• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.325-342
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• 2020

The current study is focused on the evaluation of the ultimate strength of stiffened panels found in ship hull structures that are subjected to combined uniaxial thrust, in-plane and out-of-plane bending moments. This loading condition, which is in general ignored when performing buckling checks, applies to representative control geometries (stiffener with attached plating) as a consequence of the linearly varying normal stresses along the ship's depth induced by the hull-girder vertical bending moment. The problem is generalized by introducing a non-uniform thrust described by a displacement ratio and rotation angle and by introducing the slenderness ratios, within the practical range of interest. The formed design space is explored through methods sourcing from Design of Experiments and by applying non-linear finite element procedures. Surrogate empirical models have been constructed through regression analysis and Response Surface Methods. An additional empirical model is provided to the literature for predicting the ultimate strength under uniaxial thrust. The numerical experimentation has shown that is a significant influence on the ultimate strength of stiffened panels as the thrust non-uniformity increases.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.1
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• pp.47-55
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• 2023

In this study, the following conclusions were drawn by analyzing the size, proportion, shape, angle, distribution, etc. of stones in order to identify the principles of facade molding of stonework of the 5th to 7th centuries of the Silla Dynasty. First, the uniformity of the size of the stones of the stone foundations of the Silla Dynasty was low at -0.8 to 4.1. This means that stones of various sizes were used, from small stones to large stones. In addition, the distribution of large stones in stonework of the Silla Dynasty appeared evenly regardless of height. This was common in the stonework of the Silla Dynasty, regardless of structural classification such as wells and mountain fortresses. It is thought that the Silla people did not only pursue practicality and efficiency in stone construction, but also considered design elements. Second, the proportional deviation of the stones of the stone walls of the Silla Dynasty was high, ranging from 0.861 to 1.515. This means that the stonework of the Silla Dynasty did not use only long flagstone-shaped stones, but used a mixture of long and short stones. Third, the shape average of the stones of the stonework of the Silla Dynasty was low at 0.45, and the shape deviation was high at the maximum of 0.15. This means that the stones as a whole have irregular shapes, and each stone has a high difference in shape. Fourth, the angle deviation of the stones of the Silla Dynasty was 4.3 to 16.2, and the average angle was 2. This means that the angle of each stone on the stone axis of the Silla Dynasty is tilted to the left and right. Fifth, there was no correlation between stone size, slenderness ratio, shape, and angle in the stone axes of the Silla Dynasty. In the case of stone axes in the Joseon Dynasty, there was a positive correlation between stone size and slenderness, and a negative correlation between stone size and shape. It can be said that the stones of the Joseon Dynasty were relatively standardized, but the Silla Dynasty showed the beauty of moderation by keeping the nature of the material and becoming one with the material.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1043-1052
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• 2014

This paper deals with in-plane free vibrations of the horseshoe circular arch. Simultaneous ordinary differential equations governing free vibration of the arch are derived with respect to the radial and tangential deformations. Particularly, differential equations are obtained under the arc length coordinate rather than the angular one in order to extend the horseshoe arch whose subtended angle is greater than ${\pi}$ radians. The differential equations are numerically solved for calculating the natural frequencies accompanying with the corresponding mode shapes. In parametric studies, effects of the rotatory inertia, slenderness ratio and circumferential arc length ratio on frequency parameters are extensively discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.161-162
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• 2010

In this study, the impact load on concrete compression member was considered to assess the quantitative damage index. The case study was carried out using the LS-DYNA, on explicit finite element analysis program. The parameters for the case study were impact load angle, slenderness ratio, etc. Using the analysis results, the performance based design method for impact load was developed using Bayesian probabilistic method, which can be applied to reinforced concrete column design for impact loads.

• Journal of Korean Association for Spatial Structures
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• v.6 no.1 s.19
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• pp.75-82
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• 2006

The single layer latticed dome is very sensitive on the slenderness ratio and half open angle of the elements, load condition, and the connection type because it is organized by a lot of thin elements, so we have to use the geometrically nonlinear buckling load when the buckling of the structures is analyzed. But, it is very difficult to design the single layer latticed domes considered all renditions. Therefore the purpose of this paper is to propose the appropriate design method of the single layer latticed dome considered the geometrically nonlinear buckling load in base of the linear buckling load by the eigenvalue analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.4
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• pp.1-8
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• 1989

The main purpose of the present paper is to present both the fundamental frequency and some higher free vibration frequencies for circular arches with variable section, in which rotatory inertia is included. The differential equations are derived for the in-plan free vibration of elastic circular arches with variable section. These equations were solved numerically for the linear variable circular cross-section with clamped-clamped end constraint. As the numerical results, the four lowest nondimensional natural frequencies presented as functions of the nondimensional system parameters : the end moment of inertia to crown moment of inertia ratio, the slenderness ratio, and the opening angle. The effect of rotatory inertia on the nondimensional natural frequency is also reported.

