scholarly journals Influence of cure parameters in polymer matrix composites using embedded optical fibers

2020 ◽  
Vol 54 (19) ◽  
pp. 2611-2621
Author(s):  
Daniel A Drake ◽  
Rani W Sullivan ◽  
Jonathan E Spowart ◽  
Katie Thorp
Keyword(s):  
Optical Fibers ◽  
Composite Laminates ◽  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Processing Parameters ◽  
Internal Strain ◽  
Matrix Composites ◽  
Molding Process

The influence of cure processing parameters was investigated using strain distributions from embedded optical fibers. The determination of optimized cure parameters is often needed to achieve material properties which meet aerospace industry design requirements. Optical fibers were embedded near the midplane of thin (5 mm; [0/90/90/0]3s) composite laminates to monitor the internal strain during cure for two different cure cycles (manufacturer-recommended and an alternative two-step cure). Each laminate was fabricated using a vacuum-assisted resin transfer molding process. The internal strain with respect to the spatial position and time were monitored. During cure, greater variations in the strain near the vicinity of the laminate edges were observed. However, a two-step cure cycle revealed that the variation of strain near the laminate edges is reduced. The results demonstrate the capability of high-spatial resolution optical fibers to measure the in-situ cure and residual strain during the processing of composite structures.

Embedded optical nanosensors for monitoring the processing and performance of polymer matrix composites

2019 ◽  
Vol 7 (46) ◽  
pp. 14471-14492
Author(s):  
David B. Lioi ◽  
Vikas Varshney ◽  
Sarah Izor ◽  
Gregory Neher ◽  
W. Joshua Kennedy
Keyword(s):  
Spatial Resolution ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Responsive Materials ◽  
Material State ◽  
Optical Nanosensors ◽  
And Performance ◽  
Structural Polymer

We provide a broad review of optically responsive materials with potential for in situ monitoring of material state properties in structural polymer-based materials with nanoscale spatial resolution.

Effect of Interfaces on Fiber Fracture in Mg and MgLi Matrix Composites

2005 ◽  
Vol 482 ◽  
pp. 355-358 ◽  
Author(s):  
S. Kúdela ◽  
H. Wendrock ◽  
L. Ptáček ◽  
S. Menzel ◽  
K. Wetzig
Keyword(s):  
Ex Situ ◽  
Matrix Composites ◽  
Interfacial Bond ◽  
Fiber Fracture ◽  
Composite Failure ◽  
Pull Out ◽  
Fiber Fragmentation ◽  
Scanning Electron

Fibers fracture in tensile strained Mg and MgLi matrix composites strengthened with ~10% vol. short δ-Al2O3 fibers (Saffil) is investigated by „in-situ“ scanning electron microscopy and ex-situ“ determination of the length of fibers chemically recovered from tensile failed composites. Little interfacial reaction in Mg matrix composite results in poor interfacial bond so that composite failure proceeds via fiber pull-out with negligible fiber fragmentation. On the other hand, extensive fiber/matrix reaction in MgLi matrix composites promotes formation of strong interfaces which are linked with multiple fiber cross-breakage during tensile straining. These results are consistent with experimental tensile strengths of related composites.

Reorientation of carbon nanotubes in polymer matrix composites using compressive loading

2005 ◽  
Vol 20 (4) ◽  
pp. 1026-1032 ◽  
Author(s):  
Michael J. Lance ◽  
Chun-Hway Hsueh ◽  
Ilia N. Ivanov ◽  
David B. Geohegan
Keyword(s):  
Strain Energy ◽  
Polymer Matrix Composites ◽  
Compressive Loading ◽  
Local Strain ◽  
Peak Shift ◽  
Raman Peak ◽  
Matrix Composites ◽  
Raman Peak Shift ◽  
Polarized Raman

Purified single-walled nanotubes (SWNTs) were dispersed in an epoxy polymer and subjected to uniaxial compressive loading. The orientation and stress in the nanotubes were monitored in situ using polarized Raman microscopy. At strains less than 2%, the nanotubes reorient normal to the direction of compression, thereby minimizing the local strain energy. Above 2% strain, the Raman peak shift reaches a plateau. A new analytical model, which approximates the SWNT reorientation by varying the aspect ratio of a representative spheroid, predicted the rotation behavior of nanotubes under load. The results of this model suggest that the observed plateau of the Raman peak shift is caused by both polymer yielding and interfacial debonding at the ends of nanotubes.

