DOCSLIB.ORG

1 on Achieving an Optimal Riveted Lap Joint Design For

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
1 on Achieving an Optimal Riveted Lap Joint Design For ON ACHIEVING AN OPTIMAL RIVETED LAP JOINT DESIGN FOR FIBRE METAL LAMINATES A.M. Brown, C.D. Rans, and P.V. Straznicky Department of Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, K1S 5B6, Ottawa, Ontario, Canada ABSTRACT Fibre metal laminates are designed to provide a damage tolerant alternative to monolithic metallic materials in airframe structures without the need for new structural design solutions required by pure fibre reinforced composites. This advantage allows fibre metal laminates to be incorporated directly into existing airframe design practices with little effort. Although such a simple transition is possible, fibre metal laminates exhibit different properties and behaviour than monolithic metallic materials. Consequently, differences may exist in optimal design details for a given structural design solution. This paper overviews the results of a study examining this possibility for a common airframe joint design solution: the riveted lap joint. Focusing on fatigue performance, a series of studies were completed to assess how major differences between monolithic aluminum sheet and a glass fibre-aluminum fibre metal laminate variant known as GLARE could be treated and exploited to obtain an optimal GLARE joint. These studies include an examination of alternative countersinking methods for thin laminated sheets, the formation of residual stresses in GLARE due to fastener interference, and material stiffness effects on joint bending. Results from these studies will form the basis for a discussion on achieving an optimal riveted lap joint design for GLARE. INTRODUCTION Fibre metal laminates (FML’s) are a family of hybrid laminates consisting of alternating layers of monolithic metallic sheet and fibre reinforced epoxy pre-impregnated fibre (prepreg) layers (Figure 1). Originating from the development of built-up structures pioneered by Fokker Aircraft in the late 1940’s, FML’s were found to exhibit benefits from both their metallic and fibre reinforced composite constituents. Specifically, FML’s possess many of the damage tolerant properties inherent in fibre reinforced composite materials while retaining the fabrication and repair capabilities of sheet metal. Within the aerospace field, these properties are attractive as they provide an opportunity to enhance the damage tolerance of airframe structures without the need for new structural design solutions required by pure fibre-reinforced composites. Although FML’s can be incorporated directly into metallic airframe design practices with little effort, FML’s do exhibit different properties and behaviour compared to monolithic metallic materials. Consequently, differences may exist in optimal design details for a given structural design solution. This paper provides an overview of studies examining this possibility for a common airframe joint design solution: the riveted lap joint. 1 FibreLayers Metallic Layers Figure 1 Illustration of fibre metal laminate Figure 2 Illustration of fibre bridging construction. mechanism. GLARE LAMINATES Within the family of FML’s, a material known as GLARE (GLAss REinforced aluminum) has been developed as a replacement for monolithic 2024-T3 aluminum in aircraft fuselage construction. This material consists of 2024-T3 aluminum for the metallic layers and S2-glass fibre epoxy for the prepreg layers. The focus of this paper is the GLARE3-2/1-0.3 laminate which would be a suitable replacement for 1 mm 2024-T3 fuselage skin. FML’s and, more specifically, GLARE variants are known to have beneficial characteristics in the area of fatigue and damage tolerance with fatigue lives in excess of 10 times that of 2024-T3 [1]. The reason for the increased fatigue performance is the material’s superior crack propagation life through a mechanism called fibre bridging. With fibre bridging, the load normally carried by the cracked aluminum plies gets redistributed into the adjacent intact fibre layers and the stress concentration at the crack tip is effectively reduced (Figure 2). A further benefit of the sandwich lay-up is that through thickness crack propagation does not occur. A crack growing through the thickness of an aluminum ply will stop once it hits a prepreg layer. It then remains for the other intact aluminum plies to nucleate cracks. This unique laminate construction contributes to several other desirable properties [2-4] for an aircraft material but will not be discussed here. Although the fatigue propagation behaviour of GLARE is superior to 2024-T3, crack nucleation actually occurs earlier than in monolithic sheet. This stems from the difference in flexibility of the material plies and from residual tensile stresses in the aluminum plies introduced during the curing cycle of the manufacturing stage. These tensile residual stresses contribute to any applied stress and helps lead to crack nucleation. In addition to the presence of tensile residual stresses, the lower stiffness of the prepreg plies in the sandwich lay-up means that the aluminum plies will experience greater stresses than the applied bulk stress. 