scholarly journals Induction of Highly Dynamic Shock Waves in Machining Processes with Multiple Loads and Short Tool Impacts

2019 ◽  
Vol 9 (11) ◽  
pp. 2293 ◽  
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Shock Waves ◽  
High Speed ◽  
Short Pulse ◽  
Milling Process ◽  
Manufacturing Processes ◽  
Speckle Photography ◽  
Machining Processes ◽  
Initial State ◽  
Multiple Loads ◽  
Measurement Results

In order to study the mechanical loads of a workpiece in manufacturing processes such as single-tooth milling, in-process measurements of workpiece deformations are required. To enable the resolution of shock waves due to the mechanical impact of the tool, a novel measurement system based on speckle photography is introduced to measure the dynamic deformations and strains with a high temporal and spatial resolution. The measurement results indicate deformations and strains propagating through the workpiece with the speed of sound triggered by the tool impact (i.e., the tool impact is shown to induce shock waves during milling). Finite element simulations of the workpiece behavior are performed in addition, which support the experimental findings. In the considered case, the dynamic excitation subsides after 300 ms. Hence, in processes with even shorter cyclic multiple loads, the tool encounters an already excited initial state during machining, which needs to be taken into account when precisely modeling the milling process and the resulting workpiece quality. Finally, the measurement results demonstrate that speckle photography in combination with modern high-speed cameras and compact short-pulse lasers provides a deeper understanding of individual manufacturing processes.

Analysis and Research of High Speed Milling of Thin-Walled Bracket Part Based on UG NX

2010 ◽  
Vol 129-131 ◽  
pp. 256-260
Author(s):  
Yi Shu Hao ◽  
Chuang Hai ◽  
Xin Xing Zhu
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Structural Features ◽  
Milling Process ◽  
Analysis Method ◽  
Three Dimensional Model ◽  
Machining Processes ◽  
Element Analysis ◽  
High Speed Milling ◽  
Tool Paths

Treating high speed milling theory as the guidance, this paper researched high speed milling process of bracket part based on UG NX. Combined with the structural features of bracket part, three dimensional model is built by UG NX CAD and machining processes are worked out after analysis. UG CAM module was applied to fabricate tool paths. At last, finite element analysis method is introduced to study the processing deformation by UG NX NASTRAN module, based on which measures to restrain processing deformations is advanced and processing sequences are optimized.

Based on Pro/E High Speed Milling of Thin-Walled Stents of Research

2011 ◽  
Vol 295-297 ◽  
pp. 2487-2491
Author(s):  
Jian Qiang Wang
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Structural Features ◽  
Milling Process ◽  
Analysis Method ◽  
Three Dimensional Model ◽  
Machining Processes ◽  
Element Analysis ◽  
High Speed Milling ◽  
Tool Paths

Treating high speed milling theory as the guidance, this paper researched high speed milling process of bracket part based on Pro/E. Combined with the structural features of bracket part, three dimensional model is built by Pro/E and machining processes are worked out after analysis. Pro/E module was applied to fabricate tool paths. At last, finite element analysis method is introduced to study the processing deformation by Pro/E module, based on which measures to restrain processing deformations is advanced and processing sequences are optimized.

Three-Dimensional Imaging through Shock-Waves at Ultra-High Speed.

2018 ◽  
Author(s):  
Yi Chen Mazumdar ◽  
Michael E. Smyser ◽  
Jeffery Dean Heyborne ◽  
Daniel Robert Guildenbecher
Keyword(s):  
Shock Waves ◽  
High Speed ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Ultra High Speed

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

Wear resistance and cutting performance of high-speed steel ball nose end mills related to the initial state of tool surface

Wear ◽  
2021 ◽  
Vol 472-473 ◽  
pp. 203711
Author(s):  
A.S. Chaus ◽  
M.V. Sitkevich ◽  
P. Pokorný ◽  
M. Sahul ◽  
M. Haršáni ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
High Speed Steel ◽  
Steel Ball ◽  
Cutting Performance ◽  
Initial State ◽  
Tool Surface ◽  
End Mills

scholarly journals Influence of a closed-loop controlled laser metal wire deposition process of S Al 5356 on the quality of manufactured parts before and after subsequent machining

2021 ◽  
Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Closed Loop ◽  
Deposition Process ◽  
Metal Wire ◽  
Machining Process ◽  
Machining Processes ◽  
Initial State ◽  
Additive Process ◽  
Shape Accuracy ◽  
Loop Control

