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Development of a Continuum Damage Mechanics Material Model of a Graphite-Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy Absorbing Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy AbsorbingThis paper describes the development of input properties for a continuum damage mechanics based material model, Mat 58, within LS-DYNA(Registered Trademark) to simulate the response of a graphite-Kevlar(Registered Trademark) hybrid plain weave fabric. A limited set of material characterization tests were performed on the hybrid graphite-Kevlar(Registered Trademark) fabric. Simple finite element models were executed in LS-DYNA(Registered Trademark) to simulate the material characterization tests and to verify the Mat 58 material model. Once verified, the Mat 58 model was used in finite element models of two composite energy absorbers: a conical-shaped design, designated the "conusoid," fabricated of four layers of hybrid graphite-Kevlar(Registered Trademark) fabric; and, a sinusoidal-shaped foam sandwich design, designated the "sinusoid," fabricated of the same hybrid fabric face sheets with a foam core. Dynamic crush tests were performed on components of the two energy absorbers, which were designed to limit average vertical accelerations to 25- to 40-g, to minimize peak crush loads, and to generate relatively long crush stroke values under dynamic loading conditions. Finite element models of the two energy absorbers utilized the Mat 58 model that had been verified through material characterization testing. Excellent predictions of the dynamic crushing response were obtained.
Document ID
20170005463
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Jackson, Karen E.
(NASA Langley Research Center Hampton, VA, United States)
Fasanella, Edwin L.
(National Inst. of Aerospace Hampton, VA, United States)
Littell, Justin D.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
June 12, 2017
Publication Date
May 9, 2017
Subject Category
Structural Mechanics
Report/Patent Number
NF1676L-26695
Meeting Information
Meeting: AHS International Annual Forum & Technology Display
Location: Fort Worth, TX
Country: United States
Start Date: May 9, 2017
End Date: May 11, 2017
Sponsors: American Helicopter Society International
Funding Number(s)
WBS: WBS 664817.02.07.03.02.01
Distribution Limits
Public
Copyright
Public Use Permitted.
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