Synthesis And Characterization Of Biomimicked Structural Composites
- Conference
- Location
-
Honolulu, Hawaii
- Publication Date
-
June 24, 2007
- Start Date
-
June 24, 2007
- End Date
-
June 27, 2007
- ISSN
-
2153-5965
- Conference Session
- Tagged Division
-
Instrumentation
- Page Count
-
9
- Page Numbers
-
12.1338.1 - 12.1338.9
- DOI
-
10.18260/1-2--2867
- Permanent URL
-
https://peer.asee.org/2867
- Download Count
-
377
Paper Authors
Seyed Allameh Northern Kentucky University
SEYED ALLAMEH is an Assistant Professor and a full graduate faculty of Northern Kentucky
University. Prior to joining NKU, Dr. Allameh conducted research at Princeton University for 5
years in the areas of MEMS, nanotechnology and advanced materials. He has served as a guest
editor/editorial board of journals including Journal of Materials Science. Dr. Allameh holds a
PhD from The Ohio State University. He has published over 60 scientific papers/book chapters
Tom Ogonek Ogonek Northern Kentucky University
Tom Ogonek is currently an undergraduate student of the Mechanical and Manufacturing Engineering Technology of the Physics department of the Northern Kentucky University. He also serves as the general manageer of Alternative Plastics located in Erlanger KY. In the past he has worked in a microbiology lab as a research assitant and in a pharmacutical company as a control technician.
Paul Cooper Northern Kentucky University
Paul Cooper is the interim chair of Department of Technology and an Associate Professor of
Construction Management at Northern Kentucky University. He obtained his B.S. from
Southwest Missouri State University; M.S. from Murray State University and his Doctoral
candidacy in Adult and Continuing Education from University of North Texas; He is an advisor
in the Construction Technology/Management Program at Northern Kentucky University.
Abstract
NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract
Synthesis and Characterization of Biomimicked Structural Composites
Abstract
This paper presents the preliminary results of experiments conducted on the toughening of structural composites for shatter-proof applications. Layered composites inspired by tough biological structures such as nacre were fabricated and tested in tension and compression. The results are compared with monolithic structures fabricated and tested under the same conditions. Compared to monolithic samples, mechanical testing results show greater toughness associated with higher levels of ductility for the layered composites. The effect of materials selection for structural composites was investigated. It was concluded that biomimicked structures can be designed and fabricated with both higher levels of tensile strength as well as increased ductility (resulting in higher fracture toughness). The educational implications of this work in terms of the students participation and its usefulness in the outreach programs are discussed.
Introduction
Development of tough structural materials could potentially lead to a significant reduction of fatalities and property damage during earthquakes, tornados and hurricanes. Collapse of mortar and brick type structures, caused by the dynamic shear forces of earthquake can be mitigated or completely prevented if the mortar is chosen to be a thin polymer.
Robust biomechanical structures such as bone and nacre show great fracture toughness due to their intricate designs combining a soft phase polymer with a hard phase mineral. In nacre, parallel layers of aragonite tablets (Figure 1) are glued together by an inorganic polymer (proteins and polysaccharides). If the edge of the tablets are correlated into a tessellated arrangement (Figure 1) it resembles the structure of abalone. Alternative structure is the Noncorrelated edges of the tablets leading to the structures typical of pearl oyster. Superior mechanical properties of this structure include a high strength combined with high fracture toughness. Due to the lamellar nature of the structure, properties are anisotropic. Nominal strength ranges from 194-2481 obtained from the 3-point bend tests on abalone and oyster with higher numbers belonging to pearl oyster.
An initial elastic response is observed during the tensile loading of nacre parallel to its plates.. However, at a stress level of 110 MPa a steady state deformation (inelastic) commences that continues until fracture at 1% strain. This inelastic secondary deformation is not seen during compression loading. Rather, an elastic deformation takes place that continues to fracture at very high stresses (exceeding 400 MPa) associated with a shorter fracture strain (0.5%). When loading axis is at 45º with respect to the plates, a uniform shear stress occurs across the plates. The steady state inelastic response that commences at a shear stress of 40 MPa continues until fracture at 8% strain. The main role of inelasticity is its insensitivity to localized deformation sites that causes premature failure.
Allameh, S., & Ogonek, T. O., & Cooper, P. (2007, June), Synthesis And Characterization Of Biomimicked Structural Composites Paper presented at 2007 Annual Conference & Exposition, Honolulu, Hawaii. 10.18260/1-2--2867
ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2007 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015