Current Issue : January - March Volume : 2013 Issue Number : 1 Articles : 4 Articles
This paper presents the structural behavior of composite concrete slabs with CRIL DECKSPANTM (Colour Roof India\r\nLimited (CRIL), Mumbai, INDIA) type profiled steel decking by experimental and analytical studies. The slab is\r\ncreated by composite interaction between the concrete and steel deck with embossments to improve their shear\r\nbond characteristics. However, it fails under longitudinal shear bond due to the complicated phenomenon of shear\r\nbehavior. Therefore, an experimental full-size tests has been carried out to investigate the shear bond strength\r\nunder bending test in accordance to Eurocode 4 - Part 1.1. Eighteen specimens are split into six sets of three\r\nspecimens each in which all sets are tested for different shear span lengths under static and cyclic loadings on\r\nsimply supported slabs. The longitudinal shear bond strength between the concrete and steel deck is evaluated\r\nanalytically using m-k and partial shear connection (PSC) methods and compared the values. The experimental\r\nresults is verified and compared with the results of both m-k and PSC methods. Comparison of experimental and\r\nanalytical results of the load-carrying capacity of composite slabs revealed that agreements between these values\r\nare sufficiently good. As a result, m-k method proved to be more conservative than PSC method....
The research investigated the development of a wind tunnel model compared with results of method of\r\ninitial parameters and BS6399 models for dynamic analysis of a multi-storey building subjected to\r\naerodynamic loadings. The dimensional analysis which based its concept on the law of motion and\r\nenergy conservation was used as wind tunnel experimental data assessment tool, for the determination\r\nof the aerodynamic loadings for a multi-storey building. Although, this problem was earlier solved\r\nusing dimensional analysis with different approaches by many Scholars but such solutions did not\r\ninclude an important quantity; the influence of the structureâ��s deflection (d) and foundation infinitesimal\r\nrotation. The study observed that, the non-stationary component is also dependent of the stationary\r\ncomponent of the aero-dynamic force. It also explained how the product of the Strouhal number (St)\r\nand model relative displacement (Lo number), is equal to the Bernoulli universal constant, 0.5. Tests on\r\nmost important parameters capable of influencing the assessment and design of multi-storey buildings\r\nwith varying height-breadth ratio, basic wind speeds, relative displacement and aspect ratio increased\r\nwith logarithmic laws as a function of model height; but the reduced frequency, Etha (???? and Landa (????\r\ndecreased with polynomial and power laws respectively. It was therefore concluded that, aero-elastic\r\ndamping property of the structure is influenced by the Lo number and in particular, ?. Finally, the\r\ncumulative base moment from the mathematical (method of initial parameters) model is 2.108% higher\r\nthan the physical model result and the results from the BS6399 model was less by 1.732%. In general, a\r\ndifference varying between �±2.1% is within acceptable level of deviation for most conventional\r\nengineering and scientific design results....
Completion and development of reliable analytical models using finite element method could help\r\ninvestigation and prediction of the actual structure response results. Analysis of each model in finite\r\nelement software need meshing that computer results are dependent specific to geometry and\r\ndimensions of the elements, calling mesh dependence. Finding a strategy for independency of results\r\nto meshing is tangible. For the mentioned purpose and also to investigate the role of finite elements\r\nmeshing in flanged shear walls, finite element software was used. Different meshing of shear walls\r\nwhich tested by Vecchio and Palermo analyzed and studied. Finally, and after calibration, optimum\r\nforms and dimensions recommended. As an illustration, an idea presented, which indicates by using\r\nthat, flanged shear wall could be analyzed more carefully in ultimate strength and ductility. The results\r\nof this analysis showed that the results of squared mesh are closer to the fact. For example, this type of\r\nmeshing 6% error in ultimate strength and ductility in accordance to lab Specimen, presented the closer\r\nresponses. Furthermore, investigation on the optimum size of the mesh showed that if the mesh has\r\nthe same size of the thickness of the connecting element (Shear Wall Web), the results will have very\r\nhigh accuracy. For example, squared meshes with same dimension of meshes equal to web thickness,\r\nrather than those with half dimension of that led to 1% of lateral resistance, which is closer to\r\nexperimental test....
The Iranian Guideline for Seismic Rehabilitation of Existing Buildings (GSREB) is currently used for\r\nvulnerability assessment of existing buildings in Iran. In this paper, this guideline is used to assess the\r\ncase study of concrete building. The lateral resisting system of this building contains the steel bracing\r\nframes and shear wall. So the lateral seismic system of this building is dowel system. The gravitational\r\nsystem of this building is steel frames, so connection of shear walls to main frames is very important.\r\nThe connectivity is provided by shear key on column and beams. In this vulnerability assessment, the\r\nlinear dynamic procedure was used and the results, in terms of usage ratio, defined as the ratio of the\r\nstrength demand to the corresponding capacity, are evaluated. Numerical results show that all bracing\r\nand some shear walls of this building do not satisfy the immediate occupancy performance criteria in\r\nthe hazard level 1. Therefore this building is required to be rehabilitated....
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