A new strain gauge configuration on the rail web to decouple the wheel–rail lateral contact force from wayside measurement

2019 ◽  
Vol 233 (9) ◽  
pp. 951-960 ◽  
Author(s):  
Feng Yu ◽  
Michael T Hendry
Keyword(s):  
Contact Force ◽  
Strain Gauge ◽  
Wheatstone Bridge ◽  
Contact Forces ◽  
Strain Gauges ◽  
Bending Moments ◽  
Electric Resistance ◽  
Lateral Contact ◽  
Vertical Contact ◽  
Good Agreement

The simultaneous presence of bending moments and torques produced by the lateral and vertical contact forces between the wheel and the rail generates a complex strain state on the rail surface, which makes it difficult to identify the strain signals produced purely from the lateral contact force. In this study, a new strain gauge configuration is proposed to decouple strain signals of the wheel–rail lateral contact force from wayside measurements by analyzing the bending strains on the rail web using a full Wheatstone bridge. For this purpose, a finite element modeling of the wheel–rail contact is performed to analyze the bending strains on the rail web and to optimize two instrumented sections for eight electric resistance strain gauges. Laboratory testing is also used to examine the installation scheme of the strain gauges at the two optimal instrumented sections. A good agreement is observed between the experimental data and the simulation results. Strain signals are evenly distributed for about 10 cm in the middle region between the two optimal instrumented sections and only account for the lateral contact force.

scholarly journals POSSIBILITIES AND METHODS OF IN-FLIGHT LOADING MEASUREMENT

Aviation ◽  
2012 ◽  
Vol 16 (2) ◽  
pp. 47-50 ◽  
Author(s):  
Ivo Jebáček ◽  
Marek Horak
Keyword(s):  
Strain Gauge ◽  
Data Acquisition System ◽  
Static Strength ◽  
Strain Gauges ◽  
Load Factor ◽  
Bending Moments ◽  
Strength Tests ◽  
Flight Measurement ◽  
Recorded Data ◽  
Wing Structure

This article provides information about in-flight measurement of a small sport aircraft. First strain gauges were installed in the wing structure and then calibration procedures were done. After the calculation of strain gauge coefficients, equations for calculating bending moments and other variables were established. A data acquisition system was installed in the aircraft to measure responses from strain gauges and other variables such as speed, altitude, load factor, and temperature. Many flights were performed with the aircraft equipped this way, and after that the recorded data were analysed and those results were compared with the calculations and static strength tests performed before.

On-Track Measurement of Lateral/Vertical Wheel Loads of Running Railway Vehicles Based on the Neural Network

2008 ◽  
Author(s):  
Davood Younesian ◽  
Fahim Javid ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Neural Network ◽  
Probability Distribution ◽  
Contact Forces ◽  
Strain Gauges ◽  
Network Algorithm ◽  
The Neural Network ◽  
Neural Network System ◽  
Neural Network Algorithm ◽  
Vertical Contact ◽  
Electric Signals

A new approach for on-track measurement of the lateral/vertical contact forces is presented in this paper. The proposed method is based on measurement of the strain at two sides of the wheel web. Electric signals generated by the strain gauges are fed into a neural network algorithm in order to predict the lateral/vertical contact forces. Feed-forward technique is used in the neural network algorithm. A sensitivity analysis has been carried out to find the best position for the strain gauges. A dynamic model of a freight wagon is provided and a variety of numerical simulations are performed to obtain the probability distribution of the lateral and vertical contact forces. The obtained probability distribution function is then utilized to generate lateral/vertical contact forces within the practical range. In order to train the neural network system, the generated contact forces are applied to the wheel flange and the strain signals are obtained. More than 100 configurations are fed into the system in order to train it. Reliability, accuracy and sensitivity of the proposed measurement system are then investigated.

