Numerical Experiments with a Linear Force-Displacement Tooth Model

1969 ◽  
Vol 48 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Han K. Huang ◽  
Robert S. Ledley
Keyword(s):  
Numerical Experiments ◽  
Linear Force ◽  
Force Displacement

The Effect of 5 Mechanical Gaming Keyboard Key Switch Profiles on Typing and Gaming Muscle Activity, Performance and Preferences

2018 ◽  
Vol 62 (1) ◽  
pp. 1552-1556
Author(s):  
Charles Miller ◽  
Alan Barr ◽  
Raziel Riemer ◽  
Carisa Harris
Keyword(s):  
Task Performance ◽  
Muscle Activity ◽  
Word Processing ◽  
Tactile Feedback ◽  
User Preference ◽  
Displacement Curve ◽  
Study Task ◽  
Activity Performance ◽  
Linear Force ◽  
Force Displacement

Introduction:Single force-displacement characteristics of mechanical key switches have been shown to affect performance, fatigue and discomfort during keyboard use. This study compared the effects of mechanical key switches with differing force-displacement characteristics on forearm muscle activity, typing performance, Fitts Study task performance, subjective fatigue and user preference. Methods: Using a within subjects intervention study of crossover design, 64 subjects completed modified Fitts and typing tasks on five different mechanical key switches to mimic dual word processing and gaming keyboard use. Bilateral muscle activity was recorded using surface electromyography (EMG); typing and Fitts task performance measures were tracked. Results: The key switch with a linear force displacement curve had higher net strokes and lower net typing speed than two key switches with tactile feedback (p<0.05). The key switch with the longest tactile travel, operating travel and highest bottom force required slightly higher peak muscle activity compared to 2 other key switches with lower values (p<0.05). Key switches with shorter tactile and operating travel and lower bottom forces were preferred over other key switches.Conclusions: Among mechanical key switches, a linear force displacement curve had the worst outcomes; key switches with shorter tactile (1.2mm) and operating travel (2.0mm) and a lower bottom force (35-40g) had best outcomes overall.

Improved nonlinear model of a yaw damper for simulating the dynamics of a high-speed train

2018 ◽  
Vol 233 (7) ◽  
pp. 651-665 ◽  
Author(s):  
Wanxiu Teng ◽  
Huailong Shi ◽  
Ren Luo ◽  
Jing Zeng ◽  
Caihong Huang
Keyword(s):  
Nonlinear Model ◽  
High Speed ◽  
Piecewise Linear ◽  
Excitation Frequency ◽  
Maxwell Model ◽  
Railway Vehicle ◽  
High Speed Train ◽  
Force Velocity ◽  
Linear Force ◽  
Force Displacement

The aim of this paper is to establish a simple and accurate nonlinear model of a yaw damper for the dynamic numerical simulation of high-speed trains. An improved nonlinear yaw damper model is proposed based on the traditional Maxwell model. It comprises a piecewise linear force–displacement spring and a piecewise linear force–velocity damper in series. These nonlinear inputs for the model are retrieved from the dynamic performance tests of the damper, and the force–displacement and force–velocity curves are further modified to improve the modelling accuracy according to the test results. The proposed model can accurately simulate the damper's dynamic stiffness and dynamic damping characteristics with respect to the excitation frequency or displacement, which cannot be reproduced when using the traditional Maxwell model. Both the traditional Maxwell model and the improved nonlinear model presented in this work are integrated into a multibody dynamics railway vehicle model to simulate the typical dynamic problems of a high-speed train operating at 250 km/h in northeast China. Through comparative analysis, it was found that the numerical simulations are consistent with the field measurements. It can be concluded that the proposed nonlinear damper model is more suitable for studying railway vehicle system dynamics under various operating cases. By contrast, the input parameters of the traditional Maxwell model must be modified artificially according to the vehicle responses and the dynamic characteristics of the yaw damper.

scholarly journals Novel Magnetic Circuit Topology of Linear Force Motor for High Energy Utilization of Permanent Magnet: Analytical Modelling and Experiment

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 32
Author(s):  
Bin Meng ◽  
Hao Xu ◽  
Bei Liu ◽  
Mingzhu Dai ◽  
Chenhang Zhu ◽  
...  
Keyword(s):  
Analytical Model ◽  
Permanent Magnets ◽  
Magnetic Circuit ◽  
High Energy ◽  
Energy Utilization ◽  
Static Characteristics ◽  
Circuit Topology ◽  
Hydraulic Servo ◽  
Linear Force ◽  
Force Displacement

The magnetic circuit of existing linear force motors does not consider the issue of energy utilization of permanent magnets, and the structure is complicated. To achieve high energy utilization and simplify the structure, this paper presents a novel magnetic circuit topology for the linear force motors of electro-hydraulic servo-proportional valves. In order to rapidly and accurately calculate the static characteristics of the force motor, an analytical model is established by using the equivalent magnetic circuit method. The model comprehensively considers the magnetic leakage effect, edge effect, and permeability nonlinearity. A prototype of the force motor is designed and manufactured, and a special experimental platform is built. The prototype force motor has a linear force-displacement characteristic and the output force increases with the increase of the excitation currents, which can reach about 41 N at 2 A. This indicates that it is suitable as an electro-mechanical converter for electro-hydraulic servo-proportional valves. Moreover, the analytical model is used to perform parameter optimization and calculate the magnetic flux density in the working air gap and the force-displacement characteristics under different excitation currents. The results are in good agreement with the electromagnetic field finite element simulation and experimental results. They indicate that the analytical model can rapidly and accurately predict the static characteristics of the force motor. The research work provides good reference means for the design of magnetic circuit topology with consideration of the high energy utilization of permanent magnets, and also the accurate analytical modeling of valve electro-mechanical converters.

