Vibration of Lifting Rope when Cage Is Locking

2012 ◽  
Vol 472-475 ◽  
pp. 1559-1562
Author(s):  
Juan Wu
Keyword(s):  
Fundamental Frequency ◽  
Vibration Mode ◽  
Step Function ◽  
Wire Rope ◽  
Vibration Characteristics ◽  
Vibration Displacement ◽  
Mode Function ◽  
Vibration Model

Analysis of vibration characteristics when the cage is locking. Deduce vibration model by elastic lifting rope, interaction of sheave and rope. Based on step function, a wire rope vibration mode function, vibration displacement and tension solution are given. Results show that the cage locking device reduces impact and avoids the slippery rope and the security hidden danger. The vibration model of locking cage process is applied to the cage jammed situation. If the frequency during sudden jam is greater than or equal to the fundamental frequency, hoisting wire rope fracture does not occur.

Vibration Characteristics of Rotor System Considering Gear Meshing

2019 ◽  
Author(s):  
Jie Hong ◽  
XiRu Xu ◽  
LiMing Jiang ◽  
YanHong Ma
Keyword(s):  
Vibration Mode ◽  
Relative Displacement ◽  
Additional Constraint ◽  
Vibration Characteristics ◽  
Rotor System ◽  
Vibration Displacement ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Meshing Stiffness ◽  
Spiral Bevel

Abstract Spiral bevel gears are essential units in the accessories system of the aero-engine. The rotor transmits torque to the accessories system through the spiral bevel gears, which also change the direction of rotation. With the wide application of elastic support and the reduction in the number of bearing frames, the fulcrum stiffness and the rotor shaft stiffness is on the same order of magnitude of the gear meshing stiffness. For these multi-axis gear transmission systems, the effects of time-varying relative displacement between the gear meshing points and its additional constraint on the dynamic characteristics of the rotor ought be considered. In this paper, a coupled mechanical model of the bevel gear-coupled two-shaft rotor system is established. Besides, the coupled vibration mode of the gear-rotor system is studied. Finally, the influence of nonlinearity relative displacement and its additional constraint on the vibration characteristics of the rotor system are analyzed. The results show that the driven gear will produce elastic additional constraint on the rotor under the specific vibration mode. When the gear meshing stiffness is on the same magnitude as the support stiffness of the rotor, and the relative vibration displacement between the driving and driven gears is large enough, it is necessary to consider the influence of additional constraints on the rotor dynamics. The analysis in this paper provide a reference for dynamic optimization designs, fault monitoring and diagnosis of gear-rotor systems.

Online Monitoring ICE Powers Based on the Crankshaft Angular Vibration

2011 ◽  
Vol 48-49 ◽  
pp. 773-778 ◽  
Author(s):  
Chun Rong Hua ◽  
Da Wei Dong ◽  
Bing Yan ◽  
Ming Heng Xu
Keyword(s):  
Reference Point ◽  
Online Monitoring ◽  
Vibration Mode ◽  
Vibration Displacement ◽  
Rotating Speed ◽  
Rigid Body Model ◽  
Angular Vibration ◽  
Cubic Polynomial ◽  
Experimental Researches ◽  
Online Monitor

A new method of online monitoring ICE powers based on the crankshaft angular vibration is proposed. It has deduced that when each cylinder works uniformly at a certain rotating speed, and the vth order angular vibration mode of crankshaft nears plane vibration mode such as “quasi-rigid body model” or “quasi-trapeziform model”, so a cubic polynomial can represent the relationship between the vth order angular vibration displacement amplitude of the crankshaft reference point and the engine powers, thereby the angular vibration of reference point could be used to online monitor engine powers. Through the simulation and experimental researches on a 6240 and a 4100 diesel engine, it shows that the engine powers fitted with the angular vibration displacement amplitudes of reference point are close to the measured or theoretical powers comparatively, and the maximum errors is only 2.95%, which verifies the feasibility and practicability of the method consequently.

scholarly journals Vibration Characteristics for Moving Printing Membrane with Variable Density along the Lateral Direction

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mingyue Shao ◽  
Jimei Wu ◽  
Yan Wang ◽  
Qiumin Wu ◽  
Yuan Chen
Keyword(s):  
Density Distribution ◽  
Transverse Vibration ◽  
High Speed ◽  
Differential Quadrature Method ◽  
Variable Density ◽  
Vibration Characteristics ◽  
Lateral Direction ◽  
Vibration Model ◽  
The Stability ◽  
Density Coefficient

The vibration model of moving membrane with variable density distribution is established, and the density distribution of the moving membrane varies along the lateral direction. The transverse vibration differential equations of moving membrane are established based on D’Alembert’s principle and discretized by using the differential quadrature method (DQM). The relationships of the first three dimensionless complex frequencies between dimensionless speed, density coefficient, and tension ratio of the membrane are analyzed by numerical calculation. The effects of the density coefficient and the tension ratio on transverse vibration characteristics of the membrane are investigated. The relationship between density coefficient and critical speed is obtained. The numerical results show that the density coefficient and the tension ratio have important influence on the stability of moving membrane. So the study provides a theoretical basis for improving the working stability of the membrane in the high-speed printing process.

