| About this Abstract |
| Meeting |
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
| Symposium
|
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
| Presentation Title |
Testing and Simulation of an Off-Axis Composite Micro-Pillar |
| Author(s) |
David Mollenhauer, Mark Flores, Michael Keith Ballard, Robert Wheeler, Jeremiah Lipp, Mathew Schey, Eric Zhou, Kevin Hoos |
| On-Site Speaker (Planned) |
David Mollenhauer |
| Abstract Scope |
As part of a wider micro-scale composite test program, an off-axis IM7/977-3 carbon fiber/epoxy micro-pillar was mechanically tested in compression to failure under observation within an SEM. The pillar dimensions were approximately 17 by 19 by 63 microns with the fibers at ~20 degrees off-axis. Fabrication of the specimen was accomplished through a series of micro-machining operations, followed by focused ion beam (FIB) etching. The machining process left one end of the pillar free for load application and the other end as bulk composite for gripping. X-ray CT scans and SEM observations were performed to guide the FIB machining process in the production of a desired final geometry. While testing, the micro-pillar was imaged in an SEM at 20 applied loads and strains calculated from deformation changes of on-specimen fiducial marks. Failure occurred through a combination of matrix cracking and fiber-matrix debonding.
In addition to the experiment, a modeling campaign is being conducted using a discrete damage modeling approach. Simulated stress-strain curves and failure mechanisms compare favorably to experiment, with the simulated compliance being approximately 13% too stiff in the linear region This initial modeling tracks the experiment remarkably well considering the material properties used in the model were determined via inverse methods from macro specimen testing. The experimentally determined micro-pillar load drop is not represented properly by the model. It is likely that this is due to additional damage mechanisms not being modeled and/or geometric nonlinear effects such as fiber buckling. |
| Proceedings Inclusion? |
Definite: Post-meeting proceedings |