Displacement Meter Research Articles

Structure and size of ions electrochemically doped in conducting polymer

Among electroactive polymers (EAPs) for softactuators, conducting polymers have been intensively studied because of the large strain and stress caused by a low voltage operation. A larger deformation is desirable to extend their cycle life by reducing the operation voltage, and this is advantageous for their potential use in wider applications. The deformation is generated by the insertion of ions by electrochemical oxidation; hence, the magnitude of the strain depends on the bulkiness of the ions in the electrolytes. It is important, therefore, to clarify the structure and size of the ions during the electrochemical cycle, in order to achieve better performance of actuation.Anion and cation sizes (radii) in polypyrrole (PPy) film have been estimated using the precise measurement of strain against the amount of charge injected during the electrochemical cycles, assuming isotropic deformation of the film. The anion size was estimated using an anion-drive film, which was electrodeposited in TBABF4/methyl benzoate. The film was electrochemically cycled in sodium electrolytes, and the strain was measured simultaneously using a laser displacement meter. The cation size was obtained using a cation-drive film, being electropolymerized in aqueous dodecylbenzene sulfonic (DBS) acid. The cation-drive film was cycled in chloride electrolytes and measured the strain. The Cl−, Br−, , , and radii were found to be approximately 235, 245, 250, 270 and 290 pm, respectively. The radii of K+, Na+ and Li+ were approximately 230, 237 and 274 pm, respectively. The results were discussed and took the crystalline ion radius and hydrated ion radius (Stokes radius) into consideration. It was found that the structure and size of the anions were slightly larger than the crystalline ion radius. Contrary to the anions, the cation radii were close to the hydrated ion radius, being larger than the crystalline ion radius.

Experimental Study of Water Film Dynamics Under Wind Shear and Gravity

Aircraft icing poses a serious threat to flight safety. Unfrozen impinging water on the surface of the aircraft will run back under the effect of high-speed airflow, altering liquid distribution and heat transfer characteristics. In this paper, a series of experiments are conducted over a wide range of wind speeds (), film Reynolds numbers (), and inclined angles (, , ) to investigate the dynamics of thin water film on an aluminum substrate. The superficial morphology of the water film is investigated by a high-speed camera, and the instantaneous film thicknesses are measured by a laser focus displacement meter based on a confocal chromatic technique. The interface shape is found to consist of an underlying thin film and multiple scaled fluctuations; therefore, the results are divided into two parts for analysis: the mean film thickness and the root-mean-square thickness. A relationship between the mean film thickness and the wind speed, the film Reynolds number, the inclined angle is proposed. After nondimensionalized processing based on the triangular relationship, the averaged film thickness data agree with the previous model of an error within 25%. New correlations to calculate the interfacial shear stress and superficial roughness are suggested within the experimental range.

Research on Formation Process of Zonal Disintegration in Deep Rock Mass Based on Field Monitoring and Geomechanical Model Test

The zonal disintegration phenomena in deep rock mass will appear with the increase of underground engineering depth which is widely different from shallow cavern. In order to reveal the formation process and production mechanism of zonal disintegration, the field monitoring is carried out in the deep tunnel of China’s Huainan mining area. With the help of borehole television, the zonal disintegration is observed which is alternation phenomenon of the rupture zone and non-rupture zone. At the same time, using the multi-point displacement meter, the whole process change law of the deep displacement in surrounding rock is tested. Taking the field monitoring deep tunnel as engineering background, the 3D geomechanical model test is carried out based on the high stress 3D loading test system. The typical zonal disintegration phenomenon is observed, and the whole process change law of displacement and strain is measured. Based on comprehensive analysis of the whole process test data of the model test and the field monitoring data, the following conclusions are obtained. Under certain stress conditions, zonal disintegration will appear in the surrounding rock of deep tunnel. The zonal disintegration will not occur at the moment of tunnel excavation, but it will be gradually formed after the excavation completion for a period of time.

