貼附限制層阻尼之複合材料積層板殼低速衝擊特性之研究

The Characteristic of Composite Laminate Plates and Shells with Constrained Layered Damping Subjected to Low-velocity Impact

羅光閔(Guang-Min Luo)

指導教授 ： 李雅榮

國立臺灣大學/工學院/工程科學及海洋工程學研究所/博士(2008年)

https://doi.org/10.6342/NTU.2008.00877

摘要

纖維強化塑膠（FRP）複合材料具有質輕、高剛性與高比強度等優點，近年來已被廣泛地使用在各種不同結構物的建造上。但一般積層複合材料在厚度方向上沒有纖維的補強，因此耐衝擊強度較差，並造成材料應用上的限制。本文希望藉由限制層阻尼（Constrained layered damping, CLD）於振動中消散能量的特性，來提升複合材料積層板殼之衝擊強度，並透過實驗與數值模擬加以確認。
破壞模式方面，同時考慮積層材料之纖維破壞（Fiber breakage）、樹脂破壞（Matrix creaking）、脫層破壞（De-lamination），以及限制層阻尼之黏彈性膠（Visco-elastic glue）與限制層金屬之破壞。有限元素模擬時，採用漸進式剛性修正機制（Progressive stiffness degradation）修正破壞發生後之剛性，並使用ABAQUS-UMAT自行定義材料特性進行模擬。有限元素模型採用三維二階實體元素（Solid element），可獲得較精確之應力場，衝頭與試片則是考慮接觸（Contact）機制與幾何非線性，以符合實際之狀況。
本研究除了透過實驗與有限元素分析，對CLD積層板殼之特性進行探討外，為了更快速掌握CLD積層板殼低速衝擊之特性，另外提出擬靜態（Quasi-static）模擬法，將系統簡化成一質量-阻尼-彈簧系，並以能量之觀點，使用靜態壓潰之力量-位移曲線模擬CLD積層板殼動態低速衝擊行為，並考慮衝擊結束後之力量卸載路徑，可獲得低速衝擊之時間-速度-衝擊力-位移（t-v-F-s）資料，與實驗結果相比均有不錯之模擬結果。最後，使用衝擊結束之應變能，評估CLD貼附在積層板殼上之效率，證實CLD能有效地增加積層板殼之破壞應變能，並延緩後破壞之進展。

關鍵字

限制層阻尼 ； 低速衝擊

並列摘要

Because of the prominences of lightweight, high stiffness and high strength, the fiber reinforced plastic (FRP) laminate plates and shells have been widely employed in various areas. However, the absence of fiber reinforcements in the thickness direction of laminate components, the impact resistance is always poorer. In this research, the constrained layered damping (CLD) is used to improve impact resistance of laminate plates and shells, and confirmed through experiments and simulations.
The fracture simulation takes the following five modes into consideration at the same time: fiber breakage, matrix creaking, delamination failure, visco-elastic glue failure and constrained metal yielding. In finite element analysis, the progressive stiffness degradation is used to simulate the post-failure of laminate plates and shells. The finite element software adopted in this research is ABAQUS-UMAT, and the 3D second-order solid elements are used to establish the finite element models in order to obtain the more exact stress fields. The contact mechanism between the impactor and target, and the geometrical nonlinearity are also taken into account to accord with practical situation.
A quasi-static method is proposed to simulate the low-velocity impact characters of CLD laminate plates and shells. In quasi-static method, by assuming the impactor and CLD laminate specimens as a single-DOF mass-damping-spring system, and the kinetic energy release of impactor is transformed into strain energy of CLD specimens. Based on the relationship of force-displacement from the static crush experiments and the unloading path is considered, the t-v-F-s arrays of low-velocity impact can be obtained quickly through the quasi-static method simulation and have the accurate simulation results. At last, the strain energy is used to evaluate the efficiency of CLD applied to the laminate plates and shells subject to low-velocity impact. The CLD can promote the failure strain energies and delay the post-failure progresses effectively are confirmed. If the boundary conditions with the low-velocity impact and static crush are the same, the quasi-static method established in this study can simulate the low-velocity impact behavior correctly and rapidly using the static crush test and FEM simulation results.

並列關鍵字

constrained layered damping ； low-velocity impact

參考文獻

40. C. H. Huang, Y. J. Lee, A quasi-static method for the simulation of composite laminated plates subjected to low-velocity impact. Journal of the Society of Naval Architects and Marine Engineers, 2002, 21(2), 83-91.

3. E. M. Kerwin, Damping of flexural waves by a constrained viscoelastic layer. Journal of the Acoustical Society of America, 1959, 31, 952-962.

4. R. A. Ditaranto, Theory of vibratory bending for elastic and viscoelastic layered finite-length beams. Journal of Applied Mechanics, 1965, 32, 881-886.

5. J. A. Agbasiere and P. Grootenhuis, Flexural vibration of symmetrical multi-layer beams with viscoelastic damping. Journal of Mechanical Engeering Science, 1968, 10, 269-281.

6. R. A. Ditaranto and J. R. McGraw, Vibratory damping for laminated plates. Journal of Engineering for Industry, 1969, 91, 1081-1090.