Affiliations: Escola Superior de Tecnologia de Setúbal, Campus
do IPS, 2914-508 Setúbal, Portugal | Instituto Superior Técnico, Departamento de
Engenharia Mecânica, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Abstract: A design and control sensitivity analysis and multicriteria
optimization formulation is derived for flexible mechanical systems. This
formulation is implemented in an optimum design code and it is applied to the
nonlinear dynamic response. By extending the spatial domain to the space-time
domain and treating the design variables as control variables that do not
change with time, the design space is included in the control space. Thus, one
can unify in one single formulation the problems of optimum design and optimal
control. Structural dimensions as well as lumped damping and stiffness
parameters plus control driven forces, are considered as decision variables.
The dynamic response and its sensitivity with respect to the design and control
variables are discretized via space-time finite elements, and are integrated
at-once, as it is traditionally used for static response. The adjoint system
approach is used to determine the design sensitivities. Design optimization
numerical examples are performed. Nonlinear programming and optimality criteria
may be used for the optimization process. A normalized weighted bound
formulation is used to handle multicriteria problems.
Keywords: Optimization, nonlinear systems, dynamic response, space-time finite elements