The use of intraluminal strain gauges for recording ambulant small bowel motility

1990 ◽  
Vol 258 (4) ◽  
pp. G610-G615
Author(s):  
R. C. Gill ◽  
J. E. Kellow ◽  
C. Browning ◽  
D. L. Wingate
Keyword(s):  
Strain Gauge ◽  
Standard Technique ◽  
Pressure Change ◽  
Strain Gauges ◽  
Pulse Interval ◽  
Pressure Waves ◽  
Small Bowel Motility ◽  
Tape Cassette ◽  
Approximate Frequency ◽  
Good Agreement

Perfused-tube manometry has hitherto been the standard technique for recording intraluminal intestinal pressure in humans, but it is unsuitable for ambulant use. The aim of our study was to evaluate the ability of resistive strain gauge transducers attached to a fine catheter to detect pressure change. Simultaneous strain gauge and perfused-tube manometry was performed on six fasting subjects; in four, strain gauge activation was continuous and in two, the transducers were activated in a pulsed mode with data encoded as a pulse train with an approximate frequency of 20 Hz. Eight thousand eight hundred eighty-eight pressure waves were recorded by strain gauge, of which 96% were detected by perfused-tube manometry. There was good agreement in both phases II and III of the migrating motor complex. The amplitude of pressure waves recorded by strain gauge was slightly but significantly greater. A proportion (14-17%) of pressure waves recorded by strain gauge were bifid; this was not seen with the perfused tube. These differences are best explained by the greater sensitivity and more rapid rise time of the strain gauges. There was no loss of fidelity in the pulse-interval recording mode. A seventh subject underwent a continuous 72-h recording with the strain gauge catheter attached to a battery-operated encoder and magnetic tape cassette recorder and was freely ambulant during this period. The procedure was well tolerated and motility patterns could be clearly identified. We conclude that intraluminal strain gauge catheters are suitable for prolonged use in ambulant subjects and produce data that are closely comparable to the data acquired from perfused-tube manometry under laboratory conditions.

scholarly journals Effects of Toe-Out and Toe-In Gaits on Lower-Extremity Kinematics, Dynamics, and Electromyography

2019 ◽  
Vol 9 (23) ◽  
pp. 5245
Author(s):  
Weiling Cui ◽  
Changjiang Wang ◽  
Weiyi Chen ◽  
Yuan Guo ◽  
Yi Jia ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Contact Force ◽  
Repeated Measures ◽  
Joint Pain ◽  
Knee Flexion ◽  
Reaction Force ◽  
Contact Forces ◽  
Knee Adduction Moment ◽  
Positive Effects ◽  
Lateral Contact

Toe-in and toe-out gait modifications have received increasing attention as an effective, conservative treatment for individuals without severe osteoarthritis because of its potential for improving knee adduction moment (KAM) and knee flexion moment (KFM). Although toe-in and toe-out gaits have positive effects on tibiofemoral (TF) joint pain in the short term, negative impacts on other joints of the lower extremity may arise. The main purpose of this study was to quantitatively compare the effects of foot progression angle (FPA) gait modification with normal walking speeds in healthy individuals on lower-extremity joint, ground reaction force (GRF), muscle electromyography, joint moment, and TF contact force. Experimental measurements using the Vicon system and multi-body dynamics musculoskeletal modelling using OpenSim were conducted in this study. Gait analysis of 12 subjects (n = 12) was conducted with natural gait, toe-in gait, and toe-out gait. One-way repeated measures of ANOVA (p < 0.05) with Tukey’s test was used for statistical analysis. Results showed that the toe-in and toe-out gait modifications decreased the max angle of knee flexion by 8.8 and 12.18 degrees respectively (p < 0.05) and the max angle of hip adduction by 1.28 and 0.99 degrees respectively (p < 0.05) compared to the natural gait. Changes of TF contact forces caused by FPA gait modifications were not statistically significant; however, the effect on KAM and KFM were significant (p < 0.05). KAM or combination of KAM and KFM can be used as surrogate measures for TF medial contact force. Toe-in and toe-out gait modifications could relieve knee joint pain probably due to redistribution of TF contact forces on medial and lateral condylar through changing lateral contact centers and shifting bilateral contact locations.

