Experimental and numerical investigation on behavior of CFRP-strengthened circular hollow section gap K-joints

Yuguang Fu, Lewei Tong, Lang He, Xiao Ling Zhao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

47 Citations (Scopus)


An efficient technique of Carbon Fiber Reinforced Polymer (CFRP) application was proposed to promote joint capacity of general tubular K-joints fabricated from Circular Hollow Section (CHS) members. Using this technique, in order to understand the static performance of CFRP-strengthened CHS joints, a systematic investigation was carried out by means of both experiments and finite element method. Three CHS gap K-joints strengthened with CFRP sheets were tested under static axial force in braces, whilst one additional joint was served as reference joint without CFRP. The results of failure modes, deformation, Mises stress, strain intensity and load-bearing capacity of the joints were presented and compared. A series of finite element models were developed and validated for the joints with and without CFRP reinforcement. A parametric study was conducted to evaluate the effect of variables (length, layers and mechanical properties of CFRP) on load-bearing capacity. The research results revealed that the proposed technique of CFRP installation was efficient to promote performance of in-service CHS gap K-joints. Moreover, the layer of CFRP sheets has significant effect on load-bearing capacity, but the effect was negligible for either length or mechanical properties of CFRP sheets. Finally, formulas were proposed for calculating ultimate load-bearing capacity of CHS gap K-joints with CFRP composites, and their calculation results matched well with the experimental and numerical results respectively.

Original languageEnglish
Pages (from-to)80-97
Number of pages18
JournalThin-Walled Structures
Publication statusPublished - 1 May 2016
Externally publishedYes


  • Carbon Fiber Reinforced Polymer (CFRP)
  • CFRP installation technique
  • Circular hollow section gap K-joints
  • Experimental investigation
  • Finite element analysis
  • Parametric study
  • Ultimate capacity formulas

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanical Engineering


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