Applied element method simulation of experimental failure modes in RC shear walls

Corneliu Cismasiu,António Pinho Ramos,Ionut D. Moldovan,Diogo F. Ferreira,Jorge B. Filho 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.4

With the continuous evolution of the numerical methods and the availability of advanced constitutive models, it became a common practice to use complex physical and geometrical nonlinear numerical analyses to estimate the structural behavior of reinforced concrete elements. Such simulations may yield the complete time history of the structural behavior, from the first moment the load is applied until the total collapse of the structure. However, the evolution of the cracking pattern in geometrical discontinuous zones of reinforced concrete elements and the associated failure modes are relatively complex phenomena and their numerical simulation is considerably challenging. The objective of the present paper is to assess the applicability of the Applied Element Method in simulating the development of distinct failure modes in reinforced concrete walls subjected to monotonic loading obtained in experimental tests. A pushover test was simulated numerically on three distinct RC shear walls, all presenting an opening that guarantee a geometrical discontinuity zone and, consequently, a relatively complex cracking pattern. The presence of different reinforcement solutions in each wall enables the assessment of the reliability of the computational model for distinct failure modes. Comparison with available experimental tests allows concluding on the advantages and the limitations of the Applied Element Method when used to estimate the behavior of reinforced concrete elements subjected to monotonic loading.

Structural performance of an electricity tower under extreme loading using the applied element method- A case study

Jason Ah Chin,Mauricio Garcia,Jeffrey Cote,Ellen Mulcahy,Jonathan Clarke,Ahmed Elshaer 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.3

The resiliency of electricity transmission and distribution lines towards natural and man-made hazards is critical to the operation of cities and businesses. The extension of these lines throughout the country increases their risk of extreme loading conditions. This paper investigates a unique extreme loading condition of a 100-year old distribution line segment that passes across a river and got entangled with a boom of a ship. The study adopts the Applied Elements Method (AEM) for simulating 54 cases of the highly deformable structural behaviour of the tower. The most significant effects on the tower’s structural integrity were found to occur when applying the load with components in all three of the cartesian directions (i.e., X, Y and Z) with the full capacities of the four cables. The studied extreme loading condition was determined to be within the tower’s structural capacity, attributed to the shear failure of the anchor bolts, which acted as a sacrificing element that fails to protect the transfer of tensioning load to the supporting tower.

Use of Applied Element Method for Structural Analysis

Aliakbar Shakeri,Khosrow Bargi 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.5

Applied Element Method (AEM) is a numerical analysis used in prediction the behavior of structures. The modeling of objects in AEM has the ability to simulate structural behavior through all stages of loading as well as evaluating seismic behavior of structures. This paper presents the advantages of AEM in comparison with FEM (Finite Element Method). It describes the theory, formulation and algorithm of the method for static and dynamic analysis of structures. The application of AEM is illustrated through the organization of two FORTRAN source codes: AEMST and AEMDN through static and dynamic analysis of frames. The validation results of the programs are also evaluated by some examples. Results show static analysis using AEMST has high accuracy of the program despite simplicity of AEM in theory and formulation. In addition, several selection criteria in order to select the appropriate size of elements and number of connecting springs are proposed for different situations. Besides, dynamic analysis was performed in AEMDN using Newmark-β method directly and WYD (Wilson, Yuan, and Dickens) Ritz vectors. Results show high accuracy of AEM and AEMDN for dynamic analysis. It also illustrated the lowest processing time needed for WYD Ritz vectors as well as its accuracy.

AEM을 이용한 철근콘크리트 모형 구조물의 붕괴 모델링

박훈(Hoon Park),석철기(Chul-Gi Suk),김승곤(Seung-Kon Kim) 한국암반공학회 2009 터널과지하공간 Vol.19 No.1

구조물의 비선형적인 대변위 붕괴거동을 해석하기 위해 다양한 수치 해석에 대한 연구가 진행되어 왔다. 본 연구에서는 새로운 수치해석 기법인 Applied Element Method (AEM)를 이용하여 철근 콘크리트 모형 구조물의 발파해체 붕괴거동을 모사하였다. 모형 구조물의 발파해체 붕괴거동과 수치해석으로 모사된 구조물의 붕괴거동을 X 방향(수평방향)의 변위와 Z 방향(수직방향)의 변위에 대해 비교한 결과, 수치해석에서 모사된 구조물의 붕괴거동은 실제 모형 구조물의 붕괴거동을 사실적으로 모사할 수 있음을 확인하였다. In order to analyze collapse behavior of structure containing irregular and large displacement, many numerical analyses have been conducted. In this study, using a new method, Applied Element Method (AEM) for collapse analysis of structures, collapse behavior of model RC structures is simulated. From these simulations results, displacement of X-direction (or horizontal) and displacement of Y-direction (or vertical) is similar to that of model RC structures. It is confirmed that collapse behavior of structures using AEM is reliable accurately simulated with that of model RC structures.

