Research Title: Compression behavior of confined concrete masonry boundary elements

Author: Ala Taleb Obaidat, Published Year: 2017

Engineering Structures Journal, Elsevier, 132, 562–575

Faculty: Engineering and Technology

Abstract: The seismic performance of reinforced masonry (RM) walls can be enhanced by integrating confined boundary elements at the end zones of the wall. The evaluation of the compression behavior of the boundary elements is essential to the reliable assessment of displacement ductility and the seismic performance of the walls. Complementary to the experimental evaluation of the compression behavior, finite element numerical simulations are particularly useful in assessing the influence and sensitivity of various design parameters. In this study, experimental and numerical investigations are conducted to evaluate the compression stress-strain behavior of confined C-shaped reinforced concrete masonry block boundary elements (C-RMBEs). Compression tests are conducted on 16 full-scale confined C-RMBEs with different configurations of confinement reinforcement. A finite element modeling (FEM) procedure using the ABAQUS software is employed to simulate the compression behavior of a C-RMBE. The FEM procedure is validated with experimental results on a full-scale confined C-RMBE. Comparative compression stress-strain curves and damage progression are presented and discussed. The study shows the significance of the confinement reinforcement in the improvement of the compression strain capacity of the C-RMBE. Moreover, the proposed FEM procedure provides a good approximation of the compression stress-strain behavior in the elastic and inelastic regions and captures the influence of the confinement reinforcement ratio on the compression response of the C-RMBE.

Keywords: Reinforced concrete masonry walls Boundary elements Confinement Finite element ABAQUS Stress-strain Damage plasticity

Research Title: Stress-strain behavior of C-shaped confined concrete masonry boundary elements of RM shear walls

Author: Ala Taleb Obaidat, Published Year: 2018

ASCE Structural Engineering Journal, 144(8): 04018119

Faculty: Engineering and Technology

Abstract: Reliable material stress-strain relationship is the cornerstone of any analysis process. Unlike reinforced concrete, limited studies focused on the stress-strain behavior of confined reinforced masonry. Reinforced masonry boundary elements (RMBEs) added at the masonry shear wall ends allow placing of at least four longitudinal reinforcement bars restrained by transverse hoops and thus introducing confinement to the wall’s most stressed zone. This study presents the observed stress-strain relationship of 30 C-shaped half-scale fully grouted unreinforced and reinforced masonry boundary element specimens tested under concentric compression loading. The effect of changing hoop spacing, longitudinal reinforcement ratio, and the strength of grout on the axial stress-strain behavior of RMBE is investigated. This study quantifies and correlates the effect of these parameters on the RMBE peak stress, strain corresponding to peak, and postpeak behavior. Finally, this study investigates the capability of three existing stress-strain models in predicting the RMBE stress-strain relationship. Enhancement in both peak and postpeak stress-strain behavior were observed by decreasing the hoop spacing, increasing the longitudinal reinforcement ratio, and increasing the grout strength. The studied models overestimated the enhancement in the RMBE strength, significantly overestimated the enhancement in the RMBE strain capacity, and did not capture the postpeak stress drop. This study emphasizes the need for a new stress-strain model that can predict the RMBE response considering various confinement effects.

Keywords: RMBE

Research Title: Stress-strain model for C-shape confined concrete masonry boundary elements of RM shear walls

Author: Ala Taleb Obaidat, Published Year: 2018

Engineering Structures Journal, Elsevier, Volume 183, 1059-107

Faculty: Engineering and Technology

Abstract: Reinforced masonry (RM) shear walls with boundary elements have been recently presented as a more ductile alternative to RM rectangular shear walls. Evaluating the complete (i.e. including the post-peak branch) compression stress-strain behavior of the confined and unconfined masonry is essential for predicting the seismic response of the RM walls with boundary elements. Recently, the authors investigated the effect of various volumetric ratios of transverse reinforcement, vertical reinforcement ratios, and grout strength on the axial stress-strain behavior of reinforced masonry boundary elements (RMBEs). However, all the specimens had a specific height to thickness ratio (i.e., AR = 5). This study presents the observed stress-strain relationship of seventeen half-scale fully grouted unreinforced and RMBE specimens, built using C-shape blocks, tested under concentric compression loading up to failure. Thus, quantifying the effect of various aspect (height to thickness) and confinement ratios on the RMBEs peak stress, strain corresponding to peak, and post-peak behavior. The results indicate that, as the hoop spacings and/or aspect ratio decreases, the peak stress and post-peak strains increase. Moreover, this study presents a stress-strain empirical model capable of predicting the RMBE stress-strain response by computing the confined and unconfined masonry stress-strain behavior. The model is calibrated using the experimental data of thirty-three RMBE specimens, tested in this study and literature. The proposed model presents an efficient tool that can be implemented in different analytical/numerical packages.

