Equal stiffness in all directions: From theory to experiments

This work is concerned with the design of planar frames consisting of rigidly connected beams so that their ending point, which oscillates in the same plane, is characterized by equal stiffness in all directions. Consequently, when being under the action of a static force in the same plane, this point lies on a circle. Its additional property is concerned with equal frequency of vibration not only along the principal axes, but in every direction in the plane. Besides theoretical analytical considerations and a generalization of the approach, this study also provides numerical and experimental analyses and validations.