보강된 판의 국부좌굴강도에 대한 폐단면리브 단면회전 강성의 효과

Arriane Nicole P. Andico,곽재영,최병호 한국복합신소재구조학회 2017 복합신소재구조학회 학술발표회 Vol.2017 No.04

Recent studies have revealed that plates stiffened by closed-section ribs can be designed to have greater strength. Thus, this study is about the increasing effect on local plate buckling strength of isotropic plates when longitudinally stiffened with closed-section ribs, which is mainly due to the rotational restraint of the closed-section ribs. The effects on buckling strengths of the stiffened plates are examined by numerical analyses. Three-dimensional finite element models were obtained using a general structural analysis program ABAQUS and a series of eigenvalue analyses were conducted. Through this study, the increasing effect on the local buckling strength due to the rotational stiffness is numerically verified. From the parametric studies, there is an obvious tendency that the local buckling strength of the stiffened plate would converge to the buckling strength of plate with fixed boundary condition. The findings of this study would contribute in improving the optimum design of longitudinally stiffened isotropic plates.

폐단면리브에 의해 종방향으로 보강된 복합 적층판의 좌굴 거동 해석

Arriane Nicole Andico,이상형,최병호 한국복합신소재구조학회 2018 복합신소재구조학회 학술발표회 Vol.2018 No.04

Using closed-section ribs as longitudinal stiffeners have been proven to be an effective system for axially compressed members, however, studies on the application of these on laminated composite shell are insufficient. Thus, this study aims to evaluate the buckling behavior of the laminated composite shell when closed-section ribs were applied as longitudinal stiffeners. The effect of the rotational stiffness of the closed-section ribs on the buckling modes and strengths will be determined in this paper. The three-dimensional finite element modeling were set up using ABAQUS and a series of eigenvalue analysis were conducted, applying eight layers of the layup [(0°)4]s, [(45°/-45°)2]s and [(0°/90°)2]s on the orthotropic plates. Through the parametric studies, the increasing effect on the elastic buckling strengths due to the rotational stiffness are numerically verified, and the buckling strength of a longitudinally stiffened shell with a laminated composite material were compared with that of the isotropic material.

Buckling Strength Increment of Curved Panels Due to Rotational Stiff ness of Closed-Section Ribs Under Uniaxial Compression

Arriane Nicole P. Andico,박용명,최병호 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.4

Recently, there have been studies about the increasing eff ect on the local plate buckling strength of fl at plates when longitudinally stiff ened with closed-section ribs and an approximate solution to quantitatively estimate these eff ects were suggested for fl at plates. Since there are few studies to utilize such increasing eff ect on curved panels and a proper design method is not proposed, thus, this study aims to numerically evaluate such eff ect due to the rotational stiff ness of closed-section ribs on curved panels and to propose an approximate method for estimating the buckling strength. Three-dimensional fi nite element models were set up using a general structural analysis program ABAQUS and a series of parametric numerical analyses were conducted in order to examine the variation of buckling stresses along with the rotational stiff ness of closed-section ribs. By using a methodology that combine the strength increment factor due to the restraining eff ect by closed-section ribs and the buckling coeffi cient of the panel curvature, the approximate solutions for the estimation of buckling strength were suggested. The validity of the proposed methods was verifi ed through a comparative study with the numerical analysis results.

폐단면리브로 보강된 곡판의 국부판좌굴에 관한 변수해석적 연구

아레안 니콜 피 안디코(Arriane Nicole P. Andico),곽재영(Jae-Young Kwak),최병호(Byung-Ho Choi) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.1

