Experimental investigation of a doubler-plate reinforced tubular T-joint subjected to combined loadings

Abstract

A large-scale round-to-round tubular joint reinforced with a doubler-plate was fabricated, strain-gauged and tested to study its stress behaviour under the combined action of 3 types of basic load as in axial load, in-plane bending moment and out-of-plane bending moment. The experimental results showed that under basic loadings, the stresses in the reinforced joint were generally lower than an unreinforced joint of similar geometry and sizes except for axial tension and in-plane bending moment, the stresses on the doubler-plate at the doubler-plate and brace intersection were slightly higher than its unreinforced counterpart. The peak hot spot stress was observed to be located on the doubler-plate, the equivalent of the chord of an unreinforced joint, for all basic loads and combined loads. This observation is similar to that found on the chord of the unreinforced joint. The experimental peak hot spot stresses under combined loadings were compared with that predicted by a conventional method of superposition of basic loads and the results revealed that the superposition method underpredicted in most cases for this joint. © 2001 Elsevier Science Ltd. All rights reserved.