水平スチフナにより補剛されたウェブの座屈性状および水平スチフナの設計法

DOI Web Site Web Site 参考文献4件 オープンアクセス

書誌事項

タイトル別名
  • BUCKLING BEHAVIOR OF WEB STIFFENED BY LONGITUDINAL STIFFENERS AND DESIGN METHOD FOR LONGITUDINAL STIFFENERS
  • スイヘイ スチフナ ニ ヨリ ホ ツヨサレタ ウェブ ノ ザクッセイジョウ オヨビ スイヘイ スチフナ ノ セッケイホウ

この論文をさがす

抄録

<p> The purpose of this study is to establish a design method for installing stiffeners on the web. Installing stiffeners on the web as a reinforcement is one of the effective methods to prevent the local buckling of the beam members and to increase the buckling strength. Current design methods for the stiffeners, however, do not reflect its torsional rigidity. Also, the current design methods are established based on the simple assumption (e.g., pure compression, pure bending, or pure shear). In reality, the stress distribution is more complicated because the combined stress acts on the web installed the stiffeners. Therefore, it is necessary to take these effects into account to maximize the stiffening effects.</p><p> In this study, based on the energy method, the effect of installing stiffeners is investigated employing the rigidity ratios of the stiffeners to the web. The subject of this study is the web which is two stiffeners are placed equally on one side for comparison with analytical results with one stiffener. From calculation results, the stiffener size effect on the increase rate of local buckling strength has been confirmed. Also, an evaluation formula for the optimum rigidity ratio γ*, the width-to-thickness ratio for the web to ensure the full plastic moment Mp, and the elastic local buckling strength of the web installed the stiffeners have been established. Finally, a required width-to-thickness ratio that satisfies these conditions has been derived.</p><p> The following findings have been obtained.</p><p> 1) The main factor that determines the elastic buckling strength of the web installed stiffeners subjected to bending moment and shear force is the flexural rigidity ratio γ. The stiffening effect lessens when the area ratio δ and the flexural rigidity ratio γ exceed the proper range. The stiffening effect saturates when the bending moment gradient β and the ratio of the shear force to the bending moment η become large. The stiffening effect decreases with the increment of the torsional rigidity ratio γT/γ. The tendency of the stiffening effect is almost the same as the results installed one stiffener.</p><p> 2) An evaluate formula of the optimum flexural ratio for installing two stiffeners on the web has been proposed. The evaluate formula is expressed as a function ηβ which is multiplied the ratio of the shear force to the bending moment η and the bending moment gradient β. The optimum flexural ratio γ* becomes large when the value ηβ is large.</p><p> 3) In each case, the bending yielding and shear yielding, the application range of the web width-to-thickness ratio for satisfying the full plastic moment Mp by installing stiffeners with the optimum flexural rigidity ratio γ* has been examined. The boundary of the required number of stiffeners for satisfying the full plastic moment is expressed as a function α, the ratio of the shear stress to the bending moment stress.</p><p> 4) A design formula for the elastic local buckling strength of the web with the optimum longitudinal stiffeners has been proposed. And in case of the stiffeners have not enough, another solution deriving elastic buckling strength by drawing a graph has been proposed.</p><p> 5) A design method for satisfying the optimum flexural rigidity ratio has been proposed. And the satisfying the optimum rigidity can be obtained from the relationship between the width-to-thickness ratio of the stiffeners and the web.</p>

収録刊行物

参考文献 (4)*注記

もっと見る

関連プロジェクト

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