roll Forming Process

Roll forming process is an interesting process for the production of complex profiles because of its high production rate, low investment and efficient use of material. Furthermore, and due to their high yield strength, this technology is suitable for the forming of Advanced High Strength Steels which are being increasingly introduced in the automobile sector.

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