Accession Number : ADA262549


Title :   An Investigation of Graphite Peek Composite under Compression with a Centrally Located Circular Discontinuity


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING


Personal Author(s) : Wham, II, Benjamin


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a262549.pdf


Report Date : Mar 1993


Pagination or Media Count : 252


Abstract : The purpose of this thesis was to determine (both experimentally and analytically) the initiation and progression of failure, stress-strain response, and the failure loads of Graphite/Polyetheretherketone (Gr/PEEK) laminates, incorporating a centrally located circular discontinuity, loading in axial compression at room temperature. The laminates studied were (0 deg)16,(90 deg) 16, (0 deg/90 deg)4S, (+ or - 45 deg)4S, and (0 deg/+ or - 45 deg/90 deg)2S. The specimens were loaded within a Boeing Open Hole Compression Fixture. The micromechanical failure modes were identified using a Scanning Electron Microscope. The analytical progression of failure was predicted using a nonlinear finite element code developed by Dr. R.S. Sandhu of Wright Laboratories. The code utilizes a total energy method predicated upon the material properties curves obtained form experimentation to compute the stress- strain response of the material as well as the progression of failure within the model. Results were compared and conclusions were drawn. The comparison showed the finite element code did a good job in predicting the behavior of the O deg, + or - 45 deg, 0 deg/90 deg, and O deg/+ or - 45 deg/90 deg laminates well, but did not model the nonlinear behavior of the 90 deg. The analytical failure loads could not be exactly determined, but estimation were made and the code predicted failure between 2% and 25% of the actual failure load.... Compression, Composite materials, Finite elements, Nonlinear materials, Gr/PEEK,


Descriptors :   *COMPRESSION , *POLYMERS , *GRAPHITE , *ETHERS , *COMPOSITE MATERIALS , *DISCONTINUITIES , *KETONES , *CIRCULAR , SCANNING , STRESSES , ELECTRON MICROSCOPES , FAILURE , ROOM TEMPERATURE , AXIAL FLOW , MICROMECHANICS , MICROSCOPES , ULTRASONICS , NONLINEAR SYSTEMS , ELECTRONS , STRAIN(MECHANICS) , THESES , ENERGY , LAMINATES , TEMPERATURE , SCANNING ELECTRON MICROSCOPES , MODELS


Subject Categories : Polymer Chemistry
      Laminates and Composite Materials
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE