SEDL / STP / STP1227-EB / STP12915S

Predicting Performance of Adhesively Bonded Joints Based on Acousto-Ultrasonic Evaluation

Karhnak, SJ


Duke, JC
Graduate research assistant and professor, Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA

Pages: 8    Published: Jan 1994

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Abstract

Prediction of the performance of adhesively bonded joints is essential to the acceptance of this mode of fastening. In situations where the bonding is uniform throughout the joint the stress distribution depends primarily on the joint geometry. A knowledge of the bond properties and the stress distribution and magnitude can be used to determine failure initiation, subsequent load redistribution, changes in stress, additional regions of failure, and ultimately when the bonded joint will separate. However, in many actual situations the bonding is not uniform throughout the joint, and even the properties of the adhesive may vary. This paper describes work that addresses this situation. Acoustic microscopy has been used to provide a detailed image of the bonded joint, while acousto-ultrasonic measurements have been used to evaluate the stress transfer capability of modified lap shear adhesively bonded joints. The adhesively bonded composite material specimens were mechanically tested and performance correlated with NDE results.