scholarly journals Material flow control in plunge micro rotary swaging

2018 ◽  
Vol 190 ◽  
pp. 15014 ◽  
Author(s):  
Eric Moumi ◽  
Philipp Wilhelmi ◽  
Christian Schenck ◽  
Marius Herrmann ◽  
Bernd Kuhfuss
Keyword(s):  
Material Flow ◽  
Axial Direction ◽  
Axial Position ◽  
Rotary Swaging ◽  
Roll To Roll ◽  
Axial Forces ◽  
Micro Parts ◽  
Special Challenge ◽  
Axial Shift ◽  
Process Measurements

In rotary swaging, the material flow is not fully controlled by closure of the forming dies. This is especially noticeable in plunge rotary swaging of rod, where the workpiece is positioned into the forming zone und processed locally. As result, an uncontrolled elongation of the workpiece in axial direction takes place and an axial position shift of the workpiece relative to the dies occurs. This is a special challenge in production of linked micro parts, where single parts are interconnected in order to enable the handling as a strip and thereby a roll-to-roll production. The axial shift influences not only the subsequent positioning of neighbouring parts, but also the final geometry of the currently processed part. The presented investigation analyses the material flow during plunge micro rotary swaging on basis of in-process measurements of the workpiece shift on both sides of the forming zone as well as with the help of contour measurements of the processed parts. It is shown that the measured shift is strongly influenced by the workpiece clamping and fixation and that it can be controlled by applying low axial forces to the workpiece on one or both sides of the forming zone. Further, the geometry of the workpiece can be affected by these measures.

scholarly journals High productivity micro rotary swaging

2018 ◽  
Vol 190 ◽  
pp. 15002 ◽  
Author(s):  
Eric Moumi ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Material Flow ◽  
Process Variations ◽  
Main Process ◽  
Forming Process ◽  
Workpiece Material ◽  
High Productivity ◽  
Rotary Swaging ◽  
Micro Parts ◽  
Intensive Investigation ◽  
Clamping Device

Rotary swaging is an incremental forming process with two main process variations plunge and infeed rotary swaging. With plunge rotary swaging, the diameter is reduced within a limited section whereas the infeed rotary swaging enables a diameter reduction over the entire workpiece length. The process is now subject to intensive investigation for manufacturing of micro parts. By increasing the process speed, failures occur particularly due to inappropriate material flow. In plunge rotary swaging, the workpiece material can flow radially into the gap between the dies and thus the workpiece quality suffers. In infeed rotary swaging the workpiece material flows against the feeding direction and can provoke bending or braking of the workpiece. Therefore, additional measures to control both the radial and the axial material flow to enable high productivity micro rotary swaging are investigated. The radial material flow during plunge rotary swaging can be controlled by elastic intermediate elements that enable an increase of productivity by factor three. A spring-loaded clamping device that enables an increase of the productivity by factor four can temporarily buffer the axial material flow in infeed rotary swaging against the feeding direction.

scholarly journals The first observation of 4D tomography measurement of plasma structures and fluctuations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chanho Moon ◽  
Kotaro Yamasaki ◽  
Yoshihiko Nagashima ◽  
Shigeru Inagaki ◽  
Takeshi Ido ◽  
...  
Keyword(s):  
Steady State ◽  
Three Dimensional ◽  
Axial Direction ◽  
Axial Position ◽  
Entire Cross Section ◽  
Helicon Plasma ◽  
Emission Profile ◽  
Dimensional Measurement ◽  
Tomography System ◽  
Three Dimensional Measurement

AbstractA tomography system is installed as one of the diagnostics of new age to examine the three-dimensional characteristics of structure and dynamics including fluctuations of a linear magnetized helicon plasma. The system is composed of three sets of tomography components located at different axial positions. Each tomography component can measure the two-dimensional emission profile over the entire cross-section of plasma at different axial positions in a sufficient temporal scale to detect the fluctuations. The four-dimensional measurement including time and space successfully obtains the following three results that have never been found without three-dimensional measurement: (1) in the production phase, the plasma front propagates from the antenna toward the end plate with an ion acoustic velocity. (2) In the steady state, the plasma emission profile is inhomogeneous, and decreases along the axial direction in the presence of the azimuthal asymmetry. Furthermore, (3) in the steady state, the fluctuations should originate from a particular axial position located downward from the helicon antenna.

