Experimental study on compressive property of circular tube-skewed gusset X-joints

To research compressive property of circular tube-skewed gusset X-joints under compression in gusset, ten specimens with different gusset thickness and angles between gusset and circular tube were tested. The joint failure modes, compression in gusset-general deformation and strain intensity distribution curves were obtained. The effects of the ratio of thickness of gusset to thickness of circular tube and angle between gusset and circular tube on axial ultimate capacity and ductility of X-joints were also studied. Results of these tests show that value of angle between gusset and circular tube does not affect the axial ultimate capacity of X-joints with relatively thin gusset (the value is 0.89). As value of angle between gusset and circular tube increases, corresponding axial ultimate capacity of joints increases with relatively thick gusset (the value is 1.33). As value of the ratio of thickness of gusset to thickness of circular tube increases, corresponding axial ultimate capacity of X-joints increases. All spots of joints with relatively thin gusset mainly keep plasticity. Most spots of joints with relatively thick gusset mainly enter plasticity. In the condition of relatively thin gusset, calculation of IIW code is unsafe; in the condition of relatively thick gusset, calculation of IIW code is safe.