臺灣博碩士論文加值系統

本文主要在探討具裂縫撓性樑，在往復振動時的動態特性，文中利用裂縫
端點區應力、應變導致之能量散失率（Energy Release Rate），推導具
裂縫樑裂縫的局部剛度效應。文中亦分別建立有限元素模態法（Modal
Expansion Method）及雙跨踞樑解析法（Two-Span Analytical Method）
針對裂縫往復振動導致之週期性剛度變化，探討裂縫樑之動態特性與諧振
響應。裂縫深度、位置對裂縫樑動態特性之影響亦為文中分析重點。結果
顯示前述兩種分析模式均可得甚佳之結果。

The effect of finit crack on the dynamic characteristics and
the harmonic response are investigated in this thesis. The
energy release rate introduced by the crack is used to derive
the local stiffness. Two methods : the modal expansion method
and the two-span beam analytical method are proposed to analyze
the dynamic response of a cracked beam. The effect of crack
length and crack position on the beam natural frequ- encies and
mode shapes are also analyzed. Results indicate that the
proposed two methods are feasible and reliable.