Lateral Pressure Effects on the Ultimate Strength of Plates

2015 ◽  
Author(s):  
Lei Jiang ◽  
Shengming Zhang
Keyword(s):  
Ultimate Strength ◽  
Lateral Pressure ◽  
Numerical Study ◽  
Offshore Structures ◽  
Pressure Effects ◽  
Finite Element Program ◽  
Stiffened Panels ◽  
Element Program ◽  
Ocean Environment ◽  
Ultimate Load Carrying Capacity

During the operations of ships and offshore structures in the ocean environment, these structures are subjected to combined lateral pressure and in-plane stresses. However, in today’s ship design and analysis procedures, the effects of the lateral pressure on the ultimate strength of these structures are often ignored. Previous studies have indicated that the lateral pressure could have a noticeable influence on the ultimate load carrying capacity of stiffened panels when they are subjected to combined longitudinal and transverse stresses. The purpose of this paper is to present a systematic numerical study to quantify the lateral pressure effects on the ultimate strength of plates. The sensitivity of the plate’s ultimate strength to lateral pressure is characterized as a function of the plate geometry, the pressure magnitude and the ratio of the in-plane stress components. The present numerical study is performed by using LR’s in-house nonlinear finite element program VAST and the newly development LR procedure for nonlinear structural mechanics analysis was followed. The results and findings from this study are detailed in this paper.

Numerical Study of the Effect of Geometry and Boundary Conditions on the Collapse Behaviour of Stocky Stiffened Panels

2012 ◽  
Vol 154 (A2) ◽  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

Advanced Closed-Form Ultimate Strength Formulation for Ships

2001 ◽  
Vol 45 (02) ◽  
pp. 111-132 ◽  
Author(s):  
Jeom Kee Paik ◽  
Owen F. Hughes ◽  
Alaa E. Mansour
Keyword(s):  
Ultimate Strength ◽  
Structural Damage ◽  
Lateral Pressure ◽  
Local Buckling ◽  
Bending Moment ◽  
Stiffened Panels ◽  
Initial Imperfections ◽  
Ship Hulls ◽  
Collapse Column ◽  
Side Shell

The aim of this paper is to develop an advanced ultimate strength formulation for ship hulls under vertical bending moment. Since the overall failure of a ship hull is normally governed by buckling and plastic collapse of the deck, bottom, and sometimes the side shell stiffened panels, it is of crucial importance to accurately calculate the ultimate strength of stiffened panels in deck, bottom and side shell for more advanced ultimate strength analyses. In this regard, the developed formulation is designed to be more sophisticated than previous simplified theoretical methods for calculating the ultimate strength of stiffened panels under combined axial load, in-plane bending and lateral pressure. Fabrication-related initial imperfections (initial deflections and residual stresses) and potential structural damage related to corrosion, collision, or grounding are included in the panel ultimate strength calculations as parameters of influence. All possible collapse modes involved in collapse of stiffened panels, including overall buckling collapse, column or beam-column type collapse (plate or stiffener induced collapse), tripping of stiffeners and local buckling of stiffener web, are considered. As illustrative examples, the paper investigates and discusses the sensitivity of parameters such as lateral pressure, fabrication-related initial imperfections, corrosion, collision and grounding damage on the ultimate strength of a typical Cape size bulk carrier hull under vertical bending.

A Numerical Study on the Ultimate Strength of Damaged Tubular Bracing Members Under Axial Compression

2018 ◽  
Author(s):  
Ling Zhu ◽  
Jieling Kong ◽  
Qingyang Liu ◽  
Han Yang ◽  
Bin Wang
Keyword(s):  
Ultimate Strength ◽  
Axial Compression ◽  
Numerical Study ◽  
Load Capacity ◽  
Approximate Equation ◽  
Offshore Structures ◽  
Experimental Investigations ◽  
Pipe Length ◽  
Axial Load Capacity ◽  
Parametric Studies

The tubular bracing members of offshore structures may sustain collision damages from the supply ships, which lead to the deterioration of the load carrying capacity of tubular bracing members. This paper presents a numerical simulation of the ultimate strength of damaged tubular bracing members under axial compression with the nonlinear finite element code ABAQUS, based on previous experimental investigations. Parametric studies are conducted to investigate the load capacity of damaged tubular bracing members, by considering the effects of diameter (D), wall thickness (H), pipe length (L) and the damage positions on the ultimate strength of tubular members. It is found that lateral damage can cause great reduction of the axial load capacity of tubular members. In addition, an approximate equation to predict the ultimate strength of tubular members based on the given damage depth is proposed.

