Experimental and Numerical Evaluation of the Installation of Sub-Sea Equipments for Risers Support

2008 ◽  
Author(s):  
Andre´ L. C. Fujarra ◽  
Eduardo A. Tannuri ◽  
Isai´as Q. Masetti ◽  
Haroldo Igreja
Keyword(s):  
Previous Analysis ◽  
Small Scale ◽  
Wave Excitation ◽  
Safe Operation ◽  
Good Adherence ◽  
System A ◽  
Sinusoidal Motion ◽  
Dynamic Forces ◽  
Technological Research Institute ◽  
Multi Body

The installations of sub-sea equipments are very complex operations, requiring previous analysis in order to define the correct procedure and the environmental “window” for a safe operation. This paper addresses the installations of a Mid Water Arch (MWA) that consists of a structure to provide risers support. Connecting the risers to the MWA largely eliminates the dynamic forces that would otherwise cause friction and fatigue. Such structure is composed by the riser guides and several buoyancy tanks. It is kept in the water by means of tethers connected to an anchor. The MWA is to be installed 42m from the seabed. The installation procedure has several steps evolving the launching of each component of the MWA (anchor, main structure and the tethers). A tug boat with an A-frame is used during the whole launching, and an assisting vessel is required to keep the buoy away from the tether and the launching cable. The presence of exciting waves induces oscillatory motions in the whole system, and may cause large dynamic forces in the cables and tethers. Due to the complexity of the multi-body system, a comprehensive numerical and experimental analysis was then carried out in order to dimensioning the launching cables and to define the limit environmental condition. The numerical analysis was carried out in the Numerical Offshore Tank (TPN), a multi-processor offshore system simulator that considers the 6 DOF of each body and all environmental forces acting in them. The lines are modeled by finite-element method. Furthermore, a full set of small-scale experiments were carried out at the State of Sa˜o Paulo Technological Research Institute (IPT) towing tank, considering the system excited by a sinusoidal motion at the top, emulating the wave excitation. Comparisons between numerical and experimental results were performed, with good adherence between them. The validated numerical simulator was then used to make predictions of the behavior of the systems during the installation, considering several environmental conditions and configurations.

Double Closed-Loop Motor Modeling and Analysis for Lunar Rover Simulation

2012 ◽  
Vol 472-475 ◽  
pp. 1971-1976 ◽  
Author(s):  
Wei Dong Huang ◽  
Hong Kui Feng ◽  
Jin Song Bao ◽  
You Sheng Xu
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Dynamics Simulation ◽  
Motor Drive ◽  
Modeling And Analysis ◽  
Lunar Rover ◽  
System A ◽  
Drive Control ◽  
Body Dynamics ◽  
Multi Body

Motor drive control is the major study field in the development of lunar rover. Based on the double-closed DC loop adjustable-speed system, a motor drive simulation module using a position recursive PID control algorithm is developed, which is integrated into the multi-body dynamics simulation system, to carry out the whole lunar rover simulation. And the cruise process of lunar rover locomotion in the complex lunar terrain is simulated in a virtual environment.

Parallel Time-Integration of Flexible Multibody Dynamics Based on Newton-Waveform Method

2017 ◽  
Author(s):  
Shilei Han ◽  
Olivier A. Bauchau
Keyword(s):  
Multibody Dynamics ◽  
Time Integration ◽  
Flexible Multibody Dynamics ◽  
Small Scale ◽  
Time Step ◽  
Current Time ◽  
Parallel Time ◽  
Previous Time ◽  
Flexible Multibody ◽  
Multi Body

Traditionally, the time integration algorithms for multibody dynamics are in sequential. The predictions of previous time steps are necessary to get the solutions at current time step. This time-marching character impedes the application of parallel processor implementation. In this paper, the idea of computing a number of time steps concurrently is applied to flexible multi-body dynamics, which makes parallel time-integration possible. In the present method, the solution at the current time step is computed before accurate values at previous time step are available. This method is suitable for small-scale parallel analysis of flexible multibody systems.

