抄録
A new composite fabric has been developed for a balloon envelope possessing both excellent strength and gas barrier as well as low density, and perforation behavior under impact load is presently focused. The perforation test was experimentally conducted to clarify the effect of loading rate on the fracture behavior, together with the tensile test to evaluate the strain rate effect on the strength of the present material. Rate dependence of the stress strain relation of the material was clearly identified; the strength is significantly increased while the strain at fracture is decreased with a rise of strain rate. This fact well explains the experimental results where perforation strength is almost independent of loading rate, but the behavior is much more brittle due to localized deformation around perforated region at impact loading. It is also found that delamination of inter-laminar fibers in the composite fabric is able to relieve stress concentration and will be served to prevent a brittle fracturing independent of loading rate.
