繊維直交方向荷重を受けるカラマツ集成材ボルト接合部の脆性破壊に対するローカルクライテリアの通用

概要

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In this paper we studied the brittle fracture of bolt connection with Japanese larch glulam loaded perpendicular to the grain by based on local fracture approach. First we thirled two types bolt holes with a drill press and studied the conditions around the hole. Then we checked that there were cracks around the hole. The length of that cracks differ acceding to the bolt diameter. Next we conducted tension tests of glulam, tension tests with double notched glulum and tension tests with bolt joint specimens. As results, we understood that there were two fracture types in bolt joint specimen. We checked brittle fracture in the specimens which end distance was small and ductile fracture in the specimens which end distance was large. We studied the fracture in the first case with the claevage fracture stress. We studied the boltjoints strength with FEM analysis. In that analysis model, we replaced the crack around the bolt hole into the equivalent crack. As results, we can predicted the single bolt joint strength with reference to the edge distance, those joints fail in a brittle manner.
2007-01-30