Dynamics of a single mass vibrating system impacting into a deformable support

The investigated system comprises a mass attached by a deformable link to a fixed foundation, and an elastic-dissipative limiter of motion of that mass. Such types of systems are widely used in different technological devices and machines. This paper is devoted for the improvement of dynamical qualities of such systems. Free and forced stationary harmonic vibrations as well as the qualitative parameters of motions of the system are analyzed in this paper. Characteristics of vibrations are determined using analytical and numerical techniques. It is determined that for the case of zero fastening the values of eigenfrequencies of the system do not depend on the amplitude of excitation. Then the system has an infinite number of multiple eigenfrequencies. In the case of forced harmonic excitation single valued stable motions exist in the vicinity of the resonance. This gives rise to some qualities of the system which are useful in practical applications

Wave Displacement

Here the system displaced by waves with two degrees of freedom is analyzed when one member of the system, while contacting with the working profile of the input member performing wave motion, provides motion to the output system. For the analytical investigation modification of the asymptotic method is used, which is based on the division of motion into the slow and quick motions. This method is justified when the frequencies of variation of slow motions are much smaller than the frequencies of quick motions. More complicated cases are investigated by numerical methods

Measurement of plane vibrations of a two dimensional elastic structure

Plane vibrations of a two dimensional elastic structure are analyzed in this paper. The vibrations taking place according to the eigenmode are represented by using the method of stroboscopic geometric moiré. This requires to perform the investigation for two mutually perpendicular directions of moiré fringes. Here the superimposed moiré technique is proposed to represent both images at the same time

Measurement of stresses in polymeric films with Braille and tactile elements

The paper is devoted to the problem of stress measurements in polymeric films with Braille and tactile relief elements by using the method of photo-elasticity. A separate Braille and tactile relief element is analyzed numerically by using an axisymmetric model and the problem of determination of distribution of equivalent stress is investigated. Nodal stresses are calculated by using the procedure of conjugate approximation. Equivalent stresses are represented by intensity of the image. A special experimental setup was developed for the measurement of stresses in polymeric materials. The obtained results of investigations are used in the process of design of polymeric films with Braille and tactile relief elements by taking into account the stress distributions in them

Vibrations, stability and compression of elements of packages made from corrugated board

The paper considers vibrations, stability and compression of a package element made from corrugated board. The analysis is based on a model of a structure consisting from twodimensional beams taking into account the orthotropic properties of the corrugated board. The problem of initial stability was solved and the first eigenmodes of stability were obtained. Performed experimental study allowed to determine the dependence of the vertical compression force on the geometrical parameters of the multilayered board before the development of plastic deformations in the board. The results of investigation are used for the design of package elements

Selection of number of gaps in superimposed moiré measurements

Plane vibrations of a two dimensional elastic structure are investigated in this paper. Vibrations taking place according to the eigenmode are represented by using the method of stroboscopic geometric moiré. Selection of number of gaps when using the superimposed moiré technique is investigated and recommendations for choosing of their number are provided

Vibrational method of cleaning of surfaces from homogeneous waste materials

Cleaning of contaminated surfaces is closely related to the study of adhesion forces between particles and the surface. Despite numerous technological advancements, the adhesion of particles and surfaces is a phenomenon that is far from being fully understood. This is due to many factors acting during process, - such as the surface roughness and material type, size, shape, electrostatic properties of particles, etc. A surface cleaning device based on nonlinear vibration of the contact element is presented in this paper. Relationships describing the periodic motion in steady state operating regimes are obtained. Characteristics of motion as functions of the frequency of excitation are investigated. Experimental investigations were performed for the determination of the influence of the cleaning velocity on the vibration frequency. It is shown that this dependence is directly related to adhesion forces between particles and the surface. Test results are in good accordance with theoretical predictions

Measurement of stresses in a vibrating polymeric film

One dimensional model for the investigation of longitudinal vibrations of polymeric film is investigated. Comparison of stroboscopic and time averaged intensities in the photo-elastic images is performed. Results about the required number of images for performing time averaging are provided. Recommendations for simultaneous application of both stroboscopic and time averaged photo-elasticity for measurement of stresses are given. One dimensional model for the investigation of vibrations of polymeric film having two nodal degrees of freedom (longitudinal displacement and displacement of the upper surface, assuming that displacement of the lower surface is of the same value but in the opposite direction) is investigated. This model is applied for the interpretation of results of thermo-elastic analysis. Recommendations for the interpretation of the stress field by using photo-elastic and thermo-elastic methods are provided

Investigation of dynamics of fluid in the elements of a pipe robot

The dynamics of fluid in the elements of a pipe robot is investigated in this paper. Plane vibrations of ideal compressible fluid are analyzed by taking account the constraint of non-rotation by means of the penalty method. Reduced order numerical integration of the penalty term is performed. Graphical representation of rotations at the points of reduced integration is proposed for validation of the calculated eigenmodes. Fluid flow through different cross sections of nano-holes in metal sheets separating different compartments of a pipe robot is important in the design of a pipe robot. Calculation of the mass flow rate is necessary when performing the comparison of different cross-sections. A two-dimensional model performing the discretization of the cross-section is used for the solution of this problem. The obtained results are used in the process of design of a pipe robo

Development and experimental analysis of layered actuators

Calculations indicate that a layered actuator composed of constituent elements tied together with binding material is a system characterized by high static strength. For this reason, these actuating systems are implemented in mechanisms that operate under heavy loads and require very precise displacements. Layered actuator used in mechanisms requiring high precision displacements have demonstrated that accuracy depends on design and technological factors. Analysis of different parameters of the actuator has enabled optimization of the structures and determination of their capabilities under varying mechanical load