Prediction on static strength for CHS tubular K-joints at elevated temperature

This study presents a design method for predicting the static strength of a Circular Hollow Section (CHS) tubular K-joint at elevated temperature. The presented method is obtained based on a parametric study by the authors (He et al., 2015a). In determining the static strength of a tubular K-joint at elevated temperature, a deforming rate criterion is proposed, and it is proved to be much safer and more reasonable for design purposes rather than the conventional definition on that static strength by using 3% of chord ovalisation for the K-joint at ambient temperature. In the presented design method, a strength reduction factor k is proposed, and the static strength of a CHS K-joint at elevated temperature can be obtained simply by multiplying the static strength at ambient temperature with k. The strength reduction factor k is a product of two factors, a revised reduction factor of elastic modulus (λ) and a revised chord stress ratio (kn′, θ). From the finite element results of overall 57 K-joint models, the accuracy of the presented design method is assessed to be reliable and accurate.