0
RESEARCH PAPERS: Special Issue on Time-Dependent Behaviors of Polymer Matrix Composites and Polymers

Post-Curing Effects on Marine VARTM FRP Composite Material Properties for Test and Implementation

[+] Author and Article Information
Jason J. Cain1

 Materials Response Group, Department of Engineering Science Mechanics

Nathan L. Post, John J. Lesko, Scott W. Case

 Materials Response Group, Department of Engineering Science Mechanics

Yin-Nian Lin, Judy S. Riffle

Department of Chemistry,Virginia Polytechnic Institute and State University

Paul E. Hess

 Naval Surface Warfare Center, Carderock Division

1

Corresponding author.

J. Eng. Mater. Technol 128(1), 34-40 (Jun 08, 2005) (7 pages) doi:10.1115/1.2128425 History: Received August 13, 2004; Revised June 08, 2005

Structural composites are increasingly being utilized in many large naval and civil structures where it is vital that their long-term performance be predictable and their variability definable over the life of the structure. However, these properties may be influenced by the degree of cure of the resin, particularly for room-temperature-cured systems. Thus, this investigation defines the postcure effects on E-glass/vinyl-ester fiber-reinforced polymer (FRP) composites manufactured using the vacuum-assisted resin transfer molding (VARTM) method, which are typical of those used by the US Navy for ship structures. The composites are differentiated by varying levels of postcure temperature and duration, and examined for the effects of advancing cure at various points in the time after postcure. Pseudo-quasi-isotropic [0/+45/90/−45/0]s and angle ply laminate [±45]2s samples from each level of postcure are examined at 1, 10, 30, 100, and 300 days after postcure in order to track strength, stiffness, failure strain, creep, and fatigue performance as functions of time. In parallel, the matrix polymer is inspected using FTIR (Fourier transform infrared spectroscopy) to directly assess the degree of conversion. Dynamic mechanical analysis and shrinkage measurements are also undertaken to assess the Tg and the amount of shrinkage undergone during post-curing, as well as the advancing of the level of cure during the prescribed aging time. Results suggest that the degree of conversion is limited to 80% for the vinyl-ester oligomer and 90–95% for styrene following a postcure of 93°C. It is observed that after 300 days of ambient storage the nonpostcured samples approach the degree of conversion exhibited by those postcured at 93°C, as measured by FTIR. Resin dominated quasi-static properties are greatly affected by the degree of cure, whereas fiber dominated properties are not. Where the degree of cure is comparatively low, viscoelastic properties cause greater changes in creep response as well as influencing fatigue performance.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Resin oligomer and styrene monomer reaction to the vinyl ester network. The disappearance of styrene and methacrylate C=C are tracked by FTIR to assess the degree of cure quantitatively.

Grahic Jump Location
Figure 2

Cure temperature profile for all panels

Grahic Jump Location
Figure 3

Vinyl ester and styrene conversion with time

Grahic Jump Location
Figure 4

DMA storage modulus curves for all panels on day 1

Grahic Jump Location
Figure 5

Normalized DMA storage modulus for panel 4501-NPC on all days

Grahic Jump Location
Figure 6

DMA storage modulus and tanδ curves for two replicates from panel 4504-93 on day 300

Grahic Jump Location
Figure 7

Creep compliance curves for panel 4501-NPC on all days

Grahic Jump Location
Figure 8

Mean initial modulus values of pseudo-quasi-isotropic specimens as a function of time and postcure

Grahic Jump Location
Figure 9

Mean ultimate tensile strength of pseudo-quasi-isotropic specimens as a function of time and postcure

Grahic Jump Location
Figure 10

Stress-strain diagrams of panel PQ04-93 during quasi-static tension tests on all days

Grahic Jump Location
Figure 11

Mean initial shear modulus of [±45]2s samples as a function of postcure and time

Grahic Jump Location
Figure 12

Shear strength for [±45]2s panels as a function of postcure and time

Grahic Jump Location
Figure 13

Typical stiffness reduction and temperature data for all panels on fatigue testing day 1

Grahic Jump Location
Figure 14

Cycles to failure data for all panels on all testing days

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In