Abstract
In this study, the effect of presence and distribution of masonry infill walls on the mid-rise steel frame structures having soft ground storey was evaluated by implementing finite element (FE) methods. Masonry infill walls were distributed randomly in the upper storey keeping the ground storey open without any infill walls, thus generating the worst case scenario for seismic events. It was observed from the analysis that there was an increase in the seismic design forces, moments and base shear in presence of randomly distributed masonry infill walls which underlines that these design values need to be amplified when designing a mid-rise soft ground storey steel frame with randomly distributed masonry infill. In addition, it was found that the overstrength related force modification factor increased and the ductility related force modification factor decreased with the increase in the amount of masonry infilled bays and panels. These must be accounted for in the design of mid-rise steel frames. Based on the FE analysis results on two mid-rise steel frames, design equations were proposed for determining the over strength and the ductility related force modification factors. However, it was recommended that these equations to be generalized for other steel frame structure systems based on an extensive analysis.
Address
Shahriar Quayyum, M. Shahria Alam, Ahmad Rteil: School of Engineering-Okanagan, The University of British Columbia, 3333 University Way, Kelowna, BC V1V 1V7, Canada
Abstract
In recent years there has been increasing international interest about designing structures thatcost less to repair after they have been subjected to strong earthquakes. Considering this interest, aninnovative repairable fuse device has been developed for dissipative beam-to-column connections inmoment-resisting composite steel and concrete frames. The seismic performance of the device was assessedthrough an extensive experimental program comprising ten cyclic and two monotonic tests. These tests wereconducted on a single beam-to-column specimen with different fuse devices for each test. The devicesvaried in terms of the chosen geometric and mechanical parameters. The tests showed that the devices wereable to concentrate plasticity and to dissipate large amounts of energy through non-linear behavior.Numerical models were developed with Abaqus and simplified design models are also proposed.
Key Words
welded fuse device; reparability; cyclic tests; hysteretic behavior; plate buckling; energy dissipation; numerical models; design models
Address
1 Luis Calado, Jorge M. Proenca, Miguel Espinha: Department of Civil Engineering and Architecture, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal; 2 Carlo A. Castiglioni: Structural Engineering Department, Politecnico di Milano, Piazza L. da Vinci, 32 - 20133 Milan, Italy
Abstract
This paper focuses on the buckling capacity of a hybrid grid shell. The eigenvalue buckling, geometrical non-linear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. Then the influences of the shape and scale of imperfections on the elasto-plastic buckling loads were discussed. Also, the effects of different structural parameters, such as the rise-to-span ratio, beam section, area and pre-stress of cables and boundary conditions, on the failure load were investigated. Based on the comparison between elastic and elasto-plastic buckling loads, the effect of material non-linearity on the stability of the hybrid barrel vault is found significant. Furthermore, the stability of a hybrid barrel vault is sensitive to the anti-symmetrical distribution of loads. It is also shown that the structures are highly imperfection sensitive which can greatly reduce their failure loads. The results also show that the support conditions pose significant effect on the elasto-plastic buckling load of a perfect hybrid structure.
Key Words
stability; non-linear; hybrid structure; cable; elasto-plastic; failure load
Address
1 Jianguo Cai, Ya Zhou, Jian Feng: Key Laboratory of C & PC Structures of Ministry of Education, National Prestress Engineering Research Center, Southeast University, Si Pai Lou 2#, Nanjing 210096, China; 2 Yixiang Xu: Department of Civil Engineering, Strathclyde University, 16 Richmond Street, Glasgow G1 1XQ, Scotland, United Kingdom
Abstract
There are few technical documents regulated structural performance and engineering criteria in domestic market for Structural insulated panels in Korea. This paper was focused to identify fundamental performance under monotonic loading and cyclic loading for SIPs in shear wall application. Load-displacement responses of total twelve test specimens were recorded based on shear stiffness, strength, ultimate load and displacement. Finally energy dissipation of each specimen was analyzed respectively. Monotonic test results showed that ultimate load was 44.3 kN, allowable shear load was 6.1 kN/m, shear stiffness was 1.2 MN/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens: single panel and double panels. Cyclic loading results, which were equivalent to monotonic loading results, showed that ultimate load was 45.4 kN, allowable shear load was 6.3 kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. Based on results of structural performance test, it was recommended that the allowable shear load for panels should be 6.1 kN/m at least.
Address
1 Hwan-Seon Nah, Hyeon-Ju Lee: Smart Energy Lab., Korea Electric Power Corporation Research Institute, 65 Munji-ro Yusung-gu, Daejon 305-380, Korea; 2 Sung-Mo Choi: Architectural Engineering Department, University of Seoul, 163 Siripdae-ro, Dongdaemun-gu, Seoul 130-743 Korea
Abstract
This paper provides an innovative iteration technique for the large deflection problem of annular plate. After some manipulation, the problem is reduced to a couple of ODEs (ordinary differential equation). Among them, one is derived from the plane stress problem for plate, and other is derived from the bending of plate. Since the large deflection for plate is assumed in the problem, the relevant non-linear terms appear in the resulting ODEs. The pseudo-linearization procedure is suggested to solve the problem and the nonlinear ODEs can be solved in the way for the solution of linear ODE. To obtain the final solution, it is necessary to use the iteration. Several numerical examples are provided. In the study, the assumed value for non-dimensional loading is larger than those in the available references.
Key Words
large deflection bending; pseudo-linearization of ODE; nonlinear analysis; iteration technique; annular plate
Address
Y.Z. Chen: Division of Engineering Mechanics, Jiangsu University, Zhenjiang, Jiangsu, 212013, P.R. China
Abstract
Response modification factor is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake, in conformity with the point that many seismic design codes led to reduce the loads. In the present paper it\'s tried to evaluate the response modification factors of dual moment resistant frame with buckling restrained braced (BRB). Since, the response modification factor depends on ductility and overstrength; the nonlinear static analysis, nonlinear dynamic analysis and linear dynamic analysis have been done on building models including multi-floors and different brace configurations (chevron V, invert V, diagonal and X bracing). The response modification factor for each of the BRBF dual systems has been determined separately, and the tentative value of 10.47 has been suggested for allowable stress design method. It is also included that the ductility, overstrength and response modification factors for all of the models were decreased when the height of the building was increased.
Key Words R-factor; ductility and overstrength factors; dual moment resistant frame with BRB
Address
Gholamreza Abdollahzadeh, Mohammadreza Banihashemi: Faculty of Civil Engineering, Babol University of Technology, Babol, Iran