Repository logo
  • English
  • 中文
Log In
Have you forgotten your password?
  1. Home
  2. College of Engineering / 工學院
  3. Applied Mechanics / 應用力學研究所
  4. A study of one-dimensional mechanical vibrating systems with piecewise constant properties and its applications as an optical viscosimeter
 
  • Details

A study of one-dimensional mechanical vibrating systems with piecewise constant properties and its applications as an optical viscosimeter

Date Issued
2009
Date
2009
Author(s)
Stachiv, Ivo
URI
http://ntur.lib.ntu.edu.tw//handle/246246/184841
Abstract
This thesis deals with an analysis and application of the vibrating one-dimensional mechanical systems with piecewise constant properties. It is a well known fact that the fist step in a vibration analysis of any mechanical system is to find spectrum of their natural frequencies. It can be done either numerically or analytically. For simple vibrating systems like beam, string or cantilever with constant mechanical properties the analytical determination of the normal modes is known and is preferable one. However many real applications involve not a constant but a piecewise constant and, factually discontinuous properties. For composed systems the numerical determination of the normal modes is usually performed. We have found here that the normal modes for one–dimensional mechanical problems with piecewise constant properties can be obtained by solving an appropriate transcendental equation. This equation of course contains all information about given mechanical system (elastic moduli, density, cross-sectional area of material, thickness of each layer with constant mechanical properties, etc.). In this thesis transcendental equation is derived for case of one-dimensional systems with N - piecewise constant properties. The physical interpretation of normal modes for this kind of mechanical systems by introducing the “effective” propagation velocity has been put forward. An optical method utilizing a forward light scattering pattern has been carried out to test the validity of the theory for N = 2. Theoretical predictions of the first mode frequency and experimental data agree precisely. Moreover the extension of the analysis and experiments for a case of the partially submerged fiber in fluid with taking into account of a viscous damping has been performed. From obtained results a simple way for viscosity extraction from either the maximum vibrational amplitude or the power bandwidth variation has been suggested and tested experimentally. Besides an explicit formula for the achievable accuracy of the viscosity sensing is derived here as well.
Subjects
normal modes
optical viscosimeter
vibration
Type
thesis
File(s)
Loading...
Thumbnail Image
Name

ntu-98-D92543015-1.pdf

Size

23.53 KB

Format

Adobe PDF

Checksum

(MD5):c69f75bc9741a6217acc1a6071eeb152

臺大位居世界頂尖大學之列,為永久珍藏及向國際展現本校豐碩的研究成果及學術能量,圖書館整合機構典藏(NTUR)與學術庫(AH)不同功能平台,成為臺大學術典藏NTU scholars。期能整合研究能量、促進交流合作、保存學術產出、推廣研究成果。

To permanently archive and promote researcher profiles and scholarly works, Library integrates the services of “NTU Repository” with “Academic Hub” to form NTU Scholars.

總館學科館員 (Main Library)
醫學圖書館學科館員 (Medical Library)
社會科學院辜振甫紀念圖書館學科館員 (Social Sciences Library)

開放取用是從使用者角度提升資訊取用性的社會運動,應用在學術研究上是透過將研究著作公開供使用者自由取閱,以促進學術傳播及因應期刊訂購費用逐年攀升。同時可加速研究發展、提升研究影響力,NTU Scholars即為本校的開放取用典藏(OA Archive)平台。(點選深入了解OA)

  • 請確認所上傳的全文是原創的內容,若該文件包含部分內容的版權非匯入者所有,或由第三方贊助與合作完成,請確認該版權所有者及第三方同意提供此授權。
    Please represent that the submission is your original work, and that you have the right to grant the rights to upload.
  • 若欲上傳已出版的全文電子檔,可使用Open policy finder網站查詢,以確認出版單位之版權政策。
    Please use Open policy finder to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
  • 網站簡介 (Quickstart Guide)
  • 使用手冊 (Instruction Manual)
  • 線上預約服務 (Booking Service)
  • 方案一:臺灣大學計算機中心帳號登入
    (With C&INC Email Account)
  • 方案二:ORCID帳號登入 (With ORCID)
  • 方案一:定期更新ORCID者,以ID匯入 (Search for identifier (ORCID))
  • 方案二:自行建檔 (Default mode Submission)
  • 方案三:學科館員協助匯入 (Email worklist to subject librarians)

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science