The global machinery industry the last ten years actively introduces and uses new materials that combine the maximum number of special properties: strength, ductility, corrosion resistance and wear resistance, for example, two-, three - and multi-layer sheets of carbon and stainless steel, sheets of aluminum and its alloys, clad stainless steel and so on, Shipbuilding, aviation, chemical, transport and power engineering, military and missile technique widely used parts made from such materials. To the question of the destruction of laminated plates and shells supersonic two-phase flow result many actual problems of modern equipment Metalworking, mining, aerospace research, vehicles, nuclear power, disposal of explosive ordnance and other Main method of studying the dynamics of destruction is an experimental method research. One of the main objectives of the experimental study is the problem of constructing relations allowing to close the system of equations of motion continuum that describes the process the entire period of the shock interaction. But even the presence of these correlations leads to a system of equations that depend on three prostranstvennaiia and time, which seriously complicates the task.
The Study authors focused on the solution of fundamental problems of fracture mechanics of a rigid body - prediction of failure in laminated plates and shells . Forecasting fracture of layered materials under conditions of supersonic pulse interaction is an important area of research in the framework of this fundamental problem.
Theoretical research directed the destruction of laminated plates and shells supersonic two-phase flow aimed at solving two sub-problems: analytical description of the implementation of the particles flying at supersonic speed, first layer of a laminated plate or shell under various kinematic angles of attack and analytical description of the penetration of supersonic two-phase flow in layered material with regard to design features obstacles.
When modeling the penetration of a single particle supersonic flow as a model barriers used model plastically compressible medium, which when loading changes its density according to a certain law, and when unloading saves density, obtained at loading. The main equations of this medium for the case of one-dimensional motion, the continuity equation and the equations of motion of the particles of metal in the variables Lagrange. The relationship between radial and tangential stresses found from conditions limiting state for metals, in terms of Prandtl. For circuit system equations applied to the relationship between hydrostatic pressure and volume deformation. When describing the motion of the medium caused by penetrating particle supersonic stream, the assumption was made that the particles barriers in the region between the shock wave and penetrating particle must move along trajectories that coincide with the normals to the surface of the penetrating body.
The Solution of the above equations allow us to obtain expression to determine the pressure on the surface of the penetrating particles supersonic flow, which allowedopportunity to write an analytical expression for the maximum depth of penetration of a particle in the material at normal angle of attack. This will determine the amount of displacement of a single particle at different angle of attack and speed collision, physico-mechanical properties of the material obstacles, the geometry and size of the particles of a supersonic flow.
For the second subtask, the following assumptions: the number of abrasive particles involved in the cutting, constantly; the orientation and velocity of the particles participating plunge, on any one layer constantly; particle participates in the destruction of only once; material layers are isotropic. Allowing step the system of the equations of motion of the particle with the moving boundary conditions, analytical dependences of the axial and longitudinal velocity penetration of supersonic two-phase flow in layered plates and shells from the pressure of the expiration, the thickness of the layers, the nature of the material, particle shape, number of layers, the gap between the layers, the degree of hardening in the field of fracture and flow of the particles.
Studies have allowed scientists LLC ’Orlovsky abrasive plant» (www.orlaz.ru) to detect new variants of compositions abrasives, comparable grenade, but less expensive, which expanded the scope of this process.
We Recommend that you prepare the optimal abrasive mixture for waterjet cutting to provide cutting capability is not lower than using garnet abrasive due to the introduction of abrasives with high and very high hardness.
For different thickness and types of materials defined modes waterjet cutting with regard to the cutting capabilities of each component of the abrasive mixture.
It is Recommended that the type of abrasive material mixture and dosage to prescribe depending on the hardness and the required quantity for the implementation of cross cutting of material to be processed.