scholarly journals An All-Atom Simulation Study of Gas Detonation Forming Technique

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 611
Author(s):  
Ambarish Kulkarni ◽  
Vispi Karkaria ◽  
Milankumar Nandgaonkar ◽  
Sandeep P. Patil ◽  
Bernd Markert
Keyword(s):  
High Speed ◽  
Md Simulations ◽  
Dome Height ◽  
Forming Process ◽  
Gas Detonation ◽  
Failure Patterns ◽  
Deformation Response ◽  
Applied Loading ◽  
Wide Range ◽  
High Speed Forming

The high-speed forming process is the key to attaining difficult and irregular profiles on ductile materials. In the present work, we proposed the all-atom model of the gas detonation forming process, wherein molecular dynamics (MD) simulations were performed on the aluminum workpiece at different loading speeds similar to the various pressure values in the process. The deformation response of an aluminum workpiece for a wide range of loading speeds, 0.1–8 Å/ps, was investigated. The dome-height, failure patterns, and formability of the aluminum workpiece were examined for these loading speeds. We obtained an inverse relationship between the formability of the aluminum workpiece and the applied loading speed. Moreover, in this work, the influence of the different percentage of defects in the workpieces on the mechanical behavior was investigated. We observed that at lower speeds (< 2 Å/ps), the deformation is observed throughout the workpiece starting from the point of contact in the middle and that is contrary to the deformations observed due to the higher loading speed where localized deformations occur due to creation of slipping planes. We also found that the internal voids lead to the rearrangement of atoms to facilitate the movement of slipping planes leading to better formability compared to the no-void workpieces. This work helps to get a fundamental understanding of deformation behavior in the high-speed forming process with and without defects in the aluminum workpiece at the nanoscale.

scholarly journals High-speed force spectroscopy: microsecond force measurements using ultrashort cantilevers

2019 ◽  
Vol 11 (5) ◽  
pp. 689-699 ◽  
Author(s):  
Claire Valotteau ◽  
Fidan Sumbul ◽  
Felix Rico
Keyword(s):  
Time Scales ◽  
High Speed ◽  
Protein Unfolding ◽  
Deep Understanding ◽  
Force Spectroscopy ◽  
Md Simulations ◽  
Living Cells ◽  
Force Measurements ◽  
Cellular Mechanics ◽  
Wide Range

Abstract Complete understanding of the role of mechanical forces in biological processes requires knowledge of the mechanical properties of individual proteins and living cells. Moreover, the dynamic response of biological systems at the nano- and microscales span over several orders of magnitude in time, from sub-microseconds to several minutes. Thus, access to force measurements over a wide range of length and time scales is required. High-speed atomic force microscopy (HS-AFM) using ultrashort cantilevers has emerged as a tool to study the dynamics of biomolecules and cells at video rates. The adaptation of HS-AFM to perform high-speed force spectroscopy (HS-FS) allows probing protein unfolding and receptor/ligand unbinding up to the velocity of molecular dynamics (MD) simulations with sub-microsecond time resolution. Moreover, application of HS-FS on living cells allows probing the viscoelastic response at short time scales providing deep understanding of cytoskeleton dynamics. In this mini-review, we assess the principles and recent developments and applications of HS-FS using ultrashort cantilevers to probe molecular and cellular mechanics.

Joining of Tubular Parts by Electromagnetic Forming; Experimental Investigations

2014 ◽  
Vol 792 ◽  
pp. 115-120 ◽  
Author(s):  
Pál Rácz ◽  
Nándor Göbl ◽  
Daniel Horváth ◽  
Athanasios G. Mamalis
Keyword(s):  
High Speed ◽  
New Technologies ◽  
Dissimilar Materials ◽  
High Energy ◽  
Mechanical Tests ◽  
Electromagnetic Forming ◽  
High Energy Density ◽  
Experimental Investigations ◽  
Forming Process ◽  
High Speed Forming

Electromagnetic forming is a high speed forming process, wherein the forming pressure is created by high energy density electromagnetic pulse. Besides direct shaping there are other application areas as well, so electromagnetic plastic forming is a potential field of creating joints between tube and rod-like components. Connecting components of dissimilar materials is an increasing demand in the manufacturing process of structures in the automotive industry. The application of new technologies, such as electrodynamic, especially electromagnetic forming, is a possible method to satisfy these demands. The article summarizes the most important fundamentals of electromagnetic forming; in particular, tube-rod joints, the main types of such joints; interference-fit and form-fit joints are described. Experiments, which were carried out producing tube-rod joints with electromagnetic forming, are also introduced. A new type of form-fit joints for tube-rod connections has been developed, which can withstand not only tensile loads but also torsion. Experiments and mechanical tests have proved the applicability of this kind of joints.