An Experimental and Numerical Study to Analysis and Design of Sheet Hydroforming Process for an Automobile Fender Shell

2006 ◽  
Author(s):  
Mohammad Habibi Parsa ◽  
Payam Darbandi
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Fluid Pressure ◽  
Finite Element Program ◽  
New Approach ◽  
Explicit Finite Element ◽  
Sheet Hydroforming ◽  
Analysis And Design ◽  
Hydroforming Process ◽  
Element Program

A new approach for manufacturing of shell fender is proposed and has been examined numerically and experimentally. The new suggested method is based on sheet hydroforming process, which has a lot of advantages over conventional deep drawing process. After defining the shape of initial blank using an inverse finite element program, numerical evaluation of the proposed sheet hydroforming process for production of shell fender has been carried out using an explicit finite element code considering fluid pressure, boundary conditions and tools. Then experimental evaluation has been carried out using down sized specimen and the results have been compared with results of previous simulations. It has been shown that there are similar trends between finite element and experimental results.

Experimental and Numerical Study of Laterally Loaded Pile Groups with Pile Caps at Variable Elevations

2000 ◽  
Vol 1736 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Michael C. McVay ◽  
Limin Zhang ◽  
Sangjoon Han ◽  
Peter Lai
Keyword(s):  
Numerical Study ◽  
Ground Surface ◽  
Pile Group ◽  
Special Device ◽  
Pile Groups ◽  
Finite Element Program ◽  
Lateral Resistance ◽  
Pile Cap ◽  
Element Program ◽  
Pile Caps

A series of lateral load tests were performed on 3×3 and 4×4 pile groups in loose and medium-dense sands in the centrifuge with their caps located at variable heights to the ground surface. Four cases were considered: Case 1, pile caps located above the ground surface; Case 2, bottom of pile cap in contact with the ground surface; Case 3, top of pile cap at the ground surface elevation; and Case 4, top of pile cap buried one cap thickness below ground surface. All tests with the exception of Case 1 of the 4×4 group had their pile tips located at the same elevation. A special device, which was capable of both driving the piles and raining sand on the group in flight, had to be constructed to perform the tests without stopping the centrifuge (spinning at 45 g). The tests revealed that lowering the pile cap elevation increased the lateral resistance of the pile group anywhere from 50 to 250 percent. The experimental results were subsequently modeled with the bridge foundation-superstructure finite element program FLPIER, which did a good job of predicting all the cases for different load levels without the need for soil–pile cap interaction springs (i.e., p-y springs attached to the cap). The analyses suggest that the increase in lateral resistance with lower cap elevations may be due to the lower center of rotation of the pile group. However, it should be noted that this study was for pile caps embedded in loose sand and not dense sands or at significant depths. The experiments also revealed a slight effect for the case of the pile cap embedded in sand with a footprint wider than the pile row. In that case the size of the passive soil wedge in front of the pile group, and consequently the group’s lateral resistance, increased.

Behaviour and ultimate strength of continuous steel plates subjected to uniform transverse loads

1986 ◽  
Vol 13 (1) ◽  
pp. 76-85 ◽  
Author(s):  
K. P. Ratzlaff ◽  
D. J. L. Kennedy
Keyword(s):  
Lower Bound ◽  
Ultimate Strength ◽  
Poisson’S Ratio ◽  
Plastic Hinge ◽  
Offshore Structures ◽  
Poisson's Ratio ◽  
Transverse Load ◽  
The Arctic ◽  
Membrane Action ◽  
Finite Element Program

