上海大学学报(自然科学版) ›› 2019, Vol. 25 ›› Issue (6): 978-989.doi: 10.12066/j.issn.1007-2861.1976

• 研究论文 • 上一篇    下一篇

不同模量铁木辛柯梁的自由振动特性分析

杨洋, 姚文娟()   

  1. 上海大学 土木工程系, 上海 200444
  • 收稿日期:2017-05-08 出版日期:2019-12-30 发布日期:2019-12-31
  • 通讯作者: 姚文娟 E-mail:wenjuan@mail.shu.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(11572186)

Analytical solution for free vibration of Timoshenko beam with different modulus

Yang YANG, Wenjuan YAO()   

  1. Department of Civil Engineering, Shanghai University, Shanghai 200444, China
  • Received:2017-05-08 Online:2019-12-30 Published:2019-12-31
  • Contact: Wenjuan YAO E-mail:wenjuan@mail.shu.edu.cn

摘要:

研究了拉压不同弹性模量梁的自由振动问题. 利用不同模量材料纯剪切应力状态单元体, 推导了拉压不同模量材料的剪切弹性模量表达式. 基于弹性力学、结构力学及不同模量理论, 建立了不同模量铁木辛柯梁及欧拉—伯努利梁的振动微分方程, 推导计算了不同模量简支下的铁木辛柯梁的自由振动频率. 当考虑材料不同拉压弹性模量时, 中性轴在振动过程中发生跳变, 使主振型函数成为分段函数. 结果表明, 不同拉压弹性模量对梁的固有频率有较大影响, 拉压模量的不同可使结构固有振动频率减小, 这对结构振动是个值得关注的安全问题.

关键词: 模量, 铁木辛柯梁, 欧拉-伯努利梁, 自由振动, 振型函数, 固有频率

Abstract:

Free vibration of a beam with different modulus in tension and compression was studied. Unit body under a pure shear condition with different modulus in tension and compression was used to derivean expression of shear elasticity modulus with variational elasticity modulus. Based on elastic mechanics, structural mechanics, and the theory of different modulus, a vibration differential equation of Timoshenko Beam and Euler-Bernoulli beam is established, and the free vibration frequency of a simply supported Timoshenko Beam calculated. Considering different modulus, the position of neutral axis have a step change in the period of vibration, making the principle mode function piecewise. The results indicate that different modulus of a material has a great influence on the natural frequency of beam, which induces decrease in then at ural frequencies and therefore is worth consideration in structural vibration.

Key words: Timoshenko beam, Euler-Bernoulli beam, free vibration, vibration mode function, natural frequency

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