Keywords: Aspect ratio Boundary elements Concrete block Confinement Shear walls C-shape Reinforced masonry Stress-strain behavior Stress-strain masonry model

Research Title: Strengthening and repair of one-way and two-way self-compacted concrete slabs using near-surface-mounted carbon-fiber-reinforced polymers

Author: Ala Taleb Obaidat, Published Year: 2019

Advances in Structural Engineering, , First Published 17

Faculty: Engineering and Technology

Abstract: The effectiveness of near-surface-mounted carbon-fiber-reinforced polymers on strengthening and repair of self-compacted concrete slabs was investigated experimentally and numerically. Twenty slabs were cast (10 one-way and 10 two-way) and tested under four-point load. Strengthening and repair effectiveness was investigated on slabs using near-surface-mounted carbon-fiber-reinforced polymer strips with straight and inclined orientation. Repair was performed on eight slabs using near-surface-mounted carbon-fiber-reinforced polymer strips with an orientation based on the best cost/capacity ratio, with two preloading levels: 35% and 50% of the ultimate load of the control slab. The results showed that using near-surface-mounted carbon-fiber-reinforced polymers increases the ultimate strength of one-way strengthened self-compacted concrete slabs (45%–163%) for both strip orientation, with the straight orientation performing better. Also, the cracking load and stiffness increased, while deflection decreased. The increase in ultimate strength for strengthened two-way slabs was 15% to 17%. The ultimate deflection and toughness of the two-way strengthened slabs increased 43% and 34%, respectively. Using near-surface-mounted carbon-fiber-reinforced polymers restored the load capacity of repaired one-way and two-way slabs but was more effective for one-way slabs. The repaired one-way slabs regained up to 223% of the control slabs’ ultimate strength, with a significant increase in stiffness (296%). The repaired two-way slabs regained up to 116% of the control slabs’ ultimate strength. The strength was higher in the case of the 50% preload compared to 35% preload. The finite element model shows somehow a reasonable capability of predicting the experimental behavior with a gap in terms of the stiffness and the maximum load.

Keywords: near-surface-mounted carbon-fiber-reinforced polymers, one-way slabs, self-compacted concrete, strengthening and repair, two-way slabs

Research Title: Wheelchair Neuro Fuzzy Control Using Brain Computer Interface

Author: Kasim Mousa Al-Aubidy, Published Year: 2019

IEEE DeSe2019, Kazan, Russia

Faculty: Engineering and Technology

Abstract: The design and implementation of a real-time computer control of an electric wheelchair for physically disabled people is presented. This design is based on brain computer interface that receives and processes the electroencephalographic (EEG) signals to classify the required commands to drive the wheelchair. Neuro-Fuzzy technique has been used in the controller design for actuating motors of the wheelchair. This controller depends on real data received from obstacle avoidance sensors and brain computer interface. By combining the concepts of soft-computing and mechatronics, the implemented wheelchair has become more sophisticated and gives people more mobility.

Keywords: Wheelchair Control, EEG, BCI, Real-time Control, ANFIS, Mechatronics.

Research Title: Real-Time Patient Health Monitoring and Alarming Using Wireless-Sensor-Network

Author: Kasim Mousa Al-Aubidy, Published Year: 2016

13th IEEE International Multi-Conference on Signals, Systems & Devices (SSD2016) ., Leipzig, Germany

Faculty: Engineering and Technology

Abstract: The main objective of this research is design and realization of real-time monitoring and alarming system for patient health, especially for patients suffering from diseases during their normal life. The proposed system has an embedded microcontroller connected to a set of medical sensors (related to the patient case) and a wireless communication module (Bluetooth). Each patient is considered as a node in a wireless sensor network and connected to a central node installed at the medical center through an internet connection. The embedded microcontroller checks if the patient health status is going well or not by analyzing the scanned medical signals. If the analysis results are abnormal, the embedded unit uses the patient's phone to transmit these signals directly to the medical center. In this case, the doctor will send medical advice to the patient to save his/her life. The implemented prototype has been tested and calibrated with standard devices. The experimental results confirm the effectiveness of the proposed system that is accurate in scanning, clear in monitoring, intelligent in decision making, reliable in communication, and cheap (about 120 US$).

Keywords: Health care; Patient monitor; Remote device; Biomedical device; ECG monitoring; Outdoor patient monitoring.

