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.

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.

Finite Element Modeling for RC Hollow Columns Wrapped with FRP Laminates

2011 ◽  
Vol 71-78 ◽  
pp. 3347-3353 ◽  
Author(s):  
Ashraf Mohamed Mahmoud
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Concrete Element ◽  
Finite Element Program ◽  
Element Program ◽  
Failure Loads ◽  
Brick Element ◽  
Element Type ◽  
Orthotropic Properties

A finite element reinforced concrete model has been analyzed by the author with Ansys v.9 finite element program for both unstrengthened and CFRP-strengthened hollow columns using solid65 concrete element, its size 24x26x24 mm and Link8 discrete steel distribution element. 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 Lignola [6], in which using Tno Diana v. 9.1 finite element program for modeling concrete using three-dimensional solid brick element type Chx60, steel using embedded reinforcement truss element and CFRP using three-node plane bonded element. These results show that the author's model is much better than the Lignola's [6] model comparing with the experimental one. A parametric study has been done on the proposed model for obtaining the effect of using the GFRP instead of the CFRP in column strengthening by comparing the failure loads and the concrete and steel properties at failure. This study show a reduction in the failure load values by an amount 0.6 to 2.8% when using GFRP, indicating that the CFRP is more preferable in strengthening of the hollow column than the GFRP.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Reduction of Free-Edge Stress Concentration

1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Free Edge ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Interlaminar Shear ◽  
Three Dimensional Elasticity

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.

Sign in / Sign up

Export Citation Format

Share Document