Abstract
In this paper a computer program is developed for the determination of geometrical and material properties of composite thin-walled beams with arbitrary open cross-section and any arbitrary laminate stacking sequence. Theory of thin-walled composite beams is based on assumptions consistent with the Vlasov's beam theory and classical lamination theory. The program is written in Fortran 77. Some numerical examples are given, with complete information about input and output.
Key Words
thin-walled composite beam; open section; computer program; classical lamination theory; arbitrary lamination
Address
(1) A. Prokić and D. Lukić:
Faculty of Civil Engineering, University of Novi Sad, Kozaračka 2a, 24000 Subotica, Serbia;
(2) Ladjinović:
Faculty of Tehnical Sciences, University of Novi Sad, Trg Dositeja Obradovica, 21000 Novi Sad, Serbia.
Abstract
Based on the test on a 1/2.5-scaled model of a two-bay and three-story inner frame composed of reinforced concrete beams and lattice steel reinforced concrete (SRC) irregular section columns under low cyclic reversed loading, the failure process and the features of the frame were observed. The subsequence of plastic hinges of the structure, the load-displacement hysteresis loops and the skeleton curve, load bearing capacity, inter-story drift ratio, ductility, energy dissipation and stiffness degradation were analyzed. The results show that the lattice SRC inner frame is a typical strong column-weak beam structure. The hysteresis loops are spindle-shaped, and the stiffness degradation is insignificant. The elastic-plastic inter-story deformation capacity is high. Compared with the reinforced concrete frame with irregular section columns, the ductility and energy dissipation of the structure are better. The conclusions can be referred to for seismic design of this new kind of structure.
Key Words
lattice steel; steel reinforced concrete (SRC); inner frame with irregular section columns; quasi-static test; mechanical performance
Address
(1) Jianyang Xue, Liang Gao, Zuqiang Liu and Hongtie Zhao:
College of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, P.R. China;
(2) Zongping Chen:
College of Civil and Architectural Engineering, Guangxi University, Nanning, P.R. China.
Abstract
Experiments were carried out to investigate the ballistic performance of fiber reinforced plastic(FRP)-steel plates completely penetrated by hemispherical-nosed projectiles at sub-ordnance velocities greater than their ballistic limits. The FRP-steel plate consists of a front FRP laminate and a steel backing plate. Failure mechanisms and impact energy absorptions of FRP-steel plates were analyzed and compared with FRP laminates and single steel plates. The effects of relative thickness, manufacturing method and fabric type of front composite armors as well as the joining style between front composite armors and steel backing plates on the total perforation resistance of FRP-steel plates were explored. It is found that in the case of FRP-steel plates completely penetrated by hemispherical-nosed projectiles at low velocities, the failure modes of front composite armors are slightly changed while for steel backing plates, the dominate failure modes are greatly changed due to the influence of front composite armors. The relative thickness and fabric type of front composite armors as well as the joining style of FRP-steel plates have large effects whereas the manufacturing method of front composite armors has slight effect on the total perforation resistance of FRP-steel plates.
Abstract
In recent, development of construction and design technology gives taller, larger and heavier steel framed structures. With the tendency of increasing high-rise building, this study is strongly related to structural system, one of significant components in structural design. This study presents an innovative structural system, with high performance steel material, diagrid. Its detail, structural analysis, and structural experiments are all included for the development of new structures.
Key Words
high performance steel; Cyclone Tower; steel-framed diagrid; high-rise buildings; structural experiments
Address
(1) Dongkyu Lee:
Department of Architectural Engineering, Sejong University, Seoul, 143-747, Korea;
(2) Taehyu Ha, Miyoung Jung and Jinho Kim:
Building Structure & Materials Research Department, Steel Structure Research Division, Research Institute of Industrial Science and Technology, Incheon, 406-840, Korea.
Abstract
This paper presents numerical simulations of partially encased composite columns (PEC) with equivalent steel sections. The composite section of PEC column consists of thin walled welded H- shaped steel section with transverse links provided at regular intervals between the flanges. Concrete is poured in the space between the flanges and the web plate. Most of the structural analysis and design software do not handle such composite members due to highly nonlinear material behavior of concrete as well as due to the complex interfacial behaviour of steel and concrete. In this paper an attempt has been made to replace the steel concrete composite section by an equivalent steel section which can be easily incorporated in the design and analysis software. The methodology used for the formulation of the equivalent steel section is described briefly in the paper. Finite element analysis is conducted using the equivalent steel section of partially encased composite columns tested under concentric gravity loading. The reference test columns are obtained from the literature, encompassing a variety of geometric and material properties. The finite element simulations of the composite columns with equivalent steel sections are found to predict the experimental behaviour of partially encased composite columns with very good accuracy.
Key Words
composite; columns; equivalent; steel; partially; encased; finite; element
Address
Mahbuba Begum and Debaroti Ghosh:
Department of Civil Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh.
Abstract
The strength and buckling problem of a five layer sandwich beam under axial compression or bending is presented. Two faces of the beam are thin aluminium sheets and the core is made of aluminium foam. Between the faces and the core there are two thin binding glue layers. In the paper a mathematical model of the field of displacements, which includes a share effect and a bending moment, is presented. The system of partial differential equations of equilibrium for the five layer sandwich beam is derived on the basis of the principle of stationary total potential energy. The equations are analytically solved and the critical load is obtained. For comparison reasons a finite element model of the beam is formulated. For the case of bended beam the static analysis has been performed to obtain the stress distribution across the height of the beam. For the axially compressed beam the buckling analysis was carried out to determine the buckling load and buckling shape. Moreover, experimental investigations are carried out for two beams. The comparison of the results obtained in the analytical and numerical (FEM) analysis is shown in graphs and figures. The main aim of the paper is to present an analytical model of the five layer beam and to compare the results of the theoretical, numerical and experimental analyses.
Key Words
sandwich structure; buckling; metal foam; mathematical model
Address
Krzysztof Magnucki, Pawel Jasion, Waclaw Szyc and Mikolaj Jan Smyczynski:
Institute of Applied Mechanics, Poznan University of Technology, ul. Jana Pawła II 24, PL 60-965 Poznan, Poland.
