Ultrasonic Characterization of the Fiber‐Matrix Interfacial Bond in Aerospace Composites

Abstract

The properties of advanced composites rely on the quality of the fiber-matrix bonding. Service-induced damage results in deterioration of bonding quality, seriously compromising the load-bearing capacity of the structure. While traditional methods to assess bonding are destructive, herein a nondestructive methodology based on shear wave reflection is numerically investigated. Reflection relies on the bonding quality and results in discernable changes in the received waveform. The key element is the “interphase” model material with varying stiffness. The study is an example of how computational methods enhance the understanding of delicate features concerning the nondestructive evaluation of materials used in advanced structures.

Development of a Tomography Technique for Assessment of the Material Condition of Concrete Using Optimized Elastic Wave Parameters

“…The wave speed of simulation can be determined by parameters such as material density$\mathrm{normalp},$ the first and second lame constants, $\mathsf{\lambda }$ and μ. The longitudinal wave speed, V L in the medium is given by [23]: ${\mathrm{V}}_{\mathrm{L}}=\sqrt{\frac{\mathrm{sans-serif\lambda }+2\mathrm{sans-serif\mu }}{\mathrm{p}}}$…”

Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

“…The Impact Echo method, ultrasonic pulse velocity (UPV) method, infrared thermography, and acoustic emission (AE) technique are some of the popular NDT methods capable of detecting and evaluating structural deficiencies [ 3 – 5 ]. AE technique involving wave analysis has been widely used in the field of civil and mechanical engineering for structural health monitoring (SHM) [ 6 – 13 ]. One distinct advantage of using AE technique compared to other NDT techniques is that the position of developing crack in the measured structure can be determined, in addition to its nature of implementation, where no interference to the structure under service is instigated.…”