Feasible Prestress Modes for Cable-Strut Structures with Multiple Self-Stress States Using Particle Swarm Optimization

A prestressed cable-strut structure is usually regarded as a mechanism before being prestressed. Under the action of initial prestresses, the internal infinitesimal mechanisms can be rigidified, resulting in achieving the desired structural stiffness. Therefore, feasible prestress design is a key to develop and analyze novel prestressed cable-strut structures. In this study, an effective optimization method is presented to determine the optimal feasible prestress modes of a cable-strut structure with predefined geometry and multiple self-stress states. Two optimization models based on the self-stress states and the integral self-stress states are presented to compute the optimal feasible prestress modes. Thereafter, the multiobjective optimization problem is converted into a single objective optimization problem by the weight coefficient method, and the particle swarm optimization algorithm is applied to find feasible solutions. Illustrative examples verify the feasibility of the presented optimization algorithms to calculate feasible prestress modes. In comparison with the conventional optimization methods, the proposed method shows satisfactory accuracy and efficiency.