Restricted Research - Award List, Note/Discussion Page
Fiscal Year: 2023
1885 The University of Texas at El Paso (143773)
Principal Investigator: Castellanos,Alejandra G
Total Amount of Contract, Award, or Gift (Annual before 2011): $ 180,000
Exceeds $250,000 (Is it flagged?): No
Start and End Dates: 9/1/22 - 8/31/24
Restricted Research: YES
Academic Discipline: Aerospace Center
Department, Center, School, or Institute: Aerospace Center
Title of Contract, Award, or Gift: Elucidating the CNTs morphological parameters effect on crack mitigation for bonded unitized aircraft structures subjected tolow velocity impacts.
Name of Granting or Contracting Agency/Entity:
OHIO STATE UNIVERSITY
CFDA Link: DOD
12.800
Program Title:
Air Force Defense Research Sciences Program
CFDA Linked: Air Force Defense Research Sciences Program
Note:
The material system used in this project is an eight-ply woven Harness Satin (5HS) fabric C/SiC composite materials based on allyhydridopolycarbosilane (AHPCS) preceramic polymer, which is commercially available and is typically used in aerospace and military applications. Ceramic matrix composites (CMC), such as C/SiC, are well known for their high thermal and chemical stability. However, one of their main drawbacks is the unpredictability matrix microstructure formed during thermal decomposition of the polymeric precursor used in the Polymer Infiltration and Pyrolysis (PIP) processing method. To avoid this, repeated cycles of preceramic polymer infiltration and pyrolysis are used progressively to increase the density of the ceramic matrix. However, gas evolution and shrinkage of the polymer phase as it is converted to ceramic during pyrolysis results in the development of pores and cracks in the matrix. Current modeling techniques cannot capture the effect of pyrolytic decomposition in the generation and formation of defects on the surface or near- surface defects. The chemical and volume changes that accompany ceramization of the polymer during pyrolysis have been documented in several studies. However, the modeling techniques focused only on explaining the chemical compositional aspect of polymer-to-ceramic conversion. Moreover, in the case of the finite element method (FEM) techniques, the simulations tend to be oversimplified by using homogenization of the fiber and matrix. Homogenization results in the loss of information regarding the spatial distribution, size, and shape of defects
Discussion: No discussion notes