Lateral pressure effect on average compressive strength of stiffened panels for in-service vessels

2012 ◽  
Vol 9 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Joonmo Choung ◽  
Jun-Bum Park ◽  
Chang Yong Song
2011 ◽  
Vol 335-336 ◽  
pp. 1454-1458
Author(s):  
Jing Xian Zhang ◽  
Bi Qin Chen ◽  
Dong Liang Jiang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
...  

In the present work, porous HA scaffolds with well controlled pore size, porosity and high compressive strength were prepared by aqueous gelcasting. PMMA beads with different size were used as the pore forming agent. The compositions, microstructure and properties of porous HA bioceramics were analyzed by XRD, SEM, Hg porosimetry etc. The mechanical properties were also tested. For scaffolds with the porosity as 70%, the average compressive strength was 11.9±1.7 MPa. Results showed that glecasting process can be used for the preparation of porous HA biomaterials with well controlled pore size and improved mechanical properties.


Author(s):  
Ji-Myung Nam ◽  
Joonmo Choung ◽  
Se-Yung Park ◽  
Sung-Won Yoon

This paper presents the prediction of residual ultimate strength of a very large crude oil carrier considering damage extents due to collision and grounding accidents. In order to determine extents of damage, two types of probabilistic approaches are employed: deterministic approach based on regulations based on ABS [1], DNV [2], and MARPOL [3] and probabilistic approach based on IMO probability density functions (PDFs) (IMO guidelines [4]). Hull girder ultimate strength is calculated using Smith method which is dependent on how much average compressive strength of stiffened panel is accurate. For this reason, this paper uses two different methods to predict average compressive strength of stiffened panel composing hull girder section: CSR formulas and nonlinear FEA. Calculated average compressive strength curves using CSR formulas (IACS [5, 6]) and nonlinear FEA are imported by an in-house software UMADS. Residual ultimate moment capacities are presented for various heeling angles from 0° (sagging) to 180° (hogging) by 15° increments considering possible flooding scenarios. Three regulations and IMO guidelines yield minimum of reduction ratios of hull girder moment capacity (minimum of damage indices) approximately at heeling angles 90° (angle of horizontal moment) and 180° (angle of hogging moment), respectively, because damage area is located farthest from neutral axis.


2020 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
Kiki Kurniawan ◽  
Prihantono Prihantono ◽  
Rosmawita Saleh

The results showed the use of cow dung waste can increase the compressive strength of hollow brick from any composition of waste. Hollow brick with cow dung substitution of 0% has an average compressive strength value 44.75 Kg/Cm2 has an average water absorption of 14.31%, hollow brick with cow dung substitution of 5% has a value of compressive strength average 47.47 Kg/Cm2 has an average water absorption of 15.67%, Batako perforation with cow dung substitution of 7.5% has an average compressive strength value of 51.83 Kg/Cm2 has the absorption water averaging 13.71%, batako perforated with substitution of cow dung waste of 10% has an average compressive strength value 53.81 Kg/Cm2 has an average water absorption of 10.04%, hollow brick with substitution cow dung waste of 12.5% has an average compressive strength value of 50.66 Kg/Cm2 has an average water absorption of 23.6%, hollow brick with cow dung substitution of 15% average 48.84 Kg/Cm2 has an average water absorption of 19.72%. The optimum compressive strength value was obtained from percentage substitution of cow dung waste at 10% with mean value of compressive strength 53,81 Kg/Cm2 with average water absorption 10,04%.


Author(s):  
Babatunde Ogunbayo ◽  
Clinton Aigbavboa ◽  
Opeoluwa Akinradewo

Sandcrete block is a vital building material used in the construction of building structures. The sandcrete blocks are produced by different manufacturers using river sand obtained from different locations as aggregate material without recourse to the minimum quality standard for the blocks produced. The study assessed the strength parameters of river sand used as an aggregate material in block production to determine its quality and suitability in relation to the strength of block produced. Three (3) block manufacturing sites in Nigeria were visited and 27 (twenty-seven) blocks of size 450 mm x 225 mm x 225 mm were selected randomly from the sites. The properties of the river sand was analyzed through sieve analyses, bulk density, silt content and water absorption while the compressive strength of the blocks was also tested. The result of sieve analysis of the river sand used in block production for this study all satisfied the particle size requirements of BS EN 933-1:1997 for general construction work including block production. The result of the study also shows that blocks produced with the river sand after 28days have an average compressive strength of 1.23 N/mm2 (SW), 1.54 N/mm2 (SE) and 1.95N/mm2 (NE). The study, therefore, concluded and recommended that regulatory and professional bodies in partnership with relevant associations should organize seminars for producers of sandcrete blocks on the best practices involved in producing quality sandcrete blocks.


