Mechanical model and seismic study of the roller guide–rail assembly in the counterweight system of elevators

2020 ◽  
Author(s):  
Xiaoyan Wang ◽  
Selim Günay ◽  
Wensheng Lu
Keyword(s):  
Mechanical Model ◽  
Guide Rail ◽  
Roller Guide

Mechanism and affecting factors of Translohr tramway guide rail side wear

2016 ◽  
Vol 231 (21) ◽  
pp. 3898-3912 ◽  
Author(s):  
Yuanjin Ji ◽  
Lihui Ren ◽  
Jian Wang ◽  
Dao Gong
Keyword(s):  
Mechanical Model ◽  
Field Measurements ◽  
Affecting Factors ◽  
Critical Factors ◽  
Guide Rail ◽  
Factors Affecting ◽  
Rail Track ◽  
Equivalent Mechanical Model ◽  
Two Factors ◽  
Curve Radius

The wheel–rail contact can be found in two patterns. In the first pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail; in the second pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail, and the wheel edge is in contact with the guide rail web on one side. Based on these findings, an equivalent mechanical model with four unilateral springs is proposed to describe the wheel–rail contact. Additionally, a dynamic model of the Translohr tramway is established using Matlab/Simulink. The wheel–rail contact in a tramway moving along curves with different radii is calculated using simulation, and the results obtained are consistent with the observations and results of field measurements. The effects of various factors, including curve radius, tram speed, guide rail pre-pressure, and guide rod length, on the side wear of the guide rail were investigated. The results revealed that curve radius and tram speed are the critical factors affecting rail track side wear. These two factors can qualitatively determine rail track side wear, while other factors can only quantitatively affect the degree of rail track side wear.

Modeling and Simulation of the Ultrasonic Motor which Using Bending Vibration Transducer

2014 ◽  
Vol 628 ◽  
pp. 240-248
Author(s):  
Zi Li Huang ◽  
Wei Shan Chen
Keyword(s):  
Mathematical Model ◽  
Computer Simulations ◽  
Mechanical Model ◽  
Ultrasonic Motor ◽  
Guide Rail ◽  
Bending Vibration ◽  
Stick Slip ◽  
Vibration Transducer ◽  
Starting Process ◽  
The Mathematical Model

Build the mathematical model and mechanical model of ultrasonic motor which using bending vibration transducer. Based on this model, analyze the contact and friction processes between driven-foot which belonging to ultrasonic motor which using bending vibration transducer and guide rail. Analyze the influence preload force make to the process of motor’s running. Take the cases of stick, slip, flight into consideration, and explain nonlinearity of the Dynamics. Do computer simulations of starting process though this model, and summarize the motor’s working results when it works under different conditions.

TECHNOLOGICAL CONTROL OF THE CONTACT PRESSURE ON THE CYLINDRICAL SUBSTRATE FROM THE SIDE OF THE COATING ADDITIVELY FORMED ON ITS EXTERNAL SURFACE

2020 ◽  
Author(s):  
Dmitriy Parshin
Keyword(s):  
Stress State ◽  
Contact Pressure ◽  
Mechanical Model ◽  
External Surface ◽  
Layer By Layer ◽  
Layer Formation ◽  
Technological Control ◽  
Manufactured Products ◽  
Arbitrary Thickness

The article gives an example of controlling the stress state parameters of additively manufactured products. The study was carried out on the basis of a developed non-classical mechanical model of the process of layer-by-layer formation of a coating of arbitrary thickness on a cylindrical substrate. The model is based on modern concepts of the mechanics of continuously growing bodies and allows one to obtain fairly simple analytical dependencies. On the basis of the latter, the problem of technological control of the evolution of contact pressure at the substrate – coating interface is solved in the article. A number of practically significant conclusions have been made.

An instructive chemo-mechanical model for bonded geomaterials

2005 ◽  
Vol 9 (5-6) ◽  
pp. 671-688
Author(s):  
Roberto Nova ◽  
Marco Parma
Keyword(s):  
Mechanical Model

FINE-TUNING OF MODELLING STRATEGY TO SIMULATE THERMO-MECHANICAL BEHAVIOUR OF DOUBLE FRICTION PENDULUM SEISMIC ISOLATORS UST ESTIMATOR

