Flyer Thickness Effect in the Impact Welding of Aluminum to Steel

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Taeseon Lee ◽  
Shunyi Zhang ◽  
Anupam Vivek ◽  
Brad Kinsey ◽  
Glenn Daehn
Keyword(s):  
High Speed ◽  
Solid Mechanics ◽  
Weld Interface ◽  
Thickness Effect ◽  
Oblique Collision ◽  
Mechanics Model ◽  
Material Processing Technology ◽  
Impact Welding ◽  
The Impact ◽  
Collision Angle

Impact welding is a material processing technology that enables metallurgical bonding in the solid state using a high-speed oblique collision. In this study, the effects of thickness of the flier and collision angle on weld interface morphology were investigated through the vaporizing foil actuator welding (VFAW) of AA1100-O to AISI 1018 Steel. The weld interfaces at various controlled conditions show wavelength increasing with the flier thickness and collision angle. The AA1100-O flier sheets ranged in thickness from 0.127 to 1.016 mm. The velocity of the fliers was directly measured by in situ photon Doppler velocimetry (PDV) and kept nearly constant at 670 m/s. The collision angles were controlled by a customized steel target with a set of various collision angles ranging from 8 deg to 28 deg. A numerical solid mechanics model was optimized for mesh sizes and provided to confirm the wavelength variation. Temperature estimates from the model were also performed to predict local melting and its complex spatial distribution near the weld interface and to compare that prediction to experiments.

Evaluation of Sliding Behavior of Simple Structures for Oblique Collision

2014 ◽  
Vol 566 ◽  
pp. 611-616
Author(s):  
Takeru Watanabe ◽  
Naoya Nishimura ◽  
Hiroka Watanabe ◽  
Syouta Nakadate ◽  
Katsuhiko Murase
Keyword(s):  
Contact Surface ◽  
High Speed ◽  
Simple Structure ◽  
Impact Test ◽  
Testing Machine ◽  
Impact Testing ◽  
Oblique Collision ◽  
Before And After ◽  
Collapse Behavior ◽  
The Impact

When a simple structure collides with inclined barrier, behavior and deformation of the structure after impact are different in the case in which the structure slides on a contact surface or the case in which it does not slide. In order to investigate the structural collapse behavior for oblique collided structure, therefore, it is important to clarify the sliding behavior of the structure on the contact surface. The sliding behavior of the structure during collision was estimated according to theoretically obtained the equation considering the equilibrium of change in the momentum and the impulse before and after the collision. For evaluating the sliding behavior of the simple structure, the impact test by the drop type impact testing machine was carried out to collide with inclined barrier. In the impact test, the circular plate of 60 mm diameter and 10 mm thickness was used as the simple structure, and impacted with various collision velocities (range from 2 to 6 m/s). The sliding behavior of the simple structure at the collided surface was observed by high speed camera, and evaluated by the image analysis. The theoretical result was compared to evaluate with experimental results.

Dissimilar-Metal Joining Using Several Types of High-Speed Solid-State Welding Methods

2014 ◽  
Vol 794-796 ◽  
pp. 357-364
Author(s):  
Shinji Kumai
Keyword(s):  
Solid State ◽  
High Speed ◽  
Welding Process ◽  
Physical And Mechanical Properties ◽  
Diffusion Welding ◽  
Joint Interface ◽  
Friction Stir ◽  
Dissimilar Metal ◽  
Impact Welding ◽  
The Impact

Solid-state welding is useful to join dissimilar metal couples, in particular, with a large difference in physical and mechanical properties. However, conventional solid-state welding methods such as diffusion welding and roll bonding are not necessarily applicable to all metal combinations. In addition, they are time-consuming. In the present study, various dissimilar metal joints (e.g. Al/Fe, Al/Cu, Al/Ni, A2024/A5052, A6022/steel, A6022/Plated steel, A2024/AZ80) were fabricated by using several types of high-speed solid-state welding methods; friction stir spot welding, advanced stud welding and impact welding. The strength and characteristic interfacial morphology of the joints were investigated, and each joining mechanism is discussed. In particular, for the impact welding, both experimental and numerical analyses were performed. Two metal sheets were obliquely collided at a very high speed and joined by magnetic pressure or explosive force. Smoothed Particle Hydrodynamics (SPH) method was used to simulate the impact welding process. The emission of metal jet and the evolution of characteristic wavy interface at the joint interface could be clearly visualized. The effects of collision angle, collision velocity and difference in density of the metals on the wave morphology were revealed.