2014 ◽  
Vol 2 (1) ◽  
pp. 75-82
Author(s):  
Elivs M. Mbadike ◽  
N.N Osadebe

In this research work, the effect of mound soil on concrete produced with river sand was investigated. A mixed proportion of 1.1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of river sand with mound soil is 0%, 5%, 10%, 20%, 30% and 40%. Concrete cubes of 150mm x 150mm x150mm of river sand/mound soil were cast and cured at 3, 7, 28, 60 and 90 days respectively. At the end of each hydration period, the three cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength test for 5- 40% replacement of river sand with mound soil ranges from 24.00 -42.58N/mm2 a against 23.29-36.08N/mm2 for the control test (0% replacement).The workability of concrete produced with 5- 40% replacement of river sand with mound soil ranges from 47- 62mm as against 70mm for the control test.


2019 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Agil Dwi Krisna ◽  
Sigit Winarto ◽  
Ahmad Ridwan

Concrete has the disadvantage of having a low tensile strength and convincing brittle beams with steel inscriptions to anticipate. In this study, the concrete mixture was given additional bagasse and additives of cycacim bonding. This addition was carried out to study and study the effect of bagasse on the compressive strength of normal k300 concrete by replacing bagasse by 0%, 5%, 10% and 15% in compressive loads. Compressive strength specimens in the form of cubes with a size of 15 cm x 15 cm x 15 cm. Testing is done after 28 days. Concrete with increased bagasse of 5% is better able to produce high compressive strength values than others. The addition of bagasse resulted in an average compressive strength of 5%, 229.64 kg / cm2, 10%, 190.35 kg / cm2, 15%, 160.87 kg / cm2.Beton mempunyai kelemahan yaitu mempunyai kuat tarik yang rendah dan bersifat getas sehingga beton diberi tulangan baja untuk mengantisipasinya. Pada penelitian ini, campuran beton diberi bahan tambahan ampas tebu dan zat additif sikacim bonding adhesive. Penambahan ini dilakukan untuk mempelajari dan mengetahui pengaruh ampas tebu terhadap kuat tekan pada beton mutu normal k300 dengan penambahan ampas tebu sebesar 0%, 5%, 10% dan 15% pada beban tekan. Benda uji kuat tekan berbentuk kubus dengan ukuran 15 cm x 15 cm x 15 cm. Pengujian dilakukan setelah 28 hari. Beton dengan penambahan ampas tebu 5% lebih mampu menghasilkan nilai kuat tekan tinggi dari pada yang lainya. Penambahan ampas tebu menghasilakan kuat tekan rata-rata yaitu 5%,229,64 kg/cm2, 10%,190,35 kg/cm2, 15%,160,87kg/cm2.


2007 ◽  
Vol 44 (02) ◽  
pp. 93-105
Author(s):  
Jeom Kee Paik

To study the accuracy of simplified formulations for prediction of the ultimate strength of longitudinally stiffened panels under uniaxial compression, the preferred approach is to compare them with available experimental data or numerical results from more sophisticated analysis procedures. Such studies are necessary in the development of both design code calibrations and reliability analysis procedures. Existing experimental data and numerical results useful for this purpose are first collected. Salient features of existing design formulations for compressive strength are then reviewed. Selected formulations are compared with the experimental data/numerical results. It is illustrated that there can be a significant amount of scatter in strength estimates by any one formulation and among formulations. The reasons for such scatter are discussed, with the emphasis on the collapse mode(s) involved, the effective width of plating, initial imperfections, and rotational restraints due to stiffening. The experimental and numerical strength data collected are documented for convenience of future use by other investigators.


2001 ◽  
Vol 45 (02) ◽  
pp. 111-132 ◽  
Author(s):  
Jeom Kee Paik ◽  
Owen F. Hughes ◽  
Alaa E. Mansour

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.


2007 ◽  
Vol 44 (01) ◽  
pp. 16-26
Author(s):  
Ömer Eksik ◽  
R. Ajit Shenoi ◽  
Stuart S. J. Moy ◽  
Han Koo Jeong

This paper describes the development of a finite element model in order to assess the static response of a top-hat-stiffened panel under uniform lateral pressure. Systematic calculations were performed for deflection, strain, and stress using the developed model based on the ANSYS three-dimensional solid element (SOLID45). The numerical modeling results were compared to the experimental findings for validation and to further understand an internal stress pattern within the different constituents of the panel for explaining the likely causes of the panel failure. Good correlation between experimental and numerical strains and displacements was achieved.


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