Establishing Platform Foundation Capacity Using Topside Vibration Measurements

2010 ◽  
Author(s):  
Jared L. Black
Keyword(s):  
Structural Analysis ◽  
Resonance Condition ◽  
Steel Structure ◽  
Field Work ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Lateral Stiffness ◽  
Resonant Frequencies ◽  
Monitoring Procedure

This paper describes how a structural vibration monitoring procedure was used in combination with structural analysis modeling to determine the foundation capacity of an existing offshore platform. The project was initiated due to concern that the foundation capacity was marginal for a needed expansion of the topsides process system. The field work consisted of conducting a sequence of vibration measurement for a range of increasing deck loads. Since the platform’s resonant frequencies depend on the structural stiffness and mass, each deck loading (mass) produced a slightly different resonance condition. The set of resonant frequencies obtained for the different deck loads allows one to deduce the stiffness of the structure-foundation system. The stiffness of the steel structure (jacket and deck) was established with structural analysis. The remaining unknown is the axial and lateral stiffness of the pile foundation. Using the torsional resonant frequencies, the lateral stiffness of the pile array and individual piles was established. Then using the translational resonance, the axial pile stiffness was found. Based on these analyses, the platform’s foundation capacity was estimated to be significantly greater than that predicted by the standard pile capacity design recipe. The structure was deemed adequate for the planned topside modification.

Structural vibration measurement with multiple synchronous cameras

2021 ◽  
Vol 157 ◽  
pp. 107742
Author(s):  
Roberto Del Sal ◽  
Loris Dal Bo ◽  
Emanuele Turco ◽  
Andrea Fusiello ◽  
Alessandro Zanarini ◽  
...  
Keyword(s):  
Vibration Measurement ◽  
Structural Vibration

scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2528 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes, in addition to immunity to electromagnetic interference and chemical corrosions. Thus, the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within (−6°, 4°), and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

scholarly journals Structural Analysis of Steel Structures under Fire Loading

10.14311/1083 ◽  
2009 ◽  
Vol 49 (1) ◽  
Author(s):  
C. Crosti
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Steel Structure ◽  
Steel Structures ◽  
Global Behavior ◽  
Fire Load ◽  
Stiffness Reduction ◽  
Fire Loading ◽  
The Right ◽  
Real Building

This paper focuses on the structural analysis of a steel structure under fire loading. In this framework, the objective is to highlight the importance of the right choice of analyses to develop, and of the finite element codes able to model the resistance and stiffness reduction due to the temperature increase. In addition, the evaluation of the structural collapse under fire load of a real building is considered, paying attention to the global behavior of the structure itself. 

Wireless MEMS-Based Accelerometer Sensor Boards for Structural Vibration Monitoring: A Review

2017 ◽  
Vol 17 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Alessandro Sabato ◽  
Christopher Niezrecki ◽  
Giancarlo Fortino
Keyword(s):  
Vibration Monitoring ◽  
Structural Vibration ◽  
Accelerometer Sensor

Development of a Case Vibration Measurement System for the DC-990 Gas Turbine

1984 ◽  
Vol 106 (4) ◽  
pp. 935-939
Author(s):  
H. A. Kidd
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cost Effective ◽  
Industrial Applications ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Monitoring Systems ◽  
Development Programs ◽  
Field Service ◽  
Service Staff

The continued use of gas turbines in industrial applications and increased customer desires for trend analysis has led gas turbine suppliers to develop sophisticated, reliable, cost-effective vibration monitoring systems. This paper discusses the application of case vibration monitoring systems and the design criteria for each component. Engine installation, transducer mounting brackets, types of transducers, interconnecting cables and connectors, charge amplifiers, and signal conditioning and monitoring are considered. Examples are given of the benefits experienced with the final system in several of Dresser Clark’s engine development programs, by manufacturing and production testing, and by Dresser’s field service staff.

Monitoring of a controlled space flexible multibody by means of embedded piezoelectric sensors and cameras synergy

2018 ◽  
Vol 29 (14) ◽  
pp. 2966-2978 ◽  
Author(s):  
Matteo Ribet ◽  
Marco Sabatini ◽  
Luca Lampani ◽  
Paolo Gasbarri
Keyword(s):  
Optical Sensors ◽  
Attitude Control ◽  
Point Of View ◽  
Vibration Monitoring ◽  
Structural Vibration ◽  
Elastic Displacement ◽  
Experimental Point ◽  
Solar Panels ◽  
Flexible Multibody ◽  
Usual Solution

Interaction between elastic dynamics and attitude control is a serious problem in space operations, which often involve satellites with highly flexible appendages. Monitoring and eventually control of the vibrations are a major concern to avoid a decrease in the expected performance. In particular, the classic case of a central bus with two lateral appendages (solar panels) is considered. The design of a system for structural vibration monitoring is proposed both from a numerical and an experimental point of view. Piezoelectric devices are a usual solution for measuring the deformation of the structures. In the proposed work, optical sensors are also implemented: the combined use of the two sets allows for the monitoring of the elastic displacement of the solar panels and for the reconstruction of the modal shapes of the entire flexible multibody system.

