抄録
The purpose of this experiment is to clarify the distribution and the magnitude of strain in the section of column flange of beam-to-column connection, when beam flange is subjected to monotonic and cyclic plastic strain. Specimens were designed so as to represent the welded joints which consist of column flange, beam flange and horizontal stiffener, and they were manufactured by saw cutting from the rolled steel plates to imitate the shape of the welded joints. In experiment the constant and variable axial loads were applied on column flange, and the two-dimensional strain distribution were measured by Moire method. The following conclusions were obtained. (1) The yield loads in the thru-thickness direction of column flange increase with the reinforcement of weld of the joints, but are not proportional to the cross-sectional area of welded part. The effects of bi-axial stress in column flange on the yield loads can be explained by Von Mises yielding criterion. (2) The strain in the section of column flange except in the region near by toe of weld have the largest value at the point of the midthickness of column flange after the considerable plastic strain are observed in column flange. (3) When cyclic plastic strain is applied to beam flange with constant amplitude, the maximum value of the strain at the point of the midthickness of column flange can be predicted from the equivalent strain under monotonically increased load.