Register control of roll-to-roll gravure-offset printing equipment considering time difference between measurement and actuation

2012 ◽  
Vol 226 (11) ◽  
pp. 2726-2738 ◽  
Author(s):  
Chung Hwan Kim ◽  
Ha-Il You ◽  
Seung-Hyun Lee
Keyword(s):  
Measurement System ◽  
Position Control ◽  
Printed Electronics ◽  
Control Method ◽  
Axial Direction ◽  
Time Difference ◽  
Offset Printing ◽  
Drying Time ◽  
Roll To Roll ◽  
The Web

The manufacture of printed electronics by roll-to-roll printing machine requires more accurate register performance than conventional media printing technology. Moreover, high drying temperature and long drying time to sinter the inks can induce the substantial changes in the length of the substrate and consequently register errors. Among the roll-to-roll printing methods, the gravure one, despite its relatively fast productivity and fine-line printing capacity, has difficulty in achieving the required register specifications for printed electronics because of the dependence of the register control on web dynamics. This study proposes a roll-to-roll gravure-offset printing equipment, including the register measurement system designed to enhance register performance and the related register control method for the application of printed electronics. Each cylinder constituting the printing unit is driven independently by an individual servomotor. Moreover, the printing patterns of the plate cylinder can move in the axial direction by position control, as well as in the web transport direction by a phase shift of the plate cylinder, without affecting the dynamics of the web. The time difference between the measurement and the actual control action is considered and modeled. The register measurement system, including selections of sensors and marks is also proposed to consider the effect of the time difference. The simulation results and the experiments of the register control are shown to verify the effect of the time difference on the control performances. It is found that a proper estimation of time difference should be obtained in order to guarantee more accurate and stable control performances.

Advances In The Modeling And Dynamic Simulation of Reeving Systems Using The Arbitrary Lagrangian-Eulerian Modal Method

2021 ◽  
Author(s):  
José L. Escalona ◽  
Narges Mohammadi
Keyword(s):  
Finite Elements ◽  
Axial Force ◽  
Axial Direction ◽  
Rotary Inertia ◽  
Arbitrary Lagrangian Eulerian ◽  
Original Formulation ◽  
Absolute Position ◽  
Axial Forces ◽  
Modal Coordinates ◽  
Modal Method

Abstract This paper presents new advances in the arbitrary Lagrangian-Eulerian modal method (ALEM) recently developed for the systematic simulation of the dynamics of general reeving systems. These advances are related to a more convenient model of the sheaves dynamics and the use of axial deformation modes to account for non-constant axial forces within the finite elements. Regarding the sheaves dynamics, the original formulation uses kinematic constraints to account for the torque transmission at the sheaves by neglecting the rotary inertia. One of the advances described in this paper is the use of the rotation angles of the sheaves as generalized coordinates together with the rope-to-sheave no-slip assumption as linear constraint equations. This modeling option guarantees the exact torque balance the sheave without including any non-linear kinematic constraint. Numerical results show the influence in the system dynamics of the sheave rotary inertia. Regarding the axial forces within the finite elements, the original formulation uses a combination of absolute position coordinates and transverse local modal coordinates to account for the rope absolute position and deformation shape. The axial force, which only depends on the absolute position coordinates, is constant along the element because linear shape functions are assumed to describe the axial displacements. For reeving systems with very long rope spans, as the elevators of high buildings, the constant axial force is inaccurate because the weight of the ropes becomes important and the axial force varies approximately linearly within the rope free span. To account for space-varying axial forces, this paper also introduces modal coordinates in the axial direction. Numerical results show that a set of three modal coordinates in the axial direction is enough to simulate linearly varying axial forces.

scholarly journals Axial and Radial Material Flow Analysis in Infeed Rotary Swaging of Tubes

