Low-density porous materials are useful in the design of shock absorption structure due to the properties of shock absorption, lightweight and formability. The mechanical behaviors of the materials have high-nonlinearity because they have complex inner structure in comparison with dense materials, and the structure causes difficulties in the analysis of their problems for the design. In this paper, the nonlinear behavior of the materials before the macroscopic crush condition is inspected to define the elastic properties of them by some tests of compression and shearing. Here, the nonlinearities in the initial of compression is eliminated by the adhered contact condition of specimen because the condition can reduce the localization of the mesoscopic cellular crush of the materials. Then, the elastic properties derived from the tests are compared with each other for validation, and it is revealed that the derived properties are coincided and the compression test with adhered contact condition can measure the Young's modulus with less influence of the localization of the mesoscopic cellular crush.
