Investigation of the Forming Process of Thin-Walled Parts from a Flat Blank with Minimal Thickness Variation

2019 ◽  
Vol 62 (3) ◽  
pp. 489-497
Author(s):  
E. G. Dem’yanenko
Keyword(s):  
Thickness Variation ◽  
Forming Process ◽  
Minimal Thickness ◽  
Thin Walled

Directional Thickness Alteration of a Thin-Walled Ring Blank Using Flanging and Forming for the Purpose of Receiving Conical Part

2016 ◽  
Vol 684 ◽  
pp. 253-262 ◽  
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov
Keyword(s):  
Experimental Studies ◽  
Thickness Variation ◽  
Conical Part ◽  
Flat Area ◽  
Minimal Thickness ◽  
Elastic Punch ◽  
Thin Walled ◽  
Ring Blank ◽  
Rigid Die

In this article the flanging method of thin-walled ring blanks using the elastic punch and rigid die scheme is investigated. Presence of a cylindrical portion near the larger edge and a flat area at the side of the blank hole is mandatory. Such conditions allow producing conical parts with minimal thickness variation by altering height of the cylindrical portion. Conducted experimental studies showed that the minimal thickness variation values are not exceeding 16% for different materials and relative thicknesses less than 0,01.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

scholarly journals Simulation of plastic forming process of shells with minimal thickness fluctuations

2017 ◽  
Vol 201 ◽  
pp. 489-494
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov ◽  
A.N. Epifanov
Keyword(s):  
Forming Process ◽  
Minimal Thickness ◽  
Plastic Forming

Thickness analysis of complex two-step micro-groove on plate during rubber pad forming process

2020 ◽  
pp. 095440622093392
Author(s):  
Fei Teng ◽  
Hongyu Wang ◽  
Juncai Sun ◽  
Xiangwei Kong ◽  
Jie Sun ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thickness Variation ◽  
Forming Process ◽  
Rubber Pad Forming ◽  
Groove Structure ◽  
Thickness Variations ◽  
Accuracy Of Results ◽  
Plane Slab ◽  
Element Method

The surface groove structure has numerous functions based on their shapes. In order to make these functions developed, both new shapes and processing forms of the surface structures are being innovated. In this paper, not only the advanced rubber pad forming process is used, but also a new kind of micro-groove with two-step structures is designed. A model based on multi-plane slab method is proposed to analyze the process. According to the stress acting condition, a half of two-step micro-groove structure is divided into seven areas in the width direction. The thickness variation of plate in each area is obtained. When the shape, depth, width, and height ratio of the first and second-step micro-groove are different, the thickness variations of the plate are analyzed. In order to verify the accuracy of the model, both finite element method and pressing experiment are done. Based on the results provided by both finite element method and experiment, the accuracy of results calculated by analytical model is verified.

Scanning and Modeling of Large Thin-Walled Curved Surface Part

2011 ◽  
Vol 299-300 ◽  
pp. 810-815 ◽  
Author(s):  
Chun Wang ◽  
Xuan Ming Zhang ◽  
Xiao Wang
Keyword(s):  
Sandwich Structure ◽  
Laser Scanner ◽  
Welding Process ◽  
Point Clouds ◽  
Cnc Machining ◽  
Curved Surface ◽  
Surface Model ◽  
Forming Process ◽  
Thin Walled ◽  
Sandwich Core

The large sandwich structure composed of thin-walled aluminum alloy panels, and variable thickness of honeycomb or Polymethacrylimide (PMI) foam core is usually manufactured by pre-bonded forming process, that is pre-forming panels and sandwich core, and then curing adhesive them to be sandwich structure. Welding process of large thin-walled panel causes the panel surface to be irregular and have greater errors relative to the design surface. Simply CNC machining the sandwich core according to the design surface cannot guarantee an exact match sandwich core consistent with the panels. The actual topography of the panels must be scanned. It is proposed that the use of a new hand-held laser scanner, Handyscan to scan large thin-walled curved surface parts, of Geomagic software to handle the acquired point clouds and construct the surface model.

Researches on Control and Application of Wrinkles in the Thin-Walled Metal Plastic Forming Process

2013 ◽  
Vol 446-447 ◽  
pp. 1193-1196
Author(s):  
Zhu Lin Hu ◽  
Lian Fa Yang ◽  
Yu Lin He
Keyword(s):  
Metal Forming ◽  
Thin Metal ◽  
Forming Process ◽  
Forming Technology ◽  
Plastic Forming ◽  
The Common ◽  
Thin Walled

The thin metal plastic forming is an indispensable metal forming technology. Wrinkling is one of the common defects in plastic forming. If this kind of defects can be used properly, the formability of metal will be better. In this paper, the recent researches on the methods of identifying wrinkles, distinction of the useful wrinkles and harmful wrinkles, control and application of the wrinkles are summarized. The useful wrinkles are expected to improve the forming property.

