Abstract
This paper describes an experimental study on the strength of directly welded tubular joints. The most basic models of two-member connection, of which the branch tube is welded to the chord member perpendicularly, were tested to evaluate each effect of factors having influence upon the local deformation and strength of joints, that is, sectional dimensions of the members, shear spans and supporting conditions of the chord member. Here branch tubes were subjected to axial compressive force only, tensile tests will be performed in Part 2. Test results were investigated by using a parameter α=sin^<-1>d/D, where d/D is the ratio between the outside diameters d of the branch and D of the chord. It is shown that the effects of d/D and T/D, the ratio between the wall thickness T and outside diameter D of the chord, are able to be evaluated sparately, and that the effect of t/d, the ratio between the wall thickness t and d of the branch, has less influence upon the local behavior of joints. Numerical study will be described in Part 2. By examining the effects of shear spans and supporting conditions of the chord, above conclusions, introduced from specific test results whose specimens have equal chord length and are stiffened at supporting ends, were verified to be applicable to general T joints with some modifications.