Mechanical model of human eye compliance for volumetric occlusion break surge measurements

To develop a mechanical model of human eye compliance for volumetric studies. Alcon Research, Ltd., Lake Forest, California, USA. Experimental study. Enucleated human eyes underwent pressurization and depressurization cycles with peak intraocular pressures (IOPs) of 60 to 100mm Hg; anterior chamber pressure and volume changes were measured. Average net volume change curves were calculated as a function of IOP for each eye. Overall mean volumes were computed from each eye's average results at pressure points extrapolated over the range of 5 to 90 mm Hg. A 2-term exponential function was fit to these results. A fluid chamber with a displaceable piston was created as a mechanical model of this equation. A laser confocal displacement meter was used to measure piston displacement. A test bed incorporated the mechanical model with a mounted phacoemulsification probe and allowed for simulated occlusion breaks. Surge volume was calculated from piston displacement. An exponential function, V = C1 × exp(C2 × IOP) + C3×exp(C4×IOP)-V0, where V, the volume, was fit to the final depressurization curve obtained from 15 enucleated human eyes. The C1 through C4 values were -0.07141, -0.23055, -0.14972, and -0.02006, respectively. The equation was modeled using a piston system with 3 parallel springs that engaged serially. The mechanical model mimicked depressurization curves observed in human cadaver eyes. The resulting mechanical compliance model measured ocular volumetric changes and thus would be helpful in characterizing the postocclusion break surge response.

Estimation of ion dimension doped in conducting polymers electrochemically

ABSTRACTElectroactive conducting polymers are suitable for soft actuators (artificial muscles). The actuation is induced by electrochemical oxidation of conducting polymer (film) in an electrolyte solution, due to insertion of bulky counter ions (dopant ions). The magnitude of deformation (strain) depends on the size of dopant ions and the degree of oxidation. It is worthwhile to know the relationship between the magnitudes of deformation and ion size. An electrodeposited Polypyrrole film was electrochemically cycled in aqueous electrolytes of NaCl, NaBr, NaNO3, NaBF4 and NaClO4. The strain of film during electrochemical oxidation and reduction was precisely measured using a laser displacement meter and a handmade apparatus. From the strain and electrical charges inserted in the film during oxidation, the volumes and radii of dopant ions were estimated, assuming the isotropic expansion of the film. The estimated anion radii of Cl-, Br-, NO3-, BF4- and ClO4- were 235, 246, 250, 270 and 290, respectively. The results were discussed taking the crystallographic and hydrated ion radii in literatures into consideration.

Accurate Online Measurement of Iron Concentration in Galvannealed Coating Layers by Shift of X-ray Diffraction Peak

The authors have developed a new online measurement system for the Fe concentration in galvannealed (GA) coating layers based on the proportionality between the X-ray diffraction (XRD) peak angle of the δ1 phase and the Fe concentration. The online system was realized by high speed measurement of the XRD peak angle by a one-dimensional detector and use of a correction algorithm for the angular error caused by the displacement of the GA strip surface from the measurement position. The XRD profile and displacement were simultaneously measured by the one-dimensional detector and a laser displacement meter, respectively. The high accuracy of this new online system was demonstrated in a continuous galvanizing line with GA steel strips of Si-added and Si-free base steels. The developed system showed sufficiently high accuracy even with the Si-added base steel, with which adequate accuracy could not be obtained with conventional online systems, based on the diffracted intensity of the Γ phase, due to the suppression of Γ phase formation. Since the δ1 phase is the major phase of the GA layers, the main advantage of the developed system is that its accuracy is less sensitive to the composition of the base steel. The developed system can be applied to other online measurement applications in the steel industry for various purposes such as measurement of phase transition, orientation, crystallinity, strain and other features.

Detection principle and verification of non-contact displacement meter with pico-meter resolution

Detection principle and verification of non-contact displacement meter with pico-meter resolution

Depth of Floor Failure of Stope with Medium-Thickness Coal Seam

In rock mechanics, the problem of floor failure of a coal seam must be solved for mining coal above a confined aquifer. In this study, we aim to build an analytical mechanical model of coal-seam-floor failure based on plasticity theory and the Mohr–Coulomb failure criterion. Based on an analysis of the geological and hydrological conditions in the Chenghe mining area and factors affecting water inrush from the floor of the coal seam No. 5 coal, we introduce a failure coefficient ξ for the mass of floor rock of the coal seam. We monitor floor displacement and the depth of floor failure by using a displacement meter and drilling a peep hole, respectively, in working face No. 5206 of coal seam No. 5 of the inclined shaft of the Wangcun Coal Mine in the Chenghe mining area. The results indicate a maximum floor failure of 11.5 m deep immediately under the working face. A comparison of the results of calculations with those of the in situ measurements reveals a high anastomotic degree, which provides a technical reference for determining the effective confining bed thickness for mining under pressure. This approach is expected to increase the safety of the mining process at the Dongjiahe Coal Mine and other similar mines.

