Zhvan O. Determination of the deflected mode of steel structures with allowance for elastic flexibility of side fillet welds

Thesis is focused on determination of the deflected mode of welded steel structures and their assembling through side fillet welds with allowance for longitudinal linear elastic weld flexibility. The Thesis presents analytical solutions, based on displacement method, for determination of the deflected mode of 3-layer compound bars working in tension, compression, and bending with allowance for influence of the longitudinal linear elastic flexibility of ties. Qualitative analysis of the obtained analytical solutions is carried out and outlined in the paper; as well as the advantages and weak points of such solutions are showed. The Thesis presents numerical solutions generated for determination of the deflected mode of 3-layer compound bars working in tension, compression, and bending. The factors influencing on the stability of numerical solutions, when implementing them on PC, are studied in the paper; the methods are proposed for scaling the unknown variables to improve the stability of numerical solutions. The numerical solutions are generalized to reflect the variability of inflexibility parameters along separate bar layers. As particular cases, the analytical and numerical solutions are obtained and presented in the paper for determination of the deflected mode of 2-layer compound bars working in tension, compression, and bending. The paper presents the longitudinal displacement rigidity coefficients of side fillet welds for various leg lengths determined experimentally. The Thesis describes the technique that has been developed for, and the theory of compound bars that has been practically applied to calculation of particular welded steel structures.