A New End Tab Design for Off-Axis Tension Test of Composite Materials
Abstract
In high temperature environments, testing methods must be very simple. For fiber composites, the material principal axes can be varied with respect to the loading direction to produce different states of stress in reference to the material axes. Thus, using off-axis composite specimens, a number of mechanical properties can be determined using simple tension tests on off-axis specimens. The main difficulty in using off-axis tension specimens lies in the presence of shear-extension coupling when the specimen is mounted on rigid grips in material testing machines. In order to resolve this problem, we designed a new end tab for the off-axis composite specimens. The new end tab was fabricated using a fiberglass knit in a silicone rubber matrix, and was used in the off-axis tension tests on unidirectional composites. It was shown experimentally that this new tab allowed shear deformation of the specimen to occur in the hydraulic grips and, thus, produced a uniform state of strain in the specimen. Consequently, the shear modulus could be determined accurately using this new tab. Furthermore, due to the absence of stress concentrations, this procedure could also be used to determine shear strength.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1987
- Accession Number
- ADA199310
Entities
People
- C. T. Sun
- S. P. Berreth