| An optimality criteria method for optimizing the design of steel two-dimensional structural systems subject to dynamic loading will be presented. The dynamic response is found using a time history analysis method. The dynamic constraints consist of displacements, story drift, stresses, and natural frequency. In addition to these behavioral constraints, practical design constraints such as side constraints (upper and lower limits on member sizes) and linking constraints (forcing a group of members to be the same size) are discussed. The objective function to be minimized is the weight of the structure.; Optimization through the time history presents many challenges which will be discussed. Specific areas related to the time domain optimization algorithm which will be presented are the dynamic analysis method, dynamic gradients calculations, numerical stability, convergence criteria, estimating Lagrange multipliers, and significant examples.; The algorithm developed will be used to present meaningful examples which demonstrate the efficiency, usefulness and practicality of the program to structural engineering applications. The examples will be used as a parametric study of seismically loaded structures subject to different set of behavioral and design constraints. Examples of parameters relating to seismic design include: (1) different lateral bracing schemes, (2) multiple versus single earthquake loading, (3) differing damping values, and (4) different support conditions. Typical results will be presented in the form of tables, graphs, and text to show stable convergence, constraint compliance, parametric comparison, and optimal solutions. |
