Effect of Combined Shear Stresses on the Ultimate Axial Response of the Double Bottom of a Containership

2016 ◽  
Author(s):  
Marco Gaiotti ◽  
Riccardo Bacoccoli ◽  
Masahiko Fujikubo ◽  
Cesare Mario Rizzo
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
International Association ◽  
Shear Stresses ◽  
Finite Element Models ◽  
Loading Conditions ◽  
Significant Issue ◽  
Hull Girder ◽  
Longitudinal Strength ◽  
Axial Response

Ultimate strength of the hull girder of containerships became a significant issue in the last years in view of recent accidents and related investigations. Actually, larger and larger ships were put into service and still are designed and built. Recognizing such an issue, investigations were carried out and led to the issuance of a specific longitudinal strength standard for containerships by the International Association of Classification Societies [1]. Loading conditions become more and more challenging and especially combinations of various actions were found to impair the hull girder ultimate strength. In the attempt to better understand the influence of load combinations onto the ultimate strength of the hull girder, investigations were carried out. In this paper, the effects of the shear is considered using rather refined and accurate finite element models of a typical containership double bottom.

Ultimate Strength Envelope of a 10,000TEU Container Ship’s Global Hull Girder Subjected to Combined Vertical Bending, Horizontal Bending and Torsion

2021 ◽  
Author(s):  
Qinghu Wang ◽  
Deyu Wang
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Large Deflection ◽  
Safety Performance ◽  
Nonlinear Finite Element ◽  
Container Ship ◽  
Loading Conditions ◽  
Finite Element Analyses ◽  
Hull Girder ◽  
Combined Loads

Abstract To figure out the ultimate strength picture of the global hull girder of a 10,000TEU container ship subjected to combined vertical bending, horizontal bending and torsion, a simplified global hull girder of the chosen container ship is numerically modeled and a series of large deflection and elastoplastic nonlinear finite element analyses are conducted to obtain the ultimate strength envelope of the chosen container ship’s global hull girder subjected to combined vertical bending, horizontal bending and torsion. Based on the obtained numerical results, the equations that can quantify the ultimate strength envelope of the chosen container ship’s global hull girder subjected to combined loads are developed, which can be referred as one of the most important indexes to measure the safety performance of the chosen container ship under the most extreme loading conditions.

Study on Numerical Methodologies for Assessing Ultimate Bending Moment of Ship Hull Girder

2016 ◽  
Author(s):  
Ming Cai Xu ◽  
Zhao Jun Song
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Ultimate Strength ◽  
Bending Moment ◽  
Finite Element Models ◽  
Element Analysis ◽  
Hull Girder ◽  
Computer Resource ◽  
Explicit Dynamic ◽  
Convergence Of Solution

Nonlinear finite element analysis is usually used to assess the ultimate strength of hull girder, which includes implicit analysis and explicit dynamic analysis. So far, most of researchers use the implicit analysis to assess the ultimate strength of various vessels or stiffened plates. Comparing with the implicit analysis, the explicit dynamic analysis may be more stable since this method doesn’t need to consider the convergence of solution, and can consider the transient influence of time. However, the accuracy of solution results and time in the explicit dynamic method is very important. This depends on modelling configurations, such as the loading time, geometric ranges of finite element models, element types and applying methods of loading. The purpose of the present paper is to investigate the influences of these factors, and then to figure out a reliable numerical method which meets permitted accuracy and consumes acceptable computer resource in explicit dynamic analysis.

Stresses in the Growth Plate of the Developing Proximal Femur

2001 ◽  
Vol 17 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Thomas G. Ribble ◽  
Michael H. Santare ◽  
Freeman Miller
Keyword(s):  
Finite Element ◽  
Growth Plate ◽  
Proximal Femur ◽  
Normal Development ◽  
Normal Activity ◽  
Shear Stresses ◽  
Finite Element Models ◽  
Loading Conditions ◽  
Neck Shaft Angle ◽  
Shaft Angle

Finite element models of the proximal femur at birth, 2 years of age, and at 8 years of age were constructed to investigate stress patterns under different loading conditions. These loading conditions represent typical activities of a normal developing child and abnormal activity associated with muscle spasticity. The hypothesis is that the shear stresses in the growth plate correlate with the neckshaft angle as associated with valgus and normal development. Loads for the finite element models were derived from a separate muscle model used to calculate the forces across the hip joint for an arbitrary subject and activity. Results show there is an inverse relationship between the relative magnitude of the shear stress in the growth plate and the developing neck-shaft angle. The relatively high shear stresses generated by normal activity in the 2-year-old’s growth plate correlate with the decrease in neck-shaft angle that accompanies normal development. Alternatively, lower shear stresses are generated in the growth plate by loading conditions representing spasticity. These lower magnitude shear stresses correlate with a valgus deformity, which is often observed clinically.

