BOUNDARY ELEMENT METHOD FOR DYNAMIC ANALYSIS OF TALL BUILDINGS INCLUDING DAMPING

Abstract

A dynamic analysis technique based on boundary element method is presented in this thesis. Forced damped vibration is conducted using calculated stiffness, mass and damping matrices formed by BEM. The stiffness for the slab was calculated by discretizing the boundary only assuming a super-element where vertical elements as area cells giving a realistic solution. The stiffness of the vertical elements are then calculated. The total stiffness matrix of the whole structure is then assembled. The mass matrix is lumped at the active degrees of freedom and calculated using BEM Two techniques (Rayleigh and Caughey) were used to evaluate the full damping matrix based on the value of the damping ratio. Finite difference Hilber-Hugh-Taylor method is carried out for the time history analysis. Verification of the introduced technique was done by, comparing the results calculated to those of the finite element method. Key Words: boundary element method, multi-story buildings, forced vibrations, damped vibratio