Effect of Railcar Wheel Tire Profiles on the Contact Stress Level in Subway Rails

Strength of Materials - The statistical analysis performed on the defectiveness of rails in the Kiev subway railway shows that the main cause of the occurrence of most defects is the contact...     

Automated system of research in the field of experimental mechanics of materials

The article describes an automated system for scientific research Mekhanika devised at the Institute of the Strength of Materials, Academy of Sciences of the Ukraine; the system is suitable for almost complete automation of routine operations in data processing of mechanical experiments connected with the calculation of the state of stress and strain of the test specimen, presenting the results of the calculation in the form of tables and graphs, and with the calculation of the required mechanical characteristics of the material. In addition the system offers the user great possibilities in generalizing the results of experiments, constructing various analytical approximations of the obtained data. The results of experiments and calculations can be stored in a specialized data bank.Translated from Problemy Prochnosti, No. 3, pp. 71–79, March, 1993.     

Investigation of Stress-Strain Relations of initially anisotropic metals under proportional and nonproportional loading

In plasticity theories–applied in practical calculations- are usually based on the assumption of materials isotropy. Commercially obtained structural metallic materials however are originally anisotropic due to various kinds of thermal and mechanical treatments. Aluminium, titanium and magnesium alloys are typical anisotropic structural materials. The wide application of these materials in different fields of engineering demands more accurate mechanical behaviour predictions for these alloys under various conditions of loadings. In the aper, a simple theory of plasticity for anisotropic metals is proposed which is based on the results of experimental investigations into elasto-plastic deformation of initially anisotropic aluminium alloys subjected to simple (proportional) loading as well as under loading along stress path with a corner.     

Strain hardening of metastable austenitic steel under repeated simple loading at different temperatures

On the basis of experimental data obtained under repeated simple loading of 18-10 steel at temperatures of 77, 123 and 293 K, we discovered that the direction of maximum hardening in the space of stresses does not coincide with the direction of preloading. This effect becomes more pronounced if preloading and repeated loading are performed at different temperatures. It is shown that the maximum degree of hardening is attained after repeated loading preceded by uniaxial preloading in the direction of trajectories close to uniform biaxial tension. It is also noted that the yield surface of structurally unstable steel undergoes complicated transformations. Translated from Problemy Prochnosti, No. 6, pp. 59–65, November–December, 1997.