Optimization of an Orthotropic

tobascothwackUrban and Civil

Nov 15, 2013 (3 years and 10 months ago)

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Optimization of an Orthotropic
Composite
Beam

Brian
Schmalberger

Problem Statement


A
composite
beam will be constructed to analyze
the stress distribution, stiffness,
displacement, and vibration modes as the fiber orientation and loading are
changed. The beam will be further optimized for given design constraints, such as
maximum torsional stiffness and damping of low frequency
vibrations.


The beam will be subjected to different loadings, including point, distributed and
harmonic loads. Each loading will be applied to a beam that is fixed at both ends
and to a beam that is fixed at one end and free at the other end.

Background


Composites are widely used in the automobile, aerospace, and athletics
industry.
Examples
of composites include bumpers, wings, bicycle frames, and downhill
skis.


Combined
with the light weight and high strength characteristics of composite
materials, the ability to optimize a composite structure for a specific property is
useful to a design
engineer.


Properties
of the structure, such as stiffness, stress distribution, and dynamic
response are affected by fiber and matrix material, fiber orientation, and the
number of lamina.


Methodology and Approach


A brief introduction to classical composite theory will also be discussed.


ANSYS
will then be used to a construct three
-
dimensional composite beam with a
given fiber orientation and number of lamina.


The
ends of the beam will be constrained as follows:


Fixed
-
free



Fixed
-
fixed


The beam will be loaded as follows for each set of constraints:


Point loads different locations (e.g. 0.25L, 0.50L, 0.75L and 1.0L)


Distributed loads of varying lengths and locations (e.g. 0.25L centered at 0.5L)


Harmonic loads of varying frequencies at different locations (e.g. 60Hz @ 0.5L)


Milestones


2/05/10……….Project proposal draft


2/08/10……….Description of classical composites theory


2/1510…..……Composites research in ANSYS


2/22/10……….Construction of model in ANSYS and first analysis


2/26/10……….Progress report #1


3/01/10……….Analysis of constraints and loads


3/15/10……….Optimization of model for design constraints


4/09/10……….Final draft


4/21/10……….Final
report


References


Adams, R. D. and M. R.
Maheri
. “Dynamic Flexural properties of Anisotropic
Fibrous Composite Beams.” Composites Science and Technology 50 (1994) 497
-
514.


Assarar
, Mustapha, Jean
-
Marie Berthelot,
Abderrahim

El
Mahi
, and Youssef
Sefrani
. “Damping analysis of Orthotropic Composite Materials and Laminates.”
Composites: Part B 39 (2008) 1069
-
1076.


Benchekchou
, B., M.
Coni
, and R. G. White. “The Structural Damping of Composite
Beams with Tapered Boundaries.” Composites Structures 35 (1996) 207
-
212.


Chawla
,
Krish
,
Uday

K.
Vaidya
, and
Ashutosh

Goel
. “Fatigue and Vibration
Response of Long Fiber Reinforced Thermoplastics.” Univ. of Birmingham.


Della, Christian N. and
Dongwei

Shu
. “Free Vibration of Composite Beams with
Two Non
-
overlapping
Delaminations
.” International Journal of Mechanical
Sciences 46 (2004) 509
-
526.