World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Isothermal Fatigue, Damage Accumulation, and Life Prediction of a Woven Pmc

By Gyekenyesi, Andrew L

Click here to view

Book Id: WPLBN0004293789
Format Type: PDF eBook :
File Size:
Reproduction Date: 1998-03-01

Title: Isothermal Fatigue, Damage Accumulation, and Life Prediction of a Woven Pmc  
Author: Gyekenyesi, Andrew L
Volume: Report-Number: NAS 1.26:207586; NASA/CR-95-207586
Language: English
Subject: Amino Acids, Organic Materials, Carbonaceous Chondrites
Collections: Government Library Collection
Historic
Publication Date:
1998
Publisher:

Citation

APA MLA Chicago

L, G. A. (1998). Isothermal Fatigue, Damage Accumulation, and Life Prediction of a Woven Pmc. Retrieved from http://www.netlibrary.net/


Description
Description: This dissertation focuses on the characterization of the fully reversed fatigue behavior exhibited by a carbon fiber/polyimide resin, woven laminate at room and elevated temperatures. Nondestructive video edge view microscopy and destructive sectioning techniques were used to study the microscopic damage mechanisms that evolved. The residual elastic stiffness was monitored and recorded throughout the fatigue life of the coupon. In addition, residual compressive strength tests were conducted on fatigue coupons with various degrees of damage as quantified by stiffness reduction. Experimental results indicated that the monotonic tensile properties were only minimally influenced by temperature, while the monotonic compressive and fully reversed fatigue properties displayed noticeable reductions due to the elevated temperature. The stiffness degradation, as a function of cycles, consisted of three stages; a short-lived high degradation period, a constant degradation rate segment composing the majority of the life, and a final stage demonstrating an increasing rate of degradation up to failure. Concerning the residual compressive strength tests at room and elevated temperatures, the elevated temperature coupons appeared much more sensitive to damage. At elevated temperatures, coupons experienced a much larger loss in compressive strength when compared to room temperature coupons with equivalent damage. The fatigue damage accumulation law proposed for the model incorporates a scalar representation for damage, but admits a multiaxial, anisotropic evolutionary law. The model predicts the current damage (as quantified by residual stiffness) and remnant life of a composite that has undergone a known load at temperature. The damage/life model is dependent on the applied multiaxial stress state as well as temperature. Comparisons between the model and data showed good predictive capabilities concerning stiffness degradation and cycles to failure.; CASI; Nasa Publication Center: Glenn Research Center; Unclassified; Copyright (Distribution as joint owner in the copyright) ; Unlimited; Publicly available;; Report-Number: NAS 1.26:207586; NASA/CR-95-207586


 
 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.