The results of an experimental study of damage for the structural material MoNiCa (it is high-strength cast iron VCHTG – patent of the Republic of Belarus № 15617) on sliding friction and mechano-sliding fatigue are analyzed in the report. Tests of the mechanical system shaft (a sample with a working part diameter of 10 mm made of 0.45 % carbon steel) - an insert (a prismatic counter sample with a cross section of 10 ´ 10 mm made of MoNiCa) were carried out. The kinetics of the change in average wear at 8 local points along the perimeter of the dangerous area of the sample is given for contact loads FN from 20 to 92 N of the mechanical system under study with MoNiCa inserts without heat treatment and with heat treatment. The test results of the system under study are also presented in the form of sliding friction and mechano-sliding fatigue curves in coordinates of the contact load FN – the number of cycles N until the limit state.

A. Bogdanovich and I. LisUDC 539.4We discuss the experimental research of damage regularities of a metal-to-metal active system sample piece at sliding and mechano-sliding fatigue tests. In the report, the test technique is given. Experimental values of characteristics of resistance of sliding and mechano-sliding fatigue of an examined sample piece of sliding node are received. New regularities of a back effect for mechano-sliding fatigue of the 0.45% carbon steel-siluminum active systems are found.

Дано описание разработанной на основе энергетического критерия предельных состояний методики расчетно-экспериментальной оценки долговечности и других характеристик сопротивления износоусталостным повреждениям силовой системы типа «вал -вкладыш» при регулярном и нерегулярном нагружениях в условиях фрикционно-механической усталости. Методика базируется на нелинейной гипотезе накопления износоусталостных повреждений, учитывает влияние различных по природе процессов упрочнения-разупрочнения, связанных с классом материала (циклически упрочняющиеся, разупрочняющиеся или стабильные), характером нерегулярного нагружения, со свойствами коррозионной среды и другими факторами. Разработан алгоритм расчета долговечности, учитывающий предысторию нагружения. Рассмотрен пример расчета. Построены кривые фрикционной и фрикционно-механической усталости силовой системы «вал (сталь 45) -вкладыш (силумин)».

The calculation scheme of the reel of the combine harvester “Lida-1300” is given. The operating time of the bearing of reel support for service life of the combine, the frictional loads of the bearing and the bending stresses of the shaft are determined. Loading blocks are formed with increasing, decreasing and arbitrarily changing load. The influence of values of the softening parameters α and hardening parameters β, the duration of the loading stage on the calculated wear value and durability is analyzed. It has been established that for unchanged or insignificantly changing values of the parameters α and β, the calculated wear values coincide at the end of the loading block, regardless of the order of loads (increasing, decreasing or arbitrarily changing) and the duration of the loading stage. While with a significant difference between the parameters α and β, the coincidence of the calculated wear values at the end of the loading block appears only for a short duration of the loading stage (approximately two orders of magnitude less than the estimated lifetime). A comparison of the calculated wear kinetic curves is made under regular and irregular loading with an operating time of 2.0·107 cycles.