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Integrity « Service « Excellence
3D Textile PMC Damage Evolution: Effects of Material State & Morphology Variation
David Mollenhauer, Rick Hall, Tim Breitzman -‐ AFRL/RXCC
Mul:-‐Scale Structural Mechanics & Prognosis Overview
AFOSR PM: Dr. David Stargel 22 July 2013
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• Project Timeline • Project Objec:ves • PMC “Scales” • Overview of Tasks • Details of Tasks • Collabora:ve Possibili:es
Outline
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Three – Year Effort • Scheduled to begin in October 2012 • Unfortunately, funding did not arrive un:l June 2013
• Sequestra*on related issues
• This presenta*on is an outline of what was proposed
Project Timeline
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• Develop knowledge of effects of geometric & material state variability on strength & damage in 3D tex:le composites • Geometric: fiber volume frac*on & direc*on, tow & fabric varia*ons
• Material State: resin cure extent & distribu*on
• Develop an integrated set of advanced simula:on tools to address the varia:ons of interest • Micro-‐scale & tow-‐scale variability • Mul*-‐scale Damage evolu*on • Advanced chemo-‐mechanical simula*on method
Project Objectives
Goal: predic:ve tools to capture variability and its effects in PMCs
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“Scales” in PMCs
Atomistic/Molecular
Fiber/Matrix “Micro-Scale”
Laminate/Tow
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• Task 1: Tow-‐Level Material Property Varia:on • Experimental quan*fica*on of varia*ons of interest at the micro-‐scale and tow-‐level (also at lamina-‐level)
• Task 2: Tow-‐Level Morphology Simula:on • Enhance exis*ng tex*le morphology simula*on tool to predict tow-‐level morphology varia*ons and es*mate micro-‐scale varia*ons
• Task 3: Mul:-‐Scale Damage Simula:on & Quan:fica:on • Develop simula*on tools to address micro-‐scale and tow-‐scale damage evolu*on w/experimental quan*fica*on
• Task 4: Advanced Mixture Theory Development/Applica:on • Development of simula*on technique for resin cure extent & sizing reac*ons and their effects on sta*c and fa*gue
Overview of Tasks
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• Purely Experimental Task • Manufacture/obtain specimens (laminates and 3D tex*les) • Tow-‐level cross-‐sec*onal shape varia*ons • Fiber-‐volume varia*ons (within a lamina and/or tows) • Resin cure extent and interphase property varia*ons
Tow-Level Material Property Variations (Task 1)
3D Weaving Machine
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• Fiber-‐Volume and Tow-‐Morphology Varia:ons • X-‐ray CT, Microscopy, and LEROY (3D Automated Serial Sec*oning)
Tow-Level Material Property Variations (Task 1)
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• Resin Cure Extent and Interphase Quan:fica:on • Raman Spectroscopy, FTIR, Nanoindenta*on,
Tow-Level Material Property Variations (Task 1)
Nanoindentation
A1
A2
A3
Reference Peak
FTIR
Raman
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• Tow-‐level and es:mates of micro-‐scale varia:ons • Virtual Tex*le Morphology Suite (VTMS)
• VTMS is a tex*le simula*on code that simulates the compac*on of fiber tows in a weave. It also has the capability of simula*ng micro-‐scale compac*on
• We will enhance its capability for hi-‐fidelity predic*ons of fiber volume & direc*ons within a tow
• Valida*on against data from Task 1
Tow-Level Morphology Simulation (Task 2)
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Tow-Level Morphology Simulation (Task 2)
Virtual Tex:le Morphology Suite
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Tow-Level Morphology Simulation (Task 2)
Extract and compare Vf, tow shape, fiber direction
(techniques in VTMS yet to be developed)
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• Simula:on Tool Development & Experimental Quan:fica:on • Tow/Lamina-‐level homogenized proper*es from mul*-‐scale micro-‐level simula*on
• Homogenized proper*es include moduli and strength/fracture parameters. This builds on previous research efforts.
Multi-Scale Damage Sim./Quant. (Task 3)
60% Vf
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Multi-Scale Damage Sim./Quant. (Task 3)
• Simula:on Tool Development & Experimental Quan:fica:on • Discrete matrix damage evolu*on simula*on
• AFRL tool proven on laminates but needs extension to tex*le damage analysis.
• Experimental determina*on of damage via X-‐ray CT
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Advanced Mixture Theory Dev./App. (Task 4)
• Effects of intra-‐tow/extra-‐tow interphase/interface on 3D tex:le processing/residual stresses, damage and fa:gue
• Effects of sizing diffusion/reac:on, inhomogeneous cure
• Chemical shrinkage and CTE mismatches in cons:tuents
• Model (Hall): evolving interphase, chemothermal stresses depend on local fiber frac:on
Nanoindentation
A1
A2
A3
Reference Peak
FTIR
Raman
Interphase/interface effects on individual filaments distributed within & near tows ρ (x)
Orders of magnitude fa:gue life varia:on vs interphase (Subramanian, Reifsnider, S*nchcomb IJF (1995).
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Advanced Mixture Theory Dev./App. (Task 4)
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Chemical potential
Applicable across PMCs, CMCs, biomaterials etc: processing, chemical degrada:on, diffusion-‐reac:on with deforma:on and thermal effects
N solids/liquids/gases
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• John’s Hopkins Center of Excellence on Integrated Materials Modeling • Jointly funded through AFOSR and RX • Especially relevant for micro-‐scale damage evolu*on • Nancy So^os UIUC fiber-‐tow interface/interphase property characteriza*on
• Arif Masud UIUC, K Rajagopal TAMU • Leverages ongoing collabora*on, mul*scale computa*on & damage
• RXC (Structural Materials Division) internal projects • Micro-‐structure sta*s*cal quan*fica*on (Craig Przybyla) • Mike Uchic’s work with LEROY 3D Automated Serial Sec*oning
• AFOSR funded Lab Tasks with RXCC • Mul*-‐scale Modeling of Fracture Networks in Composite SubComponents (PM -‐ Fariba Fahroo)
Potential Collaborations
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Questions
