When pull plate (i.e. flange of beam)-plate thickness is 22mm. or 28mm.-welded into wide flange section member (i. e. Column)-its flange thickness is 40mm., 50mm., or 60mm. and web thickness 25mm., 50mm., or 40mm.-by Simplified Electroslag Welding using cored wire or manual arc welding and bended the latter by pulling the former (see, Fig.-1), brittle fracture was occurred in wide flange section member at and above its full plastic load at room temperature (see, photo.5). In this case, the ratio of the maximum deflection to the elastic limit deflection is 1.5〜8.8 (see, Table 7). Also brittle fracture of wide flange section member was occurred at room temperature in Case of X-type tests (see, Fig.-2). This phenomenon of heavy steel section is very important in design of structure of multi-storey buildings, and so these results are reported in detail in this paper with the results of supplemental tests and material tests (see, Table 1 and Fig.-3〜Fig.-7), and are analyzed qualitatively.