On Force-Displacement Characteristics and Surface Deformation in Piezo Vibration Striking Treatment (PVST)

2021 ◽  
pp. 1-27
Author(s):  
Jisheng Chen ◽  
Yang Xu ◽  
Juan Sandoval ◽  
Patrick Kwon ◽  
Yang Guo
Keyword(s):  
Surface Deformation ◽  
Resonant Mode ◽  
Cnc Machine ◽  
Vibration Displacement ◽  
Workpiece Surface ◽  
Tool Vibration ◽  
Tool Surface ◽  
Linear Force ◽  
Force Displacement ◽  
Mechanical Surface

Abstract This paper presents an experimental study on a novel mechanical surface treatment process, namely piezo vibration striking treatment (PVST), which is realized by a piezo stack vibration device installed on a CNC machine. Unlike other striking-based surface treatments, PVST employs non-resonant mode piezo vibration to induce controllable tool strikes on workpiece surface. In this study, an experimental setup of PVST is implemented. Four types of experiments, i.e., tool-surface approaching, single-spot striking, 1D scan striking, and 2D scan striking, are conducted to investigate the relationships among the striking force, tool vibration displacement, and surface deformation in PVST. The study shows that PVST can induce strikes with consistent intensity in each cycle of tool vibration. Both the striking intensity and striking location can be well controlled. Such process capability is particularly demonstrated by the resulting texture and roughness of the treated surfaces. Moreover, two linear force relationships have been found in PVST. The first linear relationship is between the striking force and the reduction in vibration amplitude during striking. The second one is between the striking force and the permanent indentation depth created by the strike. These linear force relationships offer the opportunity to realize real-time monitoring and force-based feedback control of PVST. This study is the first step towards developing PVST as a more efficient deformation-based surface modification process.

Performance Enhancement of Electrostatically Actuated Microgripper with Modified Fingers for Microassembly

2012 ◽  
Vol 622-623 ◽  
pp. 1810-1814
Author(s):  
A.R. Kalaiarasi ◽  
Thilagar S. Hosimin
Keyword(s):  
Performance Enhancement ◽  
Supply Voltage ◽  
Micro Electro Mechanical Systems ◽  
Output Displacement ◽  
Electrostatically Actuated ◽  
Micro Parts ◽  
Linear Force ◽  
Simulation Results ◽  
Force Displacement ◽  
Good Agreement

The application of microgrippers for handling and assembling micro parts in the field of robotics attracts more attention by the growth in micro electro mechanical systems. In this paper an electrostatic microgripper using comb drive is designed and analyzed using IntelliSuite. The use of modified fingers in the combdrive amplifies the output displacement of microgripper for given supply voltage. It also provides a linear force displacement behavior over a range of displacement. To show this amplification, finite element simulations are performed on the proposed design of microgripper models. It was found that displacement of about 7 µm has been obtained at a voltage of 14 volts with 28 fingers only with one of the proposed designs of microgripper against 25 volts for rectangular finger microgripper with 28 fingers. The simulation results have been verified by analytical results. The results of analytical and simulation are found to be in good agreement.

scholarly journals Conical Indentation of a Viscoelastic Sphere

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
J. K. Phadikar ◽  
T. A. Bogetti ◽  
V. N. Kaliakin ◽  
A. M. Karlsson
Keyword(s):  
Finite Element ◽  
Functional Equations ◽  
Numerical Experiments ◽  
Spherical Particles ◽  
The Finite Element Method ◽  
Instrumented Indentation ◽  
Flat Substrate ◽  
Force Displacement ◽  
Good Agreement ◽  
Conical Indentation

Instrumented indentation is commonly used for determining mechanical properties of a range of materials, including viscoelastic materials. However, most—if not all—studies are limited to a flat substrate being indented by various shaped indenters (e.g., conical or spherical). This work investigates the possibility of extending instrumented indentation to nonflat viscoelastic substrates. In particular, conical indentation of a sphere is investigated where a semi-analytical approach based on “the method of functional equations” has been developed to obtain the force–displacement relationship. To verify the accuracy of the proposed methodology selected numerical experiments have been performed and good agreement was obtained. Since it takes significantly less time to obtain force–displacement relationships using the proposed method compared to conducting full finite element simulations, the proposed method is an efficient substitute of the finite element method in determining material properties of viscoelatic spherical particles using indentation testing.

Instrumentation for Measurement of Lingual Strength

1968 ◽  
Vol 11 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Lois Joan Sanders
Keyword(s):  
Single Channel ◽  
Displacement Transducer ◽  
Tongue Pressure ◽  
Maximum Pressure ◽  
Research Use ◽  
Direct Writing ◽  
Significant Difference ◽  
Pressure Unit ◽  
Force Displacement ◽  
Consistent Response

A tongue pressure unit for measurement of lingual strength and patterns of tongue pressure is described. It consists of a force displacement transducer, a single channel, direct writing recording system, and a specially designed tongue pressure disk, head stabilizer, and pressure unit holder. Calibration with known weights indicated an essentially linear and consistent response. An evaluation of subject reliability in which 17 young adults were tested on two occasions revealed no significant difference in maximum pressure exerted during the two test trials. Suggestions for clinical and research use of the instrumentation are noted.

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