하중 재분배에 의한 RC 구조물의 연쇄붕괴 저항성능 평가

박훈,석철기 한국방재학회 2013 한국방재학회논문집 Vol.13 No.6

Progressive collapse indicates the partial or total collapse of structures caused by the local damage of structural members arisingfrom an abnormal load. To induce ideal collapse behavior, the progressive collapse is applied to most explosive demolitiondesign for structures. To apply this progressive collapse phenomenon to the explosive demolition of structures, studies on progressivecollapse resisting capacity depending on load redistribution are required. In this study, the progressive collapse analysis ofa 10-story RC frame structure was performed by the applied element method for various 1st column removal cases. For each case,the progressive collapse resisting capacity of columns, girder, and slabs was evaluated by the increase rates of the vertical internalforce in columns, the normal stress of reinforcing bars in girder, and the tensile stress of slab, respectively. 비정상하중에 의해 발생하는 구조부재의 국부손상이 구조물의 국부파괴 또는 전체파괴로 이어지는 연쇄붕괴는 이상적인 붕괴거동을 유도하기 위해 대부분의 구조물 발파해체 설계에 적용된다. 이러한 연쇄붕괴 현상을 구조물 발파해체에 적용하기 위해서는 하중의 재분배에 따른 연쇄붕괴 저항성능에 대한 연구가 요구된다. 본 연구에서는 응용요소법을 이용하여 10층 철근콘크리트 구조물의 연쇄붕괴 해석을 수행하였다. 구조부재인 기둥 요소의 제거 수와 제거 위치를 달라하여 하중의 재분배에 따른 기둥, 보, 슬래브에 대한 연쇄붕괴 저항성능을 평가하였다. 기둥의 수직내력 증가율은 하중의 재분배 경로수와 재분배 면적비에영향을 받으며, 거더 하부근과 슬래브의 인장응력이 현수작용을 증대시키고, 연쇄붕괴에 저항하고 있음을 알 수 있다.

회전 및 풍하중 가진 효과를 고려한 대형 풍력발전 로터의 효율적인 슈퍼요소 구조진동해석

김동만(Kim, Dong-Man),김동현(Kim, Dong-Hyun),박강균(Park, Kang-Kyun),김유성(Kim, Yu-Sung) 한국소음진동공학회 2009 한국소음진동공학회 논문집 Vol.19 No.7

In this study, computer applied engineering(CAE) techniques are fully used to efficiently conduct structural and dynamic analyses of a huge composite rotor blade using super-element. Computational fluid dynamics(CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade. Structural vibration analysis is conducted based on the non-linear finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results are presented for comparison and the structural dynamic behaviors of the rotor blade are investigated herein.

CAE 기법을 활용한 3㎿급 풍력발전기 로터의 구조 및 진동해석

박효근(Hyo-Geun Park),김요한(Yo-Han Kim),김동현(Dong-Hyun Kim),김동만(Dong-Man Kim),황병선(Byoung-Sung Hwang),박지상(Ji-Sang Park),정성훈(Sung-Hoon Jung) 한국유체기계학회 2007 유체기계 연구개발 발표회 논문집 Vol.- No.-

In this study, computer applied engineering (CAE) techniques are fully used to conduct structural and dynamic analyses of a huge composite rotor blade. Computational fluid dynamics is used to predict aerodynamic load of the rotating wind-turbine blade model. Static and dynamic structural analyses are conducted based on finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results for aerodynamic load, static stress, buckling and dynamic analyses are presented and characteristics of structural behaviors are investigated herein.

