Study on Flow-Induced Vibration Characteristics of Hydraulic Hoist of Large-Span Upwelling Radial Steel Gate

2011 ◽  
Vol 117-119 ◽  
pp. 241-246
Author(s):  
Zhen Hai Gao ◽  
Gen Hua Yan ◽  
Peng Liu ◽  
Fa Zhan Chen ◽  
Fei Ming Lv
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Characteristics ◽  
Vibration Response ◽  
Flow Induced Vibration ◽  
Structural Dynamic ◽  
Large Span ◽  
Response Characteristics ◽  
Lever Action ◽  
Structural Dynamic Characteristics ◽  
Steel Gate

In this paper we conduct study on flow-induced vibration of large-span upwelling radial steel Gate and its hydraulic hoist. Place an emphasis on vibration response characteristics under two working conditions of diversion and drainage, which proves the safety of hydraulic hoist gate vibration caused by gate vibration. Firstly, we study on dynamic characteristics of fluid-structure interaction of association system of gate and start and stop lever, reveals the discipline of the effect fluid having on structural dynamic characteristics. On this basis, flow-induced vibration characteristics under two conditions of with and without start and stop lever action considered. The results indicate that the gate vibration response with hydraulic hoist used decreases, which explains start and stop lever has certain effect of restraining vibration on gate vibration. In addition, under the working condition of drainage the vibration magnitude of start and stop lever is smaller than that of gate body, which explains there is damping action during transference of gate vibration through start and stop lever. The results find out that on the assumption of optimized gate structure and hydraulic arrangement, it is practicable, safe and reliable to adopt hydraulic hoist. The achievement has directive significance on similar projects construction in the future

Identification and Prediction of Frame Structure Dynamics by Spatial Matrix Identification Method

2000 ◽  
Author(s):  
Masaaki Okuma ◽  
Ward Heylen ◽  
Hisayoshi Matsuoka ◽  
Paul Sas
Keyword(s):  
Boundary Condition ◽  
Dynamic Characteristics ◽  
Structural Modification ◽  
Test Structure ◽  
Frame Structure ◽  
Structural Dynamic ◽  
Identification Method ◽  
Input Multiple Output ◽  
Structural Dynamic Characteristics ◽  
Single Input

Abstract This paper presents the result of using an experimental spatial matrix identification method to predict the dynamics of a frame structure under a different boundary condition. The single-input-multiple-output frequency response functions of the test structure under the free-free boundary condition are measured by hammer testing. Using the FRFs, a set of spatial matrices is determined to represent its structural dynamic characteristics by the method. Then, using the identified spatial matrices, the dynamic characteristics of the test structure under the boundary condition of clamping 4 points is predicted. The prediction is practically accurate. The result of the prediction demonstrates that the spatial matrices identified by the method can be used for structural modification and substructure synthesis in the field of computer aided mechanical engineering.

Serviceability design factors for wind-sensitive structures

2010 ◽  
Vol 37 (5) ◽  
pp. 728-738 ◽  
Author(s):  
A. Pozos-Estrada ◽  
H. P. Hong ◽  
J. K. Galsworthy
Keyword(s):  
Standard Deviation ◽  
Dynamic Characteristics ◽  
Human Perception ◽  
Wind Loading ◽  
Peak Acceleration ◽  
Structural Dynamic ◽  
Annual Probability ◽  
Structural Dynamic Characteristics ◽  
Wind Characteristics ◽  
Design Factors

Wind-sensitive buildings can experience excessive vibrations that cause discomfort and interruption of the activities of the inhabitants of the buildings. To ensure the desired serviceability, codes, standards, and their commentaries have proposed perception curves that limit the expected (or mean) peak acceleration or standard deviation of the acceleration of the buildings. These perception curves are developed based on perceived vibration alone and do not consider the uncertainty in structural dynamic characteristics (i.e., natural frequency of vibration and ratio of damping) and loads such as the wind loading. Therefore, the annual probability that the perception curve is not exceeded for a building whose design is based on the perception curve is unknown. In this study, serviceability design factors are calibrated for selected targeted annual probability of perception levels by considering the uncertainty in the structural dynamic characteristics, wind characteristics, as well as in the human perception of motion. These serviceability design factors are to be used with the estimated mean peak acceleration caused by along-wind and cross-wind excitations given in the commentaries of the current National building code of Canada. The use of calibrated serviceability design factors for design checking is illustrated with a numerical example.

Analysis on Flow-Induced Vibration of Underwater Horizontal Gate

2010 ◽  
Vol 163-167 ◽  
pp. 293-298
Author(s):  
Wei Wei ◽  
Hao Ren
Keyword(s):  
Numerical Models ◽  
Coherence Function ◽  
Hydrodynamic Pressure ◽  
Vibration Response ◽  
Flow Induced Vibration ◽  
Structural Dynamic ◽  
Fluctuating Pressure ◽  
Frequency Components ◽  
Random Vibration Theory ◽  
Different Levels

The best is to read these instructions and follow the outline of this text. The physical and numerical models were combined to analyze flow-induced vibration response of Qingshuihe River underwater horizontal gate in this paper; the pressures acting on the gate were divided into two parts: the fluctuating pressure of flow on the stationary gate and the hydrodynamic pressure caused by the gate vibration, which is additional pressure induced by disturbed flow. The temporal-spatial correlation of fluctuating pressures obtained by model experiments between different nodes was analyzed. In the study the coherence function is defined in frequency domain with consideration of different levels of correlation for different frequency components, and the nodal load of the fluctuating pressure could be obtained. A new distribution of additional mass with considering radial vibration of the gate is adopted as equivalent hydrodynamic pressure. Based on random vibration theory, the flow-induced vibration response of the gate was obtained. The results provide the reliable reference evidence for structural dynamic design of the gate and show that the hydrodynamic stability of the gate can meet the requirement. On the other hand, it is shown that this method is reasonable and feasible.

Identification and Prediction of Frame Structure Dynamics by Spatial Matrix Identification Method

2001 ◽  
Vol 123 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Masaaki Okuma ◽  
Ward Heylen ◽  
Hisayoshi Matsuoka ◽  
Paul Sas
Keyword(s):  
Boundary Condition ◽  
Dynamic Characteristics ◽  
Test Structure ◽  
Frame Structure ◽  
Structural Dynamic ◽  
Various Boundary Conditions ◽  
Identification Method ◽  
Input Multiple Output ◽  
Structural Dynamic Characteristics ◽  
Single Input

This paper presents the results of using an experimental spatial matrix identification method to predict the dynamics of a frame structure under various boundary conditions. The single-input-multiple-output frequency response functions (FRFs) of the test structure under the free-free boundary condition are measured by hammer testing. Using the FRFs, a set of spatial matrices is constructed in order to represent the structural dynamic characteristics of the system by the new method. Using the spatial matrices, the dynamic characteristics of the test structure under the boundary condition of clamping 4 points is predicted. The prediction is adequately accurate for practical application. The results of the prediction demonstrate that the spatial matrices identified by this method can be used for structural modification and substructure synthesis in the field of computer-aided mechanical engineering.

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