Kurzfassung/Details

Dynamic Fracture of Advanced Composites With Nanoreinforced Interfaces

Kartashov, Mikhail.   The University of Nebraska - Lincoln ProQuest Dissertations Publishing,  2013. 3597444.

Kurzfassung (Zusammenfassung)

Advanced composites have been developed since 1960s and are now widely used in military, aerospace, and civilian applications. The main advantages of composites are their high specific strength and stiffness coupled with tailorability of properties. Laminated composites with unidirectionally reinforced plies are the most popular form of composites that allows high volume fraction of fibers and therefore achieves high utilization of fiber properties. However, laminated composites are prone to delaminate due to edge stresses and under impact. Existing methods of delamination suppression resulted in significant weight or cost penalties. The goal of this dissertation was systematic evaluation and analysis of dynamic fracture behavior of novel laminated composites with nanoreinforced interfaces.

Novel methods were developed for quantitative dynamic interlaminar fracture analysis under Mode I, Mode II and Mixed Mode loadings. Crack propagation was evaluated in specimens with and without nanofiber reinforcement. Significant improvements in fracture resistance were observed as a result of nanoreinforcement. Several unusual dynamic effects were observed for the first time. In particular, a possibility of suppression of ultrafast intersonic Mode II crack into the subsonic regime as a result of nanoreinforcement was demonstrated. It was also shown that a single dynamic experiment on a newly developed Mixed Mode test specimen may provide critical dynamic fracture resistance parameters for a broad range of mode mixities, a potentially highly efficient new method of dynamic material fracture characterization. Demonstration of applicability of the dynamic results from such a test for complex transient laminate delamination analysis was performed. A numerical model for composite laminate subjected to side impact was developed. The model utilized the data from the new Mixed Mode test. Laminate delamination under impact was studied numerically and significant reduction in delamination area was demonstrated as a result of nanoreinforcement. Simulated delamination areas and shapes correlated well with the ones obtained by ultrasonic analysis. The results of this work provide new insights into dynamic fracture behavior of advanced structural composites. The developed experimental methods and numerical models can be used as tools for fundamental fracture studies and further optimization of novel hierarchical composites with nanoreinforced interfaces.

Indexierung (Details)


Thema
Mechanics;
Mechanical engineering
Klassifizierung
0346: Mechanics
0548: Mechanical engineering
Identifikator/Schlüsselwort
Applied sciences; Fractures resistance; Laminated composites; Nanofiber reinforcement
Titel
Dynamic Fracture of Advanced Composites With Nanoreinforced Interfaces
Autor
Kartashov, Mikhail
Seitenanzahl
231
Studienabschlussdatum
2013
Bildungseinrichtungscode
0138
Quelle
DAI-B 75/01(E), Dissertation Abstracts International
Verlagsort
Ann Arbor
Publikationsland
United States
ISBN
978-1-303-45517-9
Doktorvater
Dzenis, Yuris A.
Komiteemitglied
Farritor, Shane; Feng, Ruqiang; Negahban, Mehrdad; Turner, Joseph A.
Universität/Einrichtung
The University of Nebraska - Lincoln
Abteilung
Engineering Mechanics
Universitätsort
United States -- Nebraska
Studienabschluss
Ph.D.
Quellentyp
Diplomarbeit oder Dissertation
Sprache
Englisch
Dokumententyp
Dissertation/Thesis
Dissertations-/Diplomarbeitsnummer
3597444
ProQuest-Dokument-ID
1455445446
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/unauthdocview/1455445446