On the structural synthesis of uncertain systems subjected to environmental loads
A method for structural synthesis of structures with uncertain parameters subjected to uncertain loads is presented. The uncertain system parameters are modelled as random variables with a prescribed joint probability density function, while the loads are modelled as stochastic processes. Constraints are imposed on system reliability. Second-order probabilistic descriptors are combined with approximate extreme response theories to obtain reliability estimates for the system. The total system reliability that accounts for the uncertainties in the system parameters as well as the uncertainties in the loads is considered explicitly in the proposed formulation. Optimization is carried out by generating a sequence of explicit approximate problems. Intermediate design variables and intermediate response quantities are used to enhance the quality of the approximations. Numerical results for an example problem are presented to illustrate the efficiency of the design procedure set forth.
random variables stochastic processes system reliability intermediate design variables probabilistic design