Using XXY Table to Construct a Verticality Calibrator and its Error Analysis

In this work, according to the characteristics of analytes, using XXY table and angular displacement tables to construct an automatic verticality measurement and correction system for three axes. For the purpose of measuring and correcting the spatial verticality of analytes in three axial directions, in this study, using a XXY table and angular displacement tables to set up a simulate carrier, these tables are driven by a four axes motion controller to adjust their posture, and then utilizing five laser displacement meters and self-developed signal processing program to carry out the measurement work. The system sets five laser displacement sensors in the surroundings of analytes respectively, and using the measured data by laser displacement sensors to calculate the yaw, pitch and roll angles of the analytes. Finally, by the four axes motion controller to adjust the motion of these tables, let laser light perpendicular to the surface of analytes as far as possible to achieve the goal of this system. After the experimental verification, the average error is not more than 0.0417 degrees.

Investigation of Hydraulic-Mechanical Properties of Paste Backfill Containing Coal Gangue-Fly Ash and Its Application in an Underground Coal Mine

Backfilling is widely used to control surface subsidence and stope stability to improve pillar recovery. Furthermore, it is also an effective way to process and dispose of mining waste such as coal gangue and tailings. In this study, the hydraulic-mechanical properties of cemented paste backfill materials (CPB) were investigated. Twenty-eight cemented coal gangue-fly ash backfill mixtures were prepared with different water, cement, fly ash and coal gangue content and the slump, segregation and water bleeding ratio tests were conducted. Increasing fly ash content increased the slump value and decreased the segregation value of the slurry. The uniaxial compressive strength (UCS) of the cemented coal gangue-fly ash backfill samples were tested at different curing times. Based on the test results, an optimized recipe was used for the field trial. Longwall cut and backfilling mining method was used in the 2300 mining district to recycle the coal pillar between longwall 2301 and 2302. Both stress and displacement meters were installed in the goaf and their performance was monitored continuously. An increase in stress and displacement values were observed to occur with the working face advanced (up to 325 m and 375 m, respectively); thereafter, a trend of stabilization was observed. The monitoring results suggest that the backfills can efficiently control the roof movement and surface subsidence as well as improve pillar recovery.

A versatile and fully instrumented test station for piezoelectric energy harvesters

This paper describes the implementation of LabVIEW software to control instruments and acquire data from a piezoelectric energy harvesting test station which is based on a cantilever structure. The experiment is run in the Clean Energy Laboratory on the Ambient Energy Harvester Test Station. A digital multimeter, a programmable resistance selector, an arbitrary waveform generator, a shaker table, an accelerometer and a laser displacement sensor are used to control and acquire data in terms of harvested energy as a function of vibration frequency and load resistance. LabVIEW software is used to control the test station which makes near real-time data measurements, displays waveforms on a PC screen, and stores data for later analysis. Acquired waveforms are presented in terms of frequency versus voltage of the vibrating cantilever at preselected ranges of load resistances in terms of either AC or DC voltages. The vibration of the cantilever beam is measured with an accelerometer and beam movement is measured with a laser displacement meter. Test results are stored in a comma separated variable text file which can be imported into any data analysis software package. All experiments are performed on an isolated optical bench to avoid interference from mechanical noise that may exist in the surrounding environment. The system provides an integrated approach to characterize key performance indicators for energy harvesting materials and devices.

Deflection of elastic beam with SMA wires eccentrically inserted

This research is intended to investigate the ability of shape memory alloys (SMA), through its activation, in generating loads to control beam deflection. An elastic beam is formed by sandwiching eccentrically SMA wires between two elastic plates. SMA wires are activated by electrical current from the power supply. Laser displacement meter (LDM) is used to measures deflection of sample. Results show that the deflection of the beam is dependent on the temperature change. The temperature-deflection response also shows the existence of hysteresis.

Behavior Evaluation of Retaining Wall by Eco-SB Displacement Meter

Behavior Evaluation of Retaining Wall by Eco-SB Displacement Meter

Detection Principle and Verification of Non-contact Displacement Meter with Pico-meter Resolution

Detection Principle and Verification of Non-contact Displacement Meter with Pico-meter Resolution

Plasma Skimming in a Spiral Groove Bearing of a Centrifugal Blood Pump.

