Study of the stress-strain and strength properties of the metal woven grids

Metal grids represented as multilayer packages are used as highly-porous easy-deformable elements to protect pressure vessels of the blasting chambers and other structural components from fragmentation damage and other impulse actions. The package of grids is typically formed by layer stacking with the same directions of the wires providing multilayer package that is considered as a highly-porous deformable structural element with orthotropic properties. As a result of experimental studies, the stress-strain curves were obtained for multilayer packages and single layer of a woven metal grid under compression along the normal to the layer and under tension along the wires up to the sample destruction. Experiments show that the tensile strength of pre-compressed single layer of a woven grid increases which is typical for multilayer packages. Mathematical modeling of the stress-strain of single layer of a woven grid confirms an increase in the tensile strength along the wires after pre-compression along the normal. According to the results of mathematical modeling, two mechanisms providing an increase in the tensile strength are revealed. The first is related to material hardening in the vicinity of grid node caused by strong compression and developed plastic flow. The second is a reason of compression of the tensed wires which are preferably in a compressed state and the addition strength is needed for their tension.