2 FATIGUE OF RIVETED LAP JOINTS The basic riveted lap joint configuration consists of two sheets joined by one or more rows of rivets. The two sheets are differentiated by their location and accessibility for inspection along the joint overlap; in an airframe application, the outer sheet would be accessible from the outside of the aircraft while the inner sheet would be accessible from the inside. Additional variables and terminology used in defining a riveted lap joint design are illustrated in Figure 3. Outer free OUTER surface Outer faying SHEET s surface (rivet pitch) t (sheet thickness) TOP ROW Do (rivet p diameter) (row pitch) BOTTOM ROW INNER SHEET Inner free Inner faying surface surface Figure 3: 3-row riveted lap joint nomenclature. Developing a lap joint design based on fatigue performance requires the designer to manipulate the local stress state around fatigue prone rivet locations in order to prolong fatigue crack nucleation and reduce the rate of propagation of existing cracks. This local stress state can be broken down into components related to load transfer, and secondary loads such as secondary bending and rivet interference as illustrated in Figure 4. These components and the influence of lap joint design variables on them will be briefly discussed in order to establish a baseline for lap joint design which will be expanded on later in the context of GLARE specific lap joint design. Load Transfer Load transfer in riveted lap joints occurs by two mechanisms. The majority of load is transferred by means of bearing between the rivets and inner and outer sheets while the remainder is transferred through friction between the faying joint surfaces. The magnitude of the bearing stress at a rivet hole is related to the load transferred by a single rivet and the bearing area (rivet diameter multiplied by sheet thickness) over which that load is transmitted into the joined sheets. Large bearing stresses promote crack nucleation and reduce the crack free life of a joint. Although bearing stresses can be reduced easily in practice by increasing the total bearing area, either through increasing the rivet diameter, increasing the number of rivets, or both, these steps negatively impact crack growth. The reduced amount of sheet material along the net section of a rivet row that 3 would accompany such efforts to reduce bearing stress increase crack propagation rates and reduce critical crack lengths. Bearing Friction Bypass Load Transfer Secondary Loads Secondary Bending Interference Figure 4: Illustration of local stress field components in a riveted lap joint. Figure 5: Illustration of load carried by inner and outer sheets in a 3-row lap joint. Friction comprises a small portion of the overall load transfer in a riveted joint and is often neglected. Any load that is transferred through friction reduces bearing stress and generally results in an improvement in fatigue performance. More important than the amount of load transferred through friction is the amount of fretting damage that occurs as a result of friction. Fretting damage is a destructive process associated with clamped bodies undergoing oscillatory loading [5]. In riveted lap splices, the evidence of fretting damage is a black oxidized region surrounding the rivet hole on the sheet faying surface. This damaging process is known to generate microcracks in the surface that, under further loading, can propagate into the substrate as a fatigue crack. In multiple-row lap joints, each rivet row transfers a portion of the applied load from the outer to inner sheet while the remainder (referred to as the bypass load) remains in the outer sheet (Figure 5). The amount of load transferred by each rivet row is related to the relative flexibilities of the rivets and sheets being joined, neglecting the contribution from friction. For a 3-row lap joint, the top and bottom rivet rows transfer the same amount of load due to joint asymmetry while the load transferred by the middle rivet row can be determined by: 4 frivet TT21 (1) ffrivet sheet where: TT12, = load transferred by top and middle row respectively frivet, f sheet = rivet and sheet flexibilities As negative flexibilities are not possible, this equation shows that the top and bottom rivet rows will always transfer (through bearing) a larger percentage of the load than the middle rivet rows. The combination of large bearing stresses and high bypass stresses along these rivet rows results in two fatigue critical locations: in the outer sheet along the top rivet row and in the inner sheet along the bottom rivet row (Figure 5). In practice, the inner sheet location is typically less critical due to improved hole filling within this sheet during riveting and due to the possible added stress concentration in the outer sheet due to countersinking. Although adding more rows of rivets beyond three can reduce the amount of load transferred through the top and bottom rivet rows, this reduction drops off exponentially with the number of rivet rows and is typically viewed as a weight and manufacturing penalty.
