抄録
In plastic design, the method of superposition are not helpful for the analysis under the superposed load. Therefore, the structure should be treated generally as the three dimensional frames on the occasion of elasto-plastic analysis. And it is also important to understand the characteristic of the three dimensional elasto-plastic behaviour. The purpose of this study is to clarify the characteristic of the three dimensional elasto-plastic behaviour on steel rigid frames. In this paper, the small scale tests were undertaken to investigate the characteristic behaviour different from that of planar frames and to get the data to establish the simple method of three dimesional elasto-plastic analysis. Test specimens were two stories-one bay rigid space frames constructed with H-section members and were tested under horizontally loading combined with axial load. From these experimental results, the followings were clarified, (1) The displacement v_1/h, v_2/h at ultimate horizontal load were 0.015〜0.030 and it's greater than that of planar frames. (2) In case of planar frames, the stability limit does not exist under the axial load less than 0.3 P_y, but tests' results indicated that the stability limit exists under the axial load less than 0.3 P_y in the three dimensional behaviour. (3) The three dimensional analysis by plastic hinge method does not often give the adequate estimation for the load-deformation relationships, especially after ultimate horizontal load. (4) The influence of warping restrained is increased by increasing the slenderness ratio and axial load of the columns.
