Executed system analysis of the types of damage to logging machines and damage them in the manufacture. It is found that defects in material, shape and size of the part have a significant impact on the reliability of the equipment. The main attention is paid to the effect of crack-like defects. If as a measure of damage to take the length of the crack and apply the methods of fracture mechanics in the calculations, it will be obvious the relationship of operational and industrial damage. It is established that the main cause of failures of logging machine details of domestic production is not enough high quality of their production. It is recommended to use more widely such as characteristic of materials as fracture toughness to assess the reliability of the design.

Keywords: Logging machine, reliability, damage, manufacturing defects, fracture toughness

The system analysis of types of damage of logging machines and their damage during operation is carried out. It is found that a significant impact on the machines reliability has mechanical energy and thermal energy. Mechanical energy affects all components and parts in the form of static and dynamic loads, which leads to the wear of mates, the emergence and development of fatigue cracks, plastic deformation or quasi-brittle fracture. The main attention is paid to the consideration of the influence of low temperatures in the operation of forest machines in winter on the properties of metals and, consequently, on the level of their reliability. It is recommended to use more widely such characteristic of materials as fracture toughness to assess the reliability of the design.

Keywords: Logging machine, reliability, damage, operating conditions, low temperature, fracture toughness

The paper deals with the investigation of exploitation technological efficiency of metall-cutting machine tools. The main goal of this study is to determine more advanced way of choice of equipment and to organize metall-cutting machine tools rational maintenance. Classification of basic and optional evaluative measures is presented in the first part of the paper. The research methodology provides the estimation of exploitation technological efficiency by calculation of the complex evaluative measure. The results of comparative estimation of two metall-cutting machine tools (Okuma LB 4000 EX, CTX Gamma 2000) are presented in the last part of the paper. According to evaluation result, Okuma LB 4000 EX stands at a higher level of exploitation technological efficiency.

Keywords: exploitation technological efficiency, comparative estimation, complex evaluative measure, methodology, data analysis