Ahmed Almadany - Academia.edu (original) (raw)

Papers by Ahmed Almadany

النجف, May 19, 2014

Notation : As :cross sectional area for steel bar Asw: cross sectional area for wire mesh. fc: co... more Notation : As :cross sectional area for steel bar Asw: cross sectional area for wire mesh. fc: concrete compressive strength fcf : fibrous concrete compressive strength fy: yield strength of bar reinforcement fyw: yield strength of wire mesh reinforcement diameter of bar L/D :(aspect ratio) length of fiber divided by the diameter of it USD :American dollar vf: fiber volume fraction (volume of fiber in the mortar mix with respect to the volume of total mix).

Kufa journal of Engineering, 2010

Transplantation Proceedings, 2017

2ND INTERNATIONAL CONFERENCE ON MATERIALS ENGINEERING & SCIENCE (IConMEAS 2019)

IOP Conference Series: Materials Science and Engineering, 2019

This paper investigates the change in the natural frequency of whole building due to the increase... more This paper investigates the change in the natural frequency of whole building due to the increase or decrease of the number of floors of a steel building model. Five steel building models were adopted in the present study to investigate the natural frequency required to be identified in each model. The first model represents a one floor building model, the second building model contains two floors and so on. The first four models were subjected to further masses distributed upon four points within the last floor. Each model consists of the same structural details that are proposed in the other models such as details of the beams, columns and slabs. The herein parameters are the number of floors and the further added masses upon the models up to four floors. All models were analyzed using ANSYS software to identify the natural frequencies for the extracted modes of vibration about X, Y, and Z building axes. The study is aimed to produce a relationship between the change of floors number and the further mass addition in the field of structural frequency attenuation based on the indication of the first identified mode. Results show that higher masses required to be added to attenuate value of natural frequency for the one floor building model than the further masses required for building with two floors to achieve the same purpose. This relationship continues for the other models with higher number of floors but with less further required masses.

IOP Conference Series: Materials Science and Engineering

In this study the Vierendeel bridge structural model is adopted as a complex structure case study... more In this study the Vierendeel bridge structural model is adopted as a complex structure case study scaled from a real structure located near Čačak city in Serbia. Experimental analysis is conducted under simulation of ambient vibration using shaker device for exciting the model. Frequency Domain Decomposition (FDD) technique is applied using ARTeMIS software extractor to extract the modal properties, natural frequencies and mode shapes. As a comparative study, Enhanced Frequency Domain Decomposition (EFDD) is used to verify the extracted results from FDD. A finite element model is created in ANSYS software to simulate the adopted model to estimate modal properties numerically. Calibration process is implemented to converge the numerically estimated with the experimentally extracted modal properties. Two procedures written in MATLAB environment, for calibration and damage identification, are proposed using heuristics optimization, Simulated Annealing (SA) and Tabu Search (TS). Both of proposed calibration procedures exhibit high accuracy and efficiency due to good convergence between experimentally extracted and numerically updated values of natural frequencies extracted based on ambient vibration measurements.

IOP Conference Series: Materials Science and Engineering, 2018

KSCE Journal of Civil Engineering

Frequently, construction requirements demand to provide service pipelines passing laterally withi... more Frequently, construction requirements demand to provide service pipelines passing laterally within slab thickness near the slab-column connections of flat slabs. The flat slabs including such conducted pipelines are expected to undergo a significant reduction in the punching shear capacity. For this purpose, experimental program was conducted in this study incorporating 10 specimens of reinforced concrete flat slab. One slab specimen was solid slab with no pipeline as a reference specimen and the other nine slab specimens were fabricated with either single or double pipelines passing through the slab thickness at different locations. Test results indicated that including pipelines within the slab thickness at a horizontal distance equal to or less than one-half of the slab thickness from the face of the column led to a substantial reduction in the ultimate load and the stiffness of the flat slabs. It was also found that the structural performance of a flat slab with double small pipelines horizontally aligned near tension face was more desirable than that of a flat slab with a single large pipeline. Furthermore, a modification is suggested to be introduced to the punching shear equation of Eurocode 2 to include the effect of the embedded pipelines in flat slabs.

Tehnicki vjesnik - Technical Gazette

The procedure for detecting the location and severity of damage of complex structural systems usi... more The procedure for detecting the location and severity of damage of complex structural systems using their modal properties is an important tool of Structural Health Monitoring (SHM) of civil infrastructure. The herein presented research proposes procedures for damage detection based on two heuristic optimization methods: Simulated Annealing (SA) and Tabu Search (TS). In order to test the proposed procedures in different frequency ranges, experimental and numerical analyses were conducted on a steel grid bridge model in two configurations, according to the total mass of the structure, as well as for two simulated damage cases. The calibration of model parameters, according to experimentally extracted modal properties, is carried out using the proposed procedures. Numerical computations were conducted using ANSYS package and developed routines under MATLAB environment for model calibration and damage detection procedures. Experimental modal properties were extracted from ambient vibration measurements, as state-of-the art in SHM of complex structures, by the Frequency Domain Decomposition (FDD) technique, using ARTeMIS software. Both of the proposed procedures for model calibration and damage detection, with adopted objective functions including frequency and mode shape differences, exhibit accuracy, efficiency and robustness.