• Computational Structural Engineering
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• v.9 no.3
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• pp.209-216
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• 1996

The primary objective of this paper is to grasp many characteristics of buckling behavior of latticed spherical domes under various conditions. The Arc-Length Method proposed by E.Riks is used for the computation and evaluation of geometrically nonlinear fundamental equilibrium paths and bifurcation points. And the direction of the path after the bifurcation point is decided by means of Hosono's concept. Three different nonlinear stiffness matrices of the Slope-Deflection Method are derived for the system with rigid nodes and results of the numerical analysis are examined in regard to geometrical parameters such as slenderness ratio, half-open angle, boundary conditions, and various loading types. But in case of analytical model 2 (rigid node), the post-buckling path could not be surveyed because of Newton-Raphson iteration process being diversed on the critical point since many eigenvalues become zero simultaneously.

• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.221-228
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• 2011

Because steel plate girder bridge has big slenderness ratio, buckling is a major design factor. The objective of this study is to analyze the buckling behaviors of plate girder with I-girder and corrugated steel web and to examine the advantages of plate girder with corrugated steel web. Various parametric study according to the change of web height, web thickness, and load condition are examined. It is shown that plate girder with corrugated steel web is more effective than plate girder with I-girder and proper corrugated angle(${\theta}$) is $15^{\circ}{\sim}22^{\circ}$.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.1
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• pp.19-29
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• 2019

Recent earthquakes in Korea caused some damages to stone pagodas and thereby awakened the importance of earthquake preparedness. Korean stone pagodas which have been built with very creative style of material use and construction method are worthy of world heritage. Each stone pagoda consists of three parts: top; body; and base. However each tower is uniquely defined by its own features, which makes it more difficult to generalize the seismic assessment method for stone pagodas. This study has focused on qualitative preliminary evaluation of stone pagodas that enables us to compare the relative seismic performance across major aspects among many various Korean pagodas. Specifically an analytical model for multi-block stone pagodas is to be proposed upon the investigation of structural characteristics of stone pagoda and their dynamic behavior. A strategy for seismic evaluation of heritage stone pagodas is to be established and major evaluation factors appropriate for the qualitative evaluation are identified. The evaluation factors for overall seismic resisting behavior of stone pagodas are selected based on the dynamic motions of a rigid block and its limit state. Numerical simulation analysis using discrete element method is performed to analyze the sensitivity of each factor to earthquake and discuss some effects on seismic performance.

• Steel and Composite Structures
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• v.45 no.3
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• pp.455-466
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• 2022

Despite the considerable lateral stiffness and strength of the Concentrically Braced Frame (CBF), it suffers from low ductility and low seismic dissipating energy capacity. The buckling of the diagonal members of the CBF systems under cyclic loading ended up to the shortcoming against seismic loading. Comprehensive researches have been performing to achieve helpful approaches to prevent the buckling of the diagonal member. Among the recommended ideas, metallic damper revealed a better success than other ideas to enhance the behavior of CBFs. While metallic dampers improve the behavior of the CBF system, they increase constructional costs. Therefore, in this paper, a new steel damper with flexural mechanism is proposed, which is investigated experimentally and numerically. Also, a parametrical revision was carried out to evaluate the effect of thickness, slenderness ratio, angle of the main plate, and height of the main plates on the proposed damper. For the parametrical study, 45 finite element models were analyzed and considered. Experimental results, as well as the numerical results, indicated that the proposed damper enjoys a stable hysteresis loop without any degradation up to a high rotation equal to around 31% that is significantly considerable. Moreover, it showed a suitable performance in case of ductility and energy dissipating. Besides, the necessary formulas to design the damper, the required relations were proposed to design the elements outside the damper to ensure the damper acts as a ductile fuse.