scholarly journals Investigation of ANN Architecture for Predicting Load-Carrying Capacity of Castellated Steel Beams

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Thuy-Anh Nguyen ◽  
Hai-Bang Ly ◽  
Van Quan Tran

Castellated steel beams (CSB) are an attractive option for the steel construction industry thanks to outstanding advantages, such as the ability to exceed large span, lightweight, and allowing flexible arrangement of the technical pipes through beams. In addition, the complex localized and global failures characterizing these structural members have led researchers to focus on the development of efficient design guidelines. This paper aims to propose an artificial neural network (ANN) model with optimal architecture to predict the load-carrying capacity of CSB with a scheme of the simple beam bearing load located at the center of the beam. The ANN model is built with 9 input variables, which are essential parameters equivalent to the geometrical properties and mechanical properties of the material, such as the overall depth of the castellated beam, the vertical projection of the inclined side of the opening, the web thickness, the flange width, the flange thickness, the width of web post at middepth, the horizontal projection of inclined side of the opening, the minimum web yield stress, and the minimum flange yield stress. The output variable is the load-carrying capacity of the CSB. With the optimal ANN architecture [9-1-1] containing one hidden layer, the performance of the ANN model is evaluated based on statistical criteria such as R2, RMSE, and MAE. The results show that the optimal ANN model is a highly effective predictor of the load-carrying capacity of the CSB with the best value of R2 = 0.989, RMSE = 3.328, and MAE = 2.620 for the testing part. The ANN model seems to be the best algorithm of machine learning for predicting the CSB load-carrying capacity.

2017 ◽  
Vol 79 (5) ◽  
Author(s):  
Nahushananda Chakravarthy ◽  
Sivakumar Naganathan ◽  
Jonathan Tan Hsien Aun ◽  
Sreedhar Kalavagunta ◽  
Kamal Nasharuddin Mustapha ◽  
...  

Cold formed steel differ from hot rolled steel by its lesser thickness and weight. The cold formed steel applicable in roof purlin, pipe racks and wall panels etc. Due its lesser wall thickness the cold formed steel member subjected to buckling. The enhancement of load carrying capacity of the cold formed steel member can be achieved by external strengthening of CFRP. In this study cold formed channel members connected back to back to form I shaped cross section using screws. These built up beam members were 300mm, 400mm and 500mm in length with 100mm screw spacing and edge distance of 50mm were chosen for testing. CFRP fabric cut according to length, width of built up beams and wrapped outer surface of beam using epoxy resin. Experiments were carried out in two sets firstly plain built up beams and secondly CFRP wrapped beams. The test results shows that increased load carrying capacity and reduction in deflection due to CFRP strengthening. Experimental results were compared with AISI standards which are in good agreement. Experimental results shows that CFRP strengthening is economic and reliable.


2018 ◽  
Vol 21 (16) ◽  
pp. 2534-2552 ◽  
Author(s):  
Pinelopi Kyvelou ◽  
Chi Hui ◽  
Leroy Gardner ◽  
David A Nethercot

Cold-formed steel purlin systems with overlapped or sleeved connections are alternatives to continuous two-span systems and exhibit different degrees of continuity. Both connection types are highly favourable in practice since they are both strategically placed over an interior support to provide additional moment resistance and rotational capacity where the corresponding demands are at their largest, thus improving the overall structural efficiency. Until recently, full-scale testing has been the most common way of investigating the structural behaviour of such systems. In this study, numerical modelling, capable of capturing the complex contact interactions and instability phenomena, is employed. The developed finite element models are first validated against data from physical tests on cold-formed steel beams featuring sleeved and overlapped connections that have been previously reported in the literature. Following their validation, the models are employed for parametric studies, based on which the structural behaviour of the examined systems is explored, while the applicability of conventional plastic design as well as of a previously proposed design approach is investigated. Finally, the efficiency of these systems in terms of load-carrying capacity is compared with their equivalent continuous two-span systems.


