scholarly journals Normative and methodological principles for transverse webs structural design as applicable to cargo tank area of double hull oil tankers

2020 ◽  
Author(s):  
К.В. Плотников
Keyword(s):  
Design Process ◽  
Structural Design ◽  
Design Procedure ◽  
Direct Analysis ◽  
Design Parameters ◽  
Element Analysis ◽  
Structural Rules ◽  
Functional Relations ◽  
Oil Tankers ◽  
Double Hull

Статья посвящена вопросам проектирования поперечных танкерных рам крупнотоннажных нефтеналивных судов, размеры корпусных конструкций которых должны соответствовать требованиям Общих Правил МАКО (CSR). Требования Правил CSR можно разделить на общие нормативные предписания аналитико-эмпирического характера (prescriptive-требования) и требования к выполнению проверочных расчётов (в первую очередь с использованием МКЭ). В работе рассмотрены алгоритмы проектирования поперечных рам нефтеналивных судов в соответствии с prescriptive requirements, а также предложена методика и алгоритм проектирования таких конструкций, включающие и МКЭ-анализ, которые могут использоваться в практике конструкторских бюро. Приведено обоснование необходимости анализа и обобщения проектных решений в части рамных конструкций на реальных судах, которые могут быть использованы при разработке специализированного программного обеспечения. Поскольку напряжённо-деформированное состояние рамной конструкции зависит от соотношения характеристик изгибной жесткости составляющих её балок, целесообразным является построение алгоритма проектирования, частью которого является решение оптимизационно-поисковой задачи определения требуемых размеров конструкции. Ограничения такой задачи должны формироваться на основе общих требований CSR. В тексте приведено описание нормативных требований и основные их особенности. Кратко описаны возможные варианты постановки задачи и соображения о программной реализации её решения. The paper deals with principal considerations of double-hull oil tankers primary supporting members (PSM) structural design, which meets the requirements of Common Structural Rules (CSR). The algorithms of structural design procedure for different typical arrangements of tankers are considered in the paper. The study shows main features of structural design process that lead to complexity of functional relations. As CSR requirements consist of prescriptive requirements and direct analysis requirements (that usually means finite element analysis) the suggested algorithms include both of these stages. The text explains the need of statistical data of existing designs collecting. Such data includes ratios between required and actual web depths, scantlings of brackets, ratios between moments of inertia of PSM and some others. This data can be used in structural design process and form the limitations of design parameters. As shear forces and bending moments in primary supporting members depend on ratios of its bending stiffness and relation between design parameters are rather complicated it is appropriate to use mathematical programming models, which present a decision support instrument. There are many ways of formulation and implementation of structural design task, and the paper gives general considerations about it. The brief review of previous contributions on this subject is also given.

Ramification Study on IACS Harmonized Common Structural Rules: Impact on Structural Design and Scantlings

2014 ◽  
Author(s):  
Wu Jiameng ◽  
Wang Gang ◽  
Cai Shijian
Keyword(s):  
Structural Design ◽  
Classification Rule ◽  
Design Parameters ◽  
Functional Requirements ◽  
Safety Level ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Common Structural Rules ◽  
Oil Tankers ◽  
New Criteria

The Harmonized Common Structural Rules (CSR-H) for Bulk Carriers and Oil Tankers has been issued on 1st Jan 2014, and will enter into force on 1st July 2015 to supersede the current two separate CSR versions, namely CSR-OT for Oil tankers and CSR-BC for bulk carriers. CSR-H aims at a consistent methodology harmonizing CSR-OT and CSR-BC, and establishes new criteria and requirements with the further aim of compliance with the IMO Goal Based Standard (GBS) where GBS functional requirements fall within Classification Rule scope. To maintain equivalent or higher safety level than current CSR, the rule developments within CSR-H are as a guideline aimed at scantling requirements that will be the same or higher for a given CSR vessel given the same ship design parameters and structural arrangement both globally and locally. The purpose of this study is to introduce the main changes from CSR to CSR-H, the new criteria set up for GBS compliance, and evaluate their impact on the structural design, especially on the scantlings. A carefully selected set of ten bulk carriers and eight oil tankers are investigated with the focus not only on the midship area but also on the foremost and aftmost cargo block areas as well. The typical critical areas affected by CSR-H due to fatigue or buckling criteria are identified, discussed and analyzed in detail. The impacts on scantlings and improvement suggestions for structural design based on CSR-H are further summarized and conclusions made.