Load more

Recommended publications
  • Sheet Metal Operations - Bending and Related Processes
    Sheet metal operations - Bending and related processes R. Chandramouli Associate Dean-Research SASTRA University, Thanjavur-613 401 Table of Contents 1.Quiz-Key ........................................ Error! Bookmark not defined. 1.Bending and related processes: 1.1 Sheet metal bending Bending of sheets and plates is widely used in forming parts such as corrugations, flanges, etc. Bending is a forming operation in which a sheet metal is subjected to bending stress thereby a flat straight sheet is made into a curved sheet. The sheet gets plastically deformed without change in thickness. Die and punch are used for bending. If a v shaped die and punch are used, the bending is called v-bending. If the sheet is bent on the edge using a wiping die it is called edge bending. In this process, one end of the sheet is held like a cantilever using a pressure pad and the other end is deformed by a punch which moves vertically down, bending the sheet. Usually, edge bending is done in order to obtain an angle of 90o. During bending of a strip, the material outward of the neutral axis is subjected to tensile stress. Material inside is subjected to compressive stress. Bend radius R is the radius of curvature of the bent sheet inside the bending. The neutral axis remains at the center of the thickness of the sheet for elastic bending. For plastic bending, however, the neutral axis shifts towards the inside of the bend. The rate of elongation of outer fibers is greater than the rate of contraction of inner fibers. Therefore, there is a thickness reduction at the bend section.
    [Show full text]
  • Design of an Electrically Powered Bending Machine
    Proceedings of the International Conference on Industrial Engineering and Operations Management Rabat, Morocco, April 11-13, 2017 Design of an electrically powered bending machine: Case of Zimbabwe Tawanda Mushiri Department of Mechanical Engineering University of Johannesburg P.O Box APK 524 Johannesburg South Africa [email protected], [email protected] Definite Shumba Department of Mechanical Engineering University of Zimbabwe P.O Box MP167 Mt Pleasant Harare Zimbabwe [email protected] Charles Mbohwa Faculty of Engineering and the Built Environment University of Johannesburg P.O Box APK 524 Johannesburg South Africa [email protected] Abstract This paper seeks to carry out design of a small scale electrically powered bending machine for a developing nation, case for Zimbabwe. The bending of metal is of great importance in the manufacture of products such as nut shelling machines and maize shelling machines. Currently being used at Company X engineering is a manual bending machine with a single operation hence this design will help to increase the number of metals being bent, an increase in the efficiency and production. The paper deals with manufacturing or bending of sheet metal by using power operated sheet bending machine. Especially discussion made the productivity analysis of manually or power operated sheet bending machine. Considering manual operation is replaced by power operated devices. It also gives information about limitation of manually operated sheet bending machine and power operated sheet bending machine. The existing machines are limited to a single operation. The aim of the research is to increase the number of bent parts and to place an adjustable table to suit the height of the user thereby reducing back pain internal injuries in the long run.
    [Show full text]
  • PRESS BRAKE CAPACITIES SPRINGBACK a True 90° Air Bend, the Tooling Must Formed Flanges and Causing Distortion
    www.e-ci.com 1 CONTENTS 2 Safety 2 Bending on a CI Press Brake 8 Press Brake Bending Capacity 9 Mild Steel Air Bend Capacity Chart 13 Bending Factors Chart 17 Punching on a Press Brake SAFETY Good safety practices and proper training of each press brake operator is mandatory. Comprehensive operator, maintenance and safety manuals provide instruction on proper procedures and safety methods and BENDING ON A CINCINNATI should be with the press brake at all times. Warning signs and a checklist PRESS BRAKE of operator safety guidelines should be placed at strategic locations on PRESS BRAKE RATING For thicker than 1/2” mild steel, it may the press brake. be necessary to increase the vee die All CINCINNATI press brakes are opening up to ten times the material Users are responsible for proper rated for maximum bending pressure, thickness to minimize cracking of the installation and continued use of or tonnage. Tonnage can then be material. To determine the vee opening point-of-operation safeguarding converted into bending capacities for a simple 90° bend, multiply the and other machine guards. This through an understanding of basic metal thickness by eight. The answer helps assure operator safety factors affecting the formability of is then rounded to the next higher 1/8” and compliance with OSHA metal. Bending factors, or “rules of figure. For example: 14ga. (.075”) x 8 requirements. thumb,” for press brake forming are = .600”. This is rounded to a 5/8” vee based on using mild steel (60,000 Each new CINCINNATI press opening. psi maximum tensile strength).
