気球用プラスチックフィルムの低温強度評価

概要

論文の詳細を見る
Low-temperature strength is investigated for polyethylene film used for the observation balloons. Tension tests using danbel-type specimens and crack growth tests using the edge-cracked specimens have been conducted in the temperature range from 20℃ to -40℃. The stress-strain curves show little anisotropy, and the yield stress increases as temperature decreases. The maximum load of edge-cracked specimens with the same initial crack length also increases as temperature drops, while elongation at fracture decreases after taking its maximum at 0℃. The crack-tip opening angle at steady-state propagation is a constant independent of the initial crack length and is considered to be a material constant. This value decreases as temperature decreases, and the crack tip becomes sharp at low temperatures. The net section stress at steady-state propagation is also constant under the present experimental conditions. The relationship between the J-integral and crack extension exhibits two straight lines and the value of the J-integral increases as temperature decreases.
社団法人日本機械学会の論文
1991-02-25