Dynamic response of offshore triceratops: Numerical and experimental investigations

2015 ◽  
Vol 109 ◽  
pp. 401-409 ◽  
Author(s):  
Srinivasan Chandrasekaran ◽  
S. Madhuri
Keyword(s):  
Dynamic Response ◽  
Experimental Investigations

Experimental Investigation on the Dynamic Response of a Three Legged Articulated Type Offshore Wind Tower

2016 ◽  
Author(s):  
Chinsu Mereena Joy ◽  
Anitha Joseph ◽  
Lalu Mangal
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Renewable Energy Sources ◽  
Offshore Structures ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Experimental Investigations ◽  
Offshore Wind Turbine ◽  
Ocean Engineering ◽  
Study Results

Demand for renewable energy sources is rapidly increasing since they are able to replace depleting fossil fuels and their capacity to act as a carbon neutral energy source. A substantial amount of such clean, renewable and reliable energy potential exists in offshore winds. The major engineering challenge in establishing an offshore wind energy facility is the design of a reliable and financially viable offshore support for the wind turbine tower. An economically feasible support for an offshore wind turbine is a compliant platform since it moves with wave forces and offer less resistance to them. Amongst the several compliant type offshore structures, articulated type is an innovative one. It is flexibly linked to the seafloor and can move along with the waves and restoring is achieved by large buoyancy force. This study focuses on the experimental investigations on the dynamic response of a three-legged articulated structure supporting a 5MW wind turbine. The experimental investigations are done on a 1: 60 scaled model in a 4m wide wave flume at the Department of Ocean Engineering, Indian Institute of Technology, Madras. The tests were conducted for regular waves of various wave periods and wave heights and for various orientations of the platform. The dynamic responses are presented in the form of Response Amplitude Operators (RAO). The study results revealed that the proposed articulated structure is technically feasible in supporting an offshore wind turbine because the natural frequencies are away from ocean wave frequencies and the RAOs obtained are relatively small.

Dynamic response of bridges under travelling loads

1993 ◽  
Vol 20 (2) ◽  
pp. 287-298 ◽  
Author(s):  
J. L. Humar ◽  
A. M. Kashif
Keyword(s):  
Dynamic Response ◽  
Rational Design ◽  
Weight Ratio ◽  
Experimental Investigations ◽  
Speed Ratio ◽  
Force Model ◽  
Beam Model ◽  
Dynamic Amplification Factor ◽  
Design Procedures ◽  
Dynamic Amplification

In spite of a number of analytical and experimental investigations on the dynamic response of bridges to moving vehicle loads, the controlling parameters that govern the response have not been clearly identified. This has, in turn, inhibited the development of rational design procedures. Based on an analytical investigation of the response of a simplified beam model traversed by a moving mass, the present study identifies the governing parameters. The results clearly show why attempts to correlate the response to a single parameter, either the span length or the fundamental frequency, are unsuccessful. Simple design procedures are developed based on relationships between the speed ratio, the weight ratio, and the dynamic amplification factors; and a set of design curves are provided. Key words: dynamic response of bridges, vehicle–bridge interaction, moving force model, moving sprung mass model, dynamic amplification factor.

scholarly journals Vibrations Caused By Train Passages In Underground Tunnel Compared To Vibrations From Ground Surface Transportation – Some Results Of Investigations

2014 ◽  
Vol 60 (2) ◽  
pp. 269-286
Author(s):  
Krzysztof Stypuła
Keyword(s):  
Dynamic Response ◽  
Ground Surface ◽  
Experimental Investigations ◽  
Ground Vibrations ◽  
Underground Tunnel ◽  
Surface Transportation

Abstract The paper describes experimental investigations of vibrations caused by train passages in the shallow underground tunnel (in Warsaw, Poland) in comparison to the results of measurements of vibrations from ground surface transportation (trams and buses). Propagation of surface ground vibrations from underground tunnel is presented. The problem of dynamic response of a building and influence of vibrations caused by underground on people residing in a building is discussed as well. The dynamic response of the building to underground vibrations is essentially different from the response of a building excited by surface sources of transport vibrations. Also the distribution of influence of the transport vibrations on people in the building is significantly different in both cases.

