The Effect of Steel Strength on the Behavior of a K‐Joint in a Slim‐floor Truss

Abstract

This paper studies the applicability of the strain‐limit criterion in the Eurocode 3 to defining the limit load for a K‐type truss joint, which connects two tubular braces to a plate chord. The joint is used in a novel Finnish slim‐floor system with integrated load‐bearing members of High‐Strength Steel (HSS). The Finite‐Element Model (FEM) of the joint is validated by the experimental results of scaled‐down, isolated joint specimens made of S420 and S700 steel. The validated FEM is used to study the failure of the joint and the effect of steel strength on the failure mode. For the specific geometry of this joint, the criterion based on the 5% strain limit proposed by the Eurocode 3 was found to be well justified for the steel grades S235 and S355 and reasonably applicable to the steel grades S460 and S550. However, the results indicated that the value of 5% for the strain limit was too large, if the joint was made of the S690 steel grade.