Abstract

Steady state response of portal frames whose members are connected to each other continuously or by infinitesimally small rotational link elements (intermediate viscoelastic hinges) are investigated under a periodic external force within the Euler-Bernoulli beam theory by using energy based finite element method. The effect of damping of the members of portal frames, the values of rotational spring coefficient and damping coefficient of intermediate viscoelastic hinges on the steady state response are investigated numerically. Optimum damping coefficients of intermediate viscoelastic hinges are investigated for different damping coefficients of members. The results of frames constituted by connecting the members continuously and by connecting the members with intermediate viscoelastic hinges in some desired joints are compared and presented in graphics and tables. Convergence studies are made. The obtained results are compared with the results of same models constituted on the structural analysis software package SAP 2000. It is seen that the results obtained from this study are harmonious with the results obtained by using SAP 2000 package.

Key words: Portal frames, finite element method, viscoelastic hinge, steady state response, optimum damping coefficients.