Plasma skimming is a phenomenon in which discharge hematocrit is lower than feed hematocrit in microvessels. Plasma skimming has been investigated at a bearing gap in a spiral groove bearing (SGB), as this has the potential to prevent hemolysis in the SGB of a blood pump. However, it is not clear whether plasma skimming occurs in a blood pump with the SGB, because the hematocrit has not been obtained. The purpose of this study is to verify plasma skimming in an SGB of a centrifugal blood pump by developing a hematocrit measurement method in an SGB. Erythrocyte observation using a high-speed microscope and a bearing gap measurement using a laser confocal displacement meter was performed five times. In these tests, bovine blood as a working fluid was diluted with autologous plasma to adjust the hematocrit to 1.0%. A resistor was adjusted to achieve a pressure head of 100 mm Hg and a flow rate of 5.0 L/min at a rotational speed of 2800 rpm. Hematocrit on the ridge region in the SGB was measured using an image analysis based on motion image of erythrocytes, mean corpuscular volume, the measured bearing gap, and a cross-sectional area of erythrocyte. Mean hematocrit on the ridge region in the SGB was linearly reduced from 0.97 to 0.07% with the decreasing mean bearing gap from 38 to 21 μm when the rotational speed was changed from 2250 to 3000 rpm. A maximum plasma skimming efficiency of 93% was obtained with a gap of 21 μm. In conclusion, we succeeded in measuring the hematocrit on the ridge region in the SGB of the blood pump. Hematocrit decreased on the ridge region in the SGB and plasma skimming occurred with a bearing gap of less than 30 μm in the hydrodynamically levitated centrifugal blood pump.

Rebound Vibration of Two-Plates Bonded Model for an Internal Mirror of SLR Camera

In this study, the rebound vibration characteristics of the internal mirror of an SLR camera are investigated using experimental models. The mechanism of the mirror rebound phenomena is tested by using the two-rectangular-metal-plates model, which has two plates bonded by double-sided tape. The mirror (plates) model is supported by fixing its longitudinal edge on a horizontal rotatable shaft. The bonded-mirror-model swings down freely around a horizontal axis and hits a stopper. A laser displacement meter is used to measures the amount of rebound and the mirror model vibration behavior. The rebound angle varies by the stopper position and the bonded position of the double-sided tape. In the case of a small rebound angle, the mirror part of the plate (upper side plate) vibrates with large amplitude, and its movement is measured by a 3-dimentional high-speed camera.

Development of a method to test the pressurized absorption characteristics of lightweight aggregate

The pores of lightweight aggregates (LWAs) cause problems with the quality control and pumpability of lightweight aggregate concrete (LWAC), but offer a number of advantages in terms of weight saving and insulation. This paper presents pre-research for evaluating and predicting the pumpability of LWAC, which includes a test method developed for determining the pressurized absorption characteristics of LWAs. The test equipment needed for this consists of a pressure vessel combined with a plug to approximate a pump piston and provide pressurization by means of a loading device. A displacement meter is also included to measure the range of plug movement during pressurization. The testing procedure consists of six steps: adjustment of water levels, aggregate input, greasing, alignment, deaeration within the vessel, and finally pressurization with measurement. Equations to estimate porosity and provide a reference load-displacement curve are derived from the results of testing hollow spheres, and then applied to determining the absorbed void volume ratio of aggregate under pressure from the displacement of the plug. The pressurized absorptive characteristics of LWAs are also estimated by comparing the slope of their load-displacement curve to the reference curve. This reveals that the displacement of LWAC is highly dependent on the displacement of the LWA it contains.

An experimental study of a circular cylinder's two-degree-of-freedom motion induced by vortex

This paper presents results of an experimental investigation of vortex-induced vibration (VIV) of a flexibly mounted and rigid cylinder with two-degrees-of-freedom with respect to varying ratio of in-line natural frequency to cross-flow natural frequency, f∗, at a fixed low mass ratio. Combined in-line and cross-flow motion was observed in a sub-critical Reynolds number range. Three-dimensional displacement meter and tension meter were used to measure dynamic responses of the model. To validate the results and the experiment system, x and y response amplitudes and ratio of oscillation frequency to cross-flow natural frequency were compared with other experimental results. It has been found that the higher harmonics, such as third and more vibration components, can occur on a certain part of steel catenary riser under a condition of dual resonance mode. In the present work, however, due to the limitation of a size of circulating water channel, the whole test of a whole configuration of the riser at an adequate scale for VIV phenomenon was not able to be conducted. Instead, we have modeled a rigid cylinder and assumed that the cylinder is a part of steel catenary riser where the higher harmonic motions could occur. Through the experiment, we have found that even though the cylinder was assumed to be rigid, the occurrence of the higher harmonic motions was observed in a small reduced velocity (Vr) range, where the influence of the in-line response is relatively large. The transition of the vortex shedding mode from one to another was examined by using time history of x and y directional displacement over all experimental cases. We also observed the influence of in-line restoring force power spectral density with f∗.

