Akinbade, Yusuf
(2020)
Mechanical and Morphological Characterization of Full-Culm Bamboo.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Full-culm bamboo that is bamboo used in its natural, round form used as a structural load-bearing material, is receiving considerable attention but has not been widely investigated in a systematic manner. Despite prior study of the effect of fiber volume and gradation on the strength of bamboo, results are variable, not well understood, and in some cases contradictory. Most study has considered longitudinal properties which are relatively well-represented considering bamboo to be a unidirectional fiber reinforced composite material governed by the rule of mixtures. Despite the dominance of transverse failure (splitting) of bamboo in load-bearing applications, very little study of bamboo transverse properties has been conducted. The objective of this work is therefore to develop a framework and the tools required to evaluate the material and mechanical properties of full-culm bamboo. The study focuses on transverse properties and recognizes that bamboo is a heterogeneous highly orthotropic functionally graded material rather than a homogeneous fiber-reinforced composite as is often assumed. This framework brings together work conducted in the area of bamboo geometric, morphologic and material characterization to develop a correlation with mechanical properties. The effect of fiber volume ratio and gradation in the bamboo cross-section in the characterization is studied and used as a basis to establish materials- and mechanics-based constitutive models for the behavior of full-culm bamboo. The impact of material variability and uncertainty in the mechanical behavior of the full-culm is investigated and included in the presented models. Experimental, imaging and numerical results from this study indicate that considering the transverse behavior of bamboo as a fiber-reinforced material, governed by the rule of mixtures, is not appropriate. The scope of the work focuses on materials test specimens. This is believed to be the scale at which internal heterogeneity of the bamboo effects experimentally determined data and is also a scale at which complex modeling is still appropriate. The models developed in this work have two primary and related uses: 1) providing a platform for researchers to better understand the results of bamboo material property tests; and 2) providing a platform against which to validate macroelement models suitable for structural evaluation and design.
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Details
Item Type: |
University of Pittsburgh ETD
|
Status: |
Unpublished |
Creators/Authors: |
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ETD Committee: |
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Date: |
30 July 2020 |
Date Type: |
Publication |
Defense Date: |
6 March 2020 |
Approval Date: |
30 July 2020 |
Submission Date: |
2 April 2020 |
Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
Number of Pages: |
217 |
Institution: |
University of Pittsburgh |
Schools and Programs: |
Swanson School of Engineering > Civil and Environmental Engineering |
Degree: |
PhD - Doctor of Philosophy |
Thesis Type: |
Doctoral Dissertation |
Refereed: |
Yes |
Uncontrolled Keywords: |
Bamboo, Image Analysis, Morphology, Finite Element Modelling, Digital Image Correlation, Rule of Mixtures, Random Field Methodology, Parenchyma Cell, Fiber volume, Modulus of Elasticity |
Additional Information: |
Corrected version with erratum uploaded on 10/15/2021 |
Date Deposited: |
30 Jul 2020 19:35 |
Last Modified: |
15 Oct 2021 13:18 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/38530 |
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