a new methodology for systematic conceptual design by means of generalized discrete representations...
TRANSCRIPT
A New Methodology for Systematic Conceptual Design
by means ofGeneralized Discrete
Representations
Research group conducted by Dr. Offer Shai
Department of Mechanics, Materials and Systems
Faculty of Engineering
Tel-Aviv University
The methodology developed in this research group offers a
mathematical apparatus enabling engineers to systematically come up with new designs by drawing them from completely different
engineering fields.In this presentation you will see this ability
through a very simple example
In this presentation you will see a demonstration of applying our design methodology for solving the
following design problem:
The force acting upon the system is alternating, while the internal spring should sustain forces of type compression only. Design the system that will satisfy this constraint.
Our approach makes possible to detect a system in completely different engineering domain – that upon transformation will yield a system satisfying given design requirements. Such a transformation is demonstrated in this presentation.
Fin
Fout
Example of transforming electrical circuit to a new mechanical device
A
B C
D
Bridge rectifier circuit
Stage 1: constructing the graph representation of the electronic circuit.
The representation is built in accordance with the structure and other properties of the engineering system.
A
B C
D
B
A
D
C
Example of transforming electrical circuit to a new mechanical device
Stage 2: Constructing a new mechanical system from the representation. The same representation can be interpreted as a representation of an
engineering system from some other engineering domain. In this example you will see how a mechanical system is constructed from the graph.
Cable
Strut
A
B C
D
B
A
D
C
Example of transforming electrical circuit to a new mechanical device
Stage 2: Constructing a new mechanical system from the representation. The same representation can be interpreted as a representation of an
engineering system from some other engineering domain. In this example you will see how a mechanical system is constructed from the graph.
Cable
Strut
As you have noticed, till now we have not used any analysis operations. We just
transformed the structure of the system from one domain to the other through the
common representation.
Since both systems are represented by the same graph representation, there should
be correspondence between their behaviors. We shall now check this hypothesis through simulation of both
systems
Verifying the correspondence in behavior between the two engineering systems.
IinFin
Fout
Iout
Behavioral mode 1:In mechanical system: Fin>0, Fout>0
In electronic circuit: Iin>0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Iin
Iout
Fin
Fout
Behavioral mode 1:In mechanical system: Fin>0, Fout>0
In electronic circuit: Iin>0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Iin
Iout
Fin
Fout
Behavioral mode 1:In mechanical system: Fin>0, Fout>0
In electronic circuit: Iin>0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Iin
Iout
Fin
Fout
Behavioral mode 1:In mechanical system: Fin>0, Fout>0
In electronic circuit: Iin>0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Fin
Behavioral mode 2:In mechanical system: Fin<0, Fout>0
In electronic circuit: Iin<0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Fout
Iin
Iout
Iin
Iout
Fin
Fout
Behavioral mode 2:In mechanical system: Fin<0, Fout>0
In electronic circuit: Iin<0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Fin
Fout
Behavioral mode 2:In mechanical system: Fin<0, Fout>0
In electronic circuit: Iin<0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Iin
Iout
Fin
Fout
Behavioral mode 2:In mechanical system: Fin<0, Fout>0
In electronic circuit: Iin<0, Iout>0
Verifying the correspondence in behavior between the two engineering systems.
Iin
Iout
Verifying the correspondence in behavior between the two engineering systems.
Conclusion: in the resulting mechanical system - the force in the output element (spring) is positive (compression) no matter the direction of the
Input force. Thus the behavior is the same as in the diode bridge circuit, where the current through the output element (resistor) is always positive - no matter the
input current
The methodology developed in this research group has been applied to develop a series of
new devices. You are going to see now only a number of such
devices.
Some of the devices developed through the approach
in
in
out
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A’
O B