The relative proportions of through-thickness bending and membrane stresses in tubular Y- and T-joints have been investigated by analysing a large number of thin-shell finite-element models. Nearly 900 finite-element runs were performed for a wide range of joint geometries and for each of axial loading, in-plane bending and out-of-plane bending. The validity of this approach is demonstrated by comparing the thin-shell finite-element results with data obtained from strain-gauged acrylic model tests and other finite-element analyses utilizing thick-shell or brick elements to model the intersection. For each mode of loading, the results are then used to construct semi-empirical equations which related the relative proportions of bending and membrane stresses to a parametric function of the joint geometry. Finally, the accuracy of the parametric equations is assessed by comparison both with the database from which they were derived and with the experimental results. © 1990.