scholarly journals Design of a Tri-Axial Force Measurement Transducer for Plantar Force Measurements

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Weizi Li ◽  
Roberto Dugnani
Keyword(s):  
Dynamic Range ◽  
Force Measurement ◽  
Pressure Sensors ◽  
Rehabilitation Medicine ◽  
Measurement Transducer ◽  
Force Measurements ◽  
Normal Loading ◽  
Shear Loads ◽  
Plantar Force ◽  
External Loads

Transducers for spatial plantar force measurements have numerous applications in biomechanics, rehabilitation medicine, and gait analysis. In this work, the design of a novel, tri-axial transducer for plantar force measurements was presented. The proposed design could resolve both the normal and the shear forces applied at the foot's sole. The novelty of the design consisted in using a rotating bump to translate the external loads into axial compressive forces which could be measured effectively by conventional pressure sensors. For the prototype presented, multilayer polydimethylsiloxane (PDMS) thin-film capacitive stacks were manufactured and used as sensing units, although in principle the design could be extended to various types of sensors. A quasi-static analytic solution to describe the behavior of the transducer was also derived and used to optimize the design. To characterize the performance of the transducer, a 3 cm diameter, 1 cm tall prototype was manufactured and tested under various combination of shear and normal loading scenarios. The tests confirmed the ability of the transducer to generate strong capacitive signals and measure both the magnitude and direction of the normal and shear loads in the dynamic range of interest.

Flow-Induced Vibration of a Large-Diameter Elbow Piping Based on Random Force Measurement Caused by Conveying Fluid: Visualization Test Results

2005 ◽  
Author(s):  
Tomomichi Nakamura ◽  
Tadashi Shiraishi ◽  
Yoshihide Ishitani ◽  
Hisato Watakabe ◽  
Hiromi Sago ◽  
...  
Keyword(s):  
Force Measurement ◽  
Large Diameter ◽  
Pressure Fluctuations ◽  
Pressure Sensors ◽  
Maximum Flow ◽  
Axial Direction ◽  
Random Force ◽  
Test Facility ◽  
Flow Induced Vibration ◽  
Correlation Lengths

A 1/3 scale flow-induced vibration test facility that simulates the hot-leg piping of the JNC sodium-cooled fast reactor (JSFR) is used to investigate the pressure fluctuations of the pipe, where the high velocity fluid flows inside the piping. By the measurement of the pressure drop in the elbow piping while changing the Reynolds number, the similarity law of this model is confirmed. To evaluate the flow-induced vibrations for the hot-leg and cold-leg pipes, the random force distributions along the pipe and their correlations are measured with pressure sensors in a water loop. It is found that a flow velocity-dependent periodic phenomenon in the rear region of the elbow, and the maximum flow-induced random vibration force in the pipe are observed in the region of flow separation downstream the elbow. Finally, a design method is proposed with power spectral densities of the pressure fluctuations classified into four sections, correlation lengths in the axial direction divided into three sections, and with correlation lengths in the tangential direction into four sections.

scholarly journals Force measurement goes to femto-Newton sensitivity of single microscopic particle

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiaohe Zhang ◽  
Bing Gu ◽  
Cheng-Wei Qiu
Keyword(s):  
Thermal Noise ◽  
Force Measurement ◽  
Force Measurements ◽  
Weak Force ◽  
Microscopic Particle ◽  
Highly Sensitive

AbstractHighly sensitive force measurements of a single microscopic particle with femto-Newton sensitivity have remained elusive owing to the existence of fundamental thermal noise. Now, researchers have proposed an optically controlled hydrodynamic manipulation method, which can measure the weak force of a single microscopic particle with femto-Newton sensitivity.

Erfahrungen mit alternativen Kraftmessungen/Experiences with alternative force measurements - Comparing sensor-integrated toolholders to traditional piezo-based measurement technology

2020 ◽  
Vol 110 (01-02) ◽  
pp. 24-31
Author(s):  
Patrick Georgi ◽  
Ssrah Eschelbacher ◽  
Thomas Stehle ◽  
Hans-Christian Möhring
Keyword(s):  
Cutting Force ◽  
Force Measurement ◽  
Milling Process ◽  
The Other ◽  
Strain Gauges ◽  
Measurement Technology ◽  
Optimal Parameters ◽  
Force Measurements ◽  
Measuring Systems ◽  
The One

