scholarly journals Optimum Design of Sunken Reinforced Enclosures under Buckling Condition

2020 ◽  
Vol 10 (23) ◽  
pp. 8449
Author(s):  
Mostafa Omidi Bidgoli ◽  
Kazem Reza Kashyzadeh ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů ◽  
Nima Amiri
Keyword(s):  
Finite Element ◽  
Critical Load ◽  
Optimum Design ◽  
Analytical Method ◽  
Design Principles ◽  
Offshore Structures ◽  
Finite Element Analyses ◽  
Marine Structures ◽  
Minimum Thickness ◽  
Good Agreement

Increasing the lifetime and improving the performance of structures through redesign and optimization are important, especially in marine structures. In general, there are two main groups of marine structures: onshore and offshore structures. Most marine structures are offshore, and these are divided into two categories: floating or sunken. One of the important parameters in the design of sunken structures is the critical load resulting from the buckling of walls, which can cause damage to the structure. In the present paper, three rectangular aluminum and steel compartments of different conditions and sizes were modeled using design analysis methods. Then, different finite element analyses were performed, and the compartments were optimized to reduce the weight of the structure. Finally, the buckling results of three types of rectangular reinforced compartments were calculated and were compared with each other. The results show that the stresses calculated using the analytical method are in good agreement with the results of the finite element analyses. In addition, the weight of the compartment is reduced by utilizing the reinforced conductors in accordance with the design principles and considering the minimum thickness.

Study of bolted joint axial stiffness using finite element analyses, experimental tests, and analytical calculations

2020 ◽  
Vol 234 (23) ◽  
pp. 4671-4681
Author(s):  
Raphael Calazans Cardoso ◽  
Brenno Lima Nascimento ◽  
Felipe de Freitas Thompson ◽  
Sandro Griza
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
High Reliability ◽  
Experimental Tests ◽  
Bolted Joints ◽  
Axial Stiffness ◽  
Bolted Joint ◽  
Finite Element Analyses ◽  
Load Distributions ◽  
Reliable Design

The bolted joints sizing procedures shall adequately match the conditions imposed on the joint in service, to ensure high reliability designs. Therefore, this study aims to analyze the load distributions on the bolt when applying external load on bolted joints. Finite element and extensometry analyses as well as analytical calculations were performed in order to compare the magnitude of the joint overall stiffness, with respect to several available theories. The results acquired through the analytical method prescribed in the VDI 2230 standard as well as the finite element and extensometry analyses obtained great accordance. These results indicate that VDI 2230 standard adequately represents the mechanical behavior of the joint and should be used as a guideline for the reliable design of bolted joints subjected to the loading conditions of the present paper.

Design of a 33-Knot Aluminum Catamaran Ferry

2000 ◽  
Vol 37 (02) ◽  
pp. 88-99
Author(s):  
R. G. Latorre ◽  
P. D. Herrington
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Frame Structure ◽  
Test Results ◽  
Finite Element Analyses ◽  
The Finite Element Method ◽  
Floating Frame ◽  
Good Agreement ◽  
Panel Design

This paper presents the results of an investigation on the suitability of using hull panels with alternating fixed and floating frames for a 30–40 knot aluminum catamaran ferry. A prototype 4.6 m × 1.8 m bottom hull panel with alternating frames is analyzed numerically and physically tested. The corresponding finite-element analyses and test results are in good agreement. The results show that the floating frame hull panel design is a feasible structure for an aluminum catamaran. The floating frame structure was then used for a 33-knot, 250-passenger aluminum catamaran ferry designed to meet the ABS High Speed Craft rules. A midship section of the catamaran hull was analyzed using the finite-element method. Catamaran weight estimates, heave and pitch motions, and powering estimates are also provided. The results show that the alternating floating frame structure was within the ABS rules stress allowables.

Assessment of Overlapped Internal and External Volumetric Flaws in p-M Diagram

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Shinji Konosu ◽  
Hikaru Miyata
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Pressure Vessel ◽  
Effective Cross Section ◽  
Finite Element Analyses ◽  
Diagram Method ◽  
Reference Stress ◽  
Common Problems ◽  
Good Agreement

Assessment of overlapped internal and external volumetric flaws is one of the most common problems related to pressure vessel and piping components. Under the current fitness for service rules, such as those provided in ASME, BS, and so on, the procedures for the assessment of these flaws have not yet been defined. In this paper, a reference stress, incorporating the decrease in the effective cross section as a function of flaw depth and flaw angle in a cylinder, has been proposed in order to assess the flaws using the simple p-M (pressure-moment) diagram method. Numerous finite element analyses for a cylinder with overlapped internal and external flaws were conducted to verify the proposed procedure. There is good agreement among them.