Microwave Dynamic Dielectric Analysis of Curing Neat Resins

1992 ◽  
Vol 269 ◽  
Author(s):  
Ray J. King ◽  
Michael J. Werner ◽  
Guillermo D. Mayorga
Keyword(s):  
Polymer Matrix Composites ◽  
Mechanical Analysis ◽  
Matrix Composites ◽  
Dielectric Analysis ◽  
Scanning Calorimetry ◽  
Strongly Coupled ◽  
Analysis Techniques ◽  
Noninvasive Sensors ◽  
Prototype Software

ABSTRACTMicrowave reflection resonator sensors have been developed to monitor the dynamic, in situ real and imaginary dielectric components (ε′, ε″) of thermoset polymer matrix composites and thermoplastics. These reusable and noninvasive sensors are conformably mounted in the autoclave mold in such a manner that the EM fields are strongly coupled to the resin. Tracking of (ε′, ε″) during the cure provides information about the chemical kinetics such as timing the point of minimum viscosity and monitoring the relative cure index. The sensor is readily adjustable for optimum coupling to the type of material being tested and is rated for temperatures up to 250°C (480*F). The technique is complementary to other analysis techniques such as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). A prototype software and electronics package has been developed to support the sensor.

In situ determination of the complex permittivity of ultrathin H2-infused palladium coatings for plasmonic fiber optic sensors in the near infrared

2018 ◽  
Vol 6 (19) ◽  
pp. 5161-5170 ◽  
Author(s):  
Xuejun Zhang ◽  
Shunshuo Cai ◽  
Fu Liu ◽  
Hao Chen ◽  
Peiguang Yan ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Complex Permittivity ◽  
Near Infrared ◽  
Fiber Optic ◽  
Fiber Optic Sensors

In situ determination of the complex permittivity of H2-infused palladium using near infrared plasmons over optical fibers.

SiOC Composite Structures for Intermediate Service Temperatures with Increased Friction Properties

2014 ◽  
Vol 88 ◽  
pp. 15-20 ◽  
Author(s):  
Rainer Gadow ◽  
Patrick Weichand
Keyword(s):  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Hybrid Composites ◽  
Raw Materials ◽  
Ceramic Matrix Composites ◽  
Thermal Resistivity ◽  
Limiting Factor ◽  
Matrix Composites ◽  
Reinforced Polymers ◽  
Manufacturing Technologies

Polymer Matrix Composites (PMC) are often used in lightweight applications due to their excellent mechanical properties combined with a low density. The manufacturing technologies are fully developed and raw materials are cheap. The limiting factor of these reinforced polymers is the maximum service temperature. Ceramic Matrix Composites (CMC) are suitable for service temperatures up to 1500 °C and more. These composites are composed of ceramic matrices combined with ceramic fibers based on alumina or silicon carbide. This class of composites is handicapped by the high cost of processing and raw materials and therefore only attractive for applications in astronautics and military aviation. Composite materials, bridging the gap between PMC and CMC, are manufactured by the use of polysiloxanes, carbon-and basalt fibers. Such competitive free formable Hybrid-composites are capable for service temperatures up to 800 °C in oxidative atmosphere. In order to make the material attractive also for series applications, manufacturing technologies like filament wet winding, Resin Transfer Moulding (RTM) or pressing techniques are employed. Beside the improved thermal resistivity in comparison to reinforced polymers and light metals, a major benefit of SiOC composites is investigated in the field of friction materials. The excellent properties in wear resistance and an adjustable coefficient of friction make it an interesting alternative for CFC and CMC.

Parametric optimization of pulse-echo laser ultrasonic system for inspection of thick polymer matrix composites

2020 ◽  
Vol 19 (2) ◽  
pp. 443-453 ◽  
Author(s):  
AD Abetew ◽  
TC Truong ◽  
SC Hong ◽  
JR Lee ◽  
JB Ihn
Keyword(s):  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Laser Ultrasonic ◽  
Ultrasonic Signals ◽  
Peak Energy ◽  
Pulse Echo ◽  
Non Destructive

One of the main challenges of using laser ultrasonic techniques for non-destructive testing applications is the typically low signal-to-noise ratio of the laser ultrasonic signals. In the case of thick composite structures, this is even more problematic since composite materials have very strong sound attenuation. This article investigates the effects of laser beam size and profile to the amplitude of pulse-echo laser ultrasonic signals with the constraint that the peak energy density (fluence) must be kept constant under the thermal damage threshold of material like polymer matrix composites. Such constraint is very important for the non-destructive feature of non-destructive testing, yet in a number of the existing parameter studies of laser ultrasonics, it was not fully investigated. In this article, a series of A-scan and C-scan experiments on thick composite specimens shows that the amplitude of the direct waves and the reflected waves increases with the increase in laser beam size with constant peak energy density. This amplitude enhancement significantly improves the propagation depth, thereby optimizing the system for inspection of thick composite structures. The validity of experimental results is verified theoretically by solving the thermoelastic model of epicenter displacement using Laplace–Hankel transformation.

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