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Unformatted text preview: IMPACT AND COMPOSITE MATERIALS Date(s) Performed 03/14/2008 03/21/2008 03/28/2008 Friday 11:00 am MAE 4284 Florida Institute of Technology Aerospace Engineering Program SYRUS JEANES Group Members: Marco Herrera, Joshua Gauvin, Tyler Jandreau, Anthony Costantini, Zoe Morozko, Kyle Chapman, Ben Holohan, Adam Cooper, Ivan Mravlag, Robert Radomski Introduction Impact testing is a vital tool in determining the strength of a material and its failure characteristics under dynamic loading. This is crucial because impacts do happen in the real world, unlike the idealized test conditions of, for example, a well-organized tensile test. One of the most important test metrics in an impact test, aside from the applied load, is the kinetic energy transferred to the material. This allows us to determine what impact energy a specimen can withstand before failing not just a point load. Flexure testing is another important tool in determining the usefulness of a part. Flexure testing allows one to determine how much bending stress a material can withstand before it plastically deforms and eventually fails. A certain amount of flexibility is generally desirable in aerospace structures. Other engineering disciplines, however, may require highly rigid structures for certain applications, such as rebar concrete. If a flexure test is performed on a specimen, then the materials ability to withstand predicted bending stresses can be experimentally verified for safety purposes. For the MAE 4284 experiment, impact testing was carried out on different composite samples of graphite, fiberglass, and a sandwich structure of fiberglass with a Nomex core were tested to compare their strengths and failure characteristics. Three-point bending tests, or flexure tests were performed on several samples of fiberglass, Nomex cored sandwich structure, once again to determine material strengths and failure modes. Each experiment demonstrated the ability of composite and sandwich structures to cope with sudden, strong compressive loads and non-trivial bending loads. Different ply orientations and core thicknesses were used to compare the different types of composite structures. Procedure Table 1: Test Matrix Specimen Material Layup Method Test Regime 1 Graphite [0 4 ] Impact (6 6) 2 Fiberglass [0 6 ] Impact (6 6) 3 Fiberglass [0 6 ] (Vacuum Bag) Impact (6 6) 4 Fiberglass [0/ 45] s Impact (6 6) 5 Fiberglass [0 3 /(3/16 Nomex)/0 3 ] Impact (6 6) 6 Fiberglass [0 3 /(1/4 Nomex)/0 3 ] Impact (6 6) 7 Fiberglass [0/45/-45/(3/16 Nomex)/-45/45/0] Impact (6 6) 8 Fiberglass [0/45/-45/(1/4 Nomex)/ -45/45/0] Impact (6 6) 9 Fiberglass [0 3 /(1 Nomex)/0 3 ] Flexure 3 x (2 6) 10 Fiberglass [0 4 /(1 Nomex)/0 1 ] Flexure 3 x (2 13) Composite Construction Procedure One week prior to testing, each sample listed above was laid up in an adjacent lab facility. The tables were covered with a relatively flat plastic coating as a working surface. Resin and hardener were mixed were covered with a relatively flat plastic coating as a working surface....
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This note was uploaded on 04/21/2008 for the course MAE 4281 taught by Professor Fleming during the Spring '08 term at FIT.
- Spring '08
- Composite Materials