States of Stress and Strain in Adhesive Joints, Including Photoelastic Imaging of Defects in Adherends
Abstract
Water migration across the thin epoxy resin layer in model adhesive joints causes strongly inhomogeneous swelling. The swelling is the principal cause of stress systems which are being examined by analysis of the pattern of Newton's rings formed between a glass cover slip and an optical flat. Enhancement of water migration by normal stresses fracture mechanics test piece, designed to investigate water uptake by adhesives, is reported. Photoelastic imaging of ultrasonic waves can be utilized to investigate defects in opaque solids. Instead of using a piezoelectric detector, the reflected sound from a defect is actually observed in a visualizing block of quartz, after propagating from the specimen to the block across an acoustic coupling. Experiments and a computer model are described.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1979
- Accession Number
- ADA079515
Entities
People
- J. P. Sargent
- K. H. Ashbee
- T. W. Turner
Organizations
- University of Bristol