scholarly journals Effects of Web Height Reduction and Skew Angle Variation on Behavior of RC Inverted T-Beams

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 451
Author(s):  
Bilal El-Ariss ◽  
Moustafa Mansour ◽  
Tamer El-Maaddawy
Keyword(s):  
Numerical Modeling ◽  
Structural Performance ◽  
Skew Angle ◽  
Angle Variation ◽  
Challenging Tasks ◽  
Negative Moment ◽  
T Beam ◽  
The Web ◽  
Installation Time ◽  
Nonlinear Numerical Model

The use of precast inverted T-beams has been frequently used to minimize construction activities and installation time. However, shipping and placement of large invert T-beams can become challenging tasks due to their weight. Decreasing the web height of the beam can be effective in reducing the beam weight. This paper considers inverted T-beams with two overhangs, negative moment regions, and one span, a positive moment region. The examined parameters were the web height and skew angle of the inverted T-beams. To avoid high costs of testing beams and to save time, the application of numerical modeling is, hence, inevitable. A calibrated 3D nonlinear numerical model, using ATENA software, was further used to numerically investigate the effects of reducing the weight, by decreasing the web height and varying the skew angle of inverted T-beams on their structural performance. The outcomes of this study indicated that reducing the web height of the beam was an effective tool to reduce the weight without jeopardizing the strength of the beams. Increasing the skew angle of the inverted T-beam also decreased their ductility.

Automated Detection of SQL Injection Attack on Blockchain-Based Database

2021 ◽  
pp. 321-341
Author(s):  
Keshav Sinha ◽  
Amit Kumar Keshari
Keyword(s):  
Network Analysis ◽  
Denial Of Service ◽  
Automated Detection ◽  
Distributed Environment ◽  
Sql Injection ◽  
Insider Attack ◽  
Challenging Tasks ◽  
Sql Injection Attack ◽  
The Web

In the era of computing, where the data are stored in a cloud or distributed environment, the privacy of data is one of the challenging tasks. The attacks like denial of service attacks (DoS), insider attack compromised the security of the system. In this chapter, the authors discussed a blockchain-based database, where data are encrypted and stored. The Web API is used as an interface for the storage and sharing of data in the blockchain system. There are several types of attacks that are performed by the adversary on the database to destroy the vulnerability of the system. Here, the authors are mainly focused on the SQL injection attack which is performed by the adversary on Web API. To cope with this problem, they present the case study based on the Snort and Moloch for automated detection of SQL attack, network analysis, and testing of the system.

Stress Monitoring for the Whole Construction Process of Simply Supported to Continuous T-Beam Bridge

2011 ◽  
Vol 71-78 ◽  
pp. 3954-3957
Author(s):  
Wu Yang ◽  
Wen Juan Yao ◽  
Xiao Yu Liu
Keyword(s):  
Theoretical Calculations ◽  
Continuous System ◽  
Stress Change ◽  
Construction Process ◽  
Stress Monitoring ◽  
Simply Supported ◽  
Stress Changes ◽  
Negative Moment ◽  
Beam Bridge ◽  
T Beam

In order to research on the stress change and influencing factor of whole construction process of simply supported to Continuous system T-beam bridge, combined with Guizhou Bai-long bridge, the stress change is carried out the real time inspection in each construction stage, and the finite element model is established to analyse Stress changes in whole construction process. The monitoring value is ​​more consistent with the theoretical value in each stage , monitoring dates and theoretical calculations showed that pre-stressed is the main factor of stress changes in construction process.Pre-stressed tension in negative moment region has obvious influence on the stress of middle span, the stress of top and bottom plates in wet joints will be equivalent after tendons tension in negative moment Region.

