Bending -rotational vibrations of a strip of cardboard

The eigenmodes of vibration of the plane cardboard which is considered as an element of the package made from cardboard are analyzed in this paper. It is assumed that a strip of cardboard is loaded in its plane and thus a problem of plane stress is solved. Then the eigenmodes of bending – rotational vibrations of a strip of cardboard as of a beam by taking into account the stresses obtained from the previous two – dimensional problem of plane stress are obtained and analyzed. Graphical representation of bending and of rotation for the first eigenmodes is obtained. Experimental investigations using time averaged projection moiré are performed and the correspondence between the experimental and numerical results is discussed. The obtained results are used in the process of design of elements of packages