Location

La Jolla, CA

Start Date

1-1-1993 12:00 AM

Description

There have been many applications of adhesively bonded structures in the aerospace industry and a need for nondestructive evaluation of bond strength is evident. Standard strength measurement of a lap joint requires loading until the weakest link fails. That weak link may be an adhesive interface failure, as shown by the fracture surface of an AF-191 specimen (Fig. 1), or a cohesive failure of the adhesive layer itself, as shown in the delamination of a two layer FM-300 adhesive containing carrier cloth (Fig. 2). In recent years there were several attempts to use ultrasonic measurements (e.g., velocity, attenuation, or reflection coefficients) to evaluate bond strength. The weak link that affects strength, however, may not significantly affect these linear parameters.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

12B

Chapter

Chapter 7: Nonlinearity, Deformation and Fracture

Section

Nonlinear Effects

Pages

2113-2120

DOI

10.1007/978-1-4615-2848-7_269

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Strength Assessment in Adhesive Bonds Using Nonlinear Ultrasonic Measurements

La Jolla, CA

There have been many applications of adhesively bonded structures in the aerospace industry and a need for nondestructive evaluation of bond strength is evident. Standard strength measurement of a lap joint requires loading until the weakest link fails. That weak link may be an adhesive interface failure, as shown by the fracture surface of an AF-191 specimen (Fig. 1), or a cohesive failure of the adhesive layer itself, as shown in the delamination of a two layer FM-300 adhesive containing carrier cloth (Fig. 2). In recent years there were several attempts to use ultrasonic measurements (e.g., velocity, attenuation, or reflection coefficients) to evaluate bond strength. The weak link that affects strength, however, may not significantly affect these linear parameters.