2018 ◽  
Vol 190 ◽  
pp. 04003 ◽  
Author(s):  
Yang Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Wall Thickness ◽  
Material Flow ◽  
Flow Direction ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Relative Wall Thickness ◽  
Cold Forming ◽  
Rotary Swaging ◽  
Fundamental Insight ◽  
Actual Ratio

In rotary swaging – an incremental cold forming production technique to reduce the diameter of axisymmetric parts – the material flow can be assumed to be predominantly axial and radial. The actual ratio of this axial and radial flow influences the mechanical properties and especially in tube forming the final geometry. It is known that during mandrel free infeed rotary swaging of tubes the wall thickness changes. The change is depending on the process parameters like incremental and cumulated strain. Hence, the ratio of axial and radial material flow changes. Consequently, the analysis of the wall thickness of rotary swaged tubes enables fundamental insight how to control the material flow direction. In this study, the infeed rotary swaging process of steel tubes with different wall thicknesses from 3 mm to 7 mm and rods were investigated with FEM under two feeding velocities. The axial and radial material flow and the resulting geometry were studied by the relative wall thickness. It could be seen that the relative wall thickness was affected by the feeding velocity as well as the initial wall thickness. The findings of the simulation were validated by rotary swaging experiments.

Solutions for Increasing the Bearing Capacity of Thrust Bearings

2014 ◽  
Vol 630 ◽  
pp. 208-219 ◽  
Author(s):  
Vasyl Martsynkovskyy ◽  
Volodymyr Yurko
Keyword(s):  
Bearing Capacity ◽  
Oil Consumption ◽  
Thrust Bearings ◽  
Consumption Ratio ◽  
Operating Modes ◽  
Axial Forces ◽  
High Efficient ◽  
Petroleum Chemical ◽  
Axial Shift ◽  
Rotor Balancing

Design faults, imperfect manufacturing processes, change of technological operating modes of the turbocompressors in gas, petroleum, chemical and petrochemical industry cause axial rotor shifts. Therefore, the task of manufacturing the high-efficient and reliable thrust bearings is important nowadays along with effective rotor balancing, methods of axial forces calculation considering possible operating modes, improvement of static electricity elimination system, protective and monitoring systems of the axial shift. Effective methods for increasing the bearing capacity of thrust bearings, applied by TRIZ Ltd, have been studied in the report. The accepted and realized on the operating equipment solutions have enabled to increase the bearing capacity of thrust bearings significantly and to reduce oil consumption ratio, keeping down location dimensions to the equipment.

scholarly journals Optical trapping by petal-like circular Airy beam

2020 ◽  
Author(s):  
Vahid Shahabadi ◽  
Daryoush Abdollahpour
Keyword(s):  
Optical Trapping ◽  
Radial Distance ◽  
Transverse Field ◽  
Axial Direction ◽  
Axial Position ◽  
Trapped Particles ◽  
Airy Beam ◽  
Tight Focusing ◽  
New Type ◽  
Beam Parameters

Abstract Superposition of two circular Airy vortex beams (CAVB), with opposite sign topological charges (l), produces a new type of petal beams called petal-like circular Airy beam (PCAB) with a transverse field distribution in the form of azimuthally modulated concentric rings that follow Airy function over the radial distance on a transverse plane. In this paper, tight focusing of truncated PCAB and its application in optical trapping is numerically investigated. It is shown that by adjusting the beam parameters four different trapping configurations can be achieved: a single transverse trap at a single axial position, a multi-trap geometry at a single axial position, two single transverse traps at two positions along the axial direction, and two multi-trap geometries at two different axial positions. It is also shown that the number of trapped particles in the multi-trap configurations is 2l per focal plane, while the number of axial trap positions is determined by the truncation aperture size. Finally, trap stiffnesses and corresponding potential energies for the trapping configurations are presented and discussed.