Laser Forming of Varying Thickness Plate—Part I: Process Analysis

2005 ◽  
Vol 128 (3) ◽  
pp. 634-641 ◽  
Author(s):  
Peng Cheng ◽  
Yajun Fan ◽  
Jie Zhang ◽  
Y. Lawrence Yao ◽  
David P. Mika ◽  
...  
Keyword(s):  
Process Analysis ◽  
Scanning Speed ◽  
Spot Size ◽  
Laser Forming ◽  
Thickness Variation ◽  
Complex Structures ◽  
Forming Process ◽  
Forming Mechanism ◽  
Varying Thickness ◽  
Wide Range

High-intensity laser beams can be used to heat and bend metal plates, but the mechanisms of the laser forming (LF) process are not well understood or precisely controllable. The objective of the National Institute of Standards and Technology sponsored project “Laser Forming of Complex Structures” is to develop technologies for a controllable, repeatable laser forming process that shapes and reshapes a wide range of complex structures such as compressor airfoils that are complex 3D geometries with large thickness variation. In order to apply laser forming to complex 3D geometries, the process analysis and process synthesis (design process parameters such as scanning paths and heating conditions for a desired shape) of LF of varying thickness plate are conducted in this paper. In this study, experimental, numerical, and analytical methods are used to investigate the bending mechanism and parametric effects on the deformation characteristics of varying thickness plates. A transition of the laser forming mechanism was found to occur along the scanning path when the thickness varies. The effect of scanning speed, beam spot size, and multiple scanning on the degree of bending was investigated. The proposed analytical model can predict the bending angle and angle variations for laser forming of varying thickness plate.

Investigation into Influence of Pre-Forming Depth on Multi-Stage Hydrodynamic Deep Drawing of Thin-Wall Cups with Stepped Geometries

2012 ◽  
Vol 457-458 ◽  
pp. 1219-1222 ◽  
Author(s):  
Yu Zhu ◽  
Min Wan ◽  
Ying Ke Zhou ◽  
Qing Hai Liu ◽  
Nan Song Zheng ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Failure Modes ◽  
Thickness Distribution ◽  
Steel Part ◽  
Drawing Ratio ◽  
Thin Wall ◽  
Forming Process ◽  
Hydrodynamic Deep Drawing ◽  
Multi Stage ◽  
Thin Walled

Hydrodynamic deep drawing (HDD) is an effective method for manufacturing complicated and thin-walled parts. Aiming at the forming process of the stainless steel part with 0.4 mm thick and complex stepped geometries, the technology scheme of multi-stage HDD assisted by conventional deep drawing (CDD) is proposed in consideration of wrinkling and destabilization in the unsupported region of the conical wall, and finite element models are built. As a key process parameter, pre-forming depth on the quality of the parts is explored with assistance of numerical simulations and verification experiments. Furthermore, the failure modes, including wrinkling and fracture during forming process are discussed; meanwhile, the optimum pre-forming depth is realized. The results indicate that the technological method is proven to be feasible for integral forming of thin-walled parts with a large drawing ratio and stepped geometries; moreover, the parts with uniform thickness distribution and high quality are successfully formed by adopting optimum pre-forming depth.

Electromagnetic Metal Forming

1965 ◽  
Vol 180 (1) ◽  
pp. 93-110 ◽  
Author(s):  
K. Baines ◽  
J. L. Duncan ◽  
W. Johnson
Keyword(s):  
Aluminium Alloy ◽  
Metal Forming ◽  
Strain Distribution ◽  
Eddy Currents ◽  
High Rate ◽  
Process Efficiency ◽  
Primary Circuit ◽  
Forming Process ◽  
Current Frequency ◽  
Thin Walled

Some results of an experimental and theoretical investigation of the dynamic forming of thin-walled tubes and flat circular diaphragms by the electromagnetic metal forming process are given. The paper is divided into two parts. Part 1—The magnetic forming process is described and its use as a production technique is discussed. The process is a high strain-rate technique suitable for forming relatively light gauge material; the forces causing deformation result from the interaction of the current in specially constructed coils and the resulting eddy currents induced in the workpiece. The source of energy is a capacitor bank which can be discharged rapidly through the work-coil. The experiments described were performed using a specially constructed 16 kj discharge unit. The method of constructing work-coils and the failures experienced with these coils in service are described. Thin-walled copper and aluminium tubes were expanded by means of internal solenoidal work-coils of various lengths. The strain distribution and forming efficiency is presented, together with results showing the variation of process efficiency with changes in the primary circuit parameters. The strain distribution for a circular aluminium alloy diaphragm bulged by means of a flat spiral coil is given. Typical primary current waveforms are given and the changes in waveform and discharge current frequency due to different workpiece materials and changes in primary circuit parameters are indicated. Part 2—An attempt is made to determine theoretically the forces acting on one of the aluminium alloy tubes expanded and described in the work of Part 1. The currents in the work-coil and workpiece are calculated using the experimentally determined current waveform and the calculated value of workpiece inductance. A rudimentary method is developed for relating pressure on the workpiece to the primary and secondary currents and, using this, the radial motion of the tube is predicted. Although the analysis involves the use of a number of simplifications and approximations, the theoretical results obtained are of the same magnitude as would be expected by reference to other high-rate forming processes.

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