Some Aspects of Spar Platform Buoyancy Can Loads

2002 ◽  
Author(s):  
Hugh Thompson ◽  
Mehemosh B. Irani ◽  
Lyle D. Finn
Keyword(s):  
Finite Element ◽  
Field Measurements ◽  
Element Model ◽  
Scale Model ◽  
Spar Platform ◽  
Finite Element Program ◽  
Numerical Predictions ◽  
Element Program ◽  
Actual Field ◽  
The Time Domain

A finite element program is developed to analyze the dynamics of buoyancy cans within the centerwell of Spar platforms. The time domain non-linear finite element model includes the effects of the hydrodynamics of the water within the centerwell, and, the gap between the buoyancy cans and guides. The forces on the buoyancy can guide structure due to Spar motions is studied in the present paper. The theoretical results are validated with experimental and field measurements. 1:20.89 scale model tests are conducted to measure the buoyancy can motions and guide reaction forces for a range of gap sizes and specified Spar motions. A Spar platform is also instrumented to measure the guide forces in actual field conditions. The prototype field data is analyzed and compared with the numerical predictions.

Static and Dynamic Analyses of the LSES Hull Structure

1978 ◽  
Vol 22 (02) ◽  
pp. 110-122
Author(s):  
A. S. Hananel ◽  
E. J. Dent ◽  
E. J. Philips ◽  
S. H. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Surface Effect ◽  
Three Dimensional ◽  
Element Model ◽  
Finite Element Program ◽  
Hull Structure ◽  
Surface Effect Ship ◽  
Hull Design ◽  
Element Program

To avoid the conservativeness in the large surface-effect ship hull design which results from simplifying assumptions in the stress analysis, the hull structure was analyzed as a three-dimensional elastic body. The NASTRAN finite-element program, level 15.0, was selected for use in this analysis as the most suitable program available. A finite-element model representing the true hull stiffness was used in obtaining the internal load and displacement distributions. The inertia effect of the ship masses was included with each set of static loads. This was done by using the Static Analysis with Inertia Relief solution included in NASTRAN. The stress redistribution around cutouts in the hull was treated in a separate study. The interaction between hull and deckhouse was investigated by attaching a model of the deckhouse onto the hull model, and then solving for the appropriate load conditions. The natural frequencies were obtained using a reduced finite-element model of both the hull and hull/deckhouse combination. A new technique was developed for determining the dynamic stresses and their proper superposition on the static stresses.

Virtual Testing for Frontal Impact of High-Top Cab of Heavy Truck

2011 ◽  
Vol 148-149 ◽  
pp. 1081-1084
Author(s):  
Wei Wang ◽  
Xu Liang Xie ◽  
Fu Lin Shen ◽  
Xiao Feng Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Front Seat ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Commercial Code ◽  
Element Program ◽  
Heavy Truck ◽  
Survival Space ◽  
Pendulum Impact

ECE R29 regulation has legally claimed that the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash during design of truck cabin. In this paper, a finite element model of a high-top cabin of a heavy truck with a manikin on the driver seat was built with commercial code Hypermesh, The explicit finite element program Ls-Dyna was used to simulate the frontal pendulum impact on the high-top cab in the light of ECE R29 regulation. Deformation of the truck cabin and the survival space of the dummy were analyzed and discussed. Also, some suggestions were given to solve the contact possibility between steering column and the knees of manikin.

scholarly journals Evaluation of Strains at the Bottom of the Asphalt Base Layer of a Semi-Rigid Pavement Under a Class 6 Vehicle

2019 ◽  
Vol 271 ◽  
pp. 08008
Author(s):  
Mohsen Talebsafa ◽  
Stefan A. Romanoschi ◽  
Athanassios T. Papagiannakis ◽  
Constantin Popescu
Keyword(s):  
Finite Element ◽  
Longitudinal Direction ◽  
Element Model ◽  
Base Layer ◽  
Rigid Pavement ◽  
Finite Element Program ◽  
Element Program ◽  
Transverse Strains ◽  
Longitudinal Strains ◽  
Good Agreement

A newly constructed pavement on US-287 near Mansfield, TX was instrumented with gauges installed at the bottom of the asphalt concrete base layer to measure the longitudinal and transverse strains developed under a test vehicle. The finite element program Abaqus was used to compute the strains at the location of the gauges; they were found in good agreement with the measured strains. The research showed that the strains under the steering axle were of similar magnitude as the strains under the rear tandem axle. The measured transverse strains were in general slightly bigger than the corresponding longitudinal strains, while the finite element model computed higher strains in the longitudinal direction. These findings suggest the need to account for the strain responses from the steering axle of trucks and to account for both the longitudinal and the transverse strains when computing the fatigue damage induced by trucks.