    [Show full text]
  • Springback Analysis for Warm Bending of Titanium Tube Based on Coupled Thermal-Mechanical Simulation
    materials Article Springback Analysis for Warm Bending of Titanium Tube Based on Coupled Thermal-Mechanical Simulation Guangjun Li 1,*, Zirui He 1, Jun Ma 2 , Heng Yang 2 and Heng Li 2,* 1 Chengdu Aircraft Industry (Group) Co., Ltd., Chengdu 610092, China; [email protected] 2 State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China; [email protected] (J.M.); [email protected] (H.Y.) * Correspondence: [email protected] (G.L.); [email protected] (H.L.) Abstract: Titanium bent tubular parts attract extensive applications, thus meeting the ever-growing demands for light weight, high reliability, and long service life, etc. To improve bending limit and forming quality, local-heat-assisted bending has been developed. However, significant springback seriously reduces the dimensional accuracy of the bent tubular parts even under elevated forming temperatures, and coupled thermal-mechanical working conditions make springback behavior more complex and difficult to control in warm bending of titanium tubular materials. In this paper, using warm bending of thin-walled commercial pure titanium tube as a case, a coupled thermal-mechanical finite element model of through-process heating-bending-unloading is constructed and verified, for predicting the springback behavior in warm bending. Based on the model, the time-dependent evolutions of springback angle and residual stress distribution during thermal-mechanical unloading are studied. In addition, the influences of forming temperature and bending angle on springback angle, thickness variation, and cross-section flattening of bent tubes are clarified. This research Citation: Li, G.; He, Z.; Ma, J.; Yang, provides a fundamental understanding of the thermal-mechanical-affected springback behavior H.; Li, H.
    [Show full text]
  • Forming Methods
    theartofpressbrake.com http://www.theartofpressbrake.com/wordpress/?page_id=1023 Forming Methods Bend Allowance, Outside Setback, Bend Deduction If you calculate these with precision, you have a better chance of bending a good part on the first try. But, to make this happen, you need to make sure every factor in the equation is what it should be, and this includes the inside bend radius . How exactly is this inside bend radius achieved? To uncover this, we must first look at the different methods of bending on a press brake: air forming, bottom bending, and coining. The Methods of bending There are three different types of bending methods used in the forming of sheet metal: “ air forming“, “Bottom Bending and “Coining. Each of these methods has a specific purpose and application. In this chapter the benefits and the inefficiencies of each will be discussed. Coining Note that there are three bending methods, not two. Bottom bending and coining often are confused for the same process, but they are not. Unlike bottoming, coining actually penetrates and thins the material. Coining is the oldest method and for the most part, no longer practiced. Why? Because of the extreme tonnages this method requires. An amount of tonnage so great that the material “flows” on a molecular level while under this extreme pressure. Coining forces the punch nose into the material, penetrating the neutral axis, figure 1. Technically, any radius may be coined, but traditionally, coining has been used to establish a dead-sharp bend. This method not only requires excessive tonnages, it also destroys the material’s integrity.
    [Show full text]
  • Acute and Hem Bending
    theartofpressbrake.com http://www.theartofpressbrake.com/wordpress/?page_id=1037 Acute and hem bending Acute Bend Angle Tools Acute bend tools are used to achieve bend angles that are greater than 90° and are the first step in hemming or seaming. Acute tooling, comes in two basic angles: 30° and 45°. Figure 1 shows an example of an acute punch and die set. Acute tooling can only be used for air forming; bottom bending and coining operations cannot be accomplished because the angle tool cannot withstand the side loading forces. Die width selection for the acute bends is the same as any other. You will be air forming so the radius is based on the 20% rule, so you simply ignore the fact that these tools are not at 90° and continue the calculations as before. True, the answers would be slightly different if the correct die angles are used in the calculations, but due to a limited selection of die widths, the angle makes little difference while making the math easy. But, ultimately you have to pick between die width A and die width B. Figure 1 The standard acute punches measure 43° and 28° and are mated to 45°and 30° dies. One major thing that does change with die angle is the minimum flange length. An acute die requires a greater minimum flange length than a standard 90° V-die. Figure 2 illustrates the differences in minimum flange length; both of the illustrations are of the same die width but with Figure 2 different die angles. Table 1 shows the minimum allowable die width to flange length for acute tooling.