Experimental Studies on Dynamic Response Behavior of Multi-Legged Articulated Tower

2010 ◽  
Author(s):  
Srinivasan Chandrasekaran ◽  
K. Bhaskar ◽  
Mohammed Hashim
Keyword(s):  
Dynamic Response ◽  
Experimental Studies ◽  
Experimental Investigations ◽  
Random Waves ◽  
Response Behavior ◽  
Scaled Model ◽  
Response Characteristics ◽  
Sea Bed ◽  
Motion Characteristics ◽  
Stress Variations

Articulated towers consist of surface piercing columns pinned to sea floor and have increased applications in deep water oil exploration. Vital component is the buoyant shaft connected to sea bed through a universal joint. Design methodologies of these towers ensure reduced motion characteristics with less deck acceleration while loads at the articulated joint are kept to minimum; this is required to establish sufficient stability under working conditions. A Scaled model of a multi-legged articulated tower is experimentally investigated under regular and random waves. Influence of different parameters on the tower response, namely, deck load and wave approach angle are examined in detail. Apart from having increased deck area, multi-legged articulated towers showed controlled dynamic response behavior under environmental loads. Conclusions drawn from the study bring a detailed insight to the design of such platforms. Though few observations inferred from the study are not new, important dynamic response characteristics like bending stress variations are quantified through experimental investigations.

THE ROLE OF SUSPENSION STRUCTURE IN THE DYNAMIC RESPONSE OF ELECTRORHEOLOGICAL SUSPENSIONS

1994 ◽  
Vol 08 (20n21) ◽  
pp. 2789-2809 ◽  
Author(s):  
M. PARTHASARATHY ◽  
K. H. AHN ◽  
B. M. BELONGIA ◽  
D. J. KLINGENBERG
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Superposition Principle ◽  
Experimental Investigations ◽  
Linear Deformation ◽  
Rheological Response ◽  
Oscillatory Response ◽  
Electrorheological Suspensions ◽  
Suspension Structure

The dynamic response of electrorheological (ER) suspensions has received little attention relative to the effort devoted to the study of the steady shear response. We report on simulation and experimental investigations of the dynamic oscillatory response of ER suspensions, in particular focusing on the relationship between suspension structure and the rheological response. We consider the response of monodisperse and polydisperse suspensions under linear deformation, as well as the response in the nonlinear regime. Dimensional analysis of the equations of motion predict that the linear rheological response obeys a time-field strength superposition principle, which is confirmed by experiment. The response is found to exhibit a sharp dispersion that is only broadened slightly by polydispersity. Nonlinear deformation is found to significantly broaden the observed dispersion.

Transmission of Fluid Power by Pulsating-Flow (P-F) Concept in Hydraulic Systems

1966 ◽  
Vol 88 (2) ◽  
pp. 316-321 ◽  
Author(s):  
Cheng-Kuo Weng
Keyword(s):  
Dynamic Response ◽  
Hydraulic System ◽  
Power Transmission ◽  
Pulsating Flow ◽  
Fluid Power ◽  
Experimental Investigations ◽  
System Efficiency ◽  
Test Results ◽  
Hydraulic Systems ◽  
Line Loss

Theoretical and experimental investigations have been made on fluid-power transmission in hydraulic systems by pulsating flow. In particular, the system efficiency and the viscosity effect on the dynamic response of pulsating flow in the fluid line have been studied. Test results on the fluid-line dynamic response and on the system efficiency that obtained from the line-loss test setup and the miniaturized P-F hydraulic system setup, respectively, are presented.

scholarly journals Numerical and Experimental Investigations on Dynamic Response of Hydraulic Cylinder with 3D Spatial Joints considering Radial and Axial Clearances

2019 ◽  
Vol 2019 ◽  
pp. 1-24 ◽  
Author(s):  
Ke Chen ◽  
Guojun Zhang ◽  
Haishuo Wang ◽  
Rui Wu ◽  
Hongmei Zheng ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Hydraulic Cylinder ◽  
Dynamic Responses ◽  
Radial Clearance ◽  
Experimental Investigations ◽  
Force Frequency ◽  
Clearance Joints ◽  
Input Force ◽  
Contact Points ◽  
Potential Contact

Radial clearance, particularly the axial clearance in the 3D joint of a mechanism owing to the assemblage, manufacturing tolerances, wear, and other conditions, has become a research focus in the field of multibody dynamics in recent years. In this study, a hydraulic cylinder model with 3D clearance joints was constructed by combining various potential contact scenarios. The novelty of this study is that potential contact points between the bearing wall and journal were calculated when the bearing wall circle was projected to an ellipse owing to misalignment of axes. Moreover, the simulation model considered the effective bulk modulus of the hydraulic oil and applied the Lagrange multiplier method. Subsequently, an experiment was conducted to verify the simulation results. The simulation and experimental results indicated that the dynamic responses of the hydraulic cylinder with 3D clearance joints can be classified as free, rebound, slide, and contact. The effects of input force, frequency, and clearance size on the dynamic behavior of the hydraulic cylinder were also investigated. Increasing the input force and clearance size will degrade the hydraulic cylinder dynamic response; however, the input force frequency can reduce the deterioration of the dynamic response. This study aids in providing improved understanding of the hydraulic cylinder with 3D clearances in the theoretical field and for practical engineering applications.

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