力学与实践 ›› 2020, Vol. 42 ›› Issue (6): 797-801.DOI: 10.6052/1000-0879-20-051

• 教育研究 • 上一篇    下一篇

由夹芯梁弯曲谈剪切效应对许用弯矩的影响

吴晓1)   

  1. 湖南文理学院机械工程学院,湖南常德 415000
  • 收稿日期:2020-02-11 修回日期:2020-05-18 出版日期:2020-12-20 发布日期:2020-12-20
  • 通讯作者: 1)吴晓,教授,主要从事工程力学方面研究。E-mail: wx2005220@163.com

DISCUSSION OF SHEAR EFFECT ON ALLOWABLE BENDING MOMENT BASED ON THE BENDING OF SANDWICH BEAM

WU Xiao1)   

  1. College of Mechanical Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, China
  • Received:2020-02-11 Revised:2020-05-18 Online:2020-12-20 Published:2020-12-20

摘要: 利用弹性体轴向位移、横向位移与剪应变的几何关系,推导出了夹芯梁的弯曲正应力公式,并利用该式确定了夹芯梁的许用弯矩,从而克服了有关材料力学教材计算许用弯矩时,没有考虑剪切效应的不足。算例分析表明:该弯曲正应力公式计算精度较高;夹芯梁弯曲时,剪切效应对许用弯矩有一定影响。该结论对材料力学关于夹芯梁计算内容的教学有一定启发和指导作用。

关键词: 夹芯梁, 弯曲剪切效应, 正应力, 许用弯矩

Abstract: Based on the geometric relationship between the axial displacement, the transverse displacement and the shear strain in an elastic body, the bending normal stress formula of the sandwich beam is derived, and the allowable bending moment of the sandwich beam can be determined by the bending normal stress formula. Here, the shear effect is duly considered unlike the allowable bending moment calculation in the textbooks of materials mechanics. It is shown that the accuracy of the formula is high and the shear effect has a certain influence on the allowable bending moment. Thes results can be used in the teaching of the sandwich beams in the course of materials mechanics.

Key words: sandwich beam, bending shear effect, normal stress, allowable bending moment

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