scholarly journals Ultimate Compressive Strength of Stiffened Panel: An Empirical Formulation for Flat-bar Type

Author(s):  
Do Kyun Kim ◽  
Su Young Yu ◽  
Hui Ling Lim ◽  
Nak-Kyun Cho

This research aims to study the ultimate limit state (ULS) behaviour of stiffened panel under longitudinal compression by non-linear finite element method (NLFEM). There are different types of stiffeners being used in shipbuilding i.e. T-bar, flat-bar and angle-bar. However, this research focuses on the ultimate compressive strength behaviour of flat-bar stiffened panel. A total of 420 of reliable scenarios of flat-bar stiffened panel are selected for numerical simulation by ANSYS NLFEM. The ultimate strength behaviours obtained were used as data for the development of closed form shape empirical formulation. Recently, Kim et al. [1] proposed for advanced empirical formulation for T-bar stiffened panel and the applicability of the proposed formulation to flat-bar stiffened panel will be confirmed by this study. The accuracy of the empirical formulation obtained for flat-bar stiffened panel has been validated by FE simulation results of statistical analysis (R2 = 0.9435). The outcome obtained will be useful for ship structural designers in predicting the ultimate strength performance of flat-bar type stiffened panel under longitudinal compression.

2020 ◽  
Vol 8 (8) ◽  
pp. 605 ◽  
Author(s):  
Do Kyun Kim ◽  
Su Young Yu ◽  
Hui Ling Lim ◽  
Nak-Kyun Cho

This research aims to study the ultimate limit state (ULS) behaviour of stiffened panel under longitudinal compression by a non-linear finite element method (NLFEM). There are different types of stiffeners mainly being used in shipbuilding, i.e., T-bar, flat-bar, and angle-bar. However, this research focuses on the ultimate compressive strength behaviour of flat-bar stiffened panel. A total of 420 reliable scenarios of flat-bar stiffened panel were selected for numerical simulation by the ANSYS NLFEM. The ultimate strength behaviours obtained were used as data for the development of closed form shape empirical formulation. Recently, our group proposed an advanced empirical formulation for T-bar stiffened panel, and the applicability of the proposed formulation to flat-bar stiffened panel is confirmed by this study. The accuracy of the empirical formulation obtained for flat-bar stiffened panel was validated by finite element (FE) simulation results of statistical analysis (R2 = 0.9435). The outcome obtained will be useful for ship structural designers in predicting the ultimate strength performance of flat-bar type stiffened panel under longitudinal compression.


2006 ◽  
Vol 50 (03) ◽  
pp. 231-238
Author(s):  
Jeom Kee Paik ◽  
Y. V. Satish Kumar

The aim of the present paper is to investigate the ultimate strength characteristics of a longitudinally stiffened panel with cracking damage and under axial compressive or tensile loads. A series of nonlinear finite element analyses are undertaken with varying the size and location of cracking damage. A relevant theoretical model for predicting the ultimate strength of the stiffened panel with cracking damage is studied. The insights and results developed from the present study will be very useful for the ultimate limit state-based risk or reliability assessment of aging steel plated structures with cracking damage.


2005 ◽  
Author(s):  
Jeom Kee Paik ◽  
Owen F. Hughes ◽  
Paul E. Hess ◽  
Celine Renaud

The present paper is a summary of recent research and developments related to some core ultimate limit state (ULS) technologies for design and strength assessment of aluminum multi-hull ship structures, jointly undertaken by Pusan National University, Virginia Tech, U.S. Naval Surface Warfare Center and Alcan Marine. An extensive study on the subject has been undertaken by the authors theoretically, numerically and experimentally. Methods to analyze hull girder loads / load effects, stiffened panel ultimate strength and hull girder ultimate strength of aluminum multi-hull ship structures are developed in the present study. Application examples of the methodologies for the ULS structural design and strength assessment of a hypothetical 120m long all aluminum catamaran fast ship structure are presented. Important insights and conclusions developed from the present study are summarized. Some of the comparisons have shown that 5383 called Sealium (a patented Alcan Marine alloy) is superior to the standard aluminum alloy 5083 in terms of material properties, ULS characteristics and welding performance. It is our hope that the methods developed from the present study will be useful for ULS design and strength assessment of aluminum multi-hull ship structures.


2001 ◽  
Vol 38 (01) ◽  
pp. 9-25
Author(s):  
Jeom Kee Paik ◽  
Anil K. Thayamballi ◽  
Bong Ju Kim

The aim of the present study is to develop more advanced design formulations for the ultimate strength of ship plating than available at present. Plate ultimate strength subject to any combination of the following four load components—longitudinal compression/tension, transverse compression/tension, edge shear, and lateral pressure loads—is addressed. The developed formulations are designed to be more sophisticated than existing theoretically based simplified methods. The influence of post-weld initial imperfections in the form of initial deflections and residual stresses is taken into account. It has been previously recognized that a single ultimate strength interaction equation cannot successfully represent the ultimate limit state of long and/or wide plating under all possible combinations of load components involved. This is due to the fact that the collapse behavior of the long and/or wide plating depends primarily on the predominant load components, implying that more than one strength interaction formulations may be needed to more properly predict the plate ultimate limit state. In this regard, the present study derives three sets of ultimate strength formulations for the long and/or wide plating under the corresponding primary load by treating lateral pressure as a secondary dead load. The ultimate strength interaction formula under all of the load components involved is then derived by a relevant combination of the individual strength formulas. The validity of the proposed ultimate strength equations is studied by comparison with nonlinear finite-element analyses and other numerically based solutions.


Author(s):  
Yong He ◽  
Long-kun Xu ◽  
Qian Ye ◽  
Yi-hai Jiang ◽  
Wei-liang Jin

Stiffened panel is an important component of floating structures in deep water. This paper analyses of ultimate strength of stiffened panel corresponding to different failure modes. The ultimate limit state (ULS) equations are established. On the base of these equations, the safety assessments of the stiffened panel are conducted by reliability method. The reliability index is compared with the target reliability. The comparison indicates that there is no obvious correlation between different failure modes so that each failure mode could be analyzed individually. In addition, the reliability analysis is more reasonable than deterministic analysis. The method has been illustrated through application to an actual stiffen panel of a Tension Leg Platform. Advantages of the proposed method for assessment the safety of the stiffen panel is also highlighted.


2021 ◽  
Vol 322 ◽  
pp. 94-99
Author(s):  
Ondřej Šimek ◽  
Miloš Zich ◽  
Miloslav Janda ◽  
Radim Nečas

The subject of the article is a comparison of the precast reinforced concrete pillars with different types of reinforcement. These are the pillars simulating parts of walls that can, for example, form in the precast wall of residential buildings after an opening has been carved. The pillars are variously reinforced: from the simple reinforcement with wire mesh to the reinforcement with standard reinforcement bars. Behavior of the pillars, that have been subjected to two types of experiments in the past, is verified by software for non-linear analysis for concrete structures. Depending on the types of loading, the ultimate limit state, deformation and stress state of the individual pillars are studied.


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