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

scholarly journals Towards Efficient Milling of Multi-Cavity Aeronautical Structural Parts Considering ACO-Based Optimal Tool Feed Position and Path

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
Yupeng Xin ◽  
Yuanheng Li ◽  
Wenhui Li ◽  
Gangfeng Wang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Milling Process ◽  
Ant Colony ◽  
Machining Accuracy ◽  
Ant Colony Optimization Algorithm ◽  
Peripheral Milling ◽  
Structural Part ◽  
Milling Method ◽  
Structural Parts

Cavities are typical features in aeronautical structural parts and molds. For high-speed milling of multi-cavity parts, a reasonable processing sequence planning can significantly affect the machining accuracy and efficiency. This paper proposes an improved continuous peripheral milling method for multi-cavity based on ant colony optimization algorithm (ACO). Firstly, by analyzing the mathematical model of cavity corner milling process, the geometric center of the corner is selected as the initial tool feed position. Subsequently, the tool path is globally optimized through ant colony dissemination and pheromone perception for path solution of multi-cavity milling. With the advantages of ant colony parallel search and pheromone positive feedback, the searching efficiency of the global shortest processing path is effectively improved. Finally, the milling programming of an aeronautical structural part is taken as a sample to verify the effectiveness of the proposed methodology. Compared with zigzag milling and genetic algorithm (GA)-based peripheral milling modes in the computer aided manufacturing (CAM) software, the results show that the ACO-based methodology can shorten the milling time of a sample part by more than 13%.

scholarly journals Nickel-Based Alloy Dry Milling Process Induced Material Softening Effect

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3758 ◽  
Author(s):  
Jun Zha ◽  
Zelong Yuan ◽  
Hangcheng Zhang ◽  
Yipeng Li ◽  
Yaolong Chen
Keyword(s):  
High Speed ◽  
Softening Temperature ◽  
Milling Process ◽  
Dry Milling ◽  
Milling Force ◽  
Softening Effect ◽  
Milling Temperature ◽  
Nickel Based Alloy ◽  
Alloy Softening ◽  
Milling Forces

Improving the cutting efficiency is the major factor for improving the processing of nickel-based alloys. The novelty of this research is the calibrated SiAlON ceramic tool dry milling nickel-based alloy process. Firstly, the nickel-based alloy dry milling process was analyzed through the finite element method, and the required milling force and temperature were deduced. Then, several dry milling experiments were conducted with the milling temperature, and the milling force was monitored. The change in cutting speeds was from 400 m/min to 700 m/min. Experimental results verified the reduction of the dry milling force hypothesized by the simulation. The experiment also indicated that with a cut depth of 0.3 mm, cut width of 6 mm, and feed per tooth of 0.03 mm/z, when milling speed exceeded 527.52 m/min, the milling force began to decrease, and the milling temperature exceeded the nickel-based alloy softening temperature. This indicated that easy cutting could be realized under high-speed dry milling conditions. The interpolation curve about average temperature and average milling forces showed similarity to the tensile strength reduction with the rise of temperature.

Effect of Machining Parameters and Wear Mechanism in Milling Mold Steel AISI-P20 and AISI-1050

2014 ◽  
Vol 590 ◽  
pp. 294-298
Author(s):  
Pichai Janmanee ◽  
Somchai Wonthaisong ◽  
Dollathum Araganont
Keyword(s):  
Wear Mechanism ◽  
Feed Rate ◽  
High Speed ◽  
Removal Rate ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Aisi P20 ◽  
Steel Aisi ◽  
Quality Surface

In this study, effect of machining parameters and wear mechanism in milling process of mold steel AISI-P20 and AISI-1050, using 10 mm twin flute type end mill diameter. The experimental results found that characteristics of milling surfaces and wear of the mill end were directly influenced by changes of parameters for all test conditions. As a result, the quality of milling surfaces also changed. However, mould steels which had the good quality surface is AISI-1050, with roughnesses of 2.120 μm. Quality milling surfaces were milled by using the most suitable parameter feed rate of 45 mm/min, a spindle speed of 637 rpm and a cut depth level of 3 mm, for both grades. Moreover, material removal rate and duration of the milling process, the milling end mills affect wear of the edge in every bite when the feed rate is low, high speed and level depth of cut at least. It was found that limited wear less will affect the surface roughness (Ra) represents the good quality surface.

Sign in / Sign up

Export Citation Format

Share Document