Purpose: Development of a computational model of stress-strain state bearing elements of trailer frames for preliminary assessment and identification of areas with increased risk of failure. Design/methodology/approach: The object of the study is the processes of loading the load-bearing metal structures of trailers - fertilizer spreaders. The stress-strain state of the spreader bearing system is investigated for the established three typical cases of external load. To refine the values obtained as a result of modelling, they were determined in SOLIDWORKS. Findings: Computational models of load have been compiled by improving the method of minimum potential deformation energy for its effective correct use in analytical studies of a similar type of metal structures. It is proved that for a flat closed frame structure made of thin-walled profiles, loaded with forces perpendicular to the plane of the frame, the levelling of compression and shear energies, as well as axial and transverse forces and bending moments in the horizontal plane does not significantly affect the calculation results. Research limitations/implications: Horizontal components of the shear forces as well as the normal forces and as a consequence the corresponding potential deformation energy are neglected, which has some effect on the accuracy of the calculations. Practical implications: An effective tool for strength analysis with preliminary assessment and diagnostics of load-bearing metal structures based on the constructed calculation models of stress strain state load-bearing frames of typical geometry with an arbitrarily given distribution of external load. Originality/value: A universal algorithm for recording additive functions of bending and torques, as well as the potential deformation energy of welded frames of trailers.

This study was aimed to investigate  the ability of Jerusalem artichokes (Helianthus tuberous L.) to absorb heavy metals in an oil-contaminated ecosystem.  The research was carried out in a  territory of the oil and gas pipeline  at the village of  Bytkiv of Nadvirna district.  Jerusalem artichokes were used for this study and planted on an area of 25 m2.  The area of the experimental field in the village of  Maidan of Tysmenytsia district (control option № 1).  A total of eight treatments of the experiment with different rates of sewage sludge.  It is established that the concentration of heavy metals in oil-contaminated soil and Jerusalem artichoke plants increases with increasing the amount of fertilizers in the soil. The maximum content of metals in the tested soils, green mass and Jerusalem artichoke roots was observed  mainly in the variant of sewage sludge application at the rate of 40 t/ha and fertilizer N10P14K58.The green mass and roots of Jerusalem artichoke exhibited the highest content  of heavy metals absorption the transition coefficients of metals in the system "roots - green mass" increase in the following : Pb → Co → Ni → Cd.  The coefficients of biological absorption of metals by Jerusalem artichoke increase in a number of elements: Co  → Ni → Ld → Ca. Where as  The coefficients of biological accumulation of heavy metals with Jerusalem artichoke increase in a number of elements following series : L → Co → Ni → Ca. It is recommended to use Jerusalem artichoke as a phytoremediator of man-made areas.

In the modern systems of transportation of oil, gas and condensate, in the units of regasification of liquefied natural gas, two-phase flows play an increasingly important role in technological equipment used in the chemical and oil refining industry, power engineering and other industries. All available studies on the formation of gas hydrates were mainly focused on their ability to clog pipes along their entire length. While their ability to cause (initiate) corrosion remains virtually unexplored. Therefore, to increase the efficiency of industrial pipelines it is necessary to study the joint effect of hydration formation and stresses of friction on corrosion of the pipeline. The mathematical model of pipeline corrosion has been further developed by considering the influence of the gas hydrate. The influence of pressure, temperature on the speed of corrosion processes is estimated and it is shown that under the most unfavorable conditions the corrosion rate under the action of gas hydrates can increase several times.

No abstract

A study on the influence of the composition of the model media of the soil electrolyte (NS1-NS2) on the corrosion rate of tubular steels 17G1S and 13G1S-U in a long-term experiment. The phase composition and structure of corrosion products were determined by X-ray analysis. using an X-ray diffractometer Shimadzu XRD-7000. It was found that, regardless of the steel grade, the composition of corrosion products in the environment of NS1 will be mainly characterized by the presence of lepidocrocite, and in the environment of NS2 -goethite. The corroding samples in both media will have a small amount of magnetite. During the exposure (609 days) of steel samples in the studied model media, the rate of corrosion processes depends on the component composition of the model media, steel grade and pH. The obtained results are important for predicting the behavior of underground pipelines in soils of different corrosive activity.