A bead laying algorithm for enhancing the stability and dynamic behavior of thin-walled structures

Introducing beads into thin-walled structures for enhancing bending stiffness is a common practice and has been used formany decades. Typically, forms and patterns of such beads are rather based on experience as well as practical results than on analytical or numerical investigations. Recently computational methods have been developed for designing or optimizing beads. The paper at hand contributes to these attempts. It deals with increasing the buckling resistance as well as the fundamental frequency of thin-walled structures by systematic bead design. The design strategy is based on the idea to disturb the buckling mode and the fundamental vibration mode, respectively, of a structure in an efficient way by laying beads along the direction of the occurring maximum principal curvature of the corresponding mode shape. Since the beads influence this mode shape, an incremental approach is required. Numerical investigations into plate and profile structures are performed by applying this new iterative design procedure in combination with the finite element method.