Zahra Heidary

General Electric | GE · GE Capital

In this study, the influences of boundary reflections and piezoelectric sensors on the detection of propagating elastic waves emitted from newly formed damage surfaces are demonstrated using numerical and experimental models. The concepts of the displacement-based, time-domain equations of non-splitting perfectly matched layer (PML) and spectral fi...

This paper presents an efficient formulation of the problem of wave propagation along the length of axisymmetric pipes under non-axisymmetric loading such as leaks or new cracks so that wave characteristics in a pipe can be identified without the excessive computational time associated with most current 3D modeling techniques. The axisymmetric geom...

The influence of mechanical noise in an Acoustic Emission (AE) testing still obscures its successful application in monitoring various structures and systems. While advances in pattern recognition algorithms are helpful to differentiate relevant data from captured noise, the algorithms fail if the characteristics of relevant data are unknown. A bet...

Acoustic Emission (AE) has been studied as a nondestructive testing method for real time damage detection and location studies. The method relies on the propagation of the elastic waves due to the formation of new crack faces. While the method is capable of detecting damage initiation and location with an array of sensors, the variations in geometr...

The stable leak detection in gas pipelines using a continuous monitoring system can be used as an early diagnostic tool to prevent catastrophic failures. Acoustic Emission (AE) method has advantages among other Structural Health Monitoring systems through detecting leaks in real time with long range sensors as well as locating leak positions as mul...

Understanding the propagating elastic wave characteristics in materials is the foundation for quantitative Nondestructive Testing methods based on wave propagation such as guided wave ultrasonic and acoustic emission. The conventional finite element formulation requires very fine meshing and small time steps to prevent the dispersion pollution at h...

The influence of mechanical noise in an AE testing still obscures its successful application in monitoring various structures and systems. While advances in pattern recognition algorithms are helpful to differentiate relevant data from captured noise, the algorithms fail if the characteristics of relevant data are unknown. The ability to accurately...

Aluminum alloy 7075-T6 is a commonly used material in aircraft industry. A crack usually initiates at the edge of a fastener hole, and it can affect the maintenance schedule and reduce the life of an aircraft structure significantly. The fatigue property of the material has been researched widely to develop methods and models for predicting fatigue...