Die Prozessüberwachung spielt in der Zerspanung eine immer wichtiger werdende Rolle. So können zum Beispiel mittels Zerspankraftmessungen ökonomisch optimierte Parameter in Zerspanprozessen gefunden werden, die zu einer Verbesserung der Auslastung von Werkzeug und Maschine führen. Des Weiteren kann über die Zerspankraft auf den aktuellen Verschleißzustand der Werkzeuge im Prozess sowie auf die jeweils erreichbare Bearbeitungsgenauigkeit zurückgeschlossen werden. Für Zerspankraftmessungen gibt es eine Vielzahl an zur Verfügung stehenden Kraftmesssystemen; zum einen traditionelle Messtechnik auf Basis von Piezosensoren zur Kraftmessung und zum anderen Kraftmesstechnik auf der Basis von Dehnmessstreifen (DMS). Dieser Beitrag untersucht die Kraftaufnahme bei Fräs- und Bohrprozessen, bei denen beide Kraftmesssysteme simultan eingesetzt wurden.   Process monitoring plays an increasingly important role in machining. For example, through cutting force measurements, it is possible to find economically optimal parameters in the milling process, which lead to an improvement in the utilization of the tool and the machine. Furthermore, the cutting force can be used to deduce the state of wear of the tools in the process. There are varieties of available force measuring systems for this purpose; on the one hand, traditional measuring technology based on piezo sensors for force measurement and the other force measuring technology based on strain gauges (strain gauges). This article examines the force absorption in milling and drilling processes where both force-measuring systems were used simultaneously.

Development and Validation of a Wearable Plantar Force Measurement Device

2019 ◽  
Vol 19 (11) ◽  
pp. 4008-4016
Author(s):  
Lachlan B. McMillan ◽  
Theodor Di Pauli Von Treuheim ◽  
Anna Murphy ◽  
Ayse Zengin ◽  
Peter R. Ebeling ◽  
...  
Keyword(s):  
Force Measurement ◽  
Measurement Device ◽  
Plantar Force ◽  
Development And Validation

Force Measurements and Stationarity Analysis on the Flow Around a Single Square Column With Rounded Edges

2019 ◽  
Author(s):  
Dennis Gambarine ◽  
Arjen Koop ◽  
Gustavo Assi ◽  
Fabiano Rampazzo ◽  
Rodolfo T. Gonçalves
Keyword(s):  
Force Measurement ◽  
Offshore Wind ◽  
Column Height ◽  
Force Measurements ◽  
Offshore Wind Turbines ◽  
Hydrodynamic Behaviour ◽  
Floating Offshore Wind Turbines ◽  
Single Column ◽  
Sharp Edges ◽  
Current Incidence

Abstract Studies about the flow around single column are the preliminary way to understand the behaviour of multi-column systems, e.g. semi-submersible platforms and floating offshore wind turbines. The presence of a rounded edge in a square column can include advantages in the constructive phases, on the other hand, can include difficulty in understanding the hydrodynamic behaviour. With this aim this paper presents a 2dof force measurement for a fixed single square column with and without rounded edges. The columns tested have the aspect ratio (H/L) equal to 1.5 representing the typical column height for multi-column platforms. The aim is to investigate the forces between a single square column with rounded edges and sharp edges in different flow incidence. For both edges a total of seven different current incidence angles were performed; 0, 7.5, 15, 22.5, 30, 37.5 and 45. Reynolds number used for the experiment is equal to 40,000. Additional tests were performed to evaluate a quantitative analysis of the uncertainties due to the repeatability and time length of the experiments. This procedure is necessary for the VV studies of CFD codes, and due to this, the database can be utilized for benchmarking.

FORCE CALIBRATION OF NANO UNIVERSAL TESTING MACHINE USING MILLIGRAM WEIGHTS

2013 ◽  
Vol 24 ◽  
pp. 1360031
Author(s):  
CHUNG-LIN WU ◽  
CHING-FEN TUAN
Keyword(s):  
Force Measurement ◽  
Testing Machine ◽  
Calibration Method ◽  
Force Transducer ◽  
Force Measurements ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Small Force ◽  
Force Calibration ◽  
Force Range

This paper presents an approach for calibrating the force transducer on the nano universal testing machine using milligram weights. Previous research on force calibration of such a system focused on the range from 10 mN to 200 mN, ignoring forces below 10 mN. The main purpose of this study is to analyze and calculate the uncertainty of force measurements within the range from 0.2 mN to 10 mN. The ABA calibration method in accordance with OIML R111-1 is adopted to determine the uncertainty in force measurement. The results indicate that the maximum relative uncertainty of force measurement is 7.0 × 10−3 with a 95% confidence level. The investigation can be used as the basis for evaluating measurement uncertainty of the system in small force range.

