Abstract: The first project is "Matrix Enabled Damage Tolerance in Oxide Continuous Fiber Reinforced Ceramic Composites", PIs: Frank Zok, Carlos Levi and Robert McMeeking, funded by AFOSR. Here, the nanoindenter is being used for measuring the mechanical properties of fiber-matrix interfaces, through the so- called "fiber push-in" test. In essence, the test involves pushing an individual fiber past the surrounding matrix while simultaneously measuring the sliding displacement at the fiber/matrix interface. The resulting load-displacement response is then used to determine the toughness and the sliding resistance of the interface, using micromechanical models of the debonding and sliding. The second project utilizing the nanoindenter is "Improved Performance for MEMS- based Filters," funded by the AFOSR. The PIs are Kimberly L. Turner (UCSB) and Steven Shaw (Michigan State). In this project, the nanoindenter is used to characterize the stiffness of tethers in MEMS devices which are being developed as nonlinear components for MEMS based filters, The nanoindenter provides a direct force vs. displacement result, which is not obtainable using other measurement techniques in MEMS. Due to the inability to directly determine how much force is produced by electrostatic microactuators, and the uncertainty in MEMS fabrication techniques, it is difficult to get accurate stiffness values for the supporting spring structures. The nanoindenter is used to apply a load and get a resultant displacement curve, thereby measuring the stiffness. Out of plane loads have been obtained, however in plane loads are more complex, and currently being studied. Cantilevers have also been measured.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. 1 Jun 2002-31 May 2003 |
| Pages: |
6 |
| Report Date: |
AUG 2003 |
| Contract Number: |
F49620-02-1-0209 |
| Report Number: |
A505914 |
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Keywords relating to this report:
