PMMA における破面模様の定量と一次き裂伝ぱによる変化

概要

論文の詳細を見る
Dimensions of fracture surface marks of mostly one end opened marks (like parabolas) observed in a central notched sheet material of polymethyl methacrylate (abbreviated as PMMA) fractured in tension are measured using optical microphotographs. Those dimensions are an interference appearing distance (e-value) and a minimum chordal length at the secondary nucleus (l-value) of a mark. The e and l values increase as the primary crack propagates. The number of marks and heir density in a unit area increase as the primary crack propagates. The both end closed marks (like ellipses) and one end opened marks observed in PMMA are analytically expressed by the equation of marks using the e and l values and other necessary constants. The critical distance d--value, that is, the distance of the primary crack activating the secondary crack nucleus, is also calculated from the measured e-value by the equation of marks and the other constants. The variation of dynamic stress intensity factor K_D and the dynamic strain energy release-rate D_D due to the primary propagation are calculated. The experimental variation of e and d-values are shown to be supposedly controlled by these K_D and D_D values.
一般社団法人日本機械学会の論文
1987-09-25