Development of Structural Design Guidelines for Porous Asphalt Pavement

2018 ◽  
Vol 2672 (40) ◽  
pp. 197-206 ◽  
Author(s):  
Kevin D. Hall ◽  
Charles W. Schwartz
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Field Performance ◽  
Design Guidelines ◽  
Empirical Approach ◽  
Asphalt Pavements ◽  
Design Parameters ◽  
Extensive Literature ◽  
Porous Asphalt ◽  
Design Procedures

Porous asphalt pavements allow designers to introduce more sustainability into projects and lessen their environmental impact. Current design procedures are based primarily on hydrologic considerations; comparatively little attention has been paid to their structural design aspects. As their use grows, a design procedure and representative material structural properties are needed to ensure that porous pavements do not deteriorate excessively under traffic loads. The objective of this project was to develop a simple, easy to apply design procedure for the structural design of porous asphalt pavements. Two methodologies were considered for such a structural design procedure: ( a) the 1993 AASHTO Pavement Design Guide empirical approach, and ( b) the mechanistic–empirical approach employed by the AASHTOWare Pavement ME Design software. A multifactor evaluation indicated the empirical 1993 AASHTO design procedure to be the most appropriate platform at this time. It is noted, however, that both design procedures lack validation of porous asphalt pavements against field performance. AASHTO design parameters and associated material characteristics are recommended, based on an extensive literature review. For “thin” open-graded base structures (12 in. or less), the AASHTO procedure is performed as published in the 1993 Guide. For “thick” base structures (>12 in.), the base/subgrade combination is considered a composite system which supports the porous asphalt layer; an equivalent deflection-based approach is described to estimate the composite resilient modulus of the foundation system, prior to applying the 1993 AASHTO design procedure.

A Study on Impact Damage Analysis of Composite Propeller Blade of Turboprop Aircraft

2013 ◽  
Vol 577-578 ◽  
pp. 489-492
Author(s):  
Hyun Bum Park
Keyword(s):  
Structural Design ◽  
Impact Damage ◽  
Fuel Efficiency ◽  
Carbon Dioxide Emission ◽  
Design Procedure ◽  
Aerodynamic Load ◽  
Bird Strike ◽  
Propeller Blade ◽  
Element Analysis ◽  
Commercial Code

Recently, the development need of environmental and fuel efficient aircrafts has been emphasized as an eco-friendly requirement in response to high oil prices. Accordingly, it is necessary to develop the next-generation eco-friendly and high fuel efficiency engine technology to enhance the fuel efficiency and aerodynamic performance of aircrafts for the purpose of reducing carbon dioxide emission amount prior to collecting and dealing with air pollution substances being discharged. In this study, development of the turboprop propeller blade for turboprop engine including aerodynamic and structural design and analysis was performed. The proposed propeller will be used as a candidate propeller for a regional aircraft which has been developed in Korea. Because the propeller for the target aircraft must endure the high bending and twisting moment loads during the flight operation, the high stiffness and strength carbon/epoxy composite material is used as a major structure materials. As a design procedure for the present study, firstly the structural design load is estimated through the aerodynamic load case analysis, and then flanges of spars from major bending loads and the skin from shear loads are initially sized using both the netting rule and the rule of mixture. In order to investigate the structure safety and stability, the structure analysis is carried out by finite element analysis using commercial code, MSC. NASTRAN. In addition, because the propeller should be safe against the bird strike, the bird strike phenomenon is analyzed using a commercial code, ANSYS.

Designed-Oriented Methods of Ultimate Hull Girder Strength

2006 ◽  
Author(s):  
Enrong Qi ◽  
Weicheng Cui
Keyword(s):  
Single Step ◽  
Software System ◽  
Element Analysis ◽  
Hull Girder ◽  
Structural Rules ◽  
Ship Hulls ◽  
Calculation Results ◽  
Long Time ◽  
Common Structural Rules ◽  
Double Hull

Based on long-time theoretical and experimental work in authors group, assessment methods of ultimate strength of ship hulls are analyzed and improved. Nonlinear finite element analysis method (FEM), idealized structural unit method (ISUM), simplified method (SM) and analytical method (AM) are integrated into a software system of direct calculations of large tankers. Using this software system, a comparative calculation is performed on ultimate hull girder strength of a 300,000dwt double hull tanker and the calculation results are also compared with the single step procedure of Common Structural Rules for double hull tankers (JTP CSR).

Problems of Optimal Structural Design

1968 ◽  
Vol 35 (1) ◽  
pp. 102-106 ◽  
Author(s):  
W. Prager ◽  
J. E. Taylor
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Elastic Stiffness ◽  
Uniform Method ◽  
Design Parameters ◽  
Maximum Stiffness ◽  
Subsequent Determination ◽  
Elastic Design ◽  
Optimal Plastic Design

The paper presents a uniform method of treating a variety of problems of optimal design of sandwich structures. The design procedure consists of two steps: The integration of an optimality condition, which is a differential equation for the optimal displacement field that does not involve any design parameters, and the subsequent determination of the optimal distribution of elastic stiffness or plastic resistance from the usual differential equations of the structure. Optimal elastic design for maximum stiffness, maximum fundamental frequency, or maximum buckling load, and optimal plastic design for maximum safety are treated as examples.

