Method of Bending Stiffness Parameter Identification of Stay Cable

2015 ◽  
Vol 777 ◽  
pp. 52-58
Author(s):  
Hong Du ◽  
Da Yang Liu ◽  
Fu Wei Huang ◽  
Jing Bo Liao
Keyword(s):  
Parameter Identification ◽  
Bending Stiffness ◽  
Parameters Identification ◽  
Stiffness Ratio ◽  
Stiffness Parameter ◽  
Stay Cable ◽  
Cable Tension ◽  
Cable Length

In order to solve the problem of bending stiffness parameters identification of practical stay-cable, and provide bending stiffness correction for tension measurement. A method to identify cable bending stiffness parameters is proposed, and its basis theory established in paper. The method was applied to Xiazhang Sea-Crossing Bridge, the results showed that: Identification bending stiffness ratio is between 0.33 to 0.54 for relatively short cables of South Branch Bridge, and it tends to decrease with increase of cable length and force. However, the identification bending stiffness is close or equal to 0 EImax for relatively long cable of North Branch Bridge. It testified that the effect of bending stiffness for long cable tension is small in engineering.

Buckling of a Rectangular Frame Revisited

1987 ◽  
Vol 54 (3) ◽  
pp. 617-622
Author(s):  
P. Seide
Keyword(s):  
Limit Load ◽  
Bending Stiffness ◽  
Stiffness Ratio ◽  
Stiffness Parameter ◽  
Rotational Stiffness ◽  
Height Ratio ◽  
Rectangular Frame ◽  
Uniform Beam ◽  
Symmetrical Deformation ◽  
Deformation Limit

An investigation of the buckling under uniform beam load of a rectangular frame with columns restrained by linear rotational springs indicates that for certain ranges of bending stiffness ratio, length-height ratio, and support rotational stiffness parameter, the antisymmetrical bifurcation mode of buckling does not exist and buckling occurs at a symmetrical deformation limit load. The ranges of parameters for which this phenomenon may be important are studied.

Vibrations of an Intermediately Supported U-Bend Tube

1975 ◽  
Vol 97 (1) ◽  
pp. 23-32 ◽  
Author(s):  
L. S. S. Lee
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Experimental Tests ◽  
Bending Stiffness ◽  
Stiffness Ratio ◽  
Plane Vibration ◽  
Straight Beam ◽  
Out Of Plane ◽  
Straight Segments ◽  
Good Agreement

Vibrations of an intermediately supported U-bend tube fall into two independent classes as an incomplete ring of single span does, namely, the in-plane vibration and the coupled twist-bending out-of-plane vibration. Natural frequencies may be expressed in terms of a coefficient p which depends on the stiffness ratio k, the ratio of lengths of spans, and the supporting conditions. The effect of the torsional flexibility of a curved bar acts to release the bending stiffness of a straight beam and hence decrease the natural frequency. Some conclusions for an incomplete ring of single span may not be equally well applicable to the U-tube case due to the effects of intermediate supports and the presence of the supporting straight segments. Results of the analytical predictions and the experimental tests of an intermediately supported U-tube are in good agreement.

Soil Arching over Deeply Buried Thermoplastic Pipe

2003 ◽  
Vol 1849 (1) ◽  
pp. 109-123 ◽  
Author(s):  
Shad M. Sargand ◽  
Teruhisa Masada
Keyword(s):  
Strain Gauge ◽  
Bending Stiffness ◽  
Field Soil ◽  
Stiffness Parameter ◽  
Soil Pressure ◽  
Buried Pipe ◽  
Soil Arching ◽  
Pressure Cell

Soil arching associated with buried thermoplastic pipe is discussed. First, the soil arching phenomenon is described. Then two different approaches are mentioned from the literature to represent the degree of soil arching (or vertical arching factor). The elastic solutions of Burns and Richard are revisited to derive expressions for the vertical soil arching factor for buried pipe. Comparison of the elastic solutions and field soil pressure cell readings reveals the importance of incorporating a bending stiffness parameter. With this finding, the AASHTO method for calculating the load on buried pipe is evaluated against the elastic solutions. The analysis reveals that the AASHTO method is conservative, overestimating the load on thermoplastic pipe by up to 30%. Further evidence to support the finding is found within the strain gauge readings taken on the pipe walls in the field. Therefore, alternative equations derived directly from the elastic solutions are recommended to predict the load on buried thermoplastic pipe instead of the AASHTO method.

