Influence of brace-to-chord angle on the seismic behavior of circular hollow section X-joints under in-plane bending

•Effects of brace-to-chord angel on flexural performance of X-joints are studied by experiment, mechanism analysis and FEA.•Decreasing θ can increase flexural strength of X-joints, but more pinching effect of hysteresis curves after cracking.•Performance of orthogonal X-joints and X-joints (θ≠ 90°) are different which increases with θ decrease.•Positive ultimate flexural strength of X-joints is smaller than the corresponding negative ultimate flexural strength.•A load transferring mechanism is proposed to further explain reasons behind experimental observations.