The effects of temperature and moisture on the dynamic moduli of thick S2-glass composite beams were investigated. Unlike most of the previous studies in which elevated temperatures are concerned, the present investigation concentrates on the influence of low temperature on composite materials. By supporting the sample in a free-free configuration and subjecting it to impacts, its natural frequencies can be measured. Samples having different moisture contents at different temperatures were then tested to disclose the frequency dependence on the environmental conditions. Based on the measured frequencies, an inverse calculation scheme was then used to characterize the longitudinal Young's modulus and the transverse shear modulus of the sample. The moduli thus found are insensitive to the measurement errors rendering the technique a possible supplement for conventional static tests. Eventually, incorporation of the aforementioned frequency data into the inverse calculation scheme yields valuable information regarding the hygrothermal effects on the dynamic moduli of composite materials.

Date Published: 20 March 1997
PDF: 6 pages
Proc. SPIE 2921, International Conference on Experimental Mechanics: Advances and Applications, (20 March 1997); doi: 10.1117/12.269798

Published in SPIE Proceedings Vol. 2921:
International Conference on Experimental Mechanics: Advances and Applications
Fook Siong Chau; C. T. Lim, Editor(s)