    [Show full text]
  • Hemming with Pre-Bent Inner Sheet for Joining Ultra-High Strength Steel Sheets of Automobile Parts
    Journal of Manufacturing and Materials Processing Communication Hemming with Pre-Bent Inner Sheet for Joining Ultra-High Strength Steel Sheets of Automobile Parts Yohei Abe * , Wataru Ijichi, Ken-ichiro Mori and Kazuma Nakagawa Faculty of Engineering, Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580, Japan; [email protected] (W.I.); [email protected] (K.-i.M.); [email protected] (K.N.) * Correspondence: [email protected]; Tel.: +81-532-44-6705 Received: 29 June 2020; Accepted: 23 July 2020; Published: 25 July 2020 Abstract: In order to join two ultra-high strength steel sheets with low ductility for automobile parts, a joining process by hemming with a pre-bent inner sheet was developed. In this joining, the pre-bent inner sheet instead of the conventional flat inner sheet was used to relax the deformation concentration of the outer sheet. Although 780 MPa steel sheets were joined without the pre-bent inner sheet, a fracture in the outer sheet occurred in joining the 980 MPa sheets due to the low ductility of the sheets. The 980 MPa and 1180 MPa sheets were successfully joined by hemming with the pre-bent inner sheet. In this process, the deformation of the upper sheet was relaxed by contacting with the inner sheet, and then the strain on the outer surface reduced. Although softening around a weld nugget occurred by heating in the conventional welded joint, work-hardening occurred in the hemmed joint. The joint strength was investigated and then the peel strength of the hemmed sheets was about a half of the welded one.
    [Show full text]
  • SHEET METAL PROCESSES BENDING Bending Is One
    SHEET METAL PROCESSES BENDING Bending is one very common sheet metal forming operation used not only to form shapes like seams, corrugations, and flanges but also to provide stiffness to the part (by increasing its moment of inertia). As a sheet metal is bent (Fig 6.1), its fibres experience a distortion such that those nearer its outside, convex surface are forced to stretch and come in tension, while the inner fibres come in compression. Somewhere, in the cross section, there is a plane which separates the tension and compression zones. This plane is parallel to the surface around which the sheet is bending, and is called neutral axis. The position of neutral axis depends on the radius and angle of bend. Further, because of the Poisson's ratio, the width of the part L in the outer region is smaller, and in the inner region it is larger, than the initial original width. Fig 6.1 Sheet metal bending. It may be noted that the bend radius is measured to the inner surface of the bent part. BEND ALLOWANCE It is the length of the neutral axis in the bend, Fig 6.1. This determines the blank length needed for a bent part. It can be approximately estimated from the relation Lb = a ( R + kt ) where, Lb = bend allowance (mm) a = bend angle (radian) R = bend radius (mm) t = thickness of sheet (mm), and k = constant, whose value may be taken as 1/3 when R < 2t, and as 1/2 when R ³ 2t. Example : A 20 mm wide and 4 mm thick C 20 steel sheet is required to be bent at 600 at bend radius 10 mm.
    [Show full text]
  • Reduce Unwanted Sheet Marking
    MARK-FREE SOLUTIONS FOR BENDING REDUCE UNWANTED SHEET MARKING Wilson Tool International offers numerous solutions to help press brake operators reduce or eliminate sheet marking during bending operations. Urethane dies, holders, pads and drapes form a protective barrier that impedes the metal-on-metal scraping that often happens during bending. The protective fabric drape is a lightweight and flexible alternative to urethane that also provides a barrier to prevent scratching. V-series dies use a rotating action that causes much less friction than typical V dies, resulting in reduced part marking. Urethane products available from Wilson Tool include: • Urethane Dies These dies greatly reduce and, in some cases, completely eliminate sheet marking on the press brake. They are available in the most common profiles from the American and European tool style collections. • Urethane Holders and Pads Wilson Tool’s urethane holders are manufactured from 6061-T6 aluminum and hold a pad of urethane for mark free and radius bending. Two pad hardness options are available: Blue/90A is most commonly used and Red/80A helps reduce tonnage in the application by approximately 20%. • Pr otective Coverings Urethane drapes provide a protective layer across the top of your standard dies to virtually eliminate sheet marking. Our standard roll of urethane is offered in two thicknesses (.015" and .030") to fit your application. Our high density urethane offering is .022" thick, lasting significantly longer than standard urethane. URETHANE DRAPES CAT. NO. DESCRIPTION DIMENSIONS COLOR 42530 Standard .015" [.4mm] x 6" [152mm] White 42531 Standard .03" [.8mm] x 6" [152mm] White 42532 High Density .022" [.6mm] x 6" [152mm] Blue See the back page for Wilson Tool’s easy to use Protective Fabric Drape option.