본 논문은 강교량 거더, 교각, 선박이나 대형 저장 시설 등 주요 구조 부재에 활용되는 곡판 및 강관을 효과적으로 보강하는 방안에 관한 것이다. 최근 연구에서 압축을 받는 평판이 종방향 보강재의 단면회전강성에 의해 국부좌굴강도가 향상되는 특징을 정량적으로 분석하였고, 폐단면리브 단면회전강성과의 상관관계를 규명한 바 있다. 본 논문에서는 곡판에 대해 이와 같은 효과를 정량적으로 검토하고자 한다. 일축압축이 재하된 경우에 폐단면리브로 보강된 두께방향으로 곡률을 가지는 곡판의 좌굴거동을 살펴보기 위해 범용 구조해석 프로그램인 ABAQUS를 이용하여 3차원 유한요소해석 모델을 생성하였다. 이를 통해 좌굴거동에 대한 수치해석을 수행하였으며, 영향인자에 대한 변수해석적 연구를 수행하여 좌굴응력과 좌굴모드의 변동특성을 정량적으로 평가하였다. 폐단면리브 단면회전강성의 구속효과로 인한 좌굴강도 증가효과와 판의 곡률에 따른 좌굴강도 계수를 고려하여 좌굴강도를 추정하는 방법론을 이론적으로 제안하였다. 제안된 공식은 유한요소해석결과와 비교하여 서로 유의미성이 검토되었다. 또한 평판에서와 마찬가지로 일축압축 상태에서 폐단면리브의 단면강성에 의해 부여되는 양측단 회전강성의 증가로 인해 곡판의 국부좌굴강도가 이에 비례하여 증가하였고, 양측단에서 회전이 고정된 곡판의 좌굴강도에 수렴하는 경향을 확인하였다. In this study, we investigate a design technology intended to radically increase the buckling strength of vertically curved panels. Recent studies proposed a buckling strength formula which properly reflects the effect on the local plate buckling strength of flat plates when they are stiffened by closed section ribs. Herein, we attempted to quantitatively evaluate this effect on curved panels and to reveal the correlations with the design parameters. The commercial finite element software, ABAQUS, was used to build a three dimensional numerical model and numerical parametric studies were conducted to evaluate the variation of the buckling strength. In the case of flat panels, the local buckling strength of stiffened curved panels increases proportionally with increasing rotational stiffness of the closed-section ribs. After attaining a limiting value, an obvious tendency was found that the local buckling strength of the stiffened curved panel would converge towards a fixed value when the panels are supported along both sides. The parametric studies performed using the influential design parameters confirmed that the estimated partially-restrained curved panel strength is well correlated with the proposed formula.

가로보 강성에 따른 모듈러 플레이트 I-거더의 횡비틀림 좌굴강도에 관한 변수해석

최병호,Arriane Nicole Andico,곽재영,박찬희 한국복합신소재구조학회 2018 복합신소재구조학회 학술발표회 Vol.2018 No.04

Beam bracing is applied to prevent the relative displacement of the top and bottom flanges or to effectively control the twisting of the section, and the lateral stability of the beams are provided by lateral bracing, torsional bracing or a combination of both. Modular steel I-girders are laterally interconnected by torsional bracings that are installed to increase the resistance to lateral torsional buckling. In this paper, numerical parametric study was carried out by varying the crossbeam web height to examine the effects of the web torsional stiffness. Three-dimensional finite-element analysis using the commercial finite element software ABAQUS was obtained for the parametric numerical analyses of a series of feasible two-girder models, and the failure mode, lateral-torsional buckling strength and the moment-displacement behavior of the main girders was determined.

폐단면리브 보강 쉘구조의 좌굴거동 고유치 해석

최병호,Arriane Nicole P. Andico,김정원 한국복합신소재구조학회 2016 복합신소재구조학회 학술발표회 Vol.2016 No.04

This study is about the basic design technology to radically increase the structural stability of structural shell or tube, which are utilized in a variety of large structures like aircrafts, plant, bridges and buildings. Recent studies have revealed that the plates stiffened by closed-sections ribs can be designed to have greater strength as well as the reduction of used number of stiffeners. Then, the analytical models were selected based on the huge steel tube design and the finite element modeling has been conducted using the ABAQUS. Through this study, the elastic buckling strengths are compared with the flat plate buckling stress and the improved effect in the local buckling strength due to the closed-section ribs are numerically verified.