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Numerical analysis of an auxetic anti-tetrachiral sandwich panel subjected to steady-state harmonic base motion

Michalski Jakub, Stręk Tomasz

Vibrations in Physical Systems

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2022

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Vol. 33, nr 3

art. no. 2022323

EN

In this paper, the authors show the results of numerical simulations representing the test of an aluminum sandwich panel with an auxetic anti-tetrachiral core on an exciter. Steady-state vibration analyses utilizing modal superposition (linear dynamics) were performed. The bottom of the panel had all the degrees of freedom constrained and excitation in form of base acceleration in the vertical direction was applied. The obtained results were in form of contour plots of selected output variables in the frequency domain. In addition, curves showing the variation of acceleration, velocity and displacement of a selected representative point in frequency were generated. The results were compared with those obtained for the panel with a non-auxetic core, in the form of a standard hexagonal honeycomb. It was found that the auxetic panel is not superior in the whole range of frequencies but a workflow useful in the design of sandwich panels for operating conditions involving vibrations was developed.

2

The vibrations induced by fluid flow in plates with different Poisson’s ratios

Burlaga Bartłomiej, Stręk Tomasz

Vibrations in Physical Systems

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2020

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Vol. 31, nr 3

art. no. 2020301

EN

A fluid interacts with every solid object that is submerged in its flow. In this paper, the dynamic instability of elastic solid is modeled and analyzed based on the benchmark model. It is caused by a continuous stream of vortices (known as von Kármán vortex street). In the presented approach, prerequisites are calculated to meet the necessary conditions for this phenomenon to occur. The main objective of this study is to determine the influence of different Poisson ratios on the intensity of a solid body’s deflection. In the first part, governing equations are presented. The following part describes the model domain as well as assumed parameters with chosen values explanation. The third part presents simulation specific information - mesh and applied options. The conclusion and possible real-life applications are preceded by obtained results.

3

Finite element analysis of natural frequencies and mode shapes of the da Vinci medical robot arm

Geda Helena, Kuliberda Agata, Stręk Tomasz

Vibrations in Physical Systems

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2020

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Vol. 31, nr 2

art. no. 2020205

EN

This paper presents an analysis of the natural frequency and mode shapes of the arm and the working tip of the da Vinci robot, which is used in various types of surgical procedures. The survey was conducted using Autodesk Fusion 360. Using the da Vinci robot's construction data, a model was designed taking into account the characteristic dimensions and materials used. The obtained shapes of vibrations for natural frequencies allowed us to predict the influence of resonance phenomenon on the manipulator's arm. The movement of the tool along the wrong track, caused by an increase in vibration amplitude, may adversely affect the operation of the device. The results of the conducted research, therefore, provide information for which natural frequencies the values of these amplitudes increase.

4

Analysis of eigenfrequencies of the foot prosthesis with auxetic component layer

Łączna Daria, Dłużniewski Filip, Stręk Tomasz

Vibrations in Physical Systems

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2020

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Vol. 31, nr 2

art. no. 2020214

EN

In this paper, natural frequencies of a three-layered foot prosthesis are investigated. The model of foot prosthesis consisted of a three-layered base, which substitutes a human foot and an element in the shape of an arc that represents a shank of human. The base consists of three layers made of carbon fiber. In the lower part of the prosthesis, the auxetic layer is used as the inner layer. Numerical analysis is made for different parameters of the central layer: the thickness and the value of Poisson’s ratio. The simulations are used to investigate the influence of an auxetic layer on prosthesis vibrations and compare the impact of different parameters on results. Calculations are made using the finite element method implemented in Autodesk Fusion 360. The results show that the auxetic layer has a great impact on tolerance to vibrations and mobility.