Estimation of Ultimate Longitudinal Bending Moment of Ships and Box Girders

1996 ◽  
Vol 40 (03) ◽  
pp. 244-257 ◽  
Author(s):  
M. K. Rahman ◽  
M. Chowdhury
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Fortran Program ◽  
Box Girders ◽  
Limit States ◽  
Box Girder ◽  
Stiffened Panels ◽  
Complete Procedure ◽  
Longitudinal Bending ◽  
Collapse Behavior

The paper describes a methodology of computing the ultimate value of the longitudinal bending moment at any cross section of a ship or box girder. The cross section has been discretized into stiffened panels (one stiffener with its associated effective plating). The limit states for these panels, both tensile and compressive, are modeled in an appropriate manner. Since the ultimate strength of the girder section is largely governed by the behavior of the panels under compression, the authors have paid special attention in modeling the collapse as well as post-collapse behavior of these panels. A new stress-strain relationship is also introduced. The complete procedure has been coded into a FORTRAN program and tested against a number of box girder models and an actual ship for which the true behavior was known. The results obtained from the proposed program appear to be quite satisfactory. Good correlation was also found when compared with the results obtained by more complex and rigorous analytical methods.

Fatigue Evaluation of Flat Steel Box Girders with Closed Stiffeners of Large-Span Suspension Bridges under Different Heavy Trucks

2011 ◽  
Vol 147 ◽  
pp. 157-160 ◽  
Author(s):  
Yong Zeng ◽  
Hong Mei Tan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Suspension Bridges ◽  
Box Girders ◽  
Element Analysis ◽  
Box Girder ◽  
Fatigue Assessment ◽  
Steel Box Girder ◽  
Flat Steel

Due to its outstanding aerodynamic shape and light weight, the trapezoidal cross-section flat steel box girder with orthotropic decks and thin-walled longitudinal stiffeners of trapezoidal cross section are widely used in long-span suspension bridges in the world. However, because of the geometrical characteristics and the relative flexibility of their components, these structures may be quite susceptible to traffic loadings that fatigue cracks tend to appear in these structures. In this paper, Jiangyin Bridge is used as a case study to investigate the fatigue performance of the steel girders of suspension bridge Jiangyin Bridge is the second longest bridge in China, which has the main span of 1385m. The stress analysis of steel box girders is firstly carried out based on the analysis of fatigue life. Fatigue assessment method is proposed on the basis of in-situ measurement data combined with finite element analysis. A complete fatigue assessment is made in this paper. Key words: flat steel box girder; orthotropic decks; finite element analysis; fatigue assessment

scholarly journals Study on ultimate strength of ship’s hull considering cross section and beam finite element.

2018 ◽  
Vol 177 ◽  
pp. 01030
Author(s):  
Muhammad Zubair Muis Alie ◽  
Juswan ◽  
Wahyuddin ◽  
Taufiqur Rachman
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Cross Section ◽  
Bending Moment ◽  
Bulk Carrier ◽  
Longitudinal Bending ◽  
The Cross ◽  
The One ◽  
Double Hull ◽  
Oil Tanker

The objective of the present research is to study the ultimate strength of ship’s hull considering cross section and beam finite element under longitudinal bending. The single hull bulk carrier and double hull oil tanker are taken to be analysed. The one-frame space of ship is considered in the calculation. The cross section of ship’s hull is divided into element composed plate and stiffened plate. The cross section is assumed to be remained plane and the simply supported is imposed to both side of the cross section. The longitudinal bending moment is applied to the cross section for hogging and sagging condition. The Smith’s method is adopted and implemented into the in-house program of the cross section and beam finite element to calculate the ultimate strength of ship’s hull. The result of the ultimate strength for hogging and sagging condition obtained by considering the cross section and beam finite element is compared with one another.

Numerical Study for the Progressive Collapse of Scale Model for ULCS Hull Girder Under Longitudinal Bending

2018 ◽  
Author(s):  
Chonglei Wang ◽  
Deyu Wang
Keyword(s):  
Numerical Study ◽  
Progressive Collapse ◽  
Similarity Criterion ◽  
Bending Moment ◽  
Scale Model ◽  
Stiffened Panels ◽  
Hull Girder ◽  
Load Carrying ◽  
Longitudinal Bending ◽  
Large Container

For evaluating reliable load carrying capacity of actual hull girder, experiments for similar scale model are necessary. The object of the present paper is to figure out a reliable FE analysis method in the similar scale model experiment regarding hull girder ultimate strength. The compared results between the true hull girder of a typical ultra large container ship (ULCS) and the scale experimental model created by the similarity criterion proposed in this paper assessed by finite element method (FEM) under longitudinal bending moment considering the effects of initial deflections are obtained guaranteeing the similarity in both elastic and inelastic range during the progressive collapse of plates, stiffened panels and hull girder. Finally, a series of elastic-plastic large deflection analyses is conducted to ensure the failure mode of hull girder is consistent with the actual ship.