Effect of U-Bracket on the Structural Performance of Cold-Formed Steel Angle Connection

2012 ◽  
Vol 446-449 ◽  
pp. 180-185
Author(s):  
Ng Ling Ying Adeline ◽  
Mei Chee Chiang
Keyword(s):  
Experimental Investigation ◽  
Failure Mode ◽  
High Strength ◽  
Structural Performance ◽  
Biaxial Deformation ◽  
Steel Angle ◽  
Cold Formed Steel ◽  
Angle Connection ◽  
The Web

The paper presents an experimental investigation on the structural performance of high strength cold-formed steel angle connection stiffened with U-bracket. A total of 18 sets of specimens were tested using different U-bracket configurations. The parameters of the U-bracket studied were the width of the web and the length of the flanges. The behaviour of the connection under load was observed and the failure mode of the connection was identified. It was shown that biaxial deformation occurred in the U-bracket. It was also demonstrated that the capacity of the connection of angle and U-bracket was 4 times the capacity of plain angles. Results showed that it was more conservative to estimate the strength of the connection by taking the total elastic capacity of the sections. It was more effective to use U-bracket with a 40mm web and 15mm long flanges with the 50mm width angle connection.

Natural Convection Heat Transfer Enhancement in a Differentially Heated Parallelogrammic Enclosure Filled With Copper-Water Nanofluid

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Salam Hadi Hussain ◽  
Ahmed Kadhim Hussein
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Skew Angle ◽  
Angle Variation ◽  
Copper Water ◽  
Aspect Ratios ◽  
Wide Range ◽  
Volume Method ◽  
Skew Angles

Laminar natural convection of a nanofluid consists of water and copper in a differentially heated parallelogrammic enclosure has been studied numerically using the finite volume method (FVM). Governing equations are solved over a wide range of Rayleigh numbers (104 ≤ Ra ≤ 106), skew angles (−60 deg ≤ Φ ≤ +60 deg), aspect ratios (0.5 ≤ AR ≤ 4), and solid volume fractions (0 ≤ φ ≤ 0.2). Effects of all these parameters on flow and thermal fields are presented in form of streamline, isotherm contours and average Nusselt number. It is shown that the heat transfer rate increases remarkably by the addition of copper-water nanofluid and the shape of the convection vortices is sensitive to the skew angle variation.

scholarly journals Flexural Strengthening of RC Continuous T-Beams Using CFRP

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 41
Author(s):  
Ayssar Al-Khafaji ◽  
Hani Salim
Keyword(s):  
Beam Width ◽  
Experimental Investigations ◽  
Width Ratio ◽  
Flexural Strengthening ◽  
Cfrp Sheets ◽  
Modes Of Failure ◽  
Reinforced Polymer ◽  
Negative Moment ◽  
Ultimate Failure ◽  
T Beam

In this paper, experimental investigations for strengthening reinforced concrete (RC) continuous beams were performed. Eighteen T-beams were cast, twelve of which were inverted T-beams where the flange portion of the T-beam was subjected to positive flexure to represent the support region of a continuous beam. Six of the T-beams were non-inverted where the web is subjected to positive flexure. Carbon fiber reinforced polymer (CFRP) sheets with different widths were considered, and different strengthening configurations with the same area of CFRP were investigated. The use of one-layer, multiple layers, or multiple strips of CFRP were evaluated to investigate the effect of these configurations on the ultimate capacity and ductility of the strengthened beams. From the experimental observation of the non-inverted beams, it was found that the ultimate load capacities of the CFRP-strengthened beams were enhanced by 4% to 90% compared to the control beam. Using multiple layers of CFRP sheets enhanced the stiffness of the beams by 4% to 46%, depending on the CFRP area and configurations. The debonding of CFRP before the ultimate failure provided additional ductility to the tested beams. For the strengthening of the inverted beams, it was found that the addition of CFRP strips did not increase the strength of the beams when the width of CFRP to beam width ratio was less than 0.25, but the ductility of the beam was enhanced slightly. The use of multiple strips was found to be a more effective way for the strengthening of the negative moment region than using multiple layers. This can also provide more desirable modes of failure than when applying CFRP in multiple layers. Ductility was found to be lower if multiple layers were used compared to other configurations. Moreover, it was observed that as the compressive strength of concrete increased the addition of the CFRP improved the beams ductility.

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