|Author's Email Address
||This thesis had been viewed 5341 times. Download 2671 times.|
||Mechanical and Electro-Mechanical Engineering|
|Type of Document
||Fatigue and Fracture Analysis of notch AS4/PEEK Laminates|
|Date of Defense
||The purpose of thesis is aimed to analyze fracture and fatigue behaviors of notched composite laminates by numerical method. Types of notch are both central notch 4mmψand double-edged crack. We employed finite element method analysis with ANSYS to perform the numerical analysis.|
We adopted Tsai-Wu failure criterion to approach failure of central notch laminates by a step increment method and considered the effect of failure area gradually expanded, thus we obtained the ultimate stress of a laminate. In the work of fatigue testing and evaluation, we used Miner’s rule to predict the extension of fatigue damage zone, and compared it with experimental results. In the analysis of a double-edged crack laminate, it is first assumed mix mode failure. Then, we calculated the stress intensity factors of various crack length by extrapolation, and developed a function of configuration correction factor.
Finally, this study can be concluded as follows. The accuracy of ultimate stress prediction with step-by-step increment analysis is satisfactorily well. The outcome failure area of a laminate is closely corresponding with the observation of experiment. In predicting the fatigue damage zone, the predicted initial damage zone is close to experimental observation, but it is inconsistent with the actual damage extension due to crack propagation. Stress intensity factors and configuration correction factors are directly in proportion to the square root of crack length. It is corresponding with fracture mechanics. However there are some errors in quasi-isotropic laminates due to the existing of ±45°plies.
||Ding-Gui Huang - chair|
Ming Chen - co-chair
Huang-Kuang Kung - co-chair
Ming-Hwa R. Jen - advisor
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|Date of Submission