Compressive response of circular cell polycarbonate honeycombs under inplane biaxial static and dynamic loading. Part I: experiments

The crushing response of a polycarbonate circular cell honeycomb to inplane biaxial loading is analyzed. The study involves a combination of static and dynamic experiments. Static experiments corresponding to several different biaxial loading conditions under displacement control are carried out in two different inplane directions respectively. Dynamic experiments related to various impact forces under inplane biaxial loading in two different mutually orthogonal directions, respectively, are conducted. In the first phase of the response, the material deforms in a uniform fashion. Next, a nonlinear phase caused by the progressive localization of deformation is observed. This phase is characterized by the variation of overall (macroscopic) stiffness. The progressive localization causes the walls of each cell within the localized region to contact each other. These periodic honeycomb materials show different collapsed modes under different biaxial loading histories. Experimental measurements indicate how the magnitude of the collapse load varies and how the stress–strain response changes as a function of load biaxiality. The experimental crushing responses between static and dynamic cases are compared.