Lateral-Axial Pipe/Soil Interaction Events: Numerical Modelling Trends and Technical Issues

2012 ◽  
Author(s):  
Kenton Pike ◽  
Shawn Kenny
Keyword(s):  
Shear Stress ◽  
Axial Direction ◽  
Cohesive Soil ◽  
Considerable Effect ◽  
Lateral Interaction ◽  
Stress Limit ◽  
Axial Forces ◽  
Reaction Forces ◽  
Technical Issues ◽  
Definition Of

In predicting the geotechnical constraint against pipeline movement, it is imperative to properly account for frictional behavior at the pipe-soil interface, especially in the axial direction. The translation angle of the pipeline varies in reality; hence the effects of this variance must be captured in relation to the interaction forces in the lateral, axial and vertical directions. This study focuses on lateral-axial pipeline movement in cohesive soil material. The main finding of the present study is that the incorporation of a shear stress limit in the definition of tangential shear behavior has a considerable effect on the axial pipeline reaction forces. Without the shear stress limit, the axial forces are effectively doubled in comparison to a limit equal to half of the undrained shear strength. There is less of an effect on lateral interaction.

scholarly journals Technical Applicability of Low-Swirl Fuel Nozzle for a Liquid-Fueled Industrial Gas Turbine Combustor

2012 ◽  
Author(s):  
Masamichi Koyama ◽  
Shigeru Tachibana
Keyword(s):  
Gas Turbine ◽  
Flow Characteristics ◽  
Axial Direction ◽  
Flame Stabilization ◽  
Axial Position ◽  
Axial Distance ◽  
Gas Turbine Combustor ◽  
Lifted Flame ◽  
Fuel Nozzle ◽  
Industrial Gas Turbine

This paper explores the technical applicability of a low-swirl fuel nozzle designed for use with a liquid-fueled industrial gas turbine combustor. Particle image velocimetry was applied to measure nozzle flow fields with an open methane-air premixed flame configuration. Herein we discuss the effects of the chamfer dimensions of the nozzle tip on flow characteristics. The profiles indicate parallel shifts in axial direction that depend on chamfer dimensions. When velocity is normalized by bulk velocity and plotted against axial distance from the virtual origins, the profiles are consistent. This means that chamfer dimensions primarily affect the axial position of the flame, while keeping other flow characteristics, such as global stretch rate, unchanged. Then, the atmospheric combustion test was conducted with kerosene in a single-can combustor. Lifted flame stabilization was confirmed by observing the flames through a window. Lastly, an engine test was performed to assess the technical applicability of the fuel nozzle under real engine conditions. The engine testbed was a 290 kW simple-cycle liquid-fueled gas turbine engine. The configurations of the fuel nozzle were consistent with the ones used in the PIV and the atmospheric combustion test. Wall temperatures close to the fuel nozzle exit were within the acceptable range, even without the cooling air required with conventional combustors. This is an advantage of the lifted flame stabilization technique. NOx emissions were below maximum levels set under current Japanese regulations (<84 ppm@15% O2). In sum, the proposed fuel nozzle design shows promise for use with liquid-fueled industrial gas turbine engines.

Investigation of Microstructure and Hardness in Microfoming of Pure Copper Pins

2010 ◽  
Vol 447-448 ◽  
pp. 381-385
Author(s):  
Ehsan Ghassemali ◽  
Anders W.E. Jarfors ◽  
Ming Jen Tan ◽  
Samuel C.V. Lim ◽  
Mei Qian Chew
Keyword(s):  
Mechanical Properties ◽  
Material Flow ◽  
Strain Distribution ◽  
Pure Copper ◽  
Extrusion Process ◽  
Optical Microscope ◽  
Gradient Distribution ◽  
Micro Scale ◽  
Part Geometry ◽  
Micro Parts

Microforming is defined as the process of production of metallic micro-parts with sub-millimeter dimension. There is as strong interaction between the scale of the microstructure and the size of the part affecting material flow, the so-called “size effect” in microforming processes. Conventional forming rules cannot be directly applied to the micro-scale forming. To better understand the implications for part geometry and properties, further investigation of the material flow related events is necessary. The aim of this work is to investigate microstructural evolution of pure copper during a micro-extrusion process - for production of micro-pins with diameters varying from 300 to 800µm - by means of optical microscope (OM). Qualitative strain gradient distribution could be observed by those pictures. The results showed that change of micro-pins diameter and die angle affect the microstructure and strain distribution of the final product remarkably, that affect the mechanical properties of the pin formed. Furthermore, microhardness results were consistent with the microstructural observations.

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