Optimal joint positions and stiffness distribution for minimum mass frameswith damping constraints

Optimal design of frames including cross-sectional dimensions (size paramet ers) and rigid joint positions between beams (configuration parameters) is treated in the paper. The optimal design corresponds to a minimal mass stru cture with constraints set on damping capacity of free vibration modes. The sensitivity analysis of distinct as well as multiple frequencies is perfor med analytically using a complex variable sensitivity method. The linking p rocess of size and configuration variables is applied to generate different classes of optimal designs. The numerical algorithm is based on quadratic approximation of the objective function and linear approximation of active constraints. The examples are provided for 2, 12, and 124 beam frames.