DO Sherwood

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Slide1: 

Collaborative Research: James Sherwood Jennifer Gorczyca University of Massachusetts Lowell Collaborators: Northwestern University Enhancing the Understanding of the Fundamental Mechanisms of Thermostamping Woven Composites to Develop a Comprehensive Design Tool NSF Grant Number: DMI- 0331267 NSF/DOE/APC Workshop: Future of Modeling in Composites Molding Processes (Design & Optimization Session) 9-10 June 2004 Arlington, Virginia

Motivation: 

Motivation Mass production of lightweight low-cost woven-fabric reinforced composite parts Desirable in automobiles for: High strength-to-weight ratio (compared to metal counterparts) Reduce weight  Increase fuel efficiency Development of predictive design tool

Motivation – Thermostamping: 

Motivation – Thermostamping Punch Binder Ring Fabric Die

Motivation – Part Quality: 

Motivation – Part Quality [Wilks, 1999]

Our Research:: 

Our Research: Development of a friction model to capture the behavior of balanced plain-weave composite materials during thermoforming Incorporation of the friction model into the commercial finite element code ABAQUS Parametric study of the effect of processing parameters on the reaction force on the punch Use of the fabric friction model with a fabric constitutive model in a commercial finite element code such as ABAQUS to create a predictive tool

Slide6: 

ACMTRL Our Research:

Our Research:: 

Our Research: H  Hersey Number h  use Power Law viscosity model U  fabric velocity W  normal force

State of the Art – Testing Standards: 

State of the Art – Testing Standards Study of metal/fabric interface relatively new ASTM standards exist to determine friction coefficients of sheets Account for normal load and pull-out velocity Do not account for sheet viscosity and fiber orientation Researchers have developed their own test methods (many based on ASTM Standard D 1894)

State of the Art – Friction Testing: 

State of the Art – Friction Testing ACMTRL Table from: Gorczyca, Sherwood and Chen (2004). Modeling of Friction and Shear in Thermostamping of Composites – Part I. Journal of Composite Materials. In Press.

State of the Art – FEM: 

ACMTRL State of the Art – FEM Boisse et al. (1996, 2001a, 2001b) Constitutive model with FEM focuses on formability Based on Kawabata et al. (1973) Xue et al. (2003) and Peng (2003) Focus on constitutive model and incorporation into FEM Use of shell elements and nonorthogonality Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML

State of the Art – FEM: 

ACMTRL State of the Art – FEM Cherouat and Billoët (2001) Truss elements – tows Membrane elements – resin Sidhu et al. (2001) Truss elements – tows Shell elements – inter-tow friction and fiber angle jamming Li et al. (2004) [@ UML] Truss elements – tows Shell elements – increasing tangent shear modulus Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML Truss Elements Shell Element Fabric unit cell

State of the Art – FEM: 

State of the Art – FEM Reaction force comparison between fabric friction model and Coulomb friction model Details can be found in: Gorczyca (2004). A study of the frictional behavior of a plain-weave fabric during the thermostamping process. Doctoral dissertation. Mechanical Engineering Dept. UML Fabric friction model, m=f(H) Coulomb friction model, m=0.3

Vision: 

Vision Ability to compare results from different testing methods is important (i.e. shear frame and bias extension, and friction) Researchers must combine finite element modeling and testing efforts to create a robust Design Tool for thermoforming of woven-fabric composite materials Analytical Design Tool will account for changing: Constitutive properties Temperature Friction properties Material types and weaves

Vision: 

Vision Continue to collaborate with industry to: Ensure that the appropriate materials and processing techniques are being investigated Aid technology transfer from academia to industry

Perceived Gaps: 

Perceived Gaps Researchers have determined modeling techniques for specific materials, weave types and cases These methods need to be extended to include “generic” materials, weave types and cases

Perceived Gaps: 

Perceived Gaps Researchers have developed their own testing methods (true for constitutive property research and friction modeling) Work with ASTM for standardized test protocols Analytical methods for comparing test data using different test procedures must be proposed, publicized and peer-reviewed

Research Thrusts: 

Research Thrusts Collaborative research among modeling laboratories: Comparison and interpretation of differences in results among different modeling techniques Joining of different fabric models, such as friction and constitutive, in model of forming processes and interpretation and publication of results Use these methods to lead to models for “generic” materials, weaves and cases

Research Thrusts: 

Research Thrusts Collaborative research among testing laboratories: Comparison and interpretation of differences in results using different test procedures Use these comparisons to work towards standardization of tests and to determine strengths and weaknesses of the different tests that are available

Slide19: 

Collaborative Research: James Sherwood Jennifer Gorczyca University of Massachusetts Lowell Collaborators: Northwestern University Enhancing the Understanding of the Fundamental Mechanisms of Thermostamping Woven Composites to Develop a Comprehensive Design Tool NSF Grant Number: DMI- 0331267 NSF/DOE/APC Workshop: Future of Modeling in Composites Molding Processes (Design & Optimization Session) 9-10 June 2004 Arlington, Virginia

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