Stress Analysis of Pin-Loaded Composite Plates

2004 ◽  
Author(s):  
James J.-S. Stone ◽  
Shen-Haw Ju ◽  
Robert E. Rowlands
Keyword(s):  
Finite Element ◽  
Frictional Contact ◽  
Composite Plates ◽  
High Sensitivity ◽  
Element Model ◽  
Bolted Joint ◽  
Numerical Techniques ◽  
Considerable Effort ◽  
Finite Element Program ◽  
Element Program

The frictional contact of the pin-loaded joint in composite plates was studied. This included the effects of pin clearance and variations in material and geometry. Full-filed displacements were measured by high sensitivity moire´ interferometry. Considerable effort was expended to develop a loading frame, relevant fixtures and monitoring capability to ensure that the plate was loaded uniformly through its thickness, particularly at the pin-loaded hole. Numerical techniques were prepared for processing the optical fringe data. A reliable finite element model for a bolted joint was also formulated. The efficient finite element program, which is capable of handling friction and/or clearance at the loaded hole, has been validated analytically, experimentally and numerically.

Finite Element Analysis of Synchronous Belt Tooth Failure

1993 ◽  
Vol 207 (2) ◽  
pp. 145-153 ◽  
Author(s):  
K W Dalgarno ◽  
A J Day ◽  
T H C Childs
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Model ◽  
Element Model ◽  
Element Analysis ◽  
Finite Element Program ◽  
Interface Elements ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Critical Strains

This paper describes a finite element analysis of a synchronous belt tooth under operational loads and conditions with the objective of obtaining a greater understanding of belt failure by tooth root cracking through an examination of the strains within the facing fabric in the belt. The analysis used the ABAQUS finite element program, and was based on a two-dimensional finite element model incorporating a hyperelastic material model for the elastomer compound. Contact between the belt tooth face and the pulley groove was modelled using surface interface elements which allowed only compression and shear forces at the contact surfaces. It is concluded that the critical strains in the facing fabric of the belt, and therefore the belt life, are largely determined by the tangential loading condition on the belt teeth.

Numerical analysis of face-shell bedded hollow masonry walls subject to concentrated loads

1995 ◽  
Vol 22 (4) ◽  
pp. 802-818 ◽  
Author(s):  
Ezzeldin Y. Sayed-Ahmed ◽  
Nigel G. Shrive
Keyword(s):  
Finite Element ◽  
Rational Design ◽  
Element Model ◽  
Masonry Walls ◽  
Concentrated Loads ◽  
Concentrated Load ◽  
Finite Element Program ◽  
Strength Enhancement ◽  
Element Program ◽  
Iterative Procedures

A nonlinear elastoplastic finite element model has been developed for face-shell bedded hollow masonry walls subject to in-plane concentrated loads. The model takes into account geometric and material nonlinearities as well as damage due to progressive cracking. Behaviour of the masonry components subject to compressive states of stress is modelled using the theory of plasticity, and cracking is modelled using both discrete and smeared cracking approaches. The model is generated on a SUN SPARC 10/31 workstation using the preprocessor of the finite element program ANSYS; the finite element solution is obtained using the ABAQUS program on the Fujitsu VPX 240/10 and IBM RS/6000 workstation. A brief summary of the numerical modelling and the iterative procedures is discussed. Results from simulated tests of seven-course high wallettes subject to concentrated loads are used to verify the behaviour of the numerical analyses. The methodology, when combined with substructuring, allows analysis of substantially larger walls than would more typical 3-D analyses. The model can be used to check existing design rules and develop more rational design methods for hollow masonry subject to concentrated load. Key words: masonry, hollow concrete masonry, finite element modelling, cracking, failure, strength enhancement factor, concentrated loads.