Research on Skew Coefficient for Stresses of Skewly Supported Three-Span Continuous Box Girders

2014 ◽  
Vol 587-589 ◽  
pp. 1483-1487
Author(s):  
Liang Liu
Keyword(s):  
Cross Section ◽  
Shell Element ◽  
Skew Angle ◽  
Box Girders ◽  
Concentrated Load ◽  
Box Girder ◽  
Lag Effect ◽  
The Cross ◽  
Skew Angles ◽  
Bottom Slab

Skewly supported continuous box girders have special mechanical properties compared with common continuous box girders. Skew coefficient for stress of skewly supported three-span continuous box girder is introduced to reflect the decrease degree of the normal stresses at the cross section of the middle span of the box girder. The finite element models of the skewly supported three-span continuous box girders with different skew angles are established by applying the SHELL63 shell element in software ANSYS. The variation of the skew coefficient for stress at different calculation points of middle span cross section under concentrated load is analyzed and the corresponding influence law is revealed. Research results show that the skew coefficient for stress of top slab is different from that of bottom slab at the cross section of the skewly supported three-span continuous box girder. The skew coefficient for stress of top slab is smaller than that of bottom slab. Skew coefficient for stress decreases with the increasing of the skew angle. Because of the shear lag effect, the minimal skew coefficient for stress of flanges occurs at the free tip of cantilever slab while the maximal skew coefficient occurs at the intersection of web and flange slabs.

Analysis of Eccentric Load Causing Torsion Effects of Variable Cross-Section Continuous Box Girder during Cantilevered Casting

2012 ◽  
Vol 446-449 ◽  
pp. 1194-1198
Author(s):  
Min Xiang ◽  
Cong Juan Yang
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Construction Process ◽  
Analysis Model ◽  
Box Girders ◽  
Eccentric Load ◽  
Box Girder ◽  
Continuous Beam Bridge ◽  
Beam Bridge

The construction with hanging basket eccentric loading was studied for the cantilever casting of a 32m +48 m +32 m continuous box girder. The calculation of center deflecting angles of cantilever box girders with variable cross-section due to pure torsion was derived, and correspondingly a program was developed to calculate this formula. An analysis model of cantilever casting continuous beam bridge with hanging basket eccentric loading was established based on finite elements software, and the shear stress, the longitudinal normal stress and the combined stress of different section were analyzed under different construction process. The torsional effect due to hanging basket eccentric loading was studied and the results are helpful to guide the construction in practice.

scholarly journals Investigation of Load Distribution Factors for Two-Span Continuous Composite Multiple Boxgirder Bridges

2021 ◽  
Author(s):  
Manal Ibrahim
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Bending Moment ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Truck Loading ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Bridges formed of concrete deck slab over built-up steel-box girders are frequently used in bridge construction for their economic and structural advantages. Box girder bridges impose structural challenges to get the straining actions for the design of girders. The objective of this study is to determine the load distribution characteristics for continuous composite multiple–box girder bridges under CHBDC truck loading. An extensive parametric study was conducted using the three-dimensional finite element to evaluate the moment and shear distribution factors when bridges subjected to CHBDC truck loading. The parameters considered in this study are the span length, number of lanes and number of boxes. Then, simple empirical formula for the bending moment and shear force were developed for the structural design. Correlation of the developed expressions based on FEA results with available CHBDC and AASHTO-LRFD formula showed that the former allow engineers to design such bridges more economically and reliably.

scholarly journals Investigation of Load Distribution Factors for Two-Span Continuous Composite Multiple Boxgirder Bridges

2021 ◽  
Author(s):  
Manal Ibrahim
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Bending Moment ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Truck Loading ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Bridges formed of concrete deck slab over built-up steel-box girders are frequently used in bridge construction for their economic and structural advantages. Box girder bridges impose structural challenges to get the straining actions for the design of girders. The objective of this study is to determine the load distribution characteristics for continuous composite multiple–box girder bridges under CHBDC truck loading. An extensive parametric study was conducted using the three-dimensional finite element to evaluate the moment and shear distribution factors when bridges subjected to CHBDC truck loading. The parameters considered in this study are the span length, number of lanes and number of boxes. Then, simple empirical formula for the bending moment and shear force were developed for the structural design. Correlation of the developed expressions based on FEA results with available CHBDC and AASHTO-LRFD formula showed that the former allow engineers to design such bridges more economically and reliably.

