考虑失效区域的悬臂锥形钢管抗弯承载力计算

Calculation method for flexural capacity of cantilever tapered steel pipe considering failure zone

以解决目前悬臂锥形钢管抗弯承载力计算为目的,考虑径厚比、失效长度、锥度等因素,推导管径较大端的径厚比在10～ 60情况下截面失效界限位置与不同锥度的对应关系,提出考虑失效区域的承载力计算设计理论;分析锥度0.1～1.0区间内钢管各截面的抗弯承载力并确定失效长度取值.在开展端部径厚比为30的情况下,锥度0.2、0.3、0.4、0.5悬臂钢管抗弯极限承载力和锥度0.4、0.5钢管失效长度的有限元验算工作,不论承载力和失效长度都与理论推导吻合较好,说明该理论达到了控制失效区域,避免塔体整体失效的设计目的.另编制锥度和失效长度的关系表供设计计算查询.

In order to solve the calculation problems of the flexural capacity of cantilever tapered steel pipe,theoretical research considering failure zone was comducted.The relationship between tapered degree and failure position was firstly derived under the condition that the width-thickness ratio of the bigger side ranges from 10 to 60.To determine the failure length,the flexural capacity of every section was calculated with the tapered degree ranges from 0.1 to 1.0,and a table with the relationship between the tapered degree and the failure length was made to facilitate further design.Then,a calculation by finite element method was made with radius-thickness ratio of 30,at larger end and the tapered degrees 0.2,0.3,0.4 and 0.5,to prove the accuracy of design theory.As the result indicts,the flexural capacity and the failure length fit the theory well,and the research reaches the initiate goal to control the failure zone and prevent global failure.