Standard Guide for Acousto-Ultrasonic Assessment of Composites, Laminates, and Bonded Joints

Importancia y uso:

5.1 General—Conventional ultrasonics should be considered first for the detection of overt flaws such as delaminations in composites. Thereafter, AU should be considered for composites that are proved to be free of major flaws or discontinuities. The AU method is intended almost exclusively for assessing the collective effects of dispersed defects and subcritical flaw populations. These are material aberrations that influence AU measurements and also underlie mechanical property variations, dynamic load response, and impact and fracture resistance.

5.2 Specific Advantages—The AU method can be used to evaluate composite laminate and bond quality using access to only one surface as, for example, the exterior surface of pressure vessels. It is unnecessary to utilize angle beam fixtures because the method can always be applied with probes at normal incidence. The method can be applied using dry coupling with elastomer pads attached to the probes, and there is no need to immerse the examination object in water.

5.3 General Applications—The AU method was devised to assess diffuse discontinuity populations and any associated changes of the mechanical properties of composites and composite-like materials. The AU method has been used to evaluate fiber-reinforced composites (6), composite laminates (7), filament-wound pressure vessels (8), adhesive bonds (9), paper and wood products (10), and cable and rope (11). The method has been shown to be particularly practical for assessing the strength of adhesively bonded joints. It has also been shown to be useful for assessing microporosity (12), micro-cracking (13), hydrothermal aging (14), and damage produced by impacts (15) and fatigue (16).

Subcomité:

E07.04

Referida por:

C1332-18R23

Volúmen:

03.03

Número ICS:

19.100 (Non-destructive testing), 83.180 (Adhesives)

Palabras clave:

acoustic emission; acousto-ultrasonics; bonded joints; composites; laminates; materials characterization; mechanical properties assessment; nondestructive evaluation; nondestructive testing; stress wave factor; ultrasonic attenuation ;