REINFORCEMENT OF AGEING SHIP STRUCTURES

2021 ◽  
Vol 160 (A3) ◽  
Author(s):  
D Chichì ◽  
Y Garbatov
Keyword(s):  
Monte Carlo Simulation ◽  
Finite Element ◽  
Ultimate Strength ◽  
Steel Plate ◽  
Plate Thickness ◽  
Compressive Load ◽  
Finite Element Models ◽  
Uniform Corrosion ◽  
Finite Element Analyses ◽  
Longitudinal Stiffeners

The objective of the present study is to investigate the possibility to recover the ultimate strength of a rectangular steel plate with a manhole shape opening subjected to a uniaxial compressive load and non-uniform corrosion degradation reinforced by additional stiffeners. Finite element analyses have been carried out to verify the possible design solutions. A total of four finite element models are generated, including 63 sub-structured models. The non-uniform corrosion has been generated by the Monte Carlo simulation. The reinforcement process covers three scenarios that include mounting of two longitudinal stiffeners, two longitudinal and two transverse stiffeners and the flange on the opening. The positioning of the stiffeners has also been studied. A total of 10 cases has been selected and tested for the numerical experiment. Three different assessments have been performed to evaluate the ultimate strength, weight and cost. Two additional studies on the effect of the plate thickness and slenderness have been also carried out.

Development of Simplified Spot Weld Models: Stiffness Prediction and Computational Performance Evaluation

2010 ◽  
Author(s):  
Noman Khandoker ◽  
Monir Takla ◽  
Thomas Ting
Keyword(s):  
Finite Element ◽  
Spot Weld ◽  
Finite Element Models ◽  
Suitable Model ◽  
Loading Conditions ◽  
Computational Costs ◽  
Automotive Body ◽  
Simple Strategy ◽  
Pull Out ◽  
Computational Performance

Simple spot weld connection models are desirable in huge and complicated finite element models of automotive body-in-white structures which generally contains thousands of spot weld joints. Hence, in this paper six different individual spot weld joint finite element models simplified in terms of their geometric and constitutive representations were developed including the one that is currently used in automotive industries. The stiffness characteristics of these developed models were compared with the experimental results obtained following a simple strategy to design the welded joint based on the desired mode of nugget pull out failure. It was found that the current spot weld modeling practice in automotive industry under predict the maximum joint strength nearly by 50% for different loading conditions. The computational costs incurred by the developed models in different loading conditions were also compared. Hence, a suitable model for spot welded joints is established which is very simple to develop but relatively cheap in terms of computational costs.

Finite Element Analysis on the Hull Girder Ultimate Strength of Asymmetrically Damaged Ships

2016 ◽  
Author(s):  
Muhammad Zubair Muis Alie ◽  
Ganding Sitepu ◽  
Juswan Sade ◽  
Wahyuddin Mustafa ◽  
Andi Mursid Nugraha ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Cross Sections ◽  
Progressive Collapse ◽  
Ship Hull ◽  
Strength Analysis ◽  
Functional Requirements ◽  
Element Analysis ◽  
Hull Girder

This paper discusses the influence of asymmetrically damaged ships on the ultimate hull girder strength. When such damages take place at the asymmetric location of cross sections, not only translation but also inclination of instantaneous neutral axis takes place during the process of the progressive collapse. To investigate this effect, the Finite Element Analysis (FEA) is employed and the damage is assumed in the middle hold. The collision damage is modeled by removing the plate and stiffener elements at the damage region assuming the complete loss of the capacity at the damage part. For the validation results obtained by Finite Element Analysis of the asymmetrically damaged ship hull girder, the simplified method is adopted. The Finite Element method of ultimate strength analysis of a damaged hull girder can be a practical tool for the ship hull girder after damages, which has become one of the functional requirements in IMO Goal Based Ship Construction Standard.

Finite Element Analysis of Longitudinal Bending Collapse of Container Ship Considering Bottom Local Loads

2016 ◽  
Author(s):  
Akira Tatsumi ◽  
Masahiko Fujikubo
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Container Ship ◽  
Element Analysis ◽  
Local Loads ◽  
Hull Girder ◽  
Longitudinal Bending ◽  
Collapse Behavior ◽  
Large Container ◽  
Collapse Region

The purpose of this research is to clarify the effect of bottom local loads on the hull girder collapse behavior of large container ship (8000TEU class) A 1/2+1+1/2 hold model of container ship is analyzed using implicit finite element method. The results reveal two major causes of reduction of hull girder ultimate strength due to local loads. One is biaxial compressive stresses induced at outer bottom. Thus, smaller hogging moment can induce a collapse of bottom panels. The other is a reduction of effectiveness of inner bottom that is on the tension side of local bending. As a result, the container ship attains hull girder ultimate strength with smaller spread of collapse region compared to that under pure bending.

Ultimate Strength of Box Girders With Incline Cracks

2015 ◽  
Author(s):  
Lei Ao ◽  
Deyu Wang
Keyword(s):  
Finite Element ◽  
Fourier Series ◽  
Crack Length ◽  
Ultimate Strength ◽  
Finite Element Models ◽  
Torsional Loading ◽  
Box Girders ◽  
Box Beam ◽  
Crack Angle ◽  
The Relationship

The aim of the present study is to investigate the residual ultimate strength characteristics of box girders with variable inclination cracks under torsional loading. A series of finite element models are established by changing the crack length and crack angle using a commercial FEA program, ABAQUS. The cracks are located at the center and torques are applied on both ends of the box beam. The accuracy of the nonlinear FEA results is verified by a comparison with previous predicted formulas. Based on the FEA results, the relationship between the residual ultimate strength and crack parameters can be indicated in a function with period of π in the form of Fourier series.

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