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 165-172
Author(s):  
Vincenzo Bianco ◽  
Giorgio Monti ◽  
Nicola Pio Belfiore
Keyword(s):  
Multibody Dynamics ◽  
Mechanical Behaviour ◽  
Mechanical Model ◽  
Dynamic Behaviour ◽  
Experimental Testing ◽  
Fine Tuning ◽  
Proposed Model ◽  
Modelling Techniques ◽  
Friction Pendulum

The use of friction pendulum devices has recently attracted the attention of both academic and professional engineers for the protection of structures in seismic areas. Although the effectiveness of these has been shown by the experimental testing carried out worldwide, many aspects still need to be investigated for further improvement and optimisation. A thermo-mechanical model of a double friction pendulum device (based on the most recent modelling techniques adopted in multibody dynamics) is presented in this paper. The proposed model is based on the observation that sliding may not take place as ideally as is indicated in the literature. On the contrary, the fulfilment of geometrical compatibility between the constitutive bodies (during an earthquake) suggests a very peculiar dynamic behaviour composed of a continuous alternation of sticking and slipping phases. The thermo-mechanical model of a double friction pendulum device (based on the most recent modelling techniques adopted in multibody dynamics) is presented. The process of fine-tuning of the selected modelling strategy (available to date) is also described.

Causality Then and Now

1993 ◽  
Vol 10 (2) ◽  
pp. 165-177
Author(s):  
Karen Harding
Keyword(s):  
Quantum Theory ◽  
Common Sense ◽  
Mechanical Model ◽  
Physical World ◽  
Scientific Data ◽  
The World ◽  
The Common ◽  
The Universe ◽  
The Way

Ate appearances deceiving? Do objects behave the way they do becauseGod wills it? Ate objects impetmanent and do they only exist becausethey ate continuously created by God? According to a1 Ghazlli, theanswers to all of these questions ate yes. Objects that appear to bepermanent are not. Those relationships commonly tefemed to as causalare a result of God’s habits rather than because one event inevitably leadsto another. God creates everything in the universe continuously; if Heceased to create it, it would no longer exist.These ideas seem oddly naive and unscientific to people living in thetwentieth century. They seem at odds with the common conception of thephysical world. Common sense says that the universe is made of tealobjects that persist in time. Furthermore, the behavior of these objects isreasonable, logical, and predictable. The belief that the univetse is understandablevia logic and reason harkens back to Newton’s mechanical viewof the universe and has provided one of the basic underpinnings ofscience for centuries. Although most people believe that the world is accutatelydescribed by this sort of mechanical model, the appropriatenessof such a model has been called into question by recent scientificadvances, and in particular, by quantum theory. This theory implies thatthe physical world is actually very different from what a mechanicalmodel would predit.Quantum theory seeks to explain the nature of physical entities andthe way that they interact. It atose in the early part of the twentieth centuryin response to new scientific data that could not be incorporated successfullyinto the ptevailing mechanical view of the universe. Due largely ...

Effect of guide rail profile errors on the motion accuracy for a heavy-duty hydrostatic turntable

2019 ◽  
Vol 233 (15) ◽  
pp. 5350-5362 ◽  
Author(s):  
Yongsheng Zhao ◽  
Hongchao Wu ◽  
Congbin Yang ◽  
Ligang Cai ◽  
Zhifeng Liu
Keyword(s):  
Machine Tool ◽  
Reynolds Equation ◽  
Machining Accuracy ◽  
Guide Rail ◽  
Heavy Duty ◽  
Motion Equations ◽  
Rotating Speed ◽  
Proposed Model ◽  
Reaction Forces ◽  
Profile Errors

The motion accuracy of hydrostatic turntable is the key in improving the machining accuracy of heavy-duty machine tool. However, the motion accuracy of hydrostatic turntable depends not only on the offset load but also on the rotating speed of the turntable as well as the profile errors of the guide rails. In this paper, a simulation model is developed to analyze the effect of guide rail profile errors on the motion accuracy of hydrostatic turntable. The reaction forces of preload thrust bearing and hydrostatic circular oil pads are obtained based on the Reynolds equation of the lubricant film. The motion equations of hydrostatic turntable are derived in which the profile errors of two guide rails are considered. The results show that the motion accuracy of hydrostatic turntable can be affected by wavelength, amplitude of profile errors and speed, and offset load of turntable. Finally, the motion accuracy of heavy-duty hydrostatic turntable used in XCKA28105 type turning and milling composite machine tool is obtained by using the presented method. Comparing with the experimental results, the proposed model can be used to predict the machining accuracy caused by the profile errors of guide rails for any heavy-duty hydrostatic turntable.

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