| Summary: | Thesis (DTech (Mechanical Engineering))--Peninsula Technikon, 2004. === Engineers and Technologists have always been identified as those individuals
that put into practice the theories developed by scientists and physicists to
enhance the lives of human beings. In the same spirit as those that came before,
this thesis describes the development of a computational engineering tool that
will aid Engineers and Technologists to design smart or intelligent structures
comprising of NiTi shape memory alloy rods for actuation purposes.
The design of smart actuators consisting of NiTi shape memory alloy structural
members will be beneficial to industries where light weight, compactness,
reliability and failure tolerance is of utmost importance. This is mainly due to the
unique material responses exhibited by this smart material. The shape memory
effect, one of these material responses consists out of two stages: a low
temperature load induced phase transformation causing a macroscopic
deformation (either extension, contraction, etc.) also known as quasi-plasticity;
and a high temperature phase transformation that erases the low temperature
macroscopic deformation and reverts the material to some predefined geometry.
When designing actuators consisting of this smart material, the quasi-plastic
material response produces the actuation stroke while the high temperature
phase transformation produces the actuation force.
The successful engineering design of smart structures and devices particularly
suited for applications where they operate in a capacity, as actuators harnessing
the shape memory effect are dependent on a few important factors. These
include the engineers familiarity with the type of smart material used, the
availability of sound experimental data pertaining to the complex material
responses exhibited by the smart material, the engineers level of proficiency with
existing constitutive models available to simulates these material responses, and
the engineers knowledge of simulation tools consisting of a suitable control
algorithm fo~ the modeling of not only the device or structure itself but also the
actuator involved in the design.
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