scholarly journals Estimation of Ultimate Strength of Continuous Stiffened Plate under Combined Thrust and Lateral Pressure

2002 ◽  
Vol 2002 (192) ◽  
pp. 697-705 ◽  
Author(s):  
Daisuke Yanagihara ◽  
Masahiko Fujikubo ◽  
Ryutaro Morita ◽  
Yuu Setoyama
Keyword(s):  
Ultimate Strength ◽  
Lateral Pressure ◽  
Stiffened Plate

Dynamic Ultimate Strength Characteristics of Stiffened Plates Subjected to the In-Plane Impact Load and Lateral Pressure

2021 ◽  
Author(s):  
Qiang Zhong ◽  
De-yu Wang
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Lateral Pressure ◽  
Impact Load ◽  
Strength Characteristics ◽  
Stiffened Plates ◽  
Strength Theory ◽  
Explicit Finite Element ◽  
Static Conditions ◽  
The Impact

Abstract Dynamic capacity is totally different from quasi-static capacity of ship structural components, although most ultimate strength analyses at present by researchers are performed under quasi-static conditions. To investigate the dynamic ultimate strength characteristics, the dynamic ultimate strength analyses of stiffened plates subjected to impact load were studied based on a 3-D nonlinear explicit finite element method (FEM) in this paper. The impact load in the present work is characterized as a half-sine function. A series of nonlinear finite element analyses are carried out using Budiansky-Roth (B-R) criterion. The influence of impact durations, model ranges, boundary conditions, initial imperfections and impact loads on the dynamic ultimate strength of stiffened plates are discussed. In addition, the ultimate strength of stiffened plates under the in-plane impact combined with lateral pressure was also calculated, which shows lateral pressure has a negligible effect on the dynamic ultimate strength of stiffened plates subjected to the impact load with short durations. Other important conclusions can be obtained from this paper, which are useful insights for the development of ultimate strength theory of ship structures and lay a good foundation for the study of dynamic ultimate strength in the future.

Numerical Investigation of Ultimate Strength of Stiffened Plates With Various Cross-Section Forms

2018 ◽  
Author(s):  
Huilong Ren ◽  
Yifu Liu ◽  
Chenfeng Li ◽  
Xin Zhang ◽  
Zhaonian Wu
Keyword(s):  
Aluminum Alloy ◽  
Ultimate Strength ◽  
Cross Section ◽  
High Performance ◽  
Lightweight Design ◽  
Offshore Structures ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Element Analysis ◽  
Hull Structure

There is an increasing interest in the lightweight design of ship and offshore structures, more specifically, choosing aluminum alloys or other lightweight high-performance materials to build structure components and ship equipments. Due to its better mechanical properties and easy assembly nature, extruded aluminum alloy stiffened plates are widely used in hull structures. When the load on the hull reaches a certain level during sailing, partial or overall instability of stiffened plate makes significant contribution in an event of collapse of the hull structure. It is very necessary to investigate the ultimate strength of aluminum alloy stiffened plate to ensure the ultimate bearing capacity of large aluminum alloy hull structure. Most of studies of the ultimate strength of stiffened plates deal with stiffened plates with T–shaped stiffeners. Stiffeners of other shapes have seldom been explored. In this research, the ultimate strength of six different cross–section aluminum alloy stiffened plates and one steel stiffened plate was studied based on the non–linear finite element analysis (FEA). Taking into account stiffness, weight and other issues, the new cross–section aluminum stiffener has finally been concluded for replacing the original steel stiffener in upper deck of a warship.

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.

Theoretical and Experimental Study on the Ultimate Strength of Corrugated Bulkheads

1997 ◽  
Vol 41 (04) ◽  
pp. 301-317
Author(s):  
Jeom K. Paik ◽  
Anil K. Thayamballi ◽  
Min S. Chun
Keyword(s):  
Ultimate Strength ◽  
Lateral Pressure ◽  
Limit State ◽  
Plate Thickness ◽  
Experimental Information ◽  
Design Guidelines ◽  
Design Parameters ◽  
Collapse Mechanism ◽  
Ultimate Limit State ◽  
Analytical Formulation

The objectives of the present study are to obtain experimental data on collapse strength of steel corrugated bulkhead models and also to develop a simple analytical formulation for ultimate strength useful in the design of corrugated bulkheads under static lateral pressure. Collapse tests on nine mild steel corrugated bulkhead models having five bays of corrugations are carried out, varying the corrugation angle, the plate thickness and the type of loading (axial compression and/or lateral pressure). Using the test data, the characteristics of the collapse mechanism for corrugated bulkheads are investigated. For purposes of rapid first cut estimates of strength, a new and simple analytical formulation for predicting the ultimate strength of corrugated bulkheads under hydrostatic pressure is derived based on an assumed stress distribution over the corrugation cross section at the ultimate limit state. The modeling error associated with the new formulation is established by comparing its predictions with the experimental results. The development of ultimate strength based design guidelines and the effect of design parameters such as the corrugation angle on ultimate strength of a corrugated bulkhead are then discussed. All experimental information and strength data are tabulated, which is a benefit in itself.

Full-Scale Measurements of Welding-Induced Initial Deflections and Residual Stresses in Steel-Stiffened Plate Structures

2018 ◽  
Vol Vol 160 (A4) ◽  
Author(s):  
M S Yi ◽  
C M Hyun ◽  
J K Paik
Keyword(s):  
Residual Stresses ◽  
Ultimate Strength ◽  
Computational Models ◽  
Plate Thickness ◽  
Offshore Structures ◽  
Full Scale ◽  
Stiffened Plate ◽  
Plate Structures ◽  
Initial Imperfections ◽  
Numerical Predictions

Plated structures such as ships and offshore structures are constructed using welding techniques that attach support members (or stiffeners) to the plating. During this process, initial imperfections develop in the form of initial deformations (deflections or distortions) and residual stresses. These initial imperfections significantly affect the buckling and ultimate strength of these structures. Therefore, to assess the strength of welded plate structures, it is very important to predict the magnitude and pattern of welding-induced initial imperfections and their effects on buckling and ultimate strength. To determine the reliability of the prediction methods, it is desirable to validate the theoretical or numerical predictions of welding-induced initial imperfections through comparison with full-scale actual measurements. However, full-scale measurement databases are lacking, as they are costly to obtain. This study contributes to the development of a full-scale measurement database of welding-induced initial imperfections in steel-stiffened plate structures. The target structures are parts of real (full-scale) deckhouses in very large crude oil carrier class floating, production, storage and offloading unit structures. For parametric study purposes, four test structures by varying plate thickness are measured while the stiffener types and weld bead length are fixed. Modern technologies for measuring initial deformations and residual stresses are applied. The details of the measurement methods are documented for the use of other researchers and practicing engineers who want to validate their computational models for predicting welding-induced initial imperfections.

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