2019 ◽  
Vol 279 ◽  
pp. 02004
Author(s):  
Sergey Kudryavtsev

The paper presents a study of the transverse bending behaviour of corrugated web beam with and without web openings. Examined steel beams consist of two flanges and a thin triangularly corrugated web, connected by automatic welding. In the literature, the influence of web opening over transverse load carrying capacity was dealt with mostly for steel beams with plane, sinusoidal and trapezoidal corrugated webs, so researches of beams with triangularly corrugated webs were found out to be very limited. A parametric study is carried out for various web slenderness and corrugation densities. A general-purpose finite element analysis software ABAQUS was used. The corrugation densities adopted in this study represent practical geometries, which are commonly used for such structures in building practice. Models with and without web openings were analysed and examined in terms of load-deformation characteristics and ultimate web shear resistance. Recommendations are given for the practical design of corrugated web beams weakened by circular openings.


1991 ◽  
Vol 113 (4) ◽  
pp. 306-311 ◽  
Author(s):  
P. Goltermann

Short cylindrical shells are often used in offshore structures. Such cylinders are loaded by axial compression as well as hydrostatical pressure. The load-carrying capacity is for practical purposes determined for each of the two load cases separately. The determination of the load-carrying capacity for a combined loading is then based on a combination of those two load-carrying capacities. This combination differs from code to code and has a significant influence on the load-carrying capacity. This paper presents a rational way of estimating the capacity by using simple, well-known theories. The elastic, critical stress (fe) of a perfect cylinder is estimated according to the classic shell theory for the two load cases, and the respective knock-down factors (α) are calculated according to a code or according to Koiter’s classic stability theory. This leads to an estimate of the ratio between actual stress and the elastic, critical stress (fe·α) of the imperfect cylinder in the two load cases. The membrane stresses and the bending stresses due to the oval imperfection of the cylinder are calculated according to the plate theory, in which the stiffness is reduced corresponding to those ratios. The capacity is defined as the load level at which a point yields according to von Mises’ yield condition. The method is easily applicable for practical purposes and has the advantage that it estimates the capacity at the actual geometry, yield stress, imperfection level and load combination, and thus enables a better estimation. The paper shows that the interaction curves depend severely on the geometry, the level of imperfection, and the size of the yield stress.


2020 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
In-Rak Choi ◽  
Chang-Soo Kim

To investigate the behavior of various steel anchors, push-out tests were performed for 13 test specimens. Test parameters included the geometry of beams (wide-flange beams and composite beams) and the type of steel anchors (stud anchors and Z- and C-channel anchors with full- or partial-length welding). Test results showed that the performance of test specimens strongly depends on the types of steel anchors rather than the geometry of steel beams. The specimens with C-channel anchors showed the highest load-carrying capacity but the most drastic load reduction after the peak load. The specimens with Z-channel anchors showed a similar behavior to those with C-channel anchors but the load reduction occurred at a slightly slower rate. The load-carrying capacity was increased with the length of the Z- and C-channel anchors. The specimens with stud anchors reached the peak load at a slow rate and showed the most ductile behavior. The test results were compared with predictions by various design equations for steel anchors available in the literature, and the existing design equations for channel anchors with partial-length welding were considered applicable to design.


2007 ◽  
Vol 12 (3) ◽  
pp. 371-382 ◽  
Author(s):  
Z. Kala

The modern unification of the European standards EUROCODE requires securing a constant quality of metallurgical production in the EU countries. In this paper, experimentally found statistical characteristics of yield stress, ultimate tensile strength and ductility of Czech and Austrian steel are presented. In the probabilistic reliability analysis, the experimentally found yield stress histograms of structural steel S235 of both Czech and Austrian manufacturing processes are considered as basic parameters. The reliability of steel members designed according to EUROCODE 3 is investigated. The objective of the studies is the verification of partial safety factors of load-carrying capacity, and of load action given in the standard EN1990. Differences in failure probabilities of steel members of Czech and Austrian production are studied in connection with the influence of model fuzzy uncertainties in the determination of load action and load-carrying capacity values.


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