A Study on the Motion of Micro-Parts on a Saw-Tooth Surface by the PTV Method

Author(s):  
Phuong Hoai Le ◽  
Thien Xuan Dinh ◽  
Atsushi Mitani ◽  
Shinichi Hirai

This study investigates the motion of micro parts on several vibratory plates with saw-tooth surface profile driven by a piezoelectric actuator. The surfaces are made of carbide, brass, and zirconia with the same profiles as a saw-tooth. The velocity and position of micro-parts are time-dependently measured by the particle tracking velocimetry (PTV) method where the Canny edge detection technique is used. In the present experiment, 2012-type micro-parts whose dimensions are 2.0 × 1.2 × 0.6 mm3 in length, width, and depth, respectively, are employed. The mass of each micro-part is 7.5 mg. Using a high-speed camera, the tracked longitudinal displacement resolution is found to be about 0.01 mm, which is small in comparison with the length of each micro-part. The obtained results show that unidirectional motion can be attained by the present feeder system. For the same oscillating frequencies and amplitudes applied to the sawtooth surfaces, the motion behavior of micro-parts varies for different experiments and surfaces. This implies that the motion of micro-parts is affected by uncertain causes. However, the probability distribution of the micro-parts’ velocity can be approached by a Gaussian distribution.

2013 ◽  
Vol 740 ◽  
pp. 99-104
Author(s):  
Phuong Hoai Le ◽  
Thien Xuan Dinh ◽  
Atsushi Mitani ◽  
Shinichi Hirai

In this work, we study experimentally the effect of the geometry parameters of saw-tooth surface and micro-part on the motion of micro-parts. The experiments are performed for a range of saw-tooth pitch,p, micro-part length,l, and exciting frequency applied to the surface,f. By the use of particle tracking velocimetry method, we can achieve time-dependent velocity, and then ensemble-averaged velocity of the micro-parts. The results show that for differentlandpbut the same relative scalel/p, the profiles of micro-part velocity against the characteristic surface velocitypfare similar. However, they shift alongpfaxis depending onp. Furthermore, the profiles are the similar for the relative scalel/pof 4 to 100. It seems that the motion of micro-part depends on characteristic surface velocitypfthan the relative scalel/pforl/plarger than a certain value.


Author(s):  
Matthieu A. Andre ◽  
Philippe M. Bardet

Shear instabilities induced by the relaxation of laminar boundary layer at the free surface of a high speed liquid jet are investigated experimentally. Physical insights into these instabilities and the resulting capillary wave growth are gained by performing non-intrusive measurements of flow structure in the direct vicinity of the surface. The experimental results are a combination of surface visualization, planar laser induced fluorescence (PLIF), particle image velocimetry (PIV), and particle tracking velocimetry (PTV). They suggest that 2D spanwise vortices in the shear layer play a major role in these instabilities by triggering 2D waves on the free surface as predicted by linear stability analysis. These vortices, however, are found to travel at a different speed than the capillary waves they initially created resulting in interference with the waves and wave growth. A new experimental facility was built; it consists of a 20.3 × 146.mm rectangular water wall jet with Reynolds number based on channel depth between 3.13 × 104 to 1.65 × 105 and 115. to 264. based on boundary layer momentum thickness.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401879065 ◽  
Author(s):  
Shuai Mo ◽  
Shengping Zhu ◽  
Guoguang Jin ◽  
Jiabei Gong ◽  
Zhanyong Feng ◽  
...  

High-speed heavy-load spiral bevel gears put forward high requirement for flexural strength; shot peening is a technique that greatly improves the bending fatigue strength of gears. During shot peening, a large number of fine pellets bombard the surface of the metal target material at very high speeds and let the target material undergo plastic deformation, at the same time strengthening layer is produced. Spiral bevel gear as the object of being bombarded inevitably brought the tooth surface micro-morphology changes. In this article, we aim to reveal the effect of microtopography of tooth shot peening on gear lubrication in spiral bevel gear, try to establish a reasonable description of the microscopic morphology for tooth surface by shot peening, to reveal the lubrication characteristics of spiral bevel gears after shot peening treatment based on the lubrication theory, and do comparative research on the surface lubrication characteristics of a variety of microstructures.


2005 ◽  
Vol 295-296 ◽  
pp. 477-482
Author(s):  
K.W. Wang ◽  
Z.J. Cai ◽  
Li Jiang Zeng

A two-dimensional surface profile imaging technique based on heterodyne interferometer is proposed. A piezo translator vibrated grating is used to generate a heterodyne signal. A high speed CCD camera is used to extract the interference signal using a five step method. The uncertainty in the displacement measurement is approximately 0.035 µm within a measurement range of 1.7 µm, confirming the two dimensional heterodyne interferometer is valid for measuring the surface profile. The method is also available for low coherence heterodyne interferometer due to the optical frequency shifts caused by the vibration of grating independent on the wavelength.


