Professor Alaa Ameer

Permanent URI for this collection

https://bspace.buid.ac.ae/handle/1234/2417

Professor Alaa A-Ameer is a Mechanical Engineer with extensive teaching and research experience in modelling, simulation, condition monitoring, and control systems. He was awarded the Degrees of Bachelors of Science (BSc) in Mechanical Engineering in 1979 and Master of Science (MSc) in Applied Mechanics (Tribology) in 1983, from the University of Technology, Baghdad-Iraq. He has worked in the automotive industry in Germany –Ulm, SCANIA – France and in the oil refinery industry in the Middle East. Following his appointment as an Assistant lecturer in Mechanical Engineering, at the University of Technical in Baghdad, he was appointed as a lecturer in Mechanical Engineering in the University of Technology in Baghdad in 1986. Since 1990, Professor Ameer worked in UK universities building a wide range of technical and research skills and liaising with numerous industries, professional and government bodies.

Browse

Now showing 1 - 4 of 4

Frequency Induced Hydraulic Fracturing
(2018) Abdul-Ameer, Alaa
Estimating the reliability of the inspection system employed for detecting defects in rail track using ultrasonic guided waves
(Springer, Cham, 2024) Khalil, Abdelgalil; Masurkar, Faeez; Abdul-Ameer, A.
This work focuses on the implementation of a data-based method to determine the inspection system reliability in terms of detecting different types of damages in rail track specimens using ultrasonic guided Rayleigh waves and a probability of detection (POD) technique. In this study, the reliability is tested against a surface crack (SC) and a sub-surface damage – a through side thickness hole (TSTH). The guided Rayleigh waves are generated using a custom-designed sensor that explicitly excited ultrasonic Rayleigh surface waves in the specimen and the propagating waves are sensed on the rail track surface. The wedge shape design of the sensor helps to excite a specific ultrasonic mode in the sample thereby hindering the ultrasonic energy of other coupled guided waves that can propagate simultaneously and the angle of the wedge is determined according to the Snell’s law relying on the wave velocity of Rayleigh wave and bulk longitudinal wave. The guided wave responses as a function of varying severity of defects are obtained through a simulation study after the verification of the obtained guided wave responses with the help of an experimental study. A damage index (DI) is defined depending on defect size that gives the trend of rising damage severity from the captured ultrasonic responses and for monitoring defects in the rail track specimens. This DI is eventually fed into the POD model to determine the probability of defect detection which in turn helps to determine the inspection system reliability. The POD method also helps to study the critical design parameters that could affect or improve the crack detection results.
HVAC multivariable system modelling and control
(2022) Touqan, Basim; Abdul-Ameer, Alaa; Salameh, Muna
Heating, Ventilation and Air Conditioning (HVAC) is a multivariable process where any alteration with one system input affects most or all of the system’s outputs simultaneously. Owing to its comprehensiveness, a readily derived multivariable HVAC mathematical model is selected for this work, mainly a hybrid distributed-lumped parameters model. As the transfer function matrix was not established in the selected HVAC model, it was exclusively developed in this study, using the time domain graphical responses of the chosen model. Based on the developed transfer function matrix, a conceptual two-step approach was followed to control HVAC model performance. The first was decoupling the interactions that affect all the system outputs, and the second was designing proper PID controllers for each decoupled loop similar to those used for single input single output (SISO) systems. A direct Nyquist Array (DNA) multivariable control strategy was used for this purpose and successfully decoupled the HVAC system into three separate (SISO) loops. Three PID controllers afterwards were applied for each decoupled loop. The results showed quite decoupled system outputs with a minor coupling percentage so that any change in a system input only affected the corresponding system output. The output responses are also underdamped with almost zero steady-state error confirming the effectiveness of the selected PID parameters. The values of steady-state responses are obtained in (10– 15) s compared with (200–600) s of open-loop response time. However, various overshoot percentages in the responses are encountered but are relatively small, with a short settling time, so they don’t affect the thermal comfort of the ventilated volume. System stability using the Nyquist criterion has also been examined and found to satisfy the criterion. The multivariable DNA control technique and the SISO closed-loop PID controllers have shown the capability to suppress external disturbances and restore the system to its original functional steady-state values.
Investigating different damages in a hybrid composite plate completely immersed in water using Ultrasonic waves
(2024) Masurkar, Faeez; Abdul-Ameer, Alaa; Cui, Fangsen
The present research investigates the ability of ultrasonic waves in detecting and localizing different types of damage in a hybrid metal-composite laminate fully immersed in water through the permanently attached piezoelectric (PZT) transducers (PZT). Based on the wave-structure analysis and dispersion diagrams obtained for the hybrid metal-composite laminate, a suitable wave excitation frequency is selected for conducting numerical simulations. Accordingly, a gaussian-windowed tone burst signal centered at 250 kHz is applied at the PZT to generate ultrasonic waves in the test specimen. It is found that Scholte wave mode is generated and propagates along the water-solid interface in addition to the anti symmetric guided wave modes. Further, mode conversion is observed during the wave mode-damage interaction. Comparing the pristine and damaged specimens, additional wave packets are seen to be propagating within the specimen that is revealed by analyzing the time-domain waveforms. This information can be further utilized in detecting as well as localizing the damage in the specimen. The location of damage found is well in harmony with the physical locations of damage. Thus, the proposed methodology is found to be capable of investigating the health status of immersed hybrid laminates non-destructively using ultrasonic waves with the help of simple and cost-effective PZT sensors.

Browse

Recent Submissions