Defense on: Fully Coupled FEA Simulation of Re-programmable Origami Micro-Matter. – Georgino Kaleng Tshikwand

Georgino Kaleng Tshikwand

15. 10. 2024, 9:00
WW8, Room 2.018-2, Dr.-Mack-Str. 77, Fürth

Georgino K. Tshikwand will defend his PhD
thesis entitled Fully Coupled FEA Simulation of Re-programmable Origami
Micro-Matter .

The talk followed by a discussion is open to the public
and will start early at 09:00 in our seminar room.

Re-programmable matter is an attempt to introduce reconfigurability to
programmable matter. Programmable matter is a material whose shape can
be programmed through bending hinge actuators and is based on the
concept of self-folding origami. In principle, programmable matter
consists of a planar network of tiles and hinge actuators that can be
folded into desired 3D structures. This is possible through Joule
heating of the hinge actuator which is made of active materials. Shape
Memory Alloys (SMA) are amongst the most used active materials in the
actuation of microsystems. The synergy of active and passive actuators
facilitates the reconfiguration of the 3D origami structures back into
the 2D planar structures and further folding in the opposite direction,
giving a bidirectional actuation of the origami structure.

The optimization of such actuation requires iterative Finite Element
Method (FEM) simulations of the entire origami system. This assists in
understanding the coupling effects between the actuators in the systems.
In this thesis, we provide a holistic approach to achieve device
simulation of the bidirectional actuation of the origami system. First,
following thermodynamic principles, we derive a fully coupled material
model to describe the shape memory effect and superelasticity properties
of shape memory alloy materials. The resolved time-dependent coupling
between the mechanical, thermal, and electrical field variables inherent
to thermal actuation is described. Tensile and bending simulations are
conducted to validate the model by direct comparison with experimental
results. A detailed procedure to realize bidirectional actuation is
provided. FEM simulation of bidirectional actuation of open-box and
pyramid origami structures is achieved. Here, thermal transport during
actuation isfound to influence the folding of the actuators in their
attempt to fold to the programmed 3D structure. Appropriate measures are
recommended to prevent the problem and achieve optimal actuation towards
the programmed 3D structure. The combination of the shape memory alloy
material model and bidirectional simulation procedure developed in this
thesis are found to be robust to simulate and optimize the actuation of
re-programmable micro origami systems.