Factors Influencing Acousto-Ultrasonic Approach to Impact Damage in Composite Materials

Abstract

This paper studied factors influencing AU detection results on different damage specimens, including simulation frequency, transducer modes and transducer location. Correlation between acousto-ultrasonic parameters (AUP1, AUP2) and impact damage severity in composite was investigated. The results showed that as damage severity increased, AUP1 and AUP2 of three different transducers decreased. Applying low frequency transducer, the variation of AUP1 may indicate a more rapid detection prospect. In addition, applying S1-transducer and WD-transducer, AUP2 was more effective for the early damage detection. Varying transducer’s location, S1-transducer applying 500khz simulation frequency presented a valuable results.

Noncontact inspection of impact damage properties of woven fabric-reinforced composites after low-velocity impact by using air-coupled ultrasonic technique

“…Various nondestructive testing (NDT) modalities, such as X-ray CT, thermography, ultrasonic, acoustic emission, etc., have been used to detect and identify damage types in composites. Over the last 20-30 years, there has been significant work performed in experimental ultrasonic testing to detect and characterize damage modes in composites [4][5][6]. The noncontact air-coupled ultrasonic testing, which has been used to detect the damage in composite structures and also has been employed to inspect a sample with rough surfaces or those with very low or high temperature.…”

Damage detection and characterization of fiber-reinforced composites using ultrasonics

“…The fourth-rank stiffness tensor in Eq. 4.1 may be rewritten in terms of the stiffness matrix by using Voigt notation, where the indices (11,22,33,23,13,12) are written as (1,2,3,4,5,6). In order to simplify the analysis, we treat the 1-axis as an axis of symmetry, therefore the material is transversely isotropic.…”

“…Various nondestructive testing (NDT) modalities, such as X-ray CT, thermography, ultrasonics, acoustic emission, etc., have been used to detect and identify damage types in composites. Over the last 20-30 years, there has been significant work performed in experimental ultrasonic testing to detect and characterize damage modes in composites [1][2][3][4]. This thesis will consider the inspection of carbon/epoxy laminates containing various damage morphologies using non-contact ultrasonic testing techniques such as water-coupled immersion and air-coupled ultrasound.…”