scholarly journals Structural Improvement of the ω-Type High-Speed Rail Clip Based on a Study of Its Failure Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xiaogang Gao ◽  
Anbin Wang ◽  
Yu He ◽  
Xiaohan Gu
Keyword(s):  
Failure Mechanism ◽  
Fatigue Test ◽  
High Frequency ◽  
High Speed ◽  
Excitation Frequency ◽  
Test System ◽  
Vibration Measurement ◽  
High Speed Rail ◽  
Resonant Frequencies ◽  
Rail Wear

In the circumstances of high-speed railways, the wheel-rail vibration is significantly aggravated by polygonal wheel wear and rail corrugation, which subsequently leads to the wheel-rail interaction at higher frequencies and potential failure of the rail fastening. In this paper, a ω-type clip of the fastening in the CRH high-speed rail was used to investigate the failure mechanism. First, a dynamic wheel-rail coupling model and a finite element analysis of the rail clip were developed, from which the rail vibration frequency and modal frequencies of the clip with different installation torques were obtained. The experimental tests and modal simulation results were mutually verified. In addition, the real-time vibration measurement and the wheel-rail wear monitoring were carried out at a CRH high-speed railway site. It was found that the resonant frequencies of the ω-type clip in the installation condition coincided with the excitation frequencies of the wheel-rail interaction induced by wheel-rail wear. The high-frequency dynamic failure mechanism of a typical ω-type clip, W300-1, is put forward for the first time. Moreover, a high-frequency rail clip fatigue test system was designed and developed specifically for this study. The loading excitation frequency of the clip test used was set as 590 Hz, and the loading amplitude was 0.05 mm. After 125-minute operation of the test system, the clip was broken at the expected location predicted by the FEA model. The high-frequency fatigue test result further verified that the failure mechanism of the ω-type clip was due to the resonance of the clip with its excitation force from the wheel-rail interaction. Finally, the clip was then structurally improved taking into account the stiffness and mass, which led to its resonant frequencies shifting away from the high-frequency excitation range, hence avoiding resonance failure of the subject clip.

Denoising in Steel Structural Impulsive Vibration Signal Based on Independent Component Analysis

2011 ◽  
Vol 219-220 ◽  
pp. 1337-1341 ◽  
Author(s):  
Jun Hong Cao ◽  
Zhuo Bin Wei
Keyword(s):  
Independent Component Analysis ◽  
Steel Structure ◽  
Vibration Signal ◽  
Component Analysis ◽  
Independent Component ◽  
Structural Vibration ◽  
Vibration Signals ◽  
Structure Vibration

The analysis of structure vibration signals is influenced by noise mixed in the signals. Independent component analysis (ICA) method is introduced to denoise the vibration signals in this paper. The representative algorithms: FastICA and JADE are told in detail. The algorithms are applied to separate steel structural vibration signals. The denoising performances in impulsive vibration signals generated by steel structure demonstrate the effectiveness and good robustness of ICA method.

Development of piezoelectric paint thick-film vibration sensors

2005 ◽  
Vol 219 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J M Hale ◽  
J R White ◽  
R Stephenson ◽  
F Liu
Keyword(s):  
Thick Film ◽  
Dynamic Range ◽  
Strain Sensors ◽  
Fabrication Process ◽  
Vibration Monitoring ◽  
Structural Vibration ◽  
Dynamic Strain ◽  
Vibration Sensors ◽  
Piezoelectric Polymer ◽  
Adverse Environments

This paper describes a programme of trials of thick-film dynamic strain sensors made using ‘piezoelectric paint’. The fabrication process is described and it is shown that the sensitivity is comparable with that of other thick-film sensors and the piezoelectric polymer polyvnylidenefluoride (PVDF). A series of dynamic and environmental tests is described. The dynamic range and bandwidth are shown to be suitable for structural vibration monitoring, and to be largely unaffected by adverse environments (rain, frost, sunlight, etc.).

Flow and Structural Analysis of a Straight and Swept Blade Near Stall Region

2011 ◽  
Author(s):  
Ryoichi S. Amano ◽  
Ilya Avdeev ◽  
Pradeep Mohan Mohan Das ◽  
Mir Zunaid Shams
Keyword(s):  
Structural Analysis ◽  
Wind Speed ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Flow Separation ◽  
Maximum Stress ◽  
Fe Analysis ◽  
Structural Vibration ◽  
Vibration Modes ◽  
Speed Range

The aerodynamics of a straight edged and a swept edged blade are investigated using a commercial CFD code. RANS equations with SST k-ω equation were utilized to study the flow separation along the blades span in a stall region. The analysis results will be used to provide inputs to future designs to improve and to enable better prediction of the stall region. The computations were carried out in a narrow wind speed range of 14 m/s to 16 m/s which as per earlier analysis was near the stall point to further understand the locations of flow separations along the blade span. The study provides some insights in to the flow physics in the region around the wind turbine blade. An FE Analysis was also performed to further understand the maximum stress and displacement regions to further provide inputs to future designs. A comparison of maximum stress, deformation and structural vibration modes for the two blades were also done.

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