Shape and force control of prestressed cable-strut structures based on nonlinear force method

Cable-strut structures are flexible structures which are very sensitive to their shape variation. Addition of actuators in selected members of cable-strut structures provides an efficient way to control the structural shape, thus enhances the structural performance. Although a large number of research studies have been performed to achieve shape control via linear force method, it has been proved that nonlinear force method is more accurate due to the existence of nonlinearity characters in cable-strut structures. The aim of this article is proposing an approach based on the nonlinear force method to change the shape of cable-strut structures under external load with respect to different control targets. The formulas and calculation procedure of structure’s nonlinear response to external load and length variation of members are established based on nonlinear force method. Then, solving strategy for determining the minimum required number of actuators and testing the feasibility for arrangement plan of actuators is provided for different control targets. Two numerical cases are demonstrated using the proposed approach to obtain the structural behavior before and after the control process. The effectiveness of the algorithm can be verified through numerical results.