This paper considers the coupled kinematic and dynamic models of a mobile crane. A full description of boom and load movement has been provided as a response of the system to the influence of kinematic forces. The linear system model was treated as rigid, and the carried load as a nondeformed static body. To describe the position of said load, Bryant angles were used. The dynamic model includes the impact of external forces (wind pressure) while load carrying and positioning. Algorithm and calculation software were developed to enable dynamic phenomena analysis during both a work cycle and free movement of said load. The initial problem was solved by means of the ode45 calculation procedure in the Matlab software based on the Runge–Kutta 4th Order Method. The work presents exemplary results of load movement simulation with respect to various wind velocities, selected on the basis of guidelines from Poland’s standards regarding safe operation of mechanical equipment.
The paper presents wind turbine simulation tests using SolidWorks software. The geometrical model of the HAWT wind turbine was developed based on a real object. It consisted of three selected parts: shell, bearing girders and stiffening ribs. The wing profile of the analyzed object was modelled using NREL’s and NACA airfoils. A numerical analysis was carried out to determine the strength of the tested structure under specific wind speed. Stresses were calculated according to the Huber-Mises hypothesis.
This paper concerns the modelling of the solidification process including the phenomena of heat transfer and fluid flow during the initial stage of the metal casting process. During this period, the molten metal motions have an essential influence on solidification kinetics. An analysis of solidification kinetics, by determining the velocity and temperature fields in a system of riser-casting was made. Velocity fields were obtained by solving the momentum equations and the continuity equation, while the thermal fields were obtained by solving the conduction equation containing the convection term. After completion of the filling process the main solidification of molten metal takes place and its shrinkage. The phenomenon of casting shrinkage cannot be avoided, but it is possible to minimize its negative effects on the casting quality. One with ways to solve this problem is to design the mould in such a way that the solidification proceeds in accordance to the assumed direction and finished in the riser. Generally, the aim of search is to obtain a casting without shrinkage defects.
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