Papers by Keyword: Contact Interaction

Abstract: The paper presents a developed a technology for producing a new abrasive material, which is a refractory ceramic matrix made of aluminum oxide with embedded diamond particles. The tests have shown its advantage over traditional diamond-bearing materials when processing high-hardness ceramics. To synthesize a new material with a predetermined set of operational parameters, it is necessary to build a wear model of a friction pair composed of diamond-bearing ceramic material and ceramics. After analyzing the results of other authors’ studies and assessing the morphology of the contacting surfaces, it is assumed that the contact of microroughnesses on the friction surfaces of abrasive diamond-bearing ceramic tools is linearly elastic. The model is built within the framework of the basic wear equation. The composite material surface was modeled by a set of same radius spherical segments; diamond grains were distributed in the material with a given bulk density. The paper uses the concept of an equivalent surface with the power law distributed of microroughnesses tops. A theoretical relationship is obtained between the micro-and macrocharacteristics of the wear process of a composite ceramic friction pair. The authors established theoretically and confirmed experimentally that the grinding productivity increases with an increase in sliding speed, applied load and diamond grain size. The diamond concentration has no significant effect on the workpiece wear. The established dependencies can help to achieve high productivity of diamond ceramic tools.

Abstract: There are results of studying the parameters of the indenter contact interaction with the surface when processing cylindrical parts made of 45 steel of different hardness by surface plastic deformation (SPD) methods with single-indenter elastic tools (diamond burnishing, ball burnishing). There were considered such characteristics as the resistance force when the indenter starts and in the steady state of SDP, the range of force fluctuations during processing, friction factor when the indenter starts and in the steady state, as well as some derivative coefficients. Adequate physical-statistical models for the quantitative estimation of the contact interaction parameters from SPD processing factors are obtained.

Abstract: Computer simulation of contact interaction between a spherical indenter and soil surface was performed by the means of ANSYS software. It was assumed that the soil was deformed elastically-plastically in accordance with the model Drucker-Prager. It was carried out the analysis of the influence of the model base physical parameters on the stress-strain state of the contacting bodies. The comparison of the calculated by linear elastic model and Drucker-Prager model stresses values for the soil showed that for the case of the elastic-plastic model are three times less than for the case of the elastic model.

Abstract: Computer simulation of contact interaction between a spherical indenter and soil surface was performed by the means of ANSYS software. It was assumed that the soil was elastically-plastically deformed in accordance with the model of Drucker-Prager. The case of indenter inserting and its contemporaneous displacement along the contact surface was considered. The results obtained by different material models show that the maximal stresses are reduced by 50% and more for the Drucker-Prager model in comparison with the results for the elastic model. The influence of horizontal movement-vertical movement ratio for the indenter on the stresses in the soil was analyzed.

Abstract: We carried out simulations of contact interaction between BCC iron crystallite and various pure FCC metals under shear loading by means of molecular dynamics. It was shown that the result of this interaction is the transformation of FCC atomic lattice of contacted material into BCC one within a thin layer in the contact zone. The results of simulations can be used to control strength of the interfacial layers of coated materials, as well as to understand the processes which are taking place in surface layers of materials under the contact.

Abstract: In this paper the problem for a periodic structure punch sliding upon a viscoelastic layer bonded to a rigid half space is considered. The semi-analytical solution of the problem is developed. Influence of incompressible fluid in the gap between two bodies upon friction force, contact size and pressure distribution is analysed. The obtained model can be used in a number of practical applications, for example in accounting of automobile tire aquaplaning upon wet road surface.

Abstract: The project Expo Axis is one of the landmark buildings of Expo Shanghai 2010, and its structural safety depends largely on the security of the six Sun Valleys, which are the important components of the Expo Axis. The simulation of the whole process of collapse and collision of the sun valley under earthquake action is conducted in this article. In the calculation multiple nonlinear factors are taken into account, such as material nonlinearity, large displacement effect, self-contact collision among the structure members, contact collision between the structure and the ground, etc. Through analyzing the results, a reasonable assessment of the structure of Sun Valley’s performance under the supper-large earthquake is given out. This method can also offer reference to other similar large-span steel single-layer lattice structure’s performance analysis.