Background
Type: Article

Proposing a practical equivalent Timoshenko beam for analysis of truss structures

Journal: Structures (23520124)Year: May 2024Volume: 63Issue:
Sabzehzar S. Majidi N. Shafizadeh A.Tajmir Riahi H.a
DOI:10.1016/j.istruc.2024.106401Language: English

Abstract

Engineers utilize truss structures constructed from various materials, including timber and steel, to achieve superior performance. The motivation behind employing truss structures lies in their ability to cover larger spans with lighter frameworks compared to traditional structural beam-column framing, resulting in cost-effective and efficient construction processes. This study introduces the concept of the equivalent beam approach, enabling designers to rapidly assess the strength and deflection of truss structures. This approach facilitates a quick estimation of the required truss material costs before conducting more precise finite element analyses. The research begins by comparing the results of equivalent Euler-Bernoulli beam and Timoshenko beam. The findings reveal that Euler-Bernoulli beam method is unsuitable, with an error of approximately 57 %. However, the accuracy of the Timoshenko beam method is contingent on the selection of the Timoshenko shear coefficient. By optimizing this coefficient, the errors in static, frequency, dynamic, stability, and thermal analyses are reduced to approximately 1 %, 5 %, 11 %, 11 %, and 11 %, respectively. To aid engineers in determining the optimal Timoshenko shear coefficient, the paper concludes by presenting an exponential relationship based on the examination of various truss sections. This approach simplifies the calculation of the optimal coefficient, enhancing the overall design process for cost-effective and reliable truss structures. © 2024 Institution of Structural Engineers