In order to study the influence of supporting conditions and the angle between branch and chords on the hot-spot stress（HSS） distribution of Y-joints in concrete-filled steel tubular（CFST） truss

ANSYS with solid element of twenty nodes is employed and finite element models of Y-joints of CFST in consideration of weld geometry are built to calculate the distributions of the hot-spot stress concentration factor（HSCF） along the weld toe when the brace is subjected to axial compression under three support conditions of one fixed end and the other pinned

both fixed end

both pinned end with the angle changing from 20° to 90°（20°

40°

60°

80°

90°）chords. The model is verified reliable by comparing the numerical results with experimental results. Research results show that under the same support condition

the HSCF along the weld toe increases with the increase of angle. The maximum HSCF of chords always takes place at the grown point and the maximum HSCF of braces moves from the grown point to the saddle point. At the same angle

with the enhancement of the boundary restraint

the hot-spot stress concentration factor（HSCF） of either braces or chords decreases to some extent

and HSCF is little affected by restraint conditions in the vicinity of saddles. Since the local stiffness and overall stiffness affect SCF simultaneously

it may be considered to change the joint form or reduce the calculation length and strengthen the end constraint to reduce SCF.