繰り返し軸方向載荷を受ける部材の履歴挙動に関する閉解 : 第 2 部解析例

Abstract

Axially loaded members play an important role in such structures as trusses or braced frames. Clarification of the performance of these structures requires the knowledge of the load-deformation characteristics of the members. Plastic action in axially loaded members ordinarily takes precedence over flexurally loaded members because of the predominance in stiffness of the former over the latter. An axially resistant member in such structures is often subjected to variable repeated loading; loads due to winds, earthquakes, cranes, transportation vehicles and some machine parts are applied repeatedly in nature, and they may act in different or opposite directions. The member may buckle under compression, deform plastically, but may partially recover in a subsequent tension. It may undergo plastic elongation and as a result become loosened, reducing the overall stiffness of the structure. This series of investigations is concerned with the analytic behaviour of a prismatic elastic-plastic bar of an effective length subjected primarily to repeated axial loading, tension and/or compression. In the present paper, Part 2, solution is first exemplified, by making use of the basic equations derived in Part 1, for typical hysteretic behaviour in the range of small deformation. An example of finite plastic elongation is then presented to examine the effect of changes in bar dimensions, indicating a subsequent significant reduction in buckling strength. Further examples of analytic behaviour will be given in Part 3 for the investigation of characteristic features in the hysteretic behaviour of isolated members as well as braced frames.