Application of Targeted Energy Transfer (TET) Techniques to the Seismic Protection of a Small Scale Multistorey Eccentric Steel Structure

2011 ◽  
Author(s):  
Concetta Tripepi ◽  
Francesco Nucera ◽  
Lawrence A. Bergman ◽  
D. Michael McFarland ◽  
Alexander F. Vakakis
Keyword(s):  
Energy Transfer ◽  
Linear System ◽  
Steel Structure ◽  
Steel Structures ◽  
Nonlinear Energy Sink ◽  
Small Scale ◽  
Targeted Energy Transfer ◽  
Resonance Capture ◽  
System A ◽  
Transient Resonance

The aim of this work is to show that is possible to apply the Nonlinear Energy Sink (NES) concept to protect seismically excited eccentric steel structures through Targeted Energy Transfer (TET). We consider, as the primary (linear) system, a small-scale four-storey unsymmetrical-plan building, modeled as a twelve-degree-of-freedom-system, with floors sufficiently rigid so that the frame can reasonably be considered as shear-type and with additional eccentric mass for each floor. To the primary (linear) system, we connect two NESs, which are non-smooth and precisely the vibro-impact devices (VI-NESs), both placed on the top floor. In order to analyze the dynamics of the controlled model (structure with VI-NESs), we study the performance and the robustness of the augmented structure excited by a set of Eurocode8 (EC8) spectrum compliant earthquakes. Our purpose is to check the effectiveness of the VI-NESs to different earthquake excitations, that is, testing that an optimal VI-NES setting computed for a specific earthquake will still produce satisfactory results for the other earthquakes. We show that the nonlinear attachments are capable of engaging in transient resonance with linear modes at arbitrary frequencies by generating a one-way irreversible (on the average) transfer of the energy of vibration from the primary structure to local attachment. There the energy is confined and locally dissipated without “spreading” back to the main structure because of the instantaneous internal resonance. As energy decreases due to damping the conditions for Transient Resonance Capture (TRC) fail and escape from resonance capture takes place.

Synthesis of Spatial Parallel Mechanisms for a Vertical and Longitudinal All-Terrain Suspension

2012 ◽  
Vol 162 ◽  
pp. 19-28 ◽  
Author(s):  
Jean Christophe Fauroux
Keyword(s):  
Power Transmission ◽  
Parallel Structure ◽  
Small Scale ◽  
Parallel Mechanisms ◽  
Dimensional Synthesis ◽  
3D Kinematics ◽  
Highly Efficient ◽  
System A ◽  
Original Contribution ◽  
2D And 3D

Fast wheeled motion on unstructured grounds requires highly efficient suspensions that damp shocks vertically but also horizontally, which is an original contribution of the author. This work describes nine 2D and 3D kinematics, most of them with parallel structure, that are suitable for guiding a wheel and providing simultaneous damping in two directions. Steering and power transmission are also included in the most advanced variants, that were previously patented. Both structural and dimensional synthesis are presented, with a kinematic description of each system. A real implementation at a small scale is also described.

611 Estimation of Dynamic Forces between 4 Wheels and Road using Multi-body Dynamics Suspension Model

2005 ◽  
Vol 2005.80 (0) ◽  
pp. _6-27_-_6-28_
Author(s):  
Hiroki Takeda ◽  
Katsuhisa Fujita ◽  
Nagao Miyazaki ◽  
Syu Ueno
Keyword(s):  
Body Dynamics ◽  
Dynamic Forces ◽  
Suspension Model ◽  
Multi Body

Thermal Effects on the Anchoring of Flexible Pipe Tensile Armors

2015 ◽  
Author(s):  
Olaf O. Otte Filho ◽  
Rafael L. Tanaka ◽  
Rafael G. Morini ◽  
Rafael N. Torres ◽  
Thamise S. V. Vilela
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thermal Effects ◽  
Current Model ◽  
Element Model ◽  
Small Scale ◽  
Flexible Pipe ◽  
System A ◽  
Flexible Pipes ◽  
Better Than

