Changes in dynamic characteristics of Lorca RC buildings from pre- and post-earthquake ambient vibration data

2013 ◽  
Vol 12 (5) ◽  
pp. 2095-2110 ◽  
Author(s):  
F. Vidal ◽  
M. Navarro ◽  
C. Aranda ◽  
T. Enomoto
Keyword(s):  
Dynamic Characteristics ◽  
Ambient Vibration ◽  
Rc Buildings ◽  
Vibration Data

Testing in-Phase Analysis for Adjacent Transmission Towers under Ambient Vibration

2011 ◽  
Vol 105-107 ◽  
pp. 112-116
Author(s):  
Xiang Mei Yan
Keyword(s):  
Dynamic Characteristics ◽  
Damping Ratio ◽  
Longitudinal Direction ◽  
Ambient Vibration ◽  
Induced Response ◽  
Line System ◽  
Vibration Data ◽  
Transmission Towers ◽  
Ambient Vibration Testing ◽  
Suspended Cables

Based on the random vibration and system identification theory, the ambient vibration testing of two adjacent transmission towers were carried out, dynamic characteristics of the towers were obtained from ambient vibration data. The result shown that the suspended cables not only have mass effects, but have coupled stiffness effects applied to tower on transverse direction and longitudinal direction. At the same, testing value shows that the two adjacent towers have basically the same dynamic characteristics and damping ratio of the two transmission towers less than 0.01. Owing to the influence of conductors, frequency of the insulators is different to the towers at the two directions. It is disadvantage for wind-induced response of transmission line system under ambient loads.

scholarly journals Effects of Precast Cladding Systems on Dynamic Characteristics of Steel Frame Buildings by Ambient and Free Vibration Tests

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Jun Ma ◽  
Shinji Nakata ◽  
Akihito Yoshida ◽  
Yukio Tamura
Keyword(s):  
Free Vibration ◽  
Dynamic Characteristics ◽  
Steel Frame ◽  
Ambient Vibration ◽  
Test Cases ◽  
Vibration Method ◽  
External Wall ◽  
Wide Range ◽  
Cladding Panels ◽  
Vibration Tests

Full-scale tests on a one-story steel frame structure with a typical precast cladding system using ambient and free vibration methods are described in detail. The cladding system is primarily composed of ALC (Autoclaved Lightweight Concrete) external wall cladding panels, gypsum plasterboard interior linings, and window glazing systems. Ten test cases including the bare steel frame and the steel frame with addition of different parts of the precast cladding system are prepared for detailed investigations. The amplitude-dependent dynamic characteristics of the test cases including natural frequencies and damping ratios determined from the tests are presented. The effects of the ALC external wall cladding panels, the gypsum plasterboard interior linings, and the window glazing systems on the stiffness and structural damping of the steel frame are discussed in detail. The effect of the precast cladding systems on the amplitude dependency of the dynamic characteristics and the tendencies of the dynamic parameters with respect to the structural response amplitude are investigated over a wide range. Furthermore, results estimated from the ambient vibration method are compared with those from the free vibration tests to evaluate the feasibility of the ambient vibration method.

An Integrated Joint Dynamics System for Elastically Jointed Structures

1991 ◽  
Author(s):  
Y. Rong ◽  
H. S. Tzou
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Measuring Device ◽  
Joint Friction ◽  
Vibration Data ◽  
Unit Structure ◽  
Joint Dynamics ◽  
Joint Clearances ◽  
Stochastic Simulator ◽  
Vibration Measuring

Abstract The dynamic behavior of elastic joints strongly affect the dynamic performance of a jointed mechanical system. The dynamic contacts introduced by joint clearances create a system with nonlinear characteristics. Special effort needs to be made to study jointed mechanical systems. This paper presents an integrated joint dynamics system, which can be used to predict the dynamic characteristics of a newly designed structure, or to analyze an existing jointed structure. This joint dynamics system can also be applied as a real time monitoring and diagnosis system when it is connected with a vibration measuring device. The joint dynamics system includes: 1) a theoretical model of jointed structures, in which the joint clearance and joint friction effects are considered; 2) a stochastic simulator which is used to generate vibration data and evaluate system dynamic characteristics; 3) a diagnostic monitoring algorithm for vibration state detection; and 4) a forecasting vibration control scheme. The joint dynamics system is applied to the dynamic analysis of a truss-cell unit structure. The results presented in this paper show that the joint dynamics system is effective.

scholarly journals Dynamic Study of a Rooftop Vertical Axis Wind Turbine Tower Based on an Automated Vibration Data Processing Algorithm

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3135 ◽  
Author(s):  
Ying Wang ◽  
Wensheng Lu ◽  
Kaoshan Dai ◽  
Miaomiao Yuan ◽  
Shen-En Chen
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Dynamic Responses ◽  
Ambient Vibration ◽  
Structural Vibration ◽  
Vertical Axis Wind Turbine ◽  
Mode Identification ◽  
Stochastic Subspace Identification ◽  
Vibration Data ◽  
Vibration Responses

When constructed on tall building rooftops, the vertical axis wind turbine (VAWT) has the potential of power generation in highly urbanized areas. In this paper, the ambient dynamic responses of a rooftop VAWT were investigated. The dynamic analysis was based on ambient measurements of the structural vibration of the VAWT (including the supporting structure), which resides on the top of a 24-story building. To help process the ambient vibration data, an automated algorithm based on stochastic subspace identification (SSI) with a fast clustering procedure was developed. The algorithm was applied to the vibration data for mode identification, and the results indicate interesting modal responses that may be affected by the building vibration, which have significant implications for the condition monitoring strategy for the VAWT. The environmental effects on the ambient vibration data were also investigated. It was found that the blade rotation speed contributes the most to the vibration responses.

scholarly journals Damage detection based on damping analysis of ambient vibration data

2008 ◽  
pp. n/a-n/a ◽  
Author(s):  
Michele Frizzarin ◽  
Maria Q. Feng ◽  
Paolo Franchetti ◽  
Serdar Soyoz ◽  
Claudio Modena
Keyword(s):  
Damage Detection ◽  
Ambient Vibration ◽  
Vibration Data
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