Experimental and numerical analysis of ultimate strength of inland catamaran subjected to vertical bending moment

2019 ◽  
Vol 188 ◽  
pp. 106320 ◽  
Author(s):  
Shuangxi Xu ◽  
Bin Liu ◽  
Y. Garbatov ◽  
Weiguo Wu ◽  
C. Guedes Soares
Keyword(s):  
Numerical Analysis ◽  
Ultimate Strength ◽  
Bending Moment ◽  
Vertical Bending Moment

Examination of Effect of Lateral Loads on the Hull Girder Ultimate Strength of Large Container Ships

2016 ◽  
Author(s):  
Toshiyuki Matsumoto ◽  
Toshiyuki Shigemi ◽  
Mitsuhiko Kidogawa ◽  
Kinya Ishibashi ◽  
Kei Sugimoto
Keyword(s):  
Ultimate Strength ◽  
Bending Moment ◽  
Lateral Loads ◽  
Hull Girder ◽  
Local Strength ◽  
The Difference ◽  
Collapse Behavior ◽  
Large Container ◽  
Vertical Bending Moment

It is known that the hull girder ultimate strength with consideration of lateral loads such as bottom sea pressures and/or cargo loads generally decreases than that without consideration of the lateral loads (i.e. the effect of lateral loads). In this study a series of elasto-plastic analyses of three cargo holds models, which can reproduce the collapse behavior of the hold structures subjected to both vertical bending moment and lateral loads such as bottom sea pressures, container cargo loads etc., were carried out on a number of container ships with various sizes, and the hull girder ultimate strength obtained through the analyses were comparatively examined focusing on the effect of the lateral loads. As results of the examination, it has been concluded that local strength of the double bottom structure against the lateral loads is closely related to the hull girder ultimate strength in the case of container ships, the effect of the lateral loads on the hull girder ultimate strength varies among container ships due to the difference of construction of the double bottom structure and it is important to assess the hull girder ultimate strength explicitly taking into consideration the effect of the lateral loads for large container ships such as Post-Panamax sizes.

scholarly journals KEKUATAN BATAS LAMBUNG KAPAL DALAM MENAHAN MOMEN LENTUR VERTIKAL

2019 ◽  
Vol 22 (1) ◽  
pp. 56-61
Author(s):  
Azhar Aras Mubarak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ultimate Strength ◽  
Internal Waves ◽  
External Load ◽  
Bending Moment ◽  
Box Model ◽  
Ship Structure ◽  
Vessel Structure ◽  
Vertical Bending Moment

On the life, the ship will constantly get the structural load caused by the external load of the internal waves and loads of the ship's load and the structure itself which then reaches the ultimate strength of the structure. This study aims to determine the strength of the boundary of the hull due to the vertical bending moment so that the ship structure can be guaranteed security. The analysis was done by using finite element method (FEM) by modeling the structure of the tanker section modified based on the shape of the girder box so that a simpler model is obtained. This calculation is done by using ANSYS 17 software. The calculation of vessel structure is simulated based on two existing models namely girder box model and modified tanker model. In the girder box model, ultimate strength is obtained at 6,311 x 108 Nmm for hogging conditions and -6.311 x 108 Nmm for sagging conditions. While on the tanker model, the ultimate strength obtained is -8.99 x 1012 Nmm for sagging conditions and 1.0277 x 1013 Nmm for hogging conditions.

scholarly journals Analisis Jarak Gading dan Kekuatan Batas Struktur Kapal Ferry Ro-ro

2019 ◽  
Vol 22 (1) ◽  
pp. 15-19
Author(s):  
Amalia Ika Wulandari
Keyword(s):  
Ultimate Strength ◽  
Bending Moment ◽  
Classification Rules ◽  
Load Redistribution ◽  
Smith Method ◽  
Load Limit ◽  
Ultimate Moment ◽  
Vertical Bending Moment ◽  
Better Than

  Abstrak Perkembangan peraturan konstruksi tidak lagi mengatur jarak gading. Sehingga para perancang kapal merencanakan jarak gading yang optimal dengan batasan resiko tekuk pada pelat menurut peraturan klasifikasi, momen batas struktur kapal harus sama dengan atau lebih besar dari 1.2 kali momen lentur vertikal (sagging dan hogging). Momen lentur vertikal dihitung dengan menggunakan formulasi yang telah diberikan oleh BKI. Penelitian ini bertujuan untuk mengetahui kekuatan batas pada struktur kapal ferry Ro-Ro yang membandingkan hasil dari dua metode yaitu Metode Smith dan NLFEA. Ro-Ro adalah kapal yang menangani muatannya dengan cara rolling it on and off di atas single or series ramps. Ramps yang dapat bekerja baik saat di kapal dan dermaga. Pada penelitian ini menunjukkan perbandingan nilai hasil dari metode NLFEA lebih besar daripada metode Smith. Hal ini dikarenakan metode NLFEA dapat menghitung redistribusi beban dan interaksi antara kegagalan lokal dan global secara kompleks sehingga keakuratan hasil perhitungan metode NLFEA lebih baik daripada metode Smith. Semakin jauh jarak gading maka semakin kecil beban batas agar pelat mengalami tekuk.   Kata Kunci: Kapal Ro-Ro,  Penampang Melintang, Jarak Gading, Tekuk, Kekuatan Batas   Abstract The development of construction's regulation is no longer determining the distance of the frame. Hence, the designers make the optimal frame distance plan with the ultimate risk of bending on the plate. According to the classification rules, the structure's ultimate moment must be equal to or greater than 1.2 times vertical bending moment (sagging and hogging). This study aims to determine the ultimate strength on the structure of a Ro-Ro ferry which comparing two methods between the Smith and NLFEA Methods. Ro-Ro is a ship that handles its cargo by rolling it on and off over a single or ramp series. Ramps that can work well on board and dock. The use of ANSYS application that applied NLFEA method in this study shows the comparison of result value of NLFEA method is greater than Smith method. This is because the NLFEA method can calculate load redistribution and the interaction between local and global failures in a complex way so that the accuracy of the NLFEA method is better than the Smith method. The further the ivory distance the smaller the load limit for the plate to buckling.