도시 물순환 회복을 위한 그린인프라 계획 및 설계에 관한 연구- 조경계획 및 설계 해외사례 분석을 중심으로

김승현,조경진 한국도시설계학회 2015 도시설계 : 한국도시설계학회지 Vol.16 No.3

This study draws technical elements, application areas, and design methods of green infrastructure for the restoration of urban hydrological cycle by analyzing 11 green infrastructure planning and design practices which are included urban wetland park, stormwater park, eco-stream, residential development, green buildings, and green streets. The result of the analysis is as follows. First, green infrastructure as a multi-dimensional system is comprised of various landscape elements such as rain gardens, stormwater planters, curb extensions, green roofs, constructed wetlands, bio-swales, permeable pavement, rain barrels and so on. These landscape elements can be applied to various land-use types such as buildings, rooftops, parking lots, walkways, roads, green spaces, and waterfronts. Secondly, green infrastructure as an ecological system can process stormwater runoff in natural ways. Green infrastructure utilize not only hard engineering technologies but also biological process which is comprised of evapotranspiration, retention, filtration, and infiltration. Thirdly, green infrastructure as an interconnected system can reduce more effectively stormwater runoff when green infrastructure elements are interconnected although each of them as an independent system can process stormwater runoff in natural ways. 본 연구는 도시의 건전한 물순환 회복을 위한 그린인프라에 관한 이론적 고찰을 토대로 해외의 그린인프라 계획 및 설계사례를 분석하여 그린인프라 기술요소, 적용지역, 계획ㆍ설계방법을도출하였다. 이를 위해 그린인프라 계획 및 설계 사례분석에 적합한 습지공원, 빗물공원, 생태하천, 주거단지, 녹색가로 등 11개의 프로젝트를 선정하여 분석하였다. 분석의 결과는 다음과 같다. 첫째, 다차원적 시스템으로서 그린인프라는 레인가든, 강우플랜터, 커브익스텐션, 옥상녹화, 인공습지, 식생수로, 투수성포장, 빗물저장시설 등의 다양한 조경요소들로 구성되어 있다. 이러한 조경요소들은 건물, 옥상, 주차장, 보행로, 도로, 녹지, 수변 등 다양한 토지이용에 적용될 수 있다. 둘째, 생태적 시스템으로서 그린인프라는 강우유출수를 자연적인 방식으로 처리할 수 있다. 그린인프라는 하드한 공학적 기술뿐만 아니라 증발산, 저류, 여과, 침투로 이루어진 소프트한 생물학적 과정을 적극적으로 활용한다. 셋째, 연결된 시스템으로서의 그리인프라는 강우유출수를효과적으로 저감시킬 수 있다. 그린인프라는 독립적인 시스템으로서 강우유출수를 자연적인 방식으로 처리할 수 있지만 그린인프라 요소들이 상호 연결되었을 때 더욱 효과적으로 작동한다.

응용 요소법을 이용한 초고층 건물의 축소 모델링 연쇄붕괴 해석

김한수(Han-Soo Kim),위해환(Hae-Hwan Wee) 한국콘크리트학회 2014 콘크리트학회논문집 Vol.26 No.5

AEM을 이용한 철근콘크리트 라이닝의 관입 방호성능 평가

주건욱 사단법인 한국터널지하공간학회 2019 한국터널지하공간학회논문집 Vol.21 No.3

Explosion after penetration of a warhead in an underground structure generally causes considerable displacement, breakage and extensive damage to the target. Therefore, in order to reduce the damage effect, it is required to design an underground structure protection against penetration. In this study, major factors for improvement of penetration protection performance of reinforced concrete underground structures using applied element method are divided into strength (concrete UCS) and density (concrete thickness, reinforcement layers, reinforcement diameters, reinforcement spacings). Based on these major factors, this study performed numerical analysis of simulation of dynamic response by penetrators under various conditions and analyzed the results. The results of this study are expected to be used as basis materials to improve penetration protection performance of reinforced concrete underground structures. 지하구조물의 내부에 탄두가 관입 후 폭발할 경우 일반적으로 목표물에 상당한 변위, 파손 및 광범위한 피해를 유발한다. 따라서 이러한 피해효과를 줄이기 위해서는 관입에 저항할 수 있는 지하구조물 방호 설계가 요구된다. 본 연구에서는 응용요소법을 이용한 철근콘크리트 지하구조물의 관입 방호성능 향상을 위한 주요 인자들을 크게 강도(콘크리트 압축강도) 및 밀도(콘크리트 두께, 철근의 피복 층수, 철근의 직경, 철근의 배근간격) 로 나누었다. 이를 바탕으로 다양한 조건에서 관통자에 의한 동적응답 시뮬레이션 전산 해석 연구를 수행하고 그 결과를 분석하였다. 본 연구 결과는 철근콘크리트 지하구조물의 관입 방호성능 향상을 위한 기초자료로 활용될 수 있을 것으로 기대된다.