In the design of flexible pipes, predict the anchoring behavior on end fittings is always challenging. In this sense, Prysmian Surflex has developed a finite element model, which should help the end fitting design as well the prediction of the structural behavior and the acceptable maximum loads. The current model considers that the contact between armor-resin is purely cohesive and has been suitable for the design of end fittings [1] and [2]. But tests and new studies [3] and [4] indicate that only cohesive assumption would not be the best approach. Experimental data from prototype tests also show that the current model would not predict acceptable results for loads higher than those used in previous projects. This document will describe a study developed considering the friction and thermal contraction, instead of the cohesive phenomenon in the anchoring behavior analysis. Small scale tests were conducted in order to understand the anchoring relation between the resin and the wire used in the tensile armor. For this purpose, a special test device was developed to simulate an enclosure system. A parametric study was also performed to identify the cooling temperatures, coefficients of friction and contact properties parameters taken from small scale tests. The finite element model considers the thermal effects during exothermic curing. Using the new parameters obtained, a second model was developed. This model consists of only one real shaped bended wire inside an end fitting cavity. To validate the model, samples were tested on laboratory according anchoring design. The results of this round of tests were studied and corroborate the argument that use friction and thermal effects is better than use only the cohesive condition.

A Theoretical and an Experimental Investigation of a Small Scale Trigeneration System: A Comparison Between Trigeneration and Separate Generation Systems

2003 ◽  
Author(s):  
Yaodong Wang ◽  
Tarik Al-Shemmeri
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Energy Input ◽  
Primary Energy ◽  
Small Scale ◽  
Generation System ◽  
Gas Emission ◽  
Environment Friendly ◽  
Co2 Gas ◽  
System A

A theoretical and an experimental investigation of a small scale trigeneration based on a diesel engine generator set is conducted. Comparing with the separate generation system, trigeneration saves primary energy input; and it reduces CO2 gas emission to the environment. A conclusion can be drawn that trigeneration is an environment friendly method, and it is financially feasible.

scholarly journals Evaluation of Physicochemical Properties and Sensory Qualities of Pasta Enriched with Freeze-Dried Sweet Whey

2020 ◽  
Vol 51 (3) ◽  
pp. 75-85
Author(s):  
S. Boudalia ◽  
Y. Gueroui ◽  
B. Boumaza ◽  
A. Bousbia ◽  
M. Benada ◽  
...  
Keyword(s):  
Raw Materials ◽  
Consumer Acceptance ◽  
Small Scale ◽  
Whey Powder ◽  
System A ◽  
Freeze Dried ◽  
Sweet Whey ◽  
Colour Parameters ◽  
Sensory Qualities

Abstract For food industry, the production of functional pasta from non-conventional raw materials represents a challenge. This study aims to evaluate the potential of animal proteins of freeze-dried whey as a component for pasta production and its effect on the pasta qualities and consumer acceptance. Sweet whey was freeze-dried, then directly incorporated to pasta at a 20% level. Two pasta types (pasta non-enriched vs. enriched with whey powder) were manufactured following a small-scale pilot procedure, and then evaluated for their physicochemical and sensory qualities. Results of all analyses (whey, semolina and pasta) met the standards according to international legislation; however, the characteristics of enriched pasta differed. Whey addition significantly increased ash, proteins content, optimal cooking time and water uptake (P < 0.05); it significantly decreased moisture levels, colour parameters (CIE system: a* redness, b* yellowness) and the swelling index (P < 0.05). Sensory analysis revealed that overall sensory and product quality of enriched pasta was not affected by whey fortification and it was found acceptable by panelists. This study points out that whey powder could be used for the functional pasta production to increase proteins levels.

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