Oscilatii mecanice
description
Transcript of Oscilatii mecanice
![Page 1: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/1.jpg)
Oscilatii mecaniceOscilatii mecanice
![Page 2: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/2.jpg)
Oscilatiile mecanice sunt Oscilatiile mecanice sunt inregistrate de animaleinregistrate de animale
• Receptori specificiReceptori specifici
• Purtatoare fizice de Purtatoare fizice de informatieinformatie
![Page 3: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/3.jpg)
SunetulSunetul• Frecvente intre 16 Hz si 20 KHzFrecvente intre 16 Hz si 20 KHz
• Pentru om, in aerPentru om, in aer
• Frecvente < 20 HzFrecvente < 20 Hz
• Frecvente > 20 KHzFrecvente > 20 KHzInfrasuneteInfrasunete
UltrasuneteUltrasunete
![Page 4: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/4.jpg)
Vibratii mecaniceVibratii mecanice• De interes pentru medicina munciiDe interes pentru medicina muncii
Exemple:Exemple:vibratii in tractoare, autocamioane, masinivibratii in tractoare, autocamioane, masini
rau de mare, dureri lombarerau de mare, dureri lombare
![Page 5: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/5.jpg)
Corpul omenesc vibreaza daca Corpul omenesc vibreaza daca este in contact cu obiecte este in contact cu obiecte solide care vibreazasolide care vibreaza• Sunt de interes:Sunt de interes:
– Intesitatea vibratiei Intesitatea vibratiei – Eficienta trasferuluiEficienta trasferului– Frecventa de rezonantaFrecventa de rezonanta
![Page 6: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/6.jpg)
FizicFizicaa
Problema Problema de: ocilatori, de: ocilatori, amortizari, amortizari, oscilatii oscilatii fortate, fortate, rezonantarezonanta
![Page 7: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/7.jpg)
![Page 8: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/8.jpg)
Oscilator armonic simplu:Oscilator armonic simplu:
max sinx x t
““Deplasarea”Deplasarea”
““Deplasarea Deplasarea maxima”maxima” AmplitudineaAmplitudinea
Frecventa Frecventa unghiularaunghiulara
PulsatiPulsatia a
![Page 9: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/9.jpg)
Prin derivare la timpPrin derivare la timp
max cosdxv x tdt
max sinx x t
![Page 10: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/10.jpg)
Proprietatile viscoelastice ale Proprietatile viscoelastice ale materialelor biologicematerialelor biologice
Efort unitar
FA
0
ll
Deformare relativa
Limita de elasticitate
Limita deformarii reversibile de vascoelasticitate
Punctul de rupere
![Page 11: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/11.jpg)
Y Modulul lui Young
![Page 12: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/12.jpg)
Element elastic
Element de amortizare
Element Maxwell
Element Voight
![Page 13: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/13.jpg)
Sistemele reale sunt formate Sistemele reale sunt formate din combinatii de elemente din combinatii de elemente Maxwell si VoightMaxwell si Voight
![Page 14: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/14.jpg)
http://www.lib.mcg.edu/edu/eshuphysio/program/section4/4ch2/s4ch2_31.htm
Elastina
Colagenul, elastina, rezilina
Proprietatile elastice ale tendoanelor si ligamentelor
![Page 15: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/15.jpg)
Ajuta la stocarea energiei Ajuta la stocarea energiei pentru miscari bruste sau pentru miscari bruste sau periodiceperiodice
www.chriss3d.com/grass/grass.rar
Eliberare de energie
~ 5 kW/kg muschi
![Page 16: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/16.jpg)
Fiecare parte a unui sistem are Fiecare parte a unui sistem are o frecventa proprie o frecventa proprie caracteristicacaracteristica• Sub actiunea unei oscilatii externeSub actiunea unei oscilatii externe
• Frecventa << frecventa Frecventa << frecventa caracteristicacaracteristica
Frecventa ~ frecventa Frecventa ~ frecventa caracteristicacaracteristica
Amplitudinea si faza Amplitudinea si faza
oscilatiei externe oscilatiei externe
Amplitudinea Amplitudinea
Amplitudinea Amplitudinea oscilatiei externeoscilatiei externe
<< >> ====
![Page 17: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/17.jpg)
![Page 18: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/18.jpg)
Frecevente sub 2 Hz nu pot fi Frecevente sub 2 Hz nu pot fi atribuite proceselor mecaniceatribuite proceselor mecanice• Ex.: 0,3 HzEx.: 0,3 Hz
http://grouper.com/video/MediaDetails.aspx?id=1738556&ml=o%3d7%26fk%3dSeasick%26fx%3d&
![Page 19: Oscilatii mecanice](https://reader033.fdocument.pub/reader033/viewer/2022061313/56815dcb550346895dcbf68f/html5/thumbnails/19.jpg)
SunetulSunetul
0
10lg ILI
Legea Weber-Legea Weber-FechnerFechnerIntensitatea sunetului (W/m2)
Intensitatea nivelului sonor – decibeli – (dB)
10-12 W/m2: sunet de referinta