A mixed-field Timoshenko beam-column element for direct analysis of tapered I-sections members

Rui Bai, Jerome F. Hajjar, Si Wei Liu, Siu Lai Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)


Tapered members produced by robotic fabrication techniques offer architectural and structural advantages and have the potential to become more prevalent than prismatic members. However, the conventional analysis and design methods based on simplified assumptions such as equivalent stiffness cannot be used to accurately evaluate a member's performance. To provide a reliable and practicable stability design method, a direct analysis method of tapered I sections is proposed. A mixed-field tapered beam-column element is derived for use within the modeling of structural frames. The effects of initial geometric imperfection and additional shear stress are directly considered in the element formulation. A polynomial describing the member's critical initial out-of-plumbness is adopted, and an arbitrarily located internal hinge is incorporated in the element to enhance the element's deformation capacity and capture the behaviors of the most critical section. Displacement and force interpolation matrices incorporating the shear deformation are utilized, and the Gauss quadrature method is employed to evaluate the element stiffness matrix. Finally, verification examples demonstrate that the proposed method can be used to accurately and efficiently evaluate the performance of tapered members, indicating that the element can be conveniently employed in member and frame analysis and design.

Original languageEnglish
Article number106157
JournalJournal of Constructional Steel Research
Early online date9 Jun 2020
Publication statusPublished - Sep 2020


  • Additional shear stress
  • Direct analysis method
  • Initial geometrical imperfection
  • One element per member
  • Tapered member
  • Timoshenko beam-column

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanics of Materials
  • Metals and Alloys

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