Structural Design and Optimization of a 3-Axis Miniaturized Machine Tool with High Precision Positioning Stages

2007 ◽  
Vol 339 ◽  
pp. 321-326
Author(s):  
J.H. Lee ◽  
Wei Wang ◽  
Sung Hwan Kweon ◽  
Young Shin Kim ◽  
Young Moon Lee ◽  
...  
Keyword(s):  
Machine Tool ◽  
Structural Design ◽  
Evaluation Method ◽  
Error Function ◽  
Design Procedure ◽  
Design Parameters ◽  
Volumetric Error ◽  
Design And Optimization ◽  
Suitable Structure ◽  
Previous Design

The procedure of structural design on miniaturized machine tool (mMT) is proposed and structural optimization by applying robustness evaluation method is presented in this paper. The design procedure of a kind of mMT which is a 3-axis miniaturized milling machine tool (mMMT) is discussed and three different structures of mMMT are proposed based on previous design procedure. The most suitable structure is selected using robustness evaluation method, which is Taguchi method, due to volumetric error function. The design parameters of selected structure are optimized.

scholarly journals Some Remarks on the Choice of Ductility Class for Earthquake-Resistant Steel Structures

2013 ◽  
Vol 21 (3) ◽  
pp. 1-10
Author(s):  
Miroslava Matejčeková-Farhat ◽  
Rudolf Ároch
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Steel Structures ◽  
Design Parameters ◽  
Eurocode 8 ◽  
Design Practice ◽  
Earthquake Resistant ◽  
Earthquake Resistant Structures ◽  
Design Requirements ◽  
National Practice

Abstract The implementation of the Eurocodes in current structural design practice has brought about a new emphasis on the design of earthquake-resistant structures. In some European countries, new earthquake zones have been defined; henceforth, the design requirements of many ongoing projects have changed as well. The choice of the ductility class of steel structures as one of the key design parameters, the consequences of this choice on design procedure, and some applications of the Eurocode 8 design criteria by comparing French and Slovak national practice are discussed, using a practical example of a structure.

On the Design of Spatial 4C Mechanisms for Rigid-Body Guidance Through 4 Positions

1995 ◽  
Author(s):  
Pierre M. Larochelle
Keyword(s):  
Rigid Body ◽  
Design Process ◽  
Design Procedure ◽  
Design Parameters ◽  
Two Dimensional ◽  
Dimensional Synthesis ◽  
Numerical Example ◽  
Cylindrical Joint ◽  
Free Parameters

Abstract This paper presents a procedure for determining the fixed and moving congruences associated with four finitely separated spatial positions. Furthermore, a methodology is derived for selecting the lines from the congruences which define the joint axes of a 4C mechanism. The result is a design procedure for performing the kinematic dimensional synthesis of spatial 4C mechanisms for four position rigid body guidance. Associated with four finitely separated positions in space are a fixed and a moving congruence. These congruences are a two dimensional set of lines, where each line defines the axis of a cylindrical joint that guides a body through the four prescribed positions. In order to uniquely determine a 4C mechanism from the congruences four free parameters must be specified. We present procedures for determining these free design parameters which result in mechanisms with joint axes that are nearest to some desired location. Moreover, included is a detailed numerical example illustrating the design process.

The effect of the percentage of steered plies on the bending-induced buckling performance of a variable stiffness composite cylinder

2015 ◽  
Vol 22 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Mohammad Rouhi ◽  
Hossein Ghayoor ◽  
Suong V. Hoa ◽  
Mehdi Hojjati
Keyword(s):  
Performance Improvement ◽  
Design Procedure ◽  
Laminated Composite ◽  
Variable Stiffness ◽  
Design Parameters ◽  
Composite Cylinder ◽  
Element Analysis ◽  
Fiber Placement ◽  
Structural Improvement ◽  
Automated Fiber Placement

AbstractThe fiber steering capability of automated fiber placement machines offers the designers more room to fully exploit the directional properties of composite materials. Circumferential stiffness tailoring by fiber steering can considerably increase the bending-induced buckling performance of laminated composite cylinders. The potential structural improvement resulting from fiber steering depends on different design parameters such as the number of plies considered for fiber steering in a laminate. In this study, the buckling performance improvement of a variable stiffness (VS) composite cylinder is investigated for different percentages of plies considered for fiber steering in a multilayered composite laminate. A surrogate-based modeling along with a multi-step optimization is used in the design procedure of this study. The improvements in the buckling performance are shown and verified using finite element analysis in ABAQUS software. The mechanisms leading to buckling performance improvement of VS composites are also investigated and presented for different percentages of fiber-steered plies.

scholarly journals Structural design of double hull oil tankers for collision

2012 ◽  
Vol 16 (2) ◽  
pp. 61-67
Author(s):  
ELsayed Hegazy ◽  
Shiref Badran ◽  
Samy Youssef
Keyword(s):  
Structural Design ◽  
Oil Tankers ◽  
Double Hull
Sign in / Sign up

Export Citation Format

Share Document