The ultimate strength of axially loaded CHS uniplanar T-joints subjected to axial chord load

摘要

In recent years, extensive numerical research was conducted into the chord stress effect of CHS uniplanar joints. Among the three basic types of geometries (K-, T- and X-joints), the effect of chord load on the ultimate strength is most complicated for a uniplanar T-joint under axial brace load since its strength is governed by a combination of (local) joint failure and failure due to (global) chord in-plane bending moments. The presence of additional axial chord load further aggravates the complexity of load transfer. As a follow-up on the investigation by Van der Vegte & Makino (2005), the current study identifies the effects of both compressive and tensile axial chord pre-load on the ultimate strength of axially loaded T-joint configurations for a wide range of the brace-to-chord diameter ratio β and chord diameter-to-chord wall thickness ratio 2γ. Based on the available FE data, a new strength formulation is established for T-joints under axial chord pre-load, describing the interaction between axial brace load and in-plane bending chord moments for the values of the chord load considered.