Research on the mechanical behavior of totally overlapped tubular N-joints under different load case

The static behavior of totally overlapped tubular N-joints with vertical brace under compression in sym-metrical Pratt truss and vertical brace under stretch in anti-symmetrical Pratt truss were studied. One vertical brace under compression and one vertical brace under stretch were tested under monotonic loading. Results of these tests showed that the failure of model vertical brace under compression was the combined failure of the vertical brace incline and slant brace face plastification, and the failure of model vertical brace under stretch was the combined failure of the chord and slant brace face plastification and base material crack. The calculation showed that the result obtained from Euroeode 3 is more accurate than the China code which turns out unsafe in vertical brace under compression;the ultimate capacity of joints in vertical brace under stretch which is higher than vertical brace under compression raised by 42%.