上海交通大学学报 ›› 2022, Vol. 56 ›› Issue (6): 710-721.doi: 10.16183/j.cnki.jsjtu.2021.071

• 船舶海洋与建筑工程 • 上一篇    下一篇

平面单元和壳单元在复合有限条法中模拟加劲肋的应用

侯彦果1, 李占杰2, 龚景海1()   

  1. 1.上海交通大学 船舶海洋与建筑工程学院, 上海 200240
    2.纽约州立大学理工学院 工程学院, 美国 纽约 13502
  • 收稿日期:2021-05-06 出版日期:2022-06-28 发布日期:2022-07-04
  • 通讯作者: 龚景海 E-mail:gongjh@sjtu.edu.cn
  • 作者简介:侯彦果 (1992-),男,湖南省长沙市人,博士生,主要从事薄壁钢结构力学性能研究.

Application of Plane Elements and Shell Elements in Imitating Ribs of Members in Compound Strip Method

HOU Yanguo1, LI Zhanjie2, GONG Jinghai1()   

  1. 1. School of Naval Architecture Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
    2. Department of Engineering, SUNY Polytechnic Institute, New York 13502, USA
  • Received:2021-05-06 Online:2022-06-28 Published:2022-07-04
  • Contact: GONG Jinghai E-mail:gongjh@sjtu.edu.cn

摘要:

有限条法是一种经典的分析薄壁构件屈曲的方法,传统的有限条法在长度方向采用三角函数,无法分析沿长度方向间隔布置加劲肋的构件的屈曲问题,而复合有限条法恰好能弥补这一缺陷.基于复合有限条法,使用平面单元和壳单元分别模拟加劲肋对分析结果的影响.相比于壳单元,平面单元的自由度数量更少, 矩阵组合更简便.而壳单元因为考虑到面外的位移自由度而更全面.分别采用两种加劲肋单元分布带加劲肋的构件,发现壳单元和平面单元对屈曲结果的影响甚小,两者之间差异的绝对平均值在0.75%以内,并且屈曲承载力和模态与有限元结果皆能良好吻合.两种形式的复合有限条法与有限元差异的绝对平均值控制在5%以内.平面单元加劲肋的精度已经满足预期要求,有助于减少程序计算量和简化分析的复杂程度;在划分单元较密的情况下,能显著提升计算速度.

关键词: 复合有限条法, 屈曲, 平面单元, 壳单元, 加劲肋

Abstract:

Finite strip method (FSM) is a classical method to analyze the buckling of thin-walled members. The traditional FSM adopting trigonometric functions longitudinally can hardly analyze the members with spaced ribs along the longitudinal direction, while the compound strip method (CSM) can compensate for this shortcoming. Based on the CSM, the influence of utilizing plane elements and shell elements to respectively imitate stiffeners on buckling is investigated. Compared with the shell-element ribs, the plane-element ribs are prone to assembling the stiffener matrices with fewer degrees of freedom. But the shell-element ribs are more comprehensive as the out-plane displacement of ribs are taken into consideration. It is found that plane element ribs and shell element ribs have little difference on the buckling capacity of members. The buckling capacity has a small difference of mean absolute error (MAE) underneath 0.75% between the two types of CSMs, and the buckling capacity and modes are in good agreement with the finite element results. The buckling loads of the two types of CSMs are close to the FEM with a MEA less than 5%. The accuracy of the plane elements satisfies the predicted requirements, which helps to reduce the program computation and simplify the analysis complexity. The efficiency of analysis can be dramatically improved for fine meshing elements.

Key words: compound strip method (CSM), buckling, plane element, shell element, ribs

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