Measurement of deformation of aircraft structures made of composite materials with fiber-optic sensors

AbstractAdvanced polymer matrix composite (PMC) materials have been more frequently employed for aerospace applications due to their light weight and high strength. Fiber-reinforced PMC materials are also being considered as potential candidates for elevated temperature applications such as supersonic vehicle airframes and propulsion system components. A new generation of high glass-transition temperature polymers has enabled this development to materialize. Clearly, there is a requirement to better understand the mechanical behaviour of this class of composite materials. In this study, polyimide-coated fiber optic sensors are employed to continuously monitor strain in a woven carbon fiber bismaleimide (BMI) matrix laminate subjected to tensile static and fatigue loading at elevated temperatures. A unique experimental test protocol is utilized to investigate the capability of the optical sensors to monitor strain and track stiffness degradation of the composite material. An advanced interrogation system and an optical spectrum analyzer are utilized to track the variation in the optical fiber wavelength and the wavelength spectrum for correlation with strain gage measurements. Isothermal tensile static and fatigue tests at room temperature, 105°C, 160°C and 205°C suggest that these optical sensors are capable of continuously monitoring strain and tracking the stiffness loss of a highly compliant PMC specimen during cyclic loading. The results illustrate that employing optical sensors for elevated temperature applications has significant advantages when compared to conventional strain gages.

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Measurement of process-induced strains in composite materials using embedded fiber optic sensors

10.1117/12.240892 ◽

1996 ◽

Cited By ~ 10

Author(s):

Craig M. Lawrence ◽

Drew V. Nelson ◽

Jay R. Spingarn ◽

Thomas E. Bennett

Keyword(s):

Composite Materials ◽

Fiber Optic ◽

Fiber Optic Sensors

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Measurement of process-induced strains in composite materials using embedded fiber optic sensors

10.2172/226060 ◽

1996 ◽

Cited By ~ 3

Author(s):

C.M. Lawrence ◽

D.V. Nelson ◽

J.R. Spingarn ◽

T.E. Bennett

Keyword(s):

Composite Materials ◽

Fiber Optic ◽

Fiber Optic Sensors

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Study Smart-layer effect on the physical and mechanical characteristics of the samples from polymer composite materials under quasi-static loading

PNRPU Mechanics Bulletin ◽

10.15593/perm.mech/2020.4.16 ◽

2020 ◽

pp. 188-200

Author(s):

G. S Shipunov ◽

M. A Baranov ◽

A. S Nikiforov ◽

D. V Golovin ◽

A. A Tihonova

Keyword(s):

Composite