PhD Research Proposal
Title: Design and Analysis of Tensegrity Mechanisms
Supervisor:
Dr.Ibrahim Ismael Hamarash
Professor of Control Engineering
Department of Electrical Engineering
College of Engineering
Salahaddin University -Erbil
Erbil, Kurdistan, Iraq
Phone: (00964)(0)750 4451357
Email: Ibrahim.hamarash@vp-salahaddin.net
Co-Supervisor: Professor Dr. Carl Crane
University of Florida, USA
Office: MAE-B 326
Office Phone: (352) 392-9461
Fax: (352) 392-1071
Email: ccrane@ufl.edu
Keywords: Tensegrity Mechanisms, Simulation, Modeling
Preliminary note
This proposal has been drafted following the possibility offered by the University of
Salahaddin-Erbil and the Ministry of Higher Education and Scientific Research/Kurdistan
Regional Governemnt (www.krg.org) to support a PhD research carried out at the
Department of Electrical Engineering/College of Engineering. It is a very first draft that
is aimed at giving a first overview of possible aspects that could be analyzed in the
framework of this research.
Abstract:
Tensegrity structures are spatial structures formed by a combination of rigid elements in
compression (struts) and connecting elements that are in tension (ties). The entire configuration
stands by itself and maintains its form solely because of the internal arrangement of the struts
and ties. A tensegrity structure consisting of three struts and nine ties is shown in the
accompanying figure. The goal of the proposed research is to develop design tools for tensegrity
devices that incorporate a combination of compliant elements, variable length struts, and compliant ties whose free-lengths can be controlled.
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Value of the project for the Kurdistan Region
Tensegrity structures are relatively new. They have become popular for architectural
applications in that the ties, which are in tension, are light weight members. This can reduce
construction cost and time. An example where tensegrity principles have been used is for the
roof of the Georgia Dome in Atlanta. The roof frame is constructed of rigid struts in
compression and ties which are in tension.
Tensegrity devices that have compliant (elastic) ties have the additional property that they are
self-deploying. The struts shown in the figure can be tied together, and when they are released,
they quickly achieve a configuration of minimal potential energy in the compliant ties. One
application for this property is the development of self-deploying shelters that can be assembled
in a very short time with virtually no tools.
The value of the project for the Kurdistan region is the application of this technology to building
construction applications. Knowledge of the dynamics of the devices will also lead to the design
of structures that can withstand disturbances such as earthquakes and bad storms. A thorough
understanding of these devices is the necessary step for their development and application.
Research Methodology
The analysis of tensegrity structures will be based on the Theory of Screws that was developed
by Sir Robert Stawell Ball in his seminal text “A Treatise on the Theory of Screws” published in
1900. Screw theory is based on a firm geometric foundation and can be used to describe systems
of forces and torques acting on a body as well as the infinitesimal motion of a body in
space.Having described the system mathematically using screw theory, different solution
techniques (numerical and symbolic) will be investigated to evaluate the response (motion and
deformation) of candidate structure designs under variable loading conditions.
Necessary Equipment and Apparatus
The primary analysis tools will be the commercial software Maple and Matlab. Academic
licenses are available at the University of Florida (UF) and can be loaded on any UF owned
computers. The software SolidWorks would also be used to develop computer models of
candidate designs. A license for each would have to be acquired for use at Salahaddin
University.A prototype will also be fabricated and mechanical components will have to be
purchased.
Necessary Training Courses
Prerequisite knowledge is found in the typical undergraduate courses of statics, dynamics,
controls, and C language programming. Specific graduate courses that are offered at UF are
EML 6281 and EML 6282, Robot Geometry I and II. These courses provide the needed
information in the areas of spatial geometry and screw theory. Several other related graduate
courses are available at UF in the areas of controls, analytical dynamics, and structural dynamics.
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Estimated Budget
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Travel of UF co-supervisor to Salahaddin University-Erbil. Two one-month visits.
Estimated travel cost of $4,000 per trip.
Travel of Salahaddin University co-supervisor to UF. Two one-month visits. Estimated
travel cost of $4.5,000 per trip.
Ph.D. student travel to UF. Two visits total. Estimated travel cost of $3,000 per trip.
Ph.D. student two semester study at UF. An estimate of living expenses is
$13,000.1Tuition at UF is currently $1,243.20 per graduate credit hour for non-Florida
residents2. Nine credit hours are required per semester for a full-time student. Eighteen
credits for two semesters of study would cost $22,378. However, this cost can be
reduced if the student is eligible for a College of Engineering Achievement Award3 .
Under this program, tuition and fees are reduced to $555.00 per credit hour. Eighteen
credit hours would then cost $9,990. For planning purposes, the tuition and fee estimate
is increased by 15% due to planned tuition increases in the coming year.
Prototype materials, $6,000.
Eligibility for Achievement Award:
Applicants must meet each of the following requirements to be considered for the award:
1. The award is open to out-of-state and international students only.
2. Nominees should intend to enroll for the first time as graduate students within the
College of Engineering.
3. Awardees may not receive any additional financial aid, including assistantships,
fellowships, and scholarships. Financial support from employment unrelated to the
student's degree program is allowed.
4. Grade Point Average or equivalent of at least 3.0, as accepted by the UF Office of
Admission.
5. GRE score (Verbal + Quantitative) = 1200, as accepted by the UF Office of Admission
office. Alternately, a nominee may present a passing score on the FE exam and 5 years
work experience.
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Living expenses at UF can be obtained at http://www.ufic.ufl.edu/iescosts.htm
Fall 2011 UF tuition rates can be obtained http://fa.ufl.edu/ufs/cashiers/2011/fee-tier-ay2011-20118.asp#credit
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Achievement Award information can be obtained at http://mse.ufl.edu/students/131.html
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