VIBRATION PROPERTIES OF TRADITIONAL MASONRY WALLS OF CORTES CHURCH

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Noriko Takiyama ◽  
Akari Yamaguchi ◽  
Kohei Hara ◽  
Verdejo Juan Ramon Jimenez
Keyword(s):  
Natural Frequency ◽  
Structural Property ◽  
Vibration Mode ◽  
Vibration Characteristics ◽  
Masonry Walls ◽  
Material Thickness ◽  
Vibration Properties ◽  
Microtremor Measurement ◽  
The Church ◽  
Microtremor Measurements

The Santo Niño Church in Bohol Island was partially damaged in the Bohol Earthquake in October 2013. In this study, we investigated the structural property of the Santo Niño Church to understand the vibration characteristics of Philippine masonry constructions by checking the main damage and conducting measurement surveys and microtremor measurement on the structure and ground. The major findings of this study can be summarized as follows: (a) Collapsed walls, peeling wall stone, corner deformation, and collapsed ceiling were the main damages that were observed. The collapsed wall was measured, and the make-up and material thickness of the wall was verified. (b) By performing microtremor measurements on the walls, the vibration property of the church, such as the natural frequency and vibration mode of the longest wall A was clarified. The 1st natural frequency of the longest wall A is the lowest.

A New Mistuning Form in Periodic Structure - Force Mistuning

2012 ◽  
Vol 562-564 ◽  
pp. 2092-2096 ◽  
Author(s):  
Guo Hui Yang ◽  
Ai Lun Wang ◽  
Xu Hui Cao
Keyword(s):  
Periodic Structure ◽  
Vibration Mode ◽  
Vibration Characteristics ◽  
Vibration Response ◽  
Engineering Practice ◽  
Characteristic Vibration ◽  
Natural Parameter ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Characteristic

The mistuning of periodic structure was generally considered to be natural parameter mistuning, such as stiffness mistuning, damping mistuning and mass mistuning. However, in engineering practice, there was another kind of mistuning——force mistuning, which has not been studied yet. Based on a typical concentrated parameter model of periodic structure, the vibration characteristics, such as natural characteristic, vibration mode and vibration localization of periodic structure with different mistuning forms, were compared and analyzed. The results show that, as a new mistuning form, force mistuning won’t bring mode localization, while it could lead to vibration response localization

Dynamic Model of Gears with Trapped Oil and Coupled Analysis in External Spur-Gear Pump

2011 ◽  
Vol 130-134 ◽  
pp. 610-615 ◽  
Author(s):  
Yu Long Li ◽  
Kun Liu ◽  
Fu Chun Sun
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Contact Stiffness ◽  
Spur Gear ◽  
Vibration Characteristics ◽  
Coupled Analysis ◽  
Vibration Velocity ◽  
Gear Pump ◽  
Vibration Displacement ◽  
The Impact

In order to understand the vibration characteristics of gears based on trapped-oil in external spur-gear pump, from the calculations of trapped-oil pressure and hydraulic load and contact stiffness and trapped-oil stiffness, etc., a dynamic model coupled with trapped-oil pressure was derived for the gears, then an iterative operation based on Runge-Kutta method was used for analyzing the model, therefore the data related to trapped-oil pressure and the vibration displacement and the vibration velocity were obtained in a periodic of trapped oil, and the impact of different backlash value and different distance between two unloading grooves on trapped oil pressure and dynamic characteristics of gears was briefly analyzed. All results of simulation showed that trapped-oil pressure and trapped-oil stiffness had greater impact on vibration characteristics of gears in external spur-gear pump, trapped-oil stiffness could reduce the vibration of the gears; in simulation of trapped-oil pressure, dynamic trapped-oil model related to dynamic characteristics of gears more accurate than the static trapped-oil model irrelated to dynamic characteristics of gears; the trapped-oil pressures in two trapped-oil cavity were different, the vibration characteristics of gears was better that in larger backlash value, etc.. Finally, by the trapped-oil stiffness of the external gear pump is unique, the important conclusions are educed that the vibration of gears in external spur-gear pump is indeed different from conventional gears and so on.

Orthogonality conditions of the transverse vibration mode function for a stepped one-dimensional plate on a Winkler foundation and subjected to an in-plane force

2002 ◽  
Vol 216 (3) ◽  
pp. 271-273
Author(s):  
Y S Zhang
Keyword(s):  
Forced Vibration ◽  
Transverse Vibration ◽  
Vibration Mode ◽  
Constant Thickness ◽  
Winkler Foundation ◽  
One Dimensional ◽  
Mode Function ◽  
Orthogonality Conditions

The transverse vibration mode equation of a stepped one-dimensional plate on a Winkler foundation and subjected to an in-plane force is derived. The orthogonality conditions for transverse vibration of such a plate are obtained. The conclusions of this work can be used to solve the problem of forced vibration of various stepped one-dimensional plates, plates of constant thickness and beams.

Influence of the Stiffeners on the Vibration Characteristics of a Stiffened Plate and Shell Coupled Structure

2012 ◽  
Vol 248 ◽  
pp. 101-106 ◽  
Author(s):  
Zhi Mei Zhao ◽  
Mei Ping Sheng
Keyword(s):  
Vibration Characteristics ◽  
Level Curve ◽  
Stiffened Plate ◽  
Coupled Vibration ◽  
Frequency Range ◽  
Stiffened Cylindrical Shell ◽  
Acceleration Level ◽  
Plate And Shell ◽  
Vibration Model ◽  
Receptance Method

A coupled vibration model of a stiffened cylindrical shell with a stiffened interior plate is established based on the receptance method to get the stiffeners' influence on the plate-shell coupled structure's vibration characteristics. Numerical analysis on how an increase of the plate's and the shell's stiffener number affect the combination's vibration is carried out. It shows that the amplitudes of both the plate's and the shell's acceleration levels would reduce and peaks of their vibration curves would shift to the higher frequency range as stiffeners on the plate increases. And increase of the shell's stiffener number has little impact on the plate's acceleration level curve except for some peaks, but it would reduce the shell's acceleration level.

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