The Effect of Vastus Medialis Forces on Patello-femoral Contact: A Model-based Study

2002 ◽  
Vol 124 (6) ◽  
pp. 758-767 ◽  
Author(s):  
Yasin Y. Dhaher ◽  
Leonard E. Kahn
Keyword(s):  
Contact Force ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Contact Forces ◽  
Vastus Medialis ◽  
Joint Angles ◽  
Simulation Data ◽  
Lateral Contact ◽  
Vastus Intermedius ◽  
The Impact

A mathematical model of the patello-femoral joint was introduced to investigate the impact of the vastus medialis (longus, obliquus) forces on the lateral contact force levels. In the model, the quadriceps were represented as five separate forces: vastus lateralis, vastus intermedius, rectus femoris, vastus medialis longus (VML), and obliquus (VMO). By varying the relative force generation ratios of the quadriceps heads, the patello-femoral contact forces were estimated. We sought to analytically determine the range of forces in the VMO and VML that cause a reduction or an increase of lateral contact forces, often the cause of patello-femoral pain. Our results indicated that increased contact forces are more dependent on combinations of muscle forces than solely VMO weakness. Moreover, our simulation data showed that the contact force levels are also highly dependent on the knee flexion angle. These findings suggest that training targeted to reduce contact forces through certain joint angles could actually result in a significant increase of the contact forces through other joint angles.

Evaluation of Regression Equations for Medial and Lateral Contact Force From Instrumented Knee Implant Data

2011 ◽  
Author(s):  
Andrew J. Meyer ◽  
Darryl D. D’Lima ◽  
Scott A. Banks ◽  
James Coburn ◽  
Melinda Harman ◽  
...  
Keyword(s):  
Contact Force ◽  
Computational Models ◽  
Contact Forces ◽  
Regression Equations ◽  
Quick Method ◽  
Lateral Contact ◽  
Knee Replacements ◽  
Clinically Significant ◽  
Neuromuscular Coordination

The ability to predict medial and lateral contact forces accurately in the knee could be useful for research on neuromuscular coordination, the development of treatments for knee osteoarthritis, and the design of knee replacements with improved durability and functionality. To improve their ability to predict medial and lateral contact forces, researchers have recently developed knee implants capable of measuring four [1] or six [2] in vivo loads applied to the tibia. These implants provide data that is useful for validating in vivo knee load predictions from computational models. A difficulty in using these experimental measurements is translating them into clinically significant measurements, i.e. medial and lateral contact force. A simple and quick method for finding these contact forces from the experimental implant data would be ideal.

Nonintrusive Measurement of Contact Forces During Vibration Dominated Impacts

2004 ◽  
Vol 126 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Satwinder Jit Singh ◽  
Anindya Chatterjee
Keyword(s):  
Contact Force ◽  
Tikhonov Regularization ◽  
Strain Gauge ◽  
Initial Conditions ◽  
Contact Point ◽  
Electrical Contact ◽  
Contact Forces ◽  
Force Estimation ◽  
Contact Duration ◽  
Gauge Data

Impact force estimation is done indirectly through, e.g., strain measurements away from the contact point, because inserting a force transducer between the contacting objects changes the force. Most prior contact force measurements involved a single contact interval. Here we study transverse impacts of a slender beam and a clamped-free plate; contact occurs more than once within one impact. Strain gauge data, electrical contact detection, and a dynamic model of the beam are used to estimate the contact force. The problem of force estimation from strain gauge data is ill-posed, and Tikhonov regularization fails initially. A reduced-order model is then developed using symmetry, and better initial conditions are estimated using a Kalman filter. Subsequently, Tikhonov regularization gives excellent force estimates, empirically supported by the contact duration measurements. Two other methods that explicitly use the contact duration measurements are also given. The first uses Tikhonov regularization within each contact interval, followed by Kalman filtering during noncontact to get initial conditions for the next contact. The second uses truncated Fourier sine series in each contact interval and is, computationally, the simplest. All three methods provide consistent force estimates. Our work complements recent work by Inoue and coworkers where the impulse response of the colliding object was measured separately using a Hopkinson bar, and electrical contact was not monitored.

