Journal of Computational Engineering and Physical ModelingJournal of Computational Engineering and Physical Modeling
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Feed provided by Journal of Computational Engineering and Physical Modeling. Click to visit.Determining the Drift in Reinforced Concrete Building using ANFIS Soft Computing Modeling
http://www.jcepm.com/article_53677_6612.html
Earthquakes are considered as one of the most significant natural disasters that can potentially cause significant damages to structures. Displacement of buildings’ floors is one of the serious failures in structures caused by earthquakes. In this paper, the drift of a concrete frame with the shear wall is estimated using ANFIS modeling. A dataset of 300 measured data points was used herein as the inputs for the ANFIS model. The dataset has totally six input parameters including frequency, magnitude, peak ground acceleration (PGA), and shear wave velocity (Vs) of an earthquake and the distance from the earthquake epicenter to use in the ANFIS model, while the model has just one output. Moreover, a sensitivity analysis was performed on the dataset in order to determine the efficiency of the individual input variables on the accuracy of the results. The results demonstrate that the ANFIS model is an effective model for predicting the drift in reinforced concrete structures. Finally, according to sensitivity analysis, the acceleration and shear wave velocity of an earthquake have the highest and lowers impacts on the accuracy of the results, respectively.Sun, 31 Dec 2017 20:30:00 +0100Numerical Simulation of Concrete Mix Structure and Detection of its Elastic Stiffness
http://www.jcepm.com/article_54011_6612.html
Concrete mix stiffness (CM) primarily relies on its ingredients, which mainly consists of stone aggregate and mortar. To analyse the role of the components of CM on its properties a numerical simulation of CM structure is conducted. Within the scope of this study, the structure and the properties of CM are simulated using ANSYS code to apply the finite element method (FEM). The size of aggregate is modelled using direct random nodes and elements and the problem is approximated as two-dimensional plane one. Different ratios of aggregate and mortar were considered to determine their influence on the stiffness of CM. The CM is treated as bi-composite and subjected to compressive loading. For determining the influence of the proportion of stone aggregate on the stiffness of CM, the used specimens only differ in the amount of stone aggregate and their shapes. Although the stone aggregates are assumed to be of cylindrical shapes (plane conditions), the compressive stiffness of CM works well with the mixture rule.Sun, 31 Dec 2017 20:30:00 +0100RELIABILITY-BASED INVESTIGATION ON COMPRESSIVE STRENGTH CHARACTERISTICS OF STRUCTURAL-SIZED ...
http://www.jcepm.com/article_54890_6612.html
This research work examined the reliability of the Nigerian grown Iroko and Mahogany timber species as column materials. The strength and physical properties of these timber species were determined to predict the suitability of the species as structural material. Forty lengths of timber species of 50mm x 50mm cross-section were purchased from timber market in Ilorin, Nigeria. The prevailing environmental conditions during the test were 31oC and 64% relative humidity. The properties tested included; air dry density, moisture content and compressive strength parallel to grain of forty test specimens each of lengths, 200, 400, 600 and 800mm done in accordance with the British Standard BS 373(1957). Mean air-dried moisture content for Iroko and Mahogany were 12.09 and 14.81% respectively. Mean density of Iroko and Mahogany were 500.8 and 830.1kg/m3 respectively. The derived continuous equations for design of Iroko column and Mahogany column are σ=ć37.552eć^(-0.005λ) and σ=ć37.125eć^(-0.007λ) respectively. The results of the reliability analysis show that Iroko and Mahogany timber species have reliability index of 0.64 and 0.65 for a service life of 50 years, assuming other serviceability conditions are met. This design procedure is distinct and more effective than the usual procedure of classifying compression members as short, intermediate and long using their slenderness ratios.Thu, 04 Jan 2018 20:30:00 +0100Seismic Fragility assessment of Local and Global failures in Low-rise non-ductile Existing RC ...
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The brittle behavior of older non-ductile reinforced concrete buildings such as shear-axial failure in columns can cause lateral instability or gravity collapse. Hence, investigating seismic fragility assessment of such building will be useful from loss estimation and rehabilitation viewpoint. Current research focuses on fragility assessment of these building emphasizing on shear-axial failure using two well-established methods; empirical limit state material versus ASCE/SEI 41-13 suggestion. To this aim, two 2D reinforced concrete models (3 and 5-story) according to typical detail of existing buildings in Iran were modeled using two aforementioned modeling approaches and analyzed under monotonic analysis and incremental dynamic analysis (IDA). In the following, seismic fragility assessment were carried out by means of obtained results from IDA. The results of fragility curves showed that, collapse capacity of buildings modelled by ASCE/SEI 41-13 are more than empirical method and fewer cases can pass the level of safety probability of failure suggested by ASCE/SEI-41.Sun, 31 Dec 2017 20:30:00 +0100The effect of diagonal stiffeners on the behaviour of stiffened steel plate shear wall
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In the current study, the nonlinear behavior of the stiffened steel plate shear wall with diagonal stiffeners is numerically studied. After nonlinear pushover analysis, the finite element modeling results are compared with un-stiffened and stiffened steel plate shear walls, with the horizontal and vertical stiffeners. First, a finite element model of steel plate shear wall is developed and validated by using Abaqus software. After assuring the behavior of the boundary elements (beams and columns) and the infill steel plate, the finite element models of the steel shear walls are developed and analyzed using nonlinear pushover method. Steel plate shear wall models are designed according to AISC 341-10 Seismic Provisions. Finally, the obtained results and the behavior of finite element models are compared with each other. The important seismic parameters (initial elastic stiffness, ultimate shear strength, and ductility) are calculated and percentage of changes are discussed. Based on the results, the performance of steel plate shear walls with diagonal stiffeners enhances as compared with unstiffened steel plate shear walls.Sun, 31 Dec 2017 20:30:00 +0100