Abstract
The described tests have been performed on polymethacrylimide (PMI) hard foams ROHACELL ®71 IG and 110 IG (series industrial grade). The tests provide reliable results and may improve the material modelling. Their results are applied in the modelling of the limit surface and the elastic properties [1, 5, 6]. They can be used to test many different types of materials like ceramics, aerated concrete, sintered materials, granular materials etc. The hydrostatic tension test is particularly difficult to perform. The reasons are the complications with the force application, the measurement of displacements, and the shape of the specimen. Some new methods are shown in [4].