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題 名 | 非均質裂紋樑之動態行為=Dynamic Behavior of Nonhomogeneous Cracked Beam |
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作 者 | 張燕玲; 周紀文; 王世章; | 書刊名 | 力學 |
卷 期 | 13:3 1997.09[民86.09] |
頁 次 | 頁225-235 |
分類號 | 441.563 |
關鍵詞 | 動態微結構有限元素法; Newmark方法; 非均質裂紋樑; 動應力強度因子; Dynamic micro-structural finite element method; Newmark method; Non-homogeneous cracked beam; Dynamic stress intensity factor; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究主要利用動態微結構有限元素法和加入位移束制條件的Newmark方法,求出 裂縫尖端的相對位移,進而計算動應力強度因子,以探討非均質裂紋樑之動態行為。動態微 結構有限元素法是以靜態微結構有限元素法為基礎,求元素內每顆粒之動能及位能,再利用 哈密頓原理而推得元素之運動方程式,所謂微結構有限元素就是將結構體視為由許多顆粒組 成, 顆粒間之變形以虛擬彈簧模擬之,此虛擬彈簧之勁度以 Hertz 之接觸理論為基礎設定 之。此外為了探討非均質樑之動態行為,本文以兩種不同之顆粒結成之微結構來模擬非均質 材料。但當裂紋樑受動力載重時,其裂縫表面會以閉合一張開的運動,為處理此動態接觸行 為,則在 Newmark 方法中加入位移束制。 最後,本文以龜裂簡支樑及懸臂樑在動荷重作用 下為例,探裂縫深度和樑深比、均質之位置裂縫之位置、及勁度變化對動應力強度因子之影 響。 |
英文摘要 | This paper is to analyze the dynamic stress intensity factor of the non -homogeneous cracked beams under dynamic loading by the dynamic micro-structural finite element method (DMFEM)in conjunction with the dis-placement-control Newmark scheme. The DMFEM based on micro-structural finite element method is ex-tended to derive the equations of motion for the system. A micro-structural finite element is assumed to comprise a number of particles. Each particle is regarded as rigid and the contact points of two particles are assumed to be j oined by pseudo springs to transmit forces through their contacts. Moreover, the granular structure consisted of two kinds of granules is used to model the non-homogeneous material. When the cracked beam is subjected to dynamic loadings, the crack surfaces will close and open regularly. In order to treat the behavior of the dynamic contact problem, the displacement con-straint is imposed in the Newmark method. Examples of cracked simple-supported and cantilever beams sub-jected to dynamic loading are studied. The effects of crack length, nonhomogeneous position, crack location, and material stiffnesses to the dynamic stress intensity factor of the cracked beams are investigated. |
本系統中英文摘要資訊取自各篇刊載內容。