The authors previously established that an initially flat rectangular steel plate, clamped on all four edges, displays three modes of behaviour as the intensity of a distributed transverse load increases: elastic flexural-membrane action, inelastic flexural-membrane action, and inelastic-membrane action.For a long narrow plate, elastic flexural-membrane action exists up to the load at which yielding of the extreme fibres along the long edges occurs. Subsequent plastic hinge formation along the long edges reduces the stiffness. The second stage ends with complete yielding in tension along the long edges. From this point onward, the plate acts essentially as a membrane straining inelastically as yielding gradually progresses from both edges toward the centre. A lower bound to this behaviour is obtained by assuming that Poisson's ratio is the elastic value and the maximum membrane stress is the yield stress. A higher lower bound is obtained using the plastic value of Poisson's ratio. The load–deflection curve gradually moves from the lower value to the higher and, because the edge forces can exceed yield, will finally exceed the latter, as confirmed by tests.A finite element program modelling plane stress conditions, the inelastic Poisson's ratio, and the stress–strain behaviour to failure gave a load–deflection response closely following the three predicted regions of behaviour. Two failure criteria have been established: a limiting tensile strain due to bending and tension at the edge and the shear resistance there. The behaviour and failure loads have been confirmed by two tests. Strain measurements taken during the tests substantiate, in general, the predicted behaviour.Implications of using the ultimate strength of plates for the design of offshore structures for oil exploration and production in the Arctic are presented. Key words: deflection, design, finite elements, inelastic, membrane, plates, steel, strains, stresses, transverse load, ultimate strength.

Nonlinear Numerical Study of Cold-Formed Lipped Channel Beam-Columns

2014 ◽  
Vol 919-921 ◽  
pp. 183-187
Author(s):  
Ming Chen ◽  
Zhi Bin Feng ◽  
Zhou Zhou ◽  
Ya Long Wang ◽  
Qiang Zhang
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Engineering Practice ◽  
Time Saving ◽  
Finite Element Program ◽  
Beam Columns ◽  
Load Carrying ◽  
Element Program ◽  
Channel Beam ◽  
Overall Buckling

Cold-formed lipped channel sections may fail in local, distortional and overall buckling under compression. With the development of computer technology, finite element analyses of these sections play increasing important roles in engineering practice for economic design and time-saving purpose. A kind of typical cold-formed lipped channel beam-column with varying load eccentricity was analyzed in this paper by using the finite element program of ANSYS to observe the buckling modes and load carrying capacities of the columns. All the results can be the reference for further studies.

The Effect of Viscous and Hysteretic Damping on Rotor Stability

2000 ◽  
Author(s):  
Anthony M. Cerminaro ◽  
Frederick C. Nelson
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Rotor System ◽  
Viscous Damping ◽  
Finite Element Program ◽  
Hysteretic Damping ◽  
Element Program

A rotordynamic finite element program has been modified to include internal viscous and hysteretic damping. A numerical study has been done on a rotor system with variable external damping to predict the effect of various amounts of internal viscous and hysteretic damping on rotor stability. Three cases are considered: (1) external viscous damping with internal viscous damping; (2) external hysteretic damping with internal hysteretic damping; and (3) external viscous damping with internal hysteretic damping.

Slipping Effects of Simple Combination Beam under the Action of Negative Bending Moment

2011 ◽  
Vol 243-249 ◽  
pp. 1117-1121
Author(s):  
Xu Hong Zhang ◽  
He Wu ◽  
Jian Ping Cao
Keyword(s):  
Numerical Study ◽  
Bending Moment ◽  
Composite Beams ◽  
Slip Effect ◽  
Finite Element Program ◽  
Shear Connection ◽  
Distribution Rules ◽  
Element Program ◽  
Negative Bending ◽  
Simple Combination

A numerical study on slip effect of simply supported composite beams under negative bending moment is conducted by means of finite element program of ANSYS based on the feasibility verification of ANSYS. The research contents include: slip distribution rules; slip effect on deflection in service stage and ultimate bearing capacity; relationship between slip effect and shear connection、lognitudinal percentage of reinforcement and working behavior of composite beams with partial shear connection under negative bending moment .

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