A Novel Method to Investigate the Principles of Impact Welding: Development and Enhancement of a Test Rig, Experimental and Numerical Results

2014 ◽  
Vol 966-967 ◽  
pp. 500-509 ◽  
Author(s):  
Christian Pabst ◽  
Semen Sharafiev ◽  
Peter Groche ◽  
Martin F.X. Wagner
Keyword(s):  
High Speed ◽  
Transient Behavior ◽  
Grain Structure ◽  
Test Rig ◽  
Safe Operation ◽  
High Speed Imaging ◽  
Impact Welding ◽  
Novel Method ◽  
Pulse Welding ◽  
The Impact

The two common processes of impact welding, explosion welding and electromagnetic pulse welding, may offer great technological advantages, but at the same time exhibit poor observability due to the use of explosives and a highly transient behavior, respectively. A novel test rig is developed and enhanced to collide and weld specimens purely mechanically. Besides its simple build-up and the easy and safe operation, the test rig allows setting crucial process parameters almost independently. The test rig’s construction and improvement is described. A trigger method for high speed imaging is developed and tested. The numerical simulation of the impact shows that the conditions directly at the welding zone are predictable and can be adjusted accurately. Finally, the preparation of specimens to evaluate the influence of surface roughness and grain structure is discussed.

Bearings Influence on the Dynamic Behavior of HSM Spindle

2012 ◽  
Author(s):  
David Noel ◽  
Mathieu Ritou ◽  
Sebastien Le Loch ◽  
Benoit Furet
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Design Parameters ◽  
Mechanics Model ◽  
Bearing Stiffness ◽  
Rough Milling ◽  
The Impact

The aeronautic industry requires high speed and high power spindles to obtain high material removal rates during long rough milling operations. The weakness of HSM spindle is the bearings, although high precision hybrid ball bearings have been developed to achieve this critical application. Inadequate use of spindles inevitably leads to shortened lifetimes. Choosing the operating conditions is a required step before machining applications. It can be achieved through either experimental tests or numerical modeling that leads to stability lobe diagrams. Stability of cuts relies on the dynamic behavior of the spindle, which is particularly due to the eigenfrequencies of the tool-shaft assembly. The frequencies depend on bearing stiffness that can change under operating conditions. That is why the impact of cutting conditions and bearing parameters on its stiffness are studied in the paper. A five degrees of freedom model of angular ball bearing is briefly presented. A complete bearing model is introduced. The originality of the approach is the complete technological modeling, notably of the radial expansions of inner and outer rings of bearing. A non-linear expression is established from continuum mechanics model. The influence of geometry of bearing, operating conditions and design parameters of spindle on the bearing stiffness are established and analysed. Then, modal analyses of the tool-spindle assembly are carried out in relation to the varying bearing stiffness. Finally, significance of the approach is demonstrated through the analyses of Frequency Response Function.

Analysis of mechanochemical reaction in dual shot peening

2021 ◽  
pp. 1-19
Author(s):  
Ye Qi ◽  
Vinh Nguyen ◽  
Shreyes Melkote ◽  
Michael Varenberg
Keyword(s):  
Shot Peening ◽  
High Speed ◽  
Solid Mechanics ◽  
Iron Sulfide ◽  
Orthogonal Cutting ◽  
High Speed Steel ◽  
Local Maximum ◽  
Impact Angle ◽  
Mechanochemical Reaction ◽  
The Impact

Abstract Using a combination of solid mechanics and reaction kinetics models, this work simulates a mechanochemical reaction in dual shot peening with a mixture of Al2O3 and Cu2S particles used to form a tribologically beneficial iron sulfide layer on treated surfaces. The model predicts that the dissociation of the Fe-Fe and Cu-S bonds needed for the formation of Fe-S bonds accelerates monotonically with increase in the shot peening particle speed, whereas its rate reaches a local maximum at the impact angle of about 75 deg. The latter finding is validated by treating the rake faces of high-speed steel cutting tools and performing orthogonal cutting experiments in which the tools peened at the impact angle of 75 deg exhibit lower cutting and thrust forces than those peened at 40 deg. Additional peening parameters, namely, the particle volume ratio and the stage speed are found to be much less statistically significant under the conditions tested. The developed approach may be instrumental in guiding process optimization to improve the tribological performance of mechanochemically treated surfaces.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

The Impact of High-Speed Rail on the Spatial Structure of Chinese Urban Agglomerations

2020 ◽  
Vol 46 (3) ◽  
pp. 379-397
Author(s):  
Chunyang Wang
Keyword(s):  
High Speed ◽  
River Delta ◽  
City Size ◽  
High Speed Rail ◽  
Local Conditions ◽  
Urban Agglomerations ◽  
Large Cities ◽  
Spatial Systems ◽  
Economic Concentration ◽  
The Impact

This paper measures the spatial evolution of urban agglomerations to understand be er the impact of high-speed rail (HSR) construction, based on panel data from fi ve major urban agglomerations in China for the period 2004–2015. It is found that there are signi ficant regional diff erences of HSR impacts. The construction of HSR has promoted population and economic diff usion in two advanced urban agglomerations, namely the Yang e River Delta and Pearl River Delta, while promoting population and economic concentration in two relatively less advanced urban agglomerations, e.g. the middle reaches of the Yang e River and Chengdu–Chongqing. In terms of city size, HSR promotes the economic proliferation of large cities and the economic concentration of small and medium-sized cities along its routes. HSR networking has provided a new impetus for restructuring urban spatial systems. Every region should optimize the industrial division with strategic functions of urban agglomeration according to local conditions and accelerate the construction of inter-city intra-regional transport network to maximize the eff ects of high-speed rail across a large regional territory.

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