Author(s):  
Allan M. Zarembski ◽  
James Blaze ◽  
Pradeep Patel

What are some of the practical obstacles to a “shared interests” between a freight railway business and the proposed new higher speed passenger entity? This paper discusses the real “tension” between the two business interests that fund freight trains versus those that support and fund higher speed passenger trains as they attempt to share the same tracks in a safe manner. There are fundamental laws of physics that have to be addressed as the two different sets of equipment are “accommodated” on a shared corridor. This may not always be an easy accommodation between the two commercial parties. One real tension between the two commercial interests involves the physical problem of accommodating two radically different train sets on areas of curved track. For one example, what will be the passenger train required future higher speeds and how will these speeds be accommodated in existing main line tracks with curves varying from 1% to 6% in degrees? How much super elevation will need to be put back into the heretofore freight train tracks? How will the resulting super elevation affect the operation of so called drag or high tonnage slow speed bulk cargo trains? Accommodating such differences in train set types, axle loadings, freight versus passenger train set speeds, requires making detailed choices at the engineering level. These may be shared interests, but they are also variables with far different outcomes by design for the two different business types. The freight railways have spent the last few decades “taking the super elevation out” because it is not needed for the modern and highly efficient freight trains. Now the requirements of the passenger trains may need for it to be replaced. What are the dynamics and fundamental engineering principles at work here? Grade crossings have a safety issue set of interests that likely require such things as “quad” gates and for the highest passenger train speeds even complete grade separation. Track accommodating very high speed passenger trains requires under federal regulations much closer physical property tolerances in gauge width, track alignment, and surface profile. This in turn increases the level of track inspection and track maintenance expenses versus the standard freight operations in a corridor. Fundamentally, how is this all going to be allocated to the two different commercial train users? What will be the equally shared cost and what are examples of the solely allocated costs when a corridor has such different train users? In summary, this paper provides a description of these shared issues and the fundamental trade-offs that the parties must agree upon related to overall track design, track geometry, track curvature, super elevation options, allowed speeds in curves, more robust protection at grade crossings, and the manner in which these changes from the freight only corridors are to be allocated given the resulting much higher track maintenance costs of these to be shared assets.


2008 ◽  
Vol 381-382 ◽  
pp. 35-38
Author(s):  
Yu Guo Cui ◽  
Bing Feng Ju ◽  
J. Aoki ◽  
Yoshikazu Arai ◽  
Wei Gao

In this paper, we applied the contact constant-height mode together with the pre-compensation technique which can realize the capability of high speed as well as faithful topographical image. Before scanning, the slope variation of the micro-structured surface was measured by the capacitance sensor and then stored in a PC. During the surface profile scanning, a piezoelectric actuator is applied which can provide the inconsecutive motion that corresponds to the pre-measured slope variation. As a result, the precision measurement can also be achieved. The validity of the proposed method and its performance are verified by compare the topographical images that were gained by the contact constant-force mode with feedback control. However, the scanning speed of our method is obviously high.


2007 ◽  
Vol 359-360 ◽  
pp. 355-359 ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Chuan Shao Liu ◽  
Xun Sheng Zhu

Ultrasonic aided high speed lapping with solid abrasive material was put forward aimed at the precision finishing of nano ZTA engineering ceramic. Through theoretical analysis and contrast lapping experiments, the influences of ultrasonic assistance on the surface machining quality were clarified. Research results show that the maximum undeformed chip thickness in ultrasonic aided lapping is smaller than that in conventional lapping under the same conditions; ultrasonic assistance is beneficial to enlarging the range of ductile lapping regime and improving the surface quality of nano ZTA ceramic; with the application of ultrasonic vibration, smaller surface roughness and more regular surface profile can be obtained.


Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  

Abstract High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.


2012 ◽  
Vol 268-270 ◽  
pp. 1349-1352
Author(s):  
Dan Liu ◽  
Xiao Long Li ◽  
Chun Xiu Wang

Abstract: Objective to acquire reasonable modification methods and values, and provide reference for gear modification of wind gearboxes. Methods the parallel level model of a MW wind gearbox is constructed which based on Romax software. To simulate the modification of high-speed gears under the method of profile modification, end relief, helical angle correction, lead crowing. Results According to the distribution of load on the tooth surface, acquired corresponding value. Conclusions Romax software greatly increase productivity, and it is a good platform for research on gear modification.


2011 ◽  
Vol 314-316 ◽  
pp. 1273-1277
Author(s):  
M. Azuddin ◽  
Z Taha ◽  
Imtiaz Ahmed Choudhury

The flow of plastic melt in macro and micro parts during the filling phase of injection molding is an interesting area to discover. The visualization technique is a common method used to understand the phenomena of polymer flow in mold cavity. Various shapes and sizes were fabricated on aluminum molds embedded with Polymethyl Methacrylate (PMMA) as observation window. Electrical discharge machining (EDM) and micro mechanical machining method were employed to fabricate plastic parts shape on aluminum mold cavity. This paper focuses and discusses in detail on the Polypropylene (PP) melt flow injected using a custom made vertical injection molding machine. The PP melt flow can be clearly seen through the PMMA window and captured using high speed camera. The captured images are then compared with result from commercially available plastic injection molding software, Autodesk MoldFlow. It was found that there is good agreement for macro plastic parts but not for the micro parts. It can be concluded that, the analysis software has less capability in predicting the flow of melt plastic in micro parts.


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