Performance Evaluation of the Vehicle Vibration Safety in the Frequency Domain

The article deals with mathematical modelling of the nonlinear system of vehicle vibration isolation. It is known that this problem can be solved both in the frequency and in the time domains. To assess the adequacy of the results obtained, a computation algorithm for evaluated performances in the frequency domain is considered at the first stage of the study. In this case, a statistical linearization procedure is used through the example of a spatial dynamic model equivalent to the primary and secondary vibration isolation systems of a two-axle vehicle (a dynamical system with seventeen degrees of freedom). A matrix method for determining the frequency characteristics of a given dynamical system is used, and the adaptation features of four known methods of statistical linearization are shown. The article focuses attention on advantages of the system frequency representation when testing it and determining the main parameters. In order to generalize the conclusions when comparing the calculation results in the frequency and time domains, computations were performed for two variations of the intensity of the disturbing action. Such a "hard-line" approach enables us to determine the impact of the nonlinear characteristics of the vibration isolation system components on the output integral and separate-frequency performance estimates, taking into account a vehicle's safety criterion.The simulation results of this system show different values of the integral and separate-frequency estimates for all four methods of statistical linearization, regardless of the intensity of disturbing action and the loss probability of contact between the tire and the wearing surface from 5% to 30%. The calculation data obtained allow comparing with the mathematical modelling results of the given dynamical system in the time domain and defining position according to recommendation of the statistical linearization method.

A deusa compõe um “mito”: o jovem Odisseu em busca de veneno (Odisseia I, 255-68)

<p class="MsoNormal" style="margin: 0cm 0cm 0pt; text-align: justify; line-height: normal; mso-layout-grid-align: none;"><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">This paper explores the inter- and extradiegetical </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">functions of a story about Odysseus narrated by Athena to Telemachos </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">in </span><em><span style="font-family: 'Aldine401BT-ItalicA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-ItalicA; mso-ansi-language: EN-US;" lang="EN-US">Odyssey </span></em><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">1, 255-68. It is argued that the representation of Odysseus </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">in search of poison for his arrows need not to be thought first and f</span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">oremost as a non-Homeric element or a morally disturbing action, </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">for it may be analyzed by means of epic themes (specially by the </span><em><span style="font-family: 'Aldine401BT-ItalicA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-ItalicA; mso-ansi-language: EN-US;" lang="EN-US">mêtis</span></em><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">-megatheme) explored not only in the </span><em><span style="font-family: 'Aldine401BT-ItalicA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-ItalicA; mso-ansi-language: EN-US;" lang="EN-US">Odyssey </span></em><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">but in the </span><em><span style="font-family: 'Aldine401BT-ItalicA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-ItalicA; mso-ansi-language: EN-US;" lang="EN-US">Iliad </span></em><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">as </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA; mso-ansi-language: EN-US;" lang="EN-US">well. Besides, this story anticipates and condenses the plot of the </span><span style="font-family: 'Aldine401BT-RomanA','serif'; font-size: 10pt; mso-bidi-font-family: Aldine401BT-RomanA;">poem.</span></p>

A deusa compõe um “mito”: o jovem Odisseu em busca de veneno (Odisseia I, 255-68)

This paper explores the inter- and extradiegetical functions of a story about Odysseus narrated by Athena to Telemachos in Odyssey 1, 255-68. It is argued that the representation of Odysseus in search of poison for his arrows need not to be thought first and foremost as a non-Homeric element or a morally disturbing action, for it may be analyzed by means of epic themes (specially by the mêtis-megatheme) explored not only in the Odyssey but in the Iliad as well. Besides, this story anticipates and condenses the plot of the poem.