Soil Dringling & Rock Cutting's New Numerical Analysis Method And New Equipmens Study

With the development of modern science and technology, our foundamental construction developing toward larger, mechanization and automatization. High-powered construction machines become to be more and more important in railway construction, waterpower projects, mining and architecture construction. But now, most of the high-powered construction machines still rely on importation. Mechanism of rock cutting and soil drilling is seldom studied and has no applicable numerical method, which is a powerful tool to study these problems, domestically. In order to improve the ablility to design new style construction machines and realize import substitution, base on MLPG method, a new numerical method was proposed for analysis of rock and soil cutting in this paper. Mechanism of rock cutting and soil drilling was studied analytically, experimentally and numerically, and the conlusions were used to design two new construction machines.First, a new numerical method-PMLPG was developed in this paper. PMLPG is a meshless method, it does not need mesh, which make it have the ability to analysis uncontinuous problem and large deform problem. It can be widely used to analysis rock cutting and soil drilling problem, so it is a useful tool for design of new construction machine. For this method, integeral was proceed by triangular Gaussian quadrature method in polygon domain, which can reduce computational time greatly. Neighbor nodes database was create which can reduce neighbor nodes searching time. Rock and soil cutting problem are two complicated problems, so a robust method is needed to treat essential boundary condition. In this paper, weight function was modified for the boundary nodes which make the trail function pass through the boundary nodes, and then"diagonal element changed to 1"method was used to solve essential boundary condition. This treatment of essential boundary congditon is so flexible that can be used to analysis soil and rock cutting.For nonlinear numerical analysis of soil and rock cutting problem, PMLPG method and Mohr-coulomb model was used to deal with the plastic deformation and large deformation in soil cutting process, improved weight function was proposed to deal with the uncontinuous problem near crack line, and then some codes were write to solve material nonlinear problem in soil cutting and crack propogation problem in rock cutting. In order to reduce the computational time, MLPG proguam in this paper improved traditional algorithm wholly without decrease of precision, and PC can be used to analysis soil and rock cutting problem. Use these programs satisfied result can be get to fit the experiment.Base on practical construction project, soil rotary cutting model was etablished in this paper, in which modified cutting angle and flank shear failure was considered. Experiment was done to validate this model. For study of rock cutting technique, most experiments and analysis were done. All these works were very useful for developments of two new construction machine in this paper. Base on our task of scientific research, underwater roller rock cutting equipment and vibrate drilling tool was developed. After the design, manufactory, experiment and improvement, these two equipments had been served in construction project for about two years. Practice proves that the developemnt of these two equipments is successful, the capability can reach to the level of German congeneric production.