Keyword: «brittle fracture»

The possibility of analytical determination abrasive particle impact velocity with the surface of any synthetic polymeric material with shock-abrasive processing in a low-temperature cooling for maximum efficiency of the process, ceteris paribus. The dependences for the calculation of such initial axial velocity of the abrasive particles in which at any distance from the nozzle of the jet device for shock-abrasion provided by the minimum time between two successive blows particles, which carried out an intense loading of the material increases its depreciation per unit of time and providing maximum the performance of the process.

A description of the equipment and possibilities of surface morphology analysis on a new profilometer model 130 with a Russian-made nanometer attachment has been given. The analysis of the fracture surface of car steering rod material is carried out by means of the developed methodology for studying the morphology of the breaks of a metal samples with a nanometer resolution. The nature of the fracture is determined as fragile mode I. A fracture core at the composite insert boundary in the steel material of the steering rod was revealed.

The article considers the problem of operation of vertical steel single-walled tanks (RVS) made of St3 steel in conditions of low climatic temperatures. The analysis of the mechanical properties and cold resistance of the material at subzero temperatures is carried out. Based on the analysis of the stress-strain state of the tank wall and the influence of temperature deformations, the need to limit the maximum level of rise (upper cut-off) is justified to prevent the development of brittle cracks in the stress concentrator areas, primarily in the near-seam zone of the mounting joint, welded joints of the bottom and lower belts of the tank. A method for calculating the safe level of take-off is proposed, taking into account the operating temperature and mechanical characteristics of steel.

The article presents the results of a study on the problems associated with the long-distance transportation of solar collector evacuated tubes. Using deliveries to the city of Yakutsk as an example, it is shown that a significant number of evacuated tubes can be damaged during transit, even on paved roads. To identify the causes of tube failure, a damage analysis was conducted. This analysis revealed characteristic failures caused by the bending moment under vibrational and impact loads. Based on a study of the tube design and their packaging, calculation models for the outer and inner bulbs were developed for subsequent strength analysis.