Pure Bending of Curved Beams of Thin-Walled Rectangular Box Section

1991 ◽  
Vol 58 (1) ◽  
pp. 154-156 ◽  
Author(s):  
R. D. Cook
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
Circumferential Stress ◽  
Closed Form Solution ◽  
Form Solution ◽  
Finite Element Analyses ◽  
Curved Beams ◽  
Pure Bending ◽  
The Subject ◽  
Thin Walled

A closed-form solution of the subject problem is presented. The analytical method resembles that used by Bleich (1933) to study curved beams of I or T section. It is found that the circumferential stress may be smaller than a perpendicular stress that arises from flexing of parts of the box. Accuracy of the solution is verified by comparison with finite element analyses.

scholarly journals Some Studies on Prestressed Reinforced Granular Beds Overlying Weak Soil

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
J. Jayamohan ◽  
R. Shivashankar
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Experimental Results ◽  
Finite Element Analyses ◽  
Granular Bed ◽  
Weak Soil ◽  
Soil Thickness ◽  
Prestressing Force ◽  
Load Carrying ◽  
Good Agreement

This paper mainly investigates, from a series of laboratory scale bearing capacity tests carried out on a model square footing, the improvement in bearing capacity and reduction in settlement of a geonet reinforced granular bed (RGB) overlying weak soil due to prestressing the reinforcement. The parameters are the strength of the underlying weak soil, thickness of the granular bed, and magnitude and direction of prestressing force. The settlements at the interface are also measured. The addition of prestress to geonet reinforcement results in significant improvement in the load carrying capacity and settlement response of the prestressed geonet RGB. Improvement in bearing capacity is found to be more with biaxial prestressing than with uniaxial prestressing. Experimental results are also used to validate a proposed numerical model. The BCR (bearing capacity ratio) values predicted from this model are found to be in good agreement with the experimentally obtained BCR values. Finite element analyses are also carried out using the programme PLAXIS, to study the effect of prestressing the reinforcement. Results obtained from finite element analyses are also found to be in good agreement with the experimental results.

Lateral Buckling Studied of Rectangular Plate with Two Opposite Edges Clamped under the Action of a Concentrated Loads

2013 ◽  
Vol 671-674 ◽  
pp. 1600-1603
Author(s):  
Song Jin Wu ◽  
Li Qiang Jiang ◽  
Wei Ning Yuan
Keyword(s):  
Finite Element ◽  
Critical Load ◽  
Engineering Design ◽  
Rectangular Plate ◽  
Analytical Method ◽  
Calculation Formula ◽  
Lateral Buckling ◽  
Concentrated Load ◽  
Finite Element Software ◽  
Ansys Analysis

This study is focus on investigating the lateral buckling of the rectangular plate with two opposite edges clamped under the action of concentrated load. A analytical method of thirty rectangular plate which fixed at two opposite edges with one hundred and fifty buckling modality of concentrated load has been calculated by using the ANSYS finite element software. The curves of lateral buckling minimum critical load could be achieved by the calculation. Compared with the results from the existing calculation formula, the limitation applicability of the formula would be determined. To have a better agreement with ANSYS analysis results, this formula would be corrected by the analysis of the comparison between existing formula and ANSYS results. This research could provide effective methods for engineering design.

Combined empirical–analytical method for determining contact radius and indenter displacement during Hertzian indentation on coating/substrate systems

2004 ◽  
Vol 19 (9) ◽  
pp. 2774-2781 ◽  
Author(s):  
Chun-Hway Hsueh ◽  
Pedro Miranda
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
Empirical Equation ◽  
Contact Radius ◽  
Finite Element Analyses ◽  
Modulus Ratio ◽  
Properties Of Coatings ◽  
Hertzian Indentation ◽  
Potential Applications

An analytical model was developed in a previous work to relate the normalized indenter displacement to both the coating-to-substrate Young's modulus ratio and the coating-thickness-to-contact-radius ratio for Hertzian indentation on coating/substrate systems. However, application of this model is contingent upon the determination of the contact radius during indentation. Using the data from finite element analyses, an empirical equation is proposed in this paper to determine the normalized contact radius. Combining this empirical equation with the previous analytical equation, both the contact radius and the indenter displacement for Hertzian indentation on coating/substrate systems are predicted. The predictions obtained by this combined empirical–analytical method are shown to agree with the finite element results in general although the indenter displacement is over-estimated when the coating is stiffer than the substrate. Finally, the potential applications of this method to determine the elastic properties of coatings from the indentation data are envisaged.

A Simple Strain-Life Approach for the Fatigue Life Evaluation of Welded Joints with Residual Stresses

2006 ◽  
Vol 306-308 ◽  
pp. 127-132
Author(s):  
Byeong Choon Goo ◽  
Sung Yong Yang ◽  
Dong Hyung Lee
Keyword(s):  
Finite Element ◽  
Young’S Modulus ◽  
Welded Joints ◽  
Young's Modulus ◽  
Brinell Hardness ◽  
Fatigue Properties ◽  
Finite Element Analyses ◽  
Life Evaluation ◽  
Fatigue Life Evaluation ◽  
Good Agreement

We surveyed literature and proposed a procedure to identify the fatigue properties from the Brinell hardness and Young’s modulus. And we developed a parameter similar to the S.W.T. parameter with the Brinell hardness and Young’s modulus. Using the parameter and finite element analyses, we evaluated fatigue lives of four kinds of welded joints. The predicted results are in a good agreement with experimental results.

Loads from Ice Ridge Keels – Analytical vs. Numerical

2015 ◽  
Vol 725-726 ◽  
pp. 229-234
Author(s):  
Aleksei M. Vakulenko ◽  
Alexander S. Bolshev
Keyword(s):  
Finite Element ◽  
Numerical Methods ◽  
Numerical Method ◽  
Analytical Method ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Analytical Results ◽  
Insight Into ◽  
Good Agreement

Action of ice ridge keel on vertical structures is studied by means of analytical and numerical methods. The analytical method involves keel load calculations using Russian and European recommendations provided in SP 38.13330.2012 and ISO/FDIS 19906 respectively. The numerical method involves finite element calculation. It is demonstrated that numerical methods can provide an important insight into ridges keels behavior. The numerical and analytical results obtained using Russian recommendations for vertical structures are in a good agreement.

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