Study of Metallic Housing of the Adder Gearbox to Reduce the Noise and to Improve the Design Solution

In the manufacture of commercial trucks, used in oil installations or the army, two identical engines are used on a single chassis, whose power is summed by a gearbox, a compact metal construction, which must meet multiple operating requirements. The paper studies the behavior of such an adding box, currently used in manufacturing, and an improved, welded solution that produces less noise and has a lower weight. The finite element method is used for modeling the gearbox in order to analyze stresses and strains and obtain a modal analysis of the system. The results obtained from the calculation are then verified by experimental measurements. The two versions are analyzed in parallel to highlight the advantages of the second version.

MODELING AND ANALYSIS OF THE DEFORMED MEDIA (METAL CONSTRUCTION ELEMENTS) NON STATIONARY THERMAL FIELDS DURING THEIR LASER SHORT WAVES PULSES TREATMENT

Substantiated mathematical model for non-stationary thermoelastic deformed media during their laser processing by short waves pulses fields analysis is proposed . Precise analytical solutions of the thermal conductivity equations which simulate the short laser pulses interaction and allow to further determine their components thermally stress-strain state of the processed materials, in particular, thin porous films, capillary-porous bodies are obtained. Two analysis methods were used: 1) traditional separating variables method (Fourier method), 2) non-Fourier analysis of the non-stationary thermal fields that described by the telegraphic equation known in the literature. The results obtained in this work can be used further to establish the thermo stress-strain state of materials interacting with short waves laser radiation pulses parameters. Such approach is used at the modern building process for the rising of the reliability, durability and strength of the metal construction elements.

Substantiation of parameters of metal structure elements of mining transport machines

The relevance of the work is due to the need to reduce the metal consumption of mining vehicles while maintaining the strength characteristics of their metal structures. An effective tool for finding the best option for combining the design parameters is optimization theory from the point of view of obtaining the design with the required properties. The implementation of the principles and approaches of this theory in relation to the metal structures of mining transport vehicles allows achieving a combination of their geometric characteristics, which makes it possible to obtain the smallest mass and dimensions. Purpose of the work: development of the principle of obtaining mathematical dependencies, allowing to determine the most suitable shape and size of the cross section for the elements that make up the metal structures of mining vehicles, taking into account the direction of the loads perceived by each element. Research methodology. An optimization approach is used, including the definition of the design parameters, the formulation of the objective function and the restrictions imposed on the design parameters. Results and their application. The factors affecting the value of the optimal parameters in the elements of the metal structures of mining vehicles are established. The optimal parameters of the cross section are substantiated for various combinations of the perceived load direction and the priority requirements for metal construction. The obtained recommendations can be applied in the design of frames with a minimum weight or dimensions. Conclusions. The recommendations presented allow us to reasonably choose the best cross-sectional shape of the metal elements of mining transport vehicles, depending on the direction of the current loads. The requirements for metal construction, such as minimum metal consumption and (or) surface area, are taken into account. For rods working in tension or compression, the most rational is the square shape of the cross section. For bending elements, a rectangular section with a height/width ratio of two is best suited. These conclusions are drawn from considerations of the least metal consumption and the smallest surface area of the metal structure. Taking the proposed recommendations into account when designing the metal structures of mining transportation machines will allow us to obtain the lowest values of metal consumption, and, consequently, the cost of the machine with the required technical characteristics.

Trematode Parthenitae Infection Rate and Distribution of Kola Bay Actic Molluscs of the Genus Littorina

The study was carried out in 2018 in the littoral zone of Kola Bay during the autumn period in the areas of Abram Mys Settlement, Mishukovo Settlement and Retinskaya Bay. Molluscs of the genus Littorina were collected from various substrates: stones, algae, metal construction and soil. In addition, samples were taken not from a particular substrate, but along the borders of the littoral zone to study species composition of molluscs and common level of infection rate in study areas. Our data showed that L. saxatilis infested by mature trematode parthenitae prefer being on the surface of algae, metal structure, stones at low tide instead of hiding under the stones, in the thickness of algae and in other possible shelters. The study of age distribution among infested Littorina molluscs living on different substrates showed that the ratio of age groups is different and varies from 1+ to 13+. Distribution data are established and considered for infested molluscs by trematode parthenitae of the group ”pygmaeus”: Microphallus pygmaeus, M. piriformes, which are characterized by the absence of free-living cercariae. Trematode parthenitae of other species which have a stage of free-living cercaria in their life cycle are absent in molluscs during the autumn period.

Quality Assessment and Process Management of Welded Joints in Metal Construction—A Review

This paper aims to express the maturity and dynamism of welding in industry. It follows the direct observation of international construction standards and rules, here described as an introduction to the most relevant themes in the area of welding processes. Quality management in welded construction involves well-regulated procedures which are, however, so vast that they are of great complexity. In fact, there are hundreds of rules to apply to each specific case. This makes it imperative to have a welding coordinator, at least in cases of greater responsibility. In fact, the application of the rules presents yet another difficulty: along with the breadth of the rules, each country may adopt certain special requirements in their own case. Thus, it is essential to know the necessary path for the proper development of responsible work. First, one must know the various welding processes, their advantages and limitations; then one must identify the regulations applicable to the work concerned; and finally, one must know what tests and qualifications are required, including the expected defects and acceptance criteria. One purpose of this work is to show the necessary path for the implementation of a welding quality management system in metal construction, as well as to present the numerous applicable norms, both for the welder and the welding coordinator, but also for the process and the product. This paper also presents an analysis of how to obtain the CE marking (Conformité Européene) for a welded metal construction and which normative ramifications apply.