Post-Ultimate Strength Behavior of Very Large Floating Structure Subjected to Extreme Wave Loads

2012 ◽  
Author(s):  
Kazuhiro Iijima ◽  
Masahiko Fujikubo
Keyword(s):  
Ultimate Strength ◽  
Cross Section ◽  
Simple Formula ◽  
Bending Moment ◽  
Wave Loads ◽  
Extreme Wave ◽  
Floating Structure ◽  
Strength Behavior ◽  
Wave Induced ◽  
Vertical Bending Moment

In this paper, post-ultimate strength behavior of VLFS to extreme wave-induced loads is investigated. A mathematical model to describe the post-ultimate strength behavior of VLFS is developed taking the hydroelasticity into account. The whole VLFS is modeled by two beams on an elastic foundation connected via a nonliner rotational spring assuming that VLFS collapses amidship under severe bending moment. The model is solved numerically by using FEM. It is shown that the extent of collapse of VLFS is smaller than that of ship structures for given amplitude of vertical bending moment on condition that the structures have the same cross section and the same moment-displacement relationship. A simple formula to represent the extent of collapse of VLFS is derived. Its efficacy is shown.

Load Combination for Fatigue Analysis of Ship Structures

2004 ◽  
Author(s):  
Yung S. Shin ◽  
Booki Kim ◽  
Alexander J. Fyfe
Keyword(s):  
Bending Moment ◽  
Linear Summation ◽  
Load Combination ◽  
Longitudinal Stiffeners ◽  
Stress Components ◽  
Tank Pressure ◽  
Wave Induced ◽  
Vertical Bending Moment ◽  
Oil Tanker

A methodology for calculating the correlation factors to combine the long-term dynamic stress components of ship structure from various loads in seas is presented. The methodology is based on a theory of a stationary ergodic narrow-banded Gaussian process. The total combined stress in short-tem sea states is expressed by linear summation of the component stresses with the corresponding combination factors. This expression is proven to be mathematically exact when applied to a single random sea. The long-term total stress is similarly expressed by linear summation of component stresses with appropriate combination factors. The stress components considered here are due to wave-induced vertical bending moment, wave-induced horizontal bending moment, external wave pressure and internal tank pressure. For application, the stress combination factors are calculated for longitudinal stiffeners in cargo and ballast tanks of a crude oil tanker at midship section. It is found that the combination factors strongly depend on wave heading and period in the short-term sea states. It is also found that the combination factors are not sensitive to the selected probability of exceedance level of the stress in the long-term sense.

scholarly journals Effect of Slam Force Duration on the Vibratory Response of a Lightweight High-Speed Wave-Piercing Catamaran

2015 ◽  
Vol 59 (02) ◽  
pp. 69-84
Author(s):  
Jason John McVicar ◽  
Jason Lavroff ◽  
Michael Richard Davis ◽  
Giles Thomas
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Experimental Studies ◽  
Bending Moment ◽  
Higher Order ◽  
Acute Angle ◽  
Beam Model ◽  
Higher Order Modes ◽  
Hull Structure ◽  
Vertical Bending Moment

When the surface of a ship meets the water surface at an acute angle with a high relative velocity, significant short-duration forces can act on the hull plating. Such an event is referred to as a slam. Slam loads imparted on ships are generally considered to be of an impulsive nature. As such, slam loads induce vibration in the global hull structure that has implications for both hull girder bending strength and fatigue life of a vessel. A modal method is often used for structural analysis whereby higher order modes are neglected to reduce computational effort. The effect of the slam load temporal distribution on the whipping response and vertical bending moment are investigated here by using a continuous beam model with application to a 112 m INCAT wave-piercing catamaran and correlation to full-scale and model-scale experimental data. Experimental studies have indicated that the vertical bending moment is dominated by the fundamental longitudinal bending mode of the structure. However, it is shown here that although the fundamental mode is dominant in the global structural response, the higher order modes play a significant role in the early stages of the response and may not be readily identifiable if measurements are not taken sufficiently close to the slam location. A relationship between the slam duration and the relative modal response magnitudes is found, which is useful in determining the appropriate truncation of a modal solution.

scholarly journals A Review on Numerical Analysis of RC Flat Slabs Exposed to Fire

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bending Moment ◽  
Mechanical And Thermal Properties ◽  
Vertical Deflection ◽  
Element Analysis ◽  
Flat Slabs ◽  
Numerical Studies ◽  
The Finite Element Analysis

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.

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.

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