Electromagnetic Sheet Bulging: Analysis of Process Parameters by FE Simulations

2013 ◽  
Vol 554-557 ◽  
pp. 741-748 ◽  
Author(s):  
Joao Pedro M. Correia ◽  
Saïd Ahzi
Keyword(s):  
Finite Element ◽  
Process Parameters ◽  
High Speed ◽  
Finite Element Simulations ◽  
Electromagnetic Forming ◽  
Forming Process ◽  
High Speed Forming ◽  
Bulging Test ◽  
High Repeatability

Electromagnetic forming is a non-conventional forming process and is classified as a high-speed forming process. It provides certain advantages as compared to conventional forming processes: improved formability, high repeatability and productivity, reduction in tooling cost and reduction of springback and of wrinkling. However, various process parameters affect the performance of the electromagnetic forming system. Finite element simulations are very useful to optimize a process because they can reduce time and costs. With the aim of investigating the effects of the process parameters on the deformed blank geometry, finite element simulations of an electromagnetic sheet bulging test have been performed in this work. Furthermore the role of first impulse of discharged current is also investigated.

Study of Electromagnetic Forming Process on Tubular Components

2014 ◽  
Vol 592-594 ◽  
pp. 894-898
Author(s):  
K. Sriram ◽  
Karibeeran Shanmuga Sundaram ◽  
P. Arumugam
Keyword(s):  
High Speed ◽  
Electromagnetic Forming ◽  
Work Piece ◽  
Forming Process ◽  
Compression Process ◽  
Aluminium Copper ◽  
High Speed Forming ◽  
Set Up ◽  
Tubular Components ◽  
Forming Methods

Forming processes are defined as to modify the shape of a work piece by deforming it, without the removal of material. To overcome a number of longstanding problems in conventional forming methods such as low production rates, difficulty in forming light weight components etc., an alternate approach of electromagnetic forming process is introduced. Electromagnetic forming (EMF) is a high speed forming process used to form thinwalled work pieces (usually sheets and tubes) that have high electrical conductivity, such as aluminium, copper etc. Electromagnetic tube compression processes, the design of an experimental set up for electromagnetic tube compression process are discussed in detail in this paper

Electromagnetic Embossing of Optical Microstructures

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Lasse Langstädtler ◽  
Lars Schönemann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Machining Process ◽  
Average Surface Roughness ◽  
Forming Process ◽  
High Deformation Rate ◽  
Average Surface ◽  
High Deformation ◽  
Cube Corner ◽  
High Speed Forming

Electromagnetic forming (EMF) is a high-speed forming process that is already established in the macroworld. Due to its advantages like high deformation rate and cheaper tools, it is introduced to microforming. In this research, the replication of prismatic optical microstructures is investigated. EN AW-1050A (Al99.5) micrometal sheets with a thickness of 50 μm and 300 μm are electromagnetically micro-embossed. With this technique, it is possible to successfully replicate triangular cross section micro V-grooves of 86.6 μm in width and 24.1 μm in depth with an average surface roughness of Sa = 44 nm. The microstructures of the embossing tool are generated by diamond micro chiseling (DMC), a novel machining process to produce microstructures with discontinuous geometry, like miniature cube corner retro reflectors and V-grooves with well-defined endings.

Experimental and Numerical Analyses of Tubular Electrohydraulic Forming Process

2021 ◽  
Vol 871 ◽  
pp. 80-86
Author(s):  
Ya Nan Wei ◽  
Fei Fei Zhang ◽  
Bo Wei ◽  
Hui Xu ◽  
Kai He
Keyword(s):  
High Speed ◽  
Discharge Voltage ◽  
Forming Process ◽  
Electrohydraulic Forming ◽  
High Speed Forming ◽  
Forming Efficiency ◽  
History Of ◽  
Instantaneous Discharge ◽  
And Performance ◽  
Forming Methods

Electrohydraulic forming (EHF) is a kind of high speed forming process, which deforms the metal by shock wave through instantaneous discharge of high voltage in water. Compared with the traditional forming methods, this high speed forming process can greatly improve the formability of the materials. There are many processing factors that affect the forming efficiency and performance of the electrohydraulic forming process, one of which is the discharge voltage between the electrodes. In this paper, three electrohydraulic forming experiments with various die shapes were carried out under various discharge voltage conditions. And the bulge height and axial length of the aluminum alloy A6061 tubes under different conditions were compared. Besides, finite element numerical simulation was also performed to quantitatively investigate the deformation history of the tube.

On Saw-Tooth Chip Formation in High Speed Cutting GH4169

2007 ◽  
Vol 10-12 ◽  
pp. 359-363 ◽  
Author(s):  
Dong Jin Zhang ◽  
Gang Liu ◽  
X. Sun ◽  
Ming Chen
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Morphology ◽  
High Yield ◽  
Forming Process ◽  
Element Analysis ◽  
High Speed Cutting ◽  
Nickel Based Superalloy ◽  
Wide Range

The nickel-based superalloy GH4169 is a typical difficult-to-cut material, but it has been used in a good many kinds of aeronautical key structures because of its high yield stress and anti-fatigue performance at the temperature below 650°C. In this paper, finite element method (FEM) was introduced to study the saw-tooth chip forming process in detail when machining nickel-based superalloy GH4169. By the way of Lagrangian visco-elastic plastic approach, adiabatic shear band (ASB) was simulated in high speed machining condition by general commercial finite element code, and the mechanism of the adiabatic shearing phenomenon at primary shear zone was analyzed with the help of finite element analysis (FEA). The comprehensive comparisons of saw-tooth chip morphology under a wide range of cutting speed were also presented.

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