A New Support Structure in Waverider Force Measurement

2013 ◽  
Vol 318 ◽  
pp. 96-99
Author(s):  
Xue Jun Zhao ◽  
Xiao Guo Guo ◽  
Chang Zhao
Keyword(s):  
Wind Tunnel ◽  
Force Measurement ◽  
Test Results ◽  
Force Measurements ◽  
Support Structure ◽  
Inlet Flow ◽  
Hypersonic Wind Tunnel ◽  
Vehicle Aerodynamics ◽  
Set Up ◽  
Opening And Closing

In this paper a new support structure was given to solve the problem met in the force measurement with engine jet. The force measurements of waverider were undertaken in the hypersonic wind tunnel. The test condition was at Ma=6, angle of attack α=-6°-6°, at which we researched the effects on the vehicle aerodynamics of inlet cowl opening and closing, support system, engine jet, and pressure ratios. To decrease the effects of strut on the jet flow-field, we took sharp belly strut to support the model in the wind tunnel. The belly strut could support the waverider model, force measurement balance, and it could make the inlet flow set up, and provide the high pressure jet. The test results showed that the belly sharp strut had little effects on the flowfield and could inject the inlet flow, and could provide very high quality jet.

On the force fluctuations acting on a circular cylinder in crossflow from subcritical up to transcritical Reynolds numbers

1983 ◽  
Vol 133 ◽  
pp. 265-285 ◽  
Author(s):  
Günter Schewe
Keyword(s):  
Reynolds Number ◽  
Critical Reynolds Number ◽  
Dynamic Range ◽  
Reynolds Numbers ◽  
Band Spectrum ◽  
Transitional Region ◽  
Force Measurements ◽  
Unsteady Forces ◽  
Number Range ◽  
Critical Reynolds Numbers

Force measurements were conducted in a pressurized wind tunnel from subcritical up to transcritical Reynolds numbers 2.3 × 104[les ]Re[les ] 7.1 × 106without changing the experimental arrangement. The steady and unsteady forces were measured by means of a piezobalance, which features a high natural frequency, low interferences and a large dynamic range. In the critical Reynolds-number range, two discontinuous transitions were observed, which can be interpreted as bifurcations at two critical Reynolds numbers. In both cases, these transitions are accompanied by critical fluctuations, symmetry breaking (the occurrence of a steady lift) and hysteresis. In addition, both transitions were coupled with a drop of theCDvalue and a jump of the Strouhal number. Similar phenomena were observed in the upper transitional region between the super- and the transcritical Reynolds-number ranges. The transcritical range begins at aboutRe≈ 5 × 106, where a narrow-band spectrum is formed withSr(Re= 7.1 × 106) = 0.29.

scholarly journals Insights into the mechanisms of myosin and kinesin molecular motors from the single-molecule unbinding force measurements

2010 ◽  
Vol 7 (suppl_3) ◽  
Author(s):  
Sergey V. Mikhailenko ◽  
Yusuke Oguchi ◽  
Shin'ichi Ishiwata
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Force Measurements ◽  
Cellular Functions ◽  
Mechanochemical Cycle ◽  
The Individual ◽  
Experimental Geometry ◽  
External Loads ◽  
Individual Motor

In cells, ATP (adenosine triphosphate)-driven motor proteins, both cytoskeletal and nucleic acid-based, operate on their corresponding ‘tracks’, that is, actin, microtubules or nucleic acids, by converting the chemical energy of ATP hydrolysis into mechanical work. During each mechanochemical cycle, a motor proceeds via several nucleotide states, characterized by different affinities for the ‘track’ filament and different nucleotide (ATP or ADP) binding kinetics, which is crucial for a motor to efficiently perform its cellular functions. The measurements of the rupture force between the motor and the track by applying external loads to the individual motor–substrate bonds in various nucleotide states have proved to be an important tool to obtain valuable insights into the mechanism of the motors' performance. We review the application of this technique to various linear molecular motors, both processive and non-processive, giving special attention to the importance of the experimental geometry.

scholarly journals Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Yuanyuan Li ◽  
Wenke Lu ◽  
Changchun Zhu ◽  
Qinghong Liu ◽  
Haoxin Zhang ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Circuit Design ◽  
Force Measurement ◽  
Pressure Sensors ◽  
Force Sensor ◽  
Piezoresistive Sensor ◽  
Detection Circuit ◽  
Micro Force Sensor ◽  
The Stability

Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW) based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established to analyze the frequency, and a peripheral circuit is designed to measure the micro force. The SAW based micro force sensor is tested to show the reasonable design of detection circuit and the stability of frequency and amplitude.

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