Plant (vegetable) oils are renewable fluids. They have been developed to replace mineral-based fluids. Due to their distinguished features including eco-friendly properties and possibility of reducing the hydrocarbon and carbon dioxide emission when being used in the industrial processes or internal combustion (IC) engines, they are considered a sustainable source of biodegradable fluids. In this work, non-edible sunflower oil is investigated as a bio hydraulic fluid under various normal loads utilizing the four-ball tribotester. Considering the American Society for Testing and Materials (ASTM 4172-B) standard, all the experiments are conducted for different loads from 45 kg to 70 kg, the balk temperature was increased until 75°C, rotational speed to 1200 rpm and every experiment was run for one hour. Compared with the mineral-based fluid sample, the outcomes shown that the sunflower oil possesses sufficient properties (anti-wear and anti-friction) especially under lower than 60 kg as a normal load. The results also shown that the sunflower oil is capable to be utilized as a hydraulic fluid.

No abstract

No abstract

No abstract

The method for constructing functions with finite support is used, which combines the properties of FEM functions and approximations in the form of series with unknown coefficients. To illustrate the properties of the approximating function constructed, we present the results of the solution of the 2D theory of elasticity for a thin plate, shown on figure 1,b. The thickness of the plate is h. One facet of the plate (at x = −a) is fixed and the other one (at x = − a) unfixed; the remaining two are under shear stresses τ and an evenly distributed load θ. The solution of the problem of determining the stress and strain in the plate can be obtained from the steady-state condition of the Lagrange functional by using the functions of class C0 of the high-degree approximation for scientific calculations. The calculations show that the obtained solution has high accuracy, even in cases when the length of the rectangular domain is considerably greater than its width.