INPLANE COMPRESSIVE RESPONSE AND CRUSHING OF HONEYCOMB

The response of hexagonal, metallic honeycomb to in-plane compressive loading is studied through a combination of experiment and analysis. T his material with periodic microstructure has a load-displacement resp onse characterized by a relatively sharp initial rise to a load maximu m followed by an extended load plateau which is terminated by a sharp rise in load. In the first part of the response, the material deforms essentially in a uniform fashion (stable). Following the load maximum, deformation tends to localize to one row of cells which collapses at a dropping overall load until the walls of each cell come into contact . Contact arrests further deformation in the collapsed row of cells an d causes spreading of deformation in the adjacent rows. Under displace ment-controlled loading, this row collapse can continue, with relative ly small changes in the required load, until the whole specimen is col lapsed. The load required for further crushing increases sharply beyon d this point. This process has been reproduced through large-scale num erical simulations of the problem. In addition, we show how the local response of the material, obtained from a compression test on a repres entative microsection, can be used to establish the elastic properties , the load at the onset of instability, and the stress level at which deformation propagates from row to row. The local response is subseque ntly used to study the problem parametrically.