In this thesis characteristics of dynamical flexibility with taking into consideration the transportation effect were presented. The considered system is the elastic beam with a symmetrical section. The beam was weighted down by the harmonic bending force and the model of mechanism was described in two reference systems: global and local.
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The paper concerns the problem of determining the dynamical flexibility of elastic beams. The standard method ot separation of variables and the Galerkin method were used. The considered systems are elastic beams with symmetrical sections. Beams were weighted down by the harmonic bending forces and the model of beam was described in one global reference system.
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One of the most popular method of vibrating systems analysis is dynamical flexibility method. This method makes possible the assignment of stability bands. The thesis is applied to the free-free damped beam systems analysis. The beam is loaded by transversal unitary force in accordance with a dynamical flexibility definition. In a mathematical model Coriolis forces, centrifugal forces and damping forces were took into the consideration. The damping forces enable active vibration control and can change dynamical characteristics of the system.
Badając drgające ogniwa robotów, stosuje się często modele tych obiektów w postaci prętów czy belek o odcinkowo stałym przekroju. Takie podejście jest często zbyt odległym przybliżeniem zmienności przekroju tych obiektów, a wyznaczone charakterystyki nie opisują w sposób zadowalający zachowania badanego układu. Aby uściślić analizę modeluje się ogniwo o zmiennym przekroju pojedynczą belką o różnych postaciach funkcji, określającej jego zmienność. W pracy przedstawiono sposób wyznaczenia podatności dynamicznych belki w przypadku zmiany przekroju według funkcji f(x) = ex.
EN
In the research of vibrating links of robots, with nonlinear changeable sections, models with segments of constant section are often applied. Such an approach may be far too inadequate to approximate sections changes, so the determined dynamic characteristics do not describe the behavior of the investigated system in a satisfactory way. To make the analysis more precise, the investigated object with changeable sections is replaced by a single bar or with a various-form function describing the section change. In the paper the way of determination of dynamical flexibilities of beam with changeable sections according to function f(x) = ex has been shown.
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One of the most popular method of analyzing vibrations and dynamical states of systems is the method of dynamical flexibility. There is considered the system of damped rod in rotational transportation. The dynamical flexibility was derived from previously recognized equations of motion. Dynamical characteristics were presented in form of charts of attenuation depending on frequency. There were compared the known characteristics of stationary systems with characteristics of systems in rotational transportation without the damping and also with characteristics of rotating systems with taking into consideration the damping.
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Purpose: High work speeds of mechanisms, using materials with high flexibility, high precision of work, etc. are the cause of searching of the new ways of modelling. One of these ways is presented in this thesis. The main purpose of this thesis is the dynamical analysis with taking into consideration the interaction between main motion and local vibrations during the model is loaded by longitudinal forces. Design/methodology/approach: Derived equations of motion were made by classical methods, with generalized coordinates and generalized velocities assumed as orthogonal projections of individual coordinates and velocities of the rod and manipulators to axes of the global inertial frame. Findings: Mathematical model of the longitudinally vibrating systems in terms of plane motion can be put to use to derivation of the dynamical flexibility of these systems, and also those equations are the starting point to the analysis of complex systems, especially we can use those equations to derivation of the substitute dynamical flexibility of n-linked systems in transportation. Research limitations/implications: In the thesis were considered mechanical systems vibrating longitudinally in terms of rotation. Next problem of dynamical analysis is the analysis of systems in non-planar transportation and systems loaded by transversal forces. Practical implications: Results of this thesis can be put to use into machines and mechanisms in transportation such as: wind power plant, high speed turbines, rotors, manipulators and in aerodynamics issues, etc. Originality/value: Up to now there were analyzed beams and rods in a separate way, first main motion of the system and after that the local vibrations. The new approach of modelling were presented by authors of this thesis, a new modelling took into consideration the interaction between those two displacements. There was defined the transportation effect for models vibrating longitudinally in this thesis.
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In the paper analysis process of continuous systems with transverse vibrations applicalion of the malrix method was described. For determination of flexibility of the n-elements robot's arms the hyper graph aggregation method was showed. As a final point the flexibility for the complex systems calculation was derived.
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