Undrained behavior of embankments on New Liskeard varved clay

1977 ◽  
Vol 14 (3) ◽  
pp. 367-388 ◽  
Author(s):  
Suzanne M. Lacasse ◽  
Charles C. Ladd ◽  
Alex K. Barsvary
Keyword(s):  
Finite Element ◽  
Effective Stress ◽  
Field Measurements ◽  
Excess Pore Pressure ◽  
Strength Parameters ◽  
Finite Element Program ◽  
Pore Pressures ◽  
Element Program ◽  
Varved Clay ◽  
Excess Pore

The performance, including a failure, of two embankments in New Liskeard, Ontario is analysed. The underlying medium-to-soft varved clay foundation is studied with respect to stability, undrained deformations, and excess pore pressure distribution.Total stress stability analyses were performed with undrained strengths based on measured and corrected field vane strengths, the average unconfined compression and unconsolidated undrained strength, and SHANSEP strength parameters with and without anisotropy. Several approaches yielded satisfactory factors of safety and reasonable critical arcs. Effective stress analyses using pore pressures predicted from finite element analyses showed that either the effective stress strength parameters were much lower than those measured in the laboratory or the predicted pore pressures at failure were much too low.Undrained deformations and excess pore pressures at end-of-construction were predicted with the finite element program FEECON. The values were generally consistent with field measurements for an embankment located 60 m from the failure area.

Strengthening of Concrete Beams Having Shear Zone Openings Using Orthotropic CFRP Modeling

2011 ◽  
Vol 147 ◽  
pp. 19-23
Author(s):  
Ashraf Mohamed Mahmoud
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Element Model ◽  
Reinforced Concrete Beams ◽  
Concrete Element ◽  
Finite Element Program ◽  
Proposed Model ◽  
Element Program ◽  
Orthotropic Properties

A finite element reinforced concrete model has been analyzed by the author with ANSYS 9 finite element program for both unstrengthened and CFRP-strengthened beams using concrete element model 25x25x25mm and discrete and smeared steel distribution with openings exist. The CFRP has been modeled using Solid46 element, which has orthotropic properties. The deflection results have been compared with an experimental and other finite element model which are performed by Mohamed [4], in which using 100x42.5x42.5 mm concrete element, smeared steel distribution with the same opening sizes, and modeling CFRP with ANSYS 5 finite element program using Link10 element which has a uniaxial properties. These results show that the author's model is much better than the Mohamed's [4] model comparing with the experimental one. A parametric study has been done on the proposed model for obtaining the maximum strains values for concrete and steel at failure loads, for different opening sizes and comparing them with the experimental one. This study show a good agreement between the proposed and experimental model results for strains values which indicate the efficiency of the proposed model for analyzing the unstrengthend and strengthened reinforced concrete beams.

Metal-to-metal full face taper-hub flanges: Finite element model evaluation and preliminary plastic analysis results

1998 ◽  
Vol 212 (2) ◽  
pp. 57-69 ◽  
Author(s):  
J Spence ◽  
D M Macfarlane ◽  
A S Tooth
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Plastic Hinge ◽  
Element Model ◽  
Finite Element Models ◽  
Bending Stress ◽  
Finite Element Program ◽  
Realistic Approach ◽  
Element Program ◽  
Full Face

The stress analysis of the flange problem is found to be sensitive to the way in which the component is modelled, particularly so when a finite element program is used to analyse the flange and bolt contact faces. The validity of a number of these finite element models are examined, by comparing the predicted maximum axial bending stress at the intersection of the taper-hub and the cylindrical vessel, with those measured on a large taper hub flange. It is found that a well-thought-through simple model can produce accurate results. In this type of flange it is considered that the magnitude of this stress is critical since, if the bending stress at this intersection reaches yield and subsequently a plastic hinge develops, then undue rotation of the flange could cause leakage. Using an appropriate finite element model, the development of plasticity is studied, from which it is shown that the use of a cylindrical shell yield surface provides a more realistic approach than the simple beam criterion which is unconservative despite its wide use in the existing pressure vessel standards.

Investigation on Mechanical Behavior of Hydrological Tower

2011 ◽  
Vol 243-249 ◽  
pp. 4524-4527
Author(s):  
Hui Xiong ◽  
Zheng Liang Li ◽  
Nuan Deng
Keyword(s):  
Finite Element ◽  
Composite Structure ◽  
Mechanical Characteristics ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Element Model ◽  
Finite Element Program ◽  
Safety And Reliability ◽  
Element Program ◽  
Static Performance

The safety and reliability of hydrological tower play an important role in the security and accuracy of the hydrological measurement. In order to simulate the space mechanical characteristics of the composite structure of tower with guy lines accurately, the finite element program is used to establish a precise three dimensional space finite element model. The structural strength and stability was also analyzed. Meanwhile, the static performance and vibration characteristics of the tower with guy lines was compared with the ones of the tower with none guy lines. The results show that the mechanical characteristics of composite structure are similar to the ones of continuous beams with lateral bearing spring. The guy lines rationalize the force distribution on structures, enhance the structural bearing capacity, and increase the structural stiffness. In addition, the paper can be a reference for the analysis of hydrological towers in aspects of numerical analysis, design methods and data.

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