Research Title: Multi-Robot Task Scheduling and Routing Using Neuro-Fuzzy Control

Author: Kasim Mousa Al-Aubidy, Published Year: 2015

12th IEEE International Multi-Conference on Signals, Systems & Devices (SSD2015), Mahdia-Tunisia

Faculty: Engineering and Technology

Abstract: Multi-robot systems have been widely used in intelligent environments such as modern flexible manufacturing systems. Task planning is the most important issue to specify how to use mobile robots and other resource efficiently. It is not an easy task to achieve effective cooperation between these robots in such a dynamic environment. An efficient scheduling methodology together with intelligent real-time control is necessary for a multi-robot system. This paper presents the analysis of a real-time fuzzy-based task scheduler and routing to deal with an intelligent framework has four programmable CNC machine, three mobile robots and other recourses. A neurofuzzy controller has been used to guide the mobile robot from the source point to its destination with real-time obstacle avoidance. The simulated results and real experiments on group of three mobile robots show that the multi-robot system can deal with the proposed scheduling methodology to achieve the required operation.

Keywords: neurofuzzy control; multi-robot system; task allocation and scheduling; mobile robot; obstacle avoidance.

Research Title: Real-Time Monitoring and Intelligent Control for Greenhouses Based on Wireless Sensor Network

Author: Kasim Mousa Al-Aubidy, Published Year: 2014

11th IEEE Intr. Multi-Conf. on Systems, Signals, Devices (SSD14), Barcelona, Spain.

Faculty: Engineering and Technology

Abstract: The main objective of this research is to design and implement a real-time monitoring and control of several environmental parameters for group of greenhouses. Each greenhouse is considered as a node in a wireless sensor network. A single-board microcontroller-based system has been designed and implemented to monitor and control several variables and maintain desired condition in each greenhouse. A rule-based fuzzy controller has been designed to control the microclimate of each greenhouse. The proposed system enables the farmer to monitor both the internal environment of the greenhouse. Also, the farmer can send commands to turn ON or OFF certain devices in a selected greenhouse through wireless communications. Simulated and real results have been achieved to demonstrate the system performance and real-time remote monitoring and control activities.

Keywords: Greenhouse automation, Remote monitoring and control, Fuzzy control, Intelligent control, Wireless sensor network.

Research Title: GPRS-Based Remote Sensing and Teleoperation of a Mobile Robot

Author: Kasim Mousa Al-Aubidy, Published Year: 2013

10th IEEE International Multi-Conference on Systems, Signals, Devices (SSD13), Tunisia

Faculty: Engineering and Technology

Abstract: The main objective of this research was to design and implement a remote sensing and monitoring system running on mobile robot with obstacle avoidance capability in unreachable area. A simple mobile robot prototype with onboard sensors has been designed and implemented to scan and monitor several variables in the surrounding environment. Teleoperation of such a mobile robot is a challenging task that requires an efficient interface and a reliable real-time robot control to avoid obstacles. The proposed system enables the user (base station) to send commands to the remote station (mobile robot), and receive scanned data and images from the environment through the internet and mobile DTMF signal. The proposed system hardware and software was implemented using PROTUS development software to obtain the suitable design parameters. Then, real experiments have been achieved to demonstrate the system performance including both the ultrasonic teleoperation of mobile robot navigation to avoid obstacles, and real-time sensing and monitoring in unreachable area.

Keywords: Mobile Robot, Robot navigation, Remote sensing and monitoring, Wireless sensor networks, Obstacles avoidance.

Research Title: Dual-Robot Navigation System for Real-Time Sensing and Monitoring

Author: Kasim Mousa Al-Aubidy, Published Year: 2014

The 15th International Workshop on Research and Education in Mechatronics (REM2014), ElGouna-Egypt

Faculty: Engineering and Technology

Abstract: The main objective of this research is to design and realize a multi-robot system for real-time sensing and monitoring suitable for hazardous and/or unreachable environment. The proposed system has two mobile robots; rover and eye. Each mobile robot has its own embedded microcontroller and set of sensors. Wireless communications between local site and these mobile robots are achieved by WiFi, ZigBee and Bluetooth techniques, and can be accessed through the internet. Wireless teleoperation of these mobile robots is a challenging task that requires an efficient interface and a reliable real-time control algorithm to avoid obstacles. The proposed system enables the authorized operator to send commands to the mobile robots, and receive scanned data and images from the environment through the internet. The mechanical part of the remote station has been built after careful selection of the design parameters using CAD/CAM tools. While, the system hardware and software parts of the embedded controllers were implemented using PROTEUS development tool to obtain the suitable design parameters. Then, real experiments have been achieved to demonstrate the system performance including the wireless teleoperation of the two mobile robots, their navigation to avoid obstacles, and real-time sensing and monitoring.

Keywords: Mobile robot, Multi-robot system, Remote sensing and monitoring, Wireless sensor networks, Obstacles avoidance.