Design and Fabrication of a Strain Gauge Type 3-axis Milling Tool Dynamometer

2016 ◽  
Vol 3 (2) ◽  
pp. 1-15 ◽  
Author(s):  
Bhargav Prajwal Pathri ◽  
Arpit Kumar Garg ◽  
Deepak Rajendra Unune ◽  
Harlal Singh Mali ◽  
Sukhdeep S. Dhami ◽  
...  
Keyword(s):  
Strain Gauge ◽  
End Milling ◽  
Low Cost ◽  
Wheatstone Bridge ◽  
Cutting Parameters ◽  
Strain Gauges ◽  
Cnc Milling ◽  
Milling Tool ◽  
Type 3 ◽  
Milling Forces

This paper presents the design and development of low cost strain gauge type milling tool dynamometer, which is suitable for measuring milling forces. The designed dynamometer contains four octagonal ring members on which strain gauges were bonded. The strain induced on the strain gauges due to milling forces during cutting was measured in terms of voltages using a Wheatstone bridge. A data acquisition system was connected to the dynamometer to acquire the data. The end milling operation was carried out on AISI 1020 steel work pieces of 60 mm x 30mm x 20 mm size using different combination of cutting parameters designed by design of experiments Taguchi approach on CNC milling machine. Machining tests were performed at different cutting parameters and measured cutting forces were compared with those measures by Kistler Dynamometer. The results showed that the dynamometer could be used reliably.

A New Measuring Method of Wheel-Rail Contact Forces

2005 ◽  
Author(s):  
Akira Matsumoto ◽  
Yasuhiro Sato ◽  
Hiroyuki Ohno ◽  
Masao Tomeoka ◽  
Kosuke Matsumoto ◽  
...  
Keyword(s):  
Contact Force ◽  
Measuring Method ◽  
Lateral Force ◽  
Sufficient Accuracy ◽  
Contact Forces ◽  
Full Size ◽  
Lateral Contact ◽  
Axial Movement ◽  
Slip Rings ◽  
Gap Sensors

A new measuring method introduced in this paper can measure contact forces between wheel and rail without special wheelsets with slip rings or telemeters. In this method the lateral contact force is measured from the lateral distortion of wheel measured by several non-contact gap sensors. The measured values are small, but accurate value of lateral force can be calculated by the compensation of axial movement and inclination of wheelset. Normal and longitudinal contact forces are also measured from the strain of parts of the truck except wheelsets. According to the results of full-size truck stand tests and train running tests, we have verified that the new method has sufficient accuracy of measuring compared with conventional methods.

Biomechanical Model of Human Index Finger During Examination

2021 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Denniz Zolnoun ◽  
Yasser Ashraf Gandomi
Keyword(s):  
Contact Force ◽  
Frictional Contact ◽  
Biomechanical Model ◽  
Contact Forces ◽  
Upper Body ◽  
Pressure Application ◽  
Contact Formulation ◽  
Pressure Algometer ◽  
Viscoelastic Contact ◽  
Good Agreement

We have developed a mathematical model based on the Hunt-Crossley’s viscoelastic contact formulation for predicting the contact forces in the upper-body. The simulations were carried out in OpenSim software package and the simulations results were compared to experimentally recorded contact forces measured using a pressure algometer for assessing pressure pain sensitivity in the pelvic region 1. We observed a very good agreement between the model prediction and algometer data. Our simulation revealed that by pressing down on the tissue both normal and frictional contact forces increase up to a point- ceiling effect. Moreover, viscoelastic properties of the examinee’s tissue were associated with force; specifically, as the stiffness of the tissue declined both normal and frictional contact forces similarly declined albeit in a different way. Once the contact force reaches a peak point (irrespective of the baseline stiffness of the tissue) additional pressure application by the examiner was associated with incremental decrease in both normal and frictional (wasted) contact force.

Sign in / Sign up

Export Citation Format

Share Document