Construction Monitoring Methods of FCM Bridge UsingTemperature Data

In this study, we have proposed a method of monitoring of bridges under construction in view of the long-term behavior of the prestress concrete bridge of which the Free Cantilever Method is applied. As a method to confirm the ability of the long-term behavior of the concrete box girder, temperature sensors and strain gauges were installed, and the measured data was used to calculate creep coefficient. Moreover, we have measured the stress of the concrete box girder during construction which was applied with creep coefficient and compared with the changes in temperature to analyze the vertical displacement along the segment. In conclusion, monitoring of the FCM bridge during construction in consideration of the long-term behavior can be analyzed efficiently by suing temperature and displacement data without the use of laser displacement meter or laser delfectometer.이 연구에서는 현장타설 캔틸레버공법(free cantilever method)을 적용한 PSC(prestressed concrete) 교량에 콘크리트의 장기거동을 고려한 시공 중 계측분석 방법을 제안하였다. 콘크리트 박스 거더의 장기 거동에 따른 응력을 확인하기 위해 온도센서와 변형률계를 함께 설치하고 계측된 데이터를 이용하여 크리프계수를 산출하였다. 또한 크리프계수를 적용한 콘크리트 박스 거더의 시공 중 응력을 분석하고 설치된 온도 센서의 변화 데이터를 비교하여 세그먼트 시공에 따른 연직변위를 분석하였다. 연구결과, 교량의 장기 거동을 고려한 FCM 교량의 시공 중 계측은 레이저 변위계나 처짐계를 사용하지 않고 온도와 변위 데이터만을 이용하여 효율적인 분석이 가능한 것으로 나타났다.

디지털 영상처리를 이용한 사장교의 변위 측정

본 논문은 돌산대교 모형 사장교에 하중을 주었을 때 발생되는 변위를 측정하기 위한 방법으로 디지털 영상처리 방법을 도입하여 실험을 하였다. 돌산대교 모형 사장교는 30:1로 축소한 경우로 길이 15.5m, 너비 400mm이다. 실험 방법은 영상처리 결과를 ANSYS 해석결과와 변위계 측정결과를 비교, 분석하여 영상처리 기법의 타당성을 검증하였다. 본 실험에 적용된 영상처리 기법은 상호상관 계수를 적용하였으며, 실험 조건은 100kgf 재하 하였을 때의 변위와 200kgf 재하 하였을 때의 변위를 측정하는 실험을 수행하였다. 분석 결과 하중이 추가적으로 증가하여 발생되는 변위가 커질수록 영상처리에 대한 신뢰성도 증가하는 것으로 나타났다. 즉, 하중이 100kgf에서 200kgf으로 증가할 때, ANSYS 결과대비 오차율이 31%에서 14%로 감소하였으며, 변위계 결과대비 오차율 역시 17%에서 4%로 감소하였다. 200kgf 재하시 14%, 4%의 차이를 보이고 있어, 영상처리 기법으로 충분히 변위를 측정할 수 있을 것으로 판단된다. 향후 연구로는 동영상 파일로 부터 고유진동수를 측정하는 방법에 대해서 연구하고자 한다. This paper introduces a method of measuring the displacement of a cable-stayed bridge using digital image processing (DIP). The validity of the DIP technique was confirmed by comparing the results with those obtained using a displacement meter and ANSYS analysis. The normalized cross-correlation (NCC) coefficient was used. 100 kgf and 200 kgf loading experiments were carried out, which showed that when the displacement is large, the reliability of the DIP technique is increased. That is, when the load was increased from 100 kgf to 200kgf, it decreased from 31% to 14% compared to the ANSYS results and from 14% to 4% compared to the displacement meter results. Therefore, the image processing method is able to measure the displacement sufficiently accurately.