Collapse Analysis on VLCC Subjected to Longitudinal Bending with Damages

2018 ◽  
Vol 874 ◽  
pp. 121-127
Author(s):  
Muhammad Zubair Muis Alie ◽  
Wahyuddin ◽  
Syamsul Asri ◽  
Farianto Fachruddin Lage ◽  
Juswan ◽  
...  
Keyword(s):  
Cross Section ◽  
Progressive Collapse ◽  
Initial Imperfection ◽  
Bending Moment ◽  
Hull Girder ◽  
Simply Supported ◽  
Collapse Analysis ◽  
Longitudinal Bending ◽  
The Cross ◽  
Vertical Bending Moment

The objective of the present study is to analyze the progressive collapse of VLCC hull girder with damages subjected to longitudinal bending. For the simple case, the cross-section is assumed to be remained plane and the vertical bending moment is applied to the cross section. The residual stress, initial imperfection, and crack are not considered. The damages scenarios are located at the center part and asymmetric position of the cross section. To analyze the progressive collapse including its behavior of VLCC ship hull, the simply supported is imposed to the cross section and taking the hogging and sagging condition into account. The results obtained for intact and damages condition by the analytical solution is compared and summarized with one another.

scholarly journals Protective and Blast Resistive Design of Posttensioned Box Girders Using Computational Geometry

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Majid Aleyaasin
Keyword(s):  
Computational Geometry ◽  
Cross Section ◽  
Cross Sections ◽  
Computational Algorithm ◽  
Optimal Shape ◽  
Box Girders ◽  
Cross Point ◽  
Box Girder ◽  
Numerical Example ◽  
Duct Geometry

The optimal tendon profile and its associated duct geometry for posttensioned box girders are investigated. A computational algorithm has been developed to determine an ideal shape for the tendon and duct. The algorithm is based on a diagonal cross point in the Magnel quadrilateral and uses computational geometry instead of graphical drawing. Thereafter, an ideal parabolic and linear tendon profiles can be calculated from which the covering duct could be shaped. To check the optimality of the results, an automatic examination of Magnel diagrams in various cross sections is incorporated in the algorithm. This enables a unique prestress level to be selected that suits all sections. Then, the mideccentricity of the two crossing points with a common prestress line is chosen as a design eccentricity in each cross section. The optimal duct shape is determined based on such automatic inspections. In a numerical example, the linear, parabolic, and optimal duct geometries are compared and drawn. It is concluded that both linear and parabolic duct shapes can be very close to an optimal shape. In a numerical example, an optimal, box girder with linear open access-type tendons is designed that can withstand extra blast load when explosion occurs.

Analytical Study on Curved Box Girder Bridges with Minimum Horizontal Stiffeners

2019 ◽  
Author(s):  
Junichi Adachi ◽  
Takashi Yamaguchi ◽  
Kohei Funayama ◽  
Shintaro Arai ◽  
Michiaki Takao
Keyword(s):  
Ultimate Strength ◽  
Urban Areas ◽  
Structural Parameters ◽  
Bending Moment ◽  
Automatic Welding ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
The Web

<p>Curved box girder bridges are widely used in viaducts in urban areas, as well as highway junctions. In fabricating curved box girders, automatic welding robots cannot be applied to welding of horizontal stiffeners to the web panel due to the girder curvature and manufacturing costs increase. <span>Elimination or reduction of the number of horizontal stiffeners is desirable. In this study, </span>FE analysis was carried out varying the curvature and the width-thickness ratio of the structural components as structural parameters to propose the curved box girder bridges without horizontal stiffeners in the web panel. In order to evaluate <span>the ultimate strength, the collapse mode (buckling of lower flange, web panel or stiffeners) has been clarified considering the </span>design sectional forces such as torsional moment, bending moment and shearing force.</p><p>From the results, it was found that the curvature has little influence on the bending buckling strength of the web panels. Even if the horizontal stiffeners are eliminated, the ultimate strength doesn’t decrease until compressive flange buckling occurs. It is concluded that the ultimate strength is governed by the buckling of the compressive flange, even when the bending buckling occurs in the web panel.</p>

Sign in / Sign up

Export Citation Format

Share Document