ДОСЛІДЖЕННЯ ВПЛИВУ ГЕТЕРОГЕННОСТІ ЗВАРНИХ ШВІВ НА РЕСУРС ТРИМАЛЬНИХ СИСТЕМ ПРИЧЕПА

Abstract

The paper considered the issues of the influence of structural heterogeneity of welds on the life of the trailer design. Mainly in the works on welded structures, the effect of stress concentration during welding on the strength and crack resistance of the weld is considered and the possibilities of reducing temperature differences and deformations, which create the main threat of microcracks, are examined. One of the essential features of welded joints is the structural-mechanical inhomogeneity of the metal. The nature and properties of this heterogeneity as a factor in the destruction of welded joints is not fully determined. Therefore, the object of this study is the structural heterogeneity of welds of the supporting structure of the trailer BMZ-887.General questions are considered regarding the trailer designs and physical properties of welded joints and the peculiarities of heterogeneity of the heat-affected zone or near the suture zone. For the study, we used the following methods: tensometric research, quantitative metallography. The paper presents experimental data that were obtained using the above mentioned methods, and a comparative analysis of these data was carried out. The relationship between the numerical values of the parameters of the weld heterogeneity and the propagation velocity of small and main fatigue cracks in welded joints is established.The numerical values of the heterogeneity parameters and the propagation speeds of fatigue cracks in the welded joints of the following types were obtained: the propagation speed of small cracks decreases slightly with increasing diameter of the second phase particles; particle diameter does not significantly affect the propagation velocity of trunk cracks; the effect of concentration (distance between particles) for small cracks is not significant; for trunk cracks with increasing particle density, the rate of propagation of cracks is somewhat reduced.