Long-Term Isothermal Aging Effects on Carbon Fabric-Reinforced PMR-15 Composites: Compression Strength
Long-Term Isothermal Aging Effects on Carbon Fabric-Reinforced PMR-15 Composites: Compression Strength

Author: Kenneth J. Bowles

Publisher:

Published: 1996

Total Pages: 20

ISBN-13:

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A study was conducted to determine the effects of long-term isothermal thermo-oxidative aging on the compressive properties of T-650-35 fabric reinforced PMR-15 composites. The temperatures that were studied were 204, 260, 288, 316, and 343 C. Specimens of different geometries were evaluated. Cut edge-to-surface ratios of 0.03 to 0.89 were fabricated and aged. Aging times extended to a period in excess of 15,000 hours for the lower temperature runs. The unaged and aged specimens were tested in compression in accordance with ASTM D-695. Both thin and thick (plasma) specimens were tested. Three specimens were tested at each time/temperature/geometry condition. The failure modes appeared to be initiated by fiber kinking with longitudinal, interlaminar splitting. In general, it appears that the thermo-oxidative degradation of the compression strength of the composite material may occur by both thermal (time-dependent) and oxidative (weight-loss) mechanisms. Both mechanisms appear to be specimen-thickness dependent.

Recent Developments in Durability Analysis of Composite Systems
Recent Developments in Durability Analysis of Composite Systems

Author: H. Dardon

Publisher: CRC Press

Published: 2022-01-26

Total Pages: 493

ISBN-13: 1000443728

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The papers from these proceedings address experimental and analytical methods for the characterization and analysis of modern composite and adhesive systems. They have been produced to provide understanding that can be used to design safe, reliable engineering components.

Nontraditional Methods of Sensing Stress, Strain, and Damage in Materials and Structures
Nontraditional Methods of Sensing Stress, Strain, and Damage in Materials and Structures

Author: David A. Stubbs

Publisher: ASTM International

Published: 1997

Total Pages: 266

ISBN-13: 0803124031

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These facsimiles of 16 contributions from the symposium held in May 1996 in Orlando provide information on the behavior of materials and structures. The authors describe novel ways to measure point to point deformation (or strain, when normalized), procedures for measuring crack length and the stres

Time Dependent and Nonlinear Effects in Polymers and Composites
Time Dependent and Nonlinear Effects in Polymers and Composites

Author: Richard Allan Schapery

Publisher: ASTM International

Published: 2000

Total Pages: 380

ISBN-13: 0803126018

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Annotation Improved reliability in commercial and military applications requires improved understanding of and predictive models for the time- dependent and nonlinear mechanical behavior of polymeric composites. The May 1998 American Society for Testing and Materials symposium sought to fuse the efforts in this direction of specialists in polymers and composites; these 18 papers are therefore grouped under the subheadings of polymers and composites. Primary polymer topics are chemical and physical aging, nonlinear viscoelasticity, and viscoplasticity. Composites' issues include: the effect of physical aging on time-dependent behavior, multiaxial nonlinear effects, compressive behavior, nonlinear viscoelasticity and viscoplasticity, failure mechanisms, hygrothermal effects, durability, and accelerated strength testing. Schapery is affiliated with the U. of Texas at Austin, and Sun is at Purdue U. Annotation copyrighted by Book News, Inc., Portland, OR.

Progress in Durability Analysis of Composite Systems
Progress in Durability Analysis of Composite Systems

Author: K.L. Reifsnider

Publisher: CRC Press

Published: 1998-01-01

Total Pages: 380

ISBN-13: 9789054109600

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Composite material systems are the basis for much of the natural world around us and are rapidly becoming the basis for many modern engineering components. A controlling feature for the general use of such systems is their damage tolerance, durability and reliability. The present book is a comprehensive cross section of the state of the art in the field of the durability of polymer-based, composite, and adhesive systems. As such, it is of special value to researchers concerned with the frontier of the field, to students concerned with the substance of the subject, and to the applied community concerned with the finding methodologies that make it possible to design safe and durable engineering components using material systems.

Mechanical Properties of Degraded PMR-15 Resin
Mechanical Properties of Degraded PMR-15 Resin

Author: Luis Christophe Tsuji

Publisher:

Published: 1998

Total Pages: 20

ISBN-13:

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Thermo-oxidative aging produces a non-uniform degradation state in PMR-15 resin. A surface layer, usually attributed to oxidative degradation, forms. This surface layer has different properties from the inner material. A set of material tests was designed to separate the properties of the oxidized surface layer from the properties of interior material. Test specimens were aged at 316°C in either air or nitrogen, for durations of up to 800 hours. The thickness of the oxidized surface layer in air aged specimens, and the shrinkage and coefficient of thermal expansion (CTE) of nitrogen aged specimens were measured directly. The nitrogen-aged specimens were assumed to have the same properties as the interior material in the air-aged specimens. Four-point-bend tests were performed to determine modulus of both the oxidized surface layer and the interior material. Bimaterial strip specimens consisting of oxidized surface material and unoxidized interior material were constructed and used to determine surface layer shrinkage and CTE. Results confirm that the surface layer and core materials have substantially different properties.

Time Dependent Constitutive Behavior and Fracture/Failure Processes, Volume 3
Time Dependent Constitutive Behavior and Fracture/Failure Processes, Volume 3

Author: Tom Proulx

Publisher: Springer Science & Business Media

Published: 2011-05-10

Total Pages: 394

ISBN-13: 1441997946

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This the third volume of six from the Annual Conference of the Society for Experimental Mechanics, 2010, brings together 56 chapters on Time-Dependent Constitutive Fracture and Failure. It presents early findings from experimental and computational investigations on Time Dependent Materials including contributions on Thermal and Mechanical Characterization, Coupled Experimental and Computational Analysis of Fracture Path Selection, Procedures for Mixed Mode Fracture Testing of Bonded Beams, and Experimental Study of Voids in High Strength Aluminum Alloys.