English  |  正體中文  |  简体中文  |  Items with full text/Total items : 68069/68069 (100%)
Visitors : 23173425      Online Users : 232
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version


    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/79661


    Title: 以有限元素法模擬單向度束制壓縮下顆粒體與容器壁間的互制行為及摩擦效應的影響
    Authors: 林育霆;Lin, Yu-Ting
    Contributors: 機械工程學系
    Keywords: 有限元素法;顆粒體;單向度束制壓縮;摩擦係數;內部性質
    Date: 2018-11-07
    Issue Date: 2019-04-02 15:11:15 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本研究的目的在使用線性彈性與多孔彈性有限元素法探討鋼珠顆粒體在壓克力圓柱形薄壁容器內受到單向度束制壓縮時的力學行為,並與鋼珠顆粒束制壓縮實驗結果比較,數值模擬採用有限元素分析軟體(ABAQUS),其中材料參數從束制壓縮物理實驗取得,此外透過多孔彈性有限元素模型以及實驗探討不同摩擦係數對鋼珠顆粒體在束制壓縮時力學性質的影響,並利用數值模擬進一步探討不同摩擦係數對鋼珠顆粒體內部力學性質的影響。
    研究結果顯示線性彈性與多孔彈性有限元素法模擬的力學行為與實驗結果一致,一致的物理量包括負載傳遞效率、壁面正向壓力、顆粒體平均垂直應力、壁面剪應力、側向壓力比、體壁啟動摩擦係數、容器環向應力和容器軸向應力,其中多孔彈性有限元素法模擬的整體勁度曲線與實驗結果較為吻合。此外由於有限元素法是基於連續體理論,造成數值模擬在圓周頂部與底部出現數學奇異點(singularity),導致較不穩定的數值出現。從不同摩擦係數的研究結果發現整體勁度、負載傳遞效率、顆粒體平均垂直應力皆隨著體壁摩擦係數的增加而減小,這是受到顆粒與容器壁間摩擦係數的影響。然而壁面正向壓力、側向壓力比、容器環向應力隨著體壁摩擦係數的增加而減小,這是受到顆粒間摩擦係數的影響。而從鋼珠顆粒體的內部力學性質來看,徑向應力與垂直應力分佈皆隨體壁摩擦係數增加而減小並隨深度增加而減小,剪應力分佈則呈現外側往內側衰減的趨勢,且影響範圍隨體壁摩擦係數的增加而越靠近內側。
    ;The purpose of this study is to investigate the mechanical behavior of steel beads under uni-axial confined compression. The main interest focuses on the interaction between the granular solid and the contacting cylindrical tube. The linear elastic and porous elastic finite element methods are used to model this compression particular system. The previous experimental results are used to validate the proposed FEM models. The influence of friction coefficient on the mechanical response of steel beads during confined compression is further explored.
    The results show that the proposed FEM models (linear elastic and porous elastic) produce good agreement with the corresponding experiments for load transfer efficiency, normal wall pressure, average vertical stress in the bulk solid, shear wall traction, lateral pressure ratio, mobilized bulk wall friction, hoop and axial stresses of the cylindrical tube. The overall loading stiffness, load transfer efficiency and average vertical stress in the bulk solid decrease with the increasing particle-wall coefficient of friction. However, the normal wall pressure, lateral pressure ratio and hoop stresses of the cylindrical tube decrease with the increasing inter-particle coefficient of friction. Both the radial and vertical stresses in the granular solid decrease with the increasing particle-wall coefficient of friction. Shear stresses in the granular solid increase with the increasing particle-wall coefficient of friction.
    Appears in Collections:[機械工程研究所] 博碩士論文

    Files in This Item:

    File Description SizeFormat
    index.html0KbHTML58View/Open


    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明