    [Show full text]
  • INTRODUCTION to PRESS BRAKES a Vital Piece of Shop Equipment Introduction to Press Brakes
    INTRODUCTION TO PRESS BRAKES A Vital Piece of Shop Equipment Introduction to Press Brakes Press Brakes are utilized in the forming lengths of sheet metal components. A press brake is a vital necessity to most shops with shape cutting capabilities and is one of the most sought after and misunderstood machines available for sheet metal working. Press Brakes are rated generally by their pressing capacity, or tonnage, and their overall bending length or machine width such as 175X10 (175 Tons of pressing force by 10’ of overall length). The press brake may be fitted with a wide variety of standard and custom tooling that are used to press the material into the desired form. There are two major types of press brakes available on the used market as are described below. Mechanical A motor spins a large flywheel at high speed the A mechanical press brake is a good solution for operator then engages a clutch which can be punching applications as the shock of punching activated via pneumatic, hydraulic or mechanical material is distributed much easier due to the engagement. Once the clutch is engaged the machines design. The major disadvantages to moving flywheel is mated to a crankshaft in which mechanical press brakes is that the ram must the machines ram is attached. The crankshaft complete a full cycle, or stroke, and typically then spins cycling the ram up and down. The cannot be reversed during operation. This poses advantage to this type of press brake is that the some safety concerns and operational limitations machine is electronically simpler and, due to the as well as provides for the possibility that the crankshaft action tonnages are generally 2-3X press brake can be “locked” into an over stroke the rated capacity of the press brake at the situation where the ram has traveled too far bottom of the machines stroke.
    [Show full text]
  • Analysis of Springback Variation in V Bending
    Published by : International Journal of Engineering Research & Technology (IJERT) http://www.ijert.org ISSN: 2278-0181 Vol. 5 Issue 02, February-2016 Analysis of Springback Variation in V Bending Bhav Gautam* Praveen Kumar Vaibhav Chandra Kamal Rawat B. Tech Tool Asst. Professor Asst. Professor M.Tech Tool Engineering Engineering D.I.T.E Campus II D.I.T.E Campus II D.I.T.E Campus II D.I.T.E Campus II New Delhi, India New Delhi, India New Delhi, India New Delhi, India Abstract— In order to get exact shape and size of components in the total deformation only plastic deformation is responsible sheet metal manufacturing, springback effect plays a pivotal for the exact shape and size of the components. role. Prediction of springback angle helps in determining the amount of over-bend (i.e. springback compensation) required so that exact V bend angle can be obtained in the component. In this study an attempt has been done to analyze the springback effect for simple V-bending operation performed on CRDQ (Cold Rolled Draw Quality) with thickness of sheet varying from 2.0 to 4.0 mm. In this work Hyperform software is used for simulating the springback effect in V bending operation. The main objective is to get the variation of amount of springback for different thickness of sheets keeping bending angle (600) and punch radius (2mm) constant. The results showed that the value of springback decreases with the increase in sheet thickness (from 2 mm) up till 3.3 mm. Further increase in sheet thickness, Fig.1: Graph showing the two zones in the stress-strain curve from 3.3 mm to 4.0 mm, increases the amount of springback for V-bending of CRDQ sheet.
    [Show full text]
  • “Sheet Metal Bending Machine”
    NOVATEUR PUBLICATIONS INTERNATIONAL JOURNAL OF INNOVATIONS IN ENGINEERING RESEARCH AND TECHNOLOGY [IJIERT] ISSN: 2394-3696 VOLUME 2, ISSUE 3, March.-2015 “SHEET METAL BENDING MACHINE” Aniruddha Kulkarni Mangesh Pawar Pravin Yadav Amit Patil Sohan Jagtap Department of Mechanical Engineering, A.I.T.R.C. Vita. Prof. Sujit Malgave Department of Mechanical Engineering, A.I.T.R.C. Vita. ABSTRACT The paper deals with manufacturing or bending of sheet metal by using power operated sheet bending machine. Especially discussion made the productivity analysis of manually or power operated sheet bending machine. Considering manual operation is replaced by power operated devices .It also gives information about limitation of manually operated sheet bending machine and power operated sheet bending machine. Key Words: Shape, Bending, Cylindrical, Automatic, Hoppers, Frame, Fabrication, Production INTRODUCTION Sheet metal fabrication plays an important role in the metal manufacturing world. Sheet metal is used in the production of materials ranging from tools, to hinges, automobiles etc. Sheet metal fabrication ranges from deep drawing, stamping, forming, and hydro forming, to high-energy-rate forming (HERF) to create desired shapes. Fascinating and elegant shapes may be folded from a single plane sheet of material without stretching, tearing or cutting, if shape rolling of sheet metal is the bending continually of the piece along a linear axis. This causes alteration of the original form of the sheet as it passes through a pathway of series of rollers. The present invention relates to plate bending machines of the type which operates with rolls. Such machines involve certain well-known difficulties in respect of bending plates into conical shape.
    [Show full text]