Parameter Identification for Nonlinear Dry-Friction Structure of Metallic Rubber

2011 ◽  
Vol 52-54 ◽  
pp. 494-499
Author(s):  
Yu Yan Li ◽  
Xie Qing Huang ◽  
Kai Song
Keyword(s):  
Parameter Identification ◽  
Dry Friction ◽  
Friction Angle ◽  
Element Model ◽  
Parameters Identification ◽  
Axial Stiffness ◽  
Model Parameters ◽  
Structural Element ◽  
Identification Method ◽  
Metallic Rubber

In order to reduce workload of parameter identification for nonlinear mechanical model of metallic rubber, in this paper, based on parameters identification method of static experimental curves, experiments were designed, and data were processed, further aimed at hollow cylindrical metallic rubber, nonlinear dry-friction structural element model’ parameters were identified, what’s more, friction coefficient, radial stiffness, axial stiffness, and friction angle of stainless wire under room temperature were obtained. It was proved by simulation that parameters identification method in this paper was effective and accurate. Based on this, errors of simulation were analyzed elaborately.

scholarly journals Synchronous Vibration Parameters Identification of Variable Rotating Speed Blades Based on New Improved Two-Parameter Method without OPR Sensor

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Liang Zhang ◽  
Huiqun Yuan ◽  
Xin Li
Keyword(s):  
Parameter Identification ◽  
Initial Phase ◽  
Parameters Identification ◽  
Identification Accuracy ◽  
Parameter Method ◽  
Vibration Parameter ◽  
Rotating Speed ◽  
Blade Tip ◽  
Vibration Parameters ◽  
Two Parameter

Blade tip-timing is one of the most effective methods for blade vibration parameters identification of turbomachinery. Once-per revolution (OPR) sensor is usually used to determine the rotating speed and as a time reference. However, the OPR sensor leads to a large measurement error or even failure, or it is difficult to install. A new improved two-parameter method without the OPR sensor is proposed to identify the synchronous vibration parameters of variable rotating speed blades. Three eddy current sensors are required to identify the excitation order, vibration amplitude, resonance rotating speed frequency, resonance frequency, and the initial phase of the blades. Numerical simulation of blade synchronous vibration parameters identification is presented, and the identification error of the method is investigated. The simulation results show that the identification accuracy of this method is better than that of the traditional two-parameter method and the improved method in reference, especially in the identification of the vibration initial phase. Experiments are conducted based on the blade tip-timing vibration measurement system. The results indicate that the standard errors of vibration parameter identification results between the new method and the method in reference are smaller, except for the initial phase. It is consistent with the results of the simulation identification. The synchronous vibration parameter identification of variable rotating speed blades without the OPR sensor is achieved based on the new improved two-parameter method.

Damping of Stay Cable-Passive Damper System with Effects of Cable Bending Stiffness and Damper Stiffness

2012 ◽  
Vol 204-208 ◽  
pp. 4513-4517 ◽  
Author(s):  
Min Liu ◽  
Guang Qiao Zhang
Keyword(s):  
Numerical Analysis ◽  
Damping Ratio ◽  
Bending Stiffness ◽  
Damping Coefficient ◽  
Stay Cable ◽  
Modal Damping Ratio ◽  
Passive Damper ◽  
Modal Damping ◽  
Optimal Damping ◽  
Coefficient Increase

In the present paper, the asymptotic solution of modal damping ratio of stay cable-passive damper system with the influence of cable bending stiffness and damper stiffness was derived. Maximum modal damping ratio and corresponding optimal damping coefficient, which indicated the relationships of the characteristics of the damper and the cable bending stiffness was theoretically analyzed to obtain their close solutions. On the basis of these close solutions, numerical analysis of modal damping of stay cable-passive damper system with the effects of cable bending stiffness and damper stiffness was conducted. The numerical and analytical results show that the maximum modal damping ratio decrease and the corresponding damping coefficient increase, when considering the influence of the damper stiffness and the cable bending stiffness.

Stay Cable Tension Estimation of Cable-Stayed Bridges Using Genetic Algorithm and Particle Swarm Optimization

2017 ◽  
Vol 22 (10) ◽  
pp. 05017008 ◽  
Author(s):  
Seyed Ehsan Haji Agha Mohammad Zarbaf ◽  
Mehdi Norouzi ◽  
Randall J. Allemang ◽  
Victor J. Hunt ◽  
Arthur Helmicki
Keyword(s):  
Genetic Algorithm ◽  
Particle Swarm Optimization ◽  
Particle Swarm ◽  
Stay Cable ◽  
Swarm Optimization ◽  
Cable Tension ◽  
Cable Stayed Bridges

Dimensionless Sensitivity Methods to Identify Vehicle Cornering Stiffness From Yaw Rate Measurements

2003 ◽  
Author(s):  
Sean N. Brennan
Keyword(s):  
Network Analysis ◽  
Parameter Identification ◽  
System Model ◽  
Model Description ◽  
Stiffness Parameter ◽  
Yaw Rate ◽  
Bicycle Model ◽  
Experimental Implementation ◽  
Simplified Method ◽  
Vehicle Chassis

A simplified method of identifying a dynamic model is presented that utilizes explicit and implicit coupling between Bode parameter sensitivities. This focus of this work is the identification, in real-time, of the Cornering Stiffness parameter. This parameter governs the tire-road interaction within the simplified bicycle model description of vehicle chassis dynamics at highway speeds. This novel sensitivity coupling method, discovered earlier as sensitivity invariance in circuit network analysis, explicitly limits the possible parameter gradients of the system model to a very small subspace. By constraining the parameter identification or adaptation to solely this possible subspace, a simplified and efficient parameter identification can be obtained at a reduced computational and modelling cost. Both simulation and experimental implementation on a research vehicle under changing road conditions are presented.

Correction Method of Cable Tension Measurement Bases on the Principle of Hamilton

2014 ◽  
Vol 1079-1080 ◽  
pp. 342-347
Author(s):  
Lei Jin ◽  
Zhen Dong Qian ◽  
Xiu Yong Wang
Keyword(s):  
Correction Method ◽  
Tension Test ◽  
Damping Coefficient ◽  
Stay Cable ◽  
Cable Tension ◽  
Measured Frequency ◽  
Rubber Damper ◽  
Measurement Bases

In order to improve the accuracy of cable tension test, the motionequation of the stay cable with the rubber damper was established bases on the principleof Hamilton. First, the correction method for the damping coefficient of rubberdamper and cable tension was proposed according to the higher modal frequencyand measured frequency of cables difference. Then, take the cable of DongtingLake Bridge as an example, the cable tension was calculated by the proposedmethod and compared with the results of measurement by frequency method.Results showed that the proposed method can improve the accuracy of cabletension test and can effectively evaluate the cable tension condition of thecable-stayed bridge.

Automated wireless monitoring system for cable tension forces using deep learning

2020 ◽  
pp. 147592172093583
Author(s):  
Seunghoo Jeong ◽  
Hyunjun Kim ◽  
Junhwa Lee ◽  
Sung-Han Sim
Keyword(s):  
Deep Learning ◽  
Monitoring System ◽  
Structural Integrity ◽  
Estimation Method ◽  
Smart Sensors ◽  
Peak Picking ◽  
Stay Cable ◽  
Cable Tension ◽  
Cable Vibration ◽  
Wireless Smart Sensors

As demand for long-span bridges is increasing worldwide, effective maintenance has become a critical issue to maintain their structural integrity and prolong their lifetime. Given that a stay-cable is the principal load-carrying component in cable-stayed bridges, monitoring tension forces in stay-cables provides critical data regarding the structural condition of bridges. Indeed, various methodologies have been proposed to measure cable tension forces, including the magneto-elastic effect-based sensor technique, direct measurement using load cells, and indirect tension estimation based on cable vibration. In particular, vibration-based tension estimation has been widely applied to systems for tension monitoring and is known as a cost-effective approach. However, full automation under different cable tension forces has not been reported in the literature thus far. This study proposes an automated cable tension monitoring system using deep learning and wireless smart sensors that enables tension forces to be estimated. A fully automated peak-picking algorithm tailored to cable vibration is developed using a region-based convolution neural network to apply the vibration-based tension estimation method to automated cable tension monitoring. The developed system features embedded processing on wireless smart sensors, which includes data acquisition, power spectral density calculation, peak-picking, post-processing for peak-selection, and tension estimation. A series of laboratory and field tests are conducted on a cable to validate the performance of the proposed automated monitoring system.

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