Abstract
In former papers it was reported that brittle fracture in plastic range at room temperature took place in the full scale tests of wide flange column-to-beam connections of which the thickness of column flanges were from 40mm. to 60mm. In this papers, some qualitative analysis is made on this problem. According to this analysis, brittle crack creates when the local stress of the connection reaches the fracture stress of the material, but the stress which brittle crack propagates is a decreasing function of the members. As for the test specimens in question, the scale of the members can be considered to be large enough to satisfy the condition of crack propagation soon after the brittle crack has been created.
