The study of cellular solids is greatly influenced by the honeycomb. However, the honeycomb is not a component as whole for bees. Instead, the bee only care the shape and mechanical property of the cells, but in the engineering field, a cell of honeycomb is seldom used. We use them as plate, shell and so on. I think we ignore another porous material called cocoons, the protection to the most fragile period of insects. It is always bearing the load as a whole component.

  Dear everyone

  If we considerer a 3D fracture stress and strain field as a combination of numerous 2D fields in thickness direction, the J integral at each 2D plane can be obtained according to Rice’s definition (Abaqus and Ansys also include this function). What I concerned is the ratio of J integral at the surface of SEB or CT specimen to that at the mid-plane of the specimen. What factors have influence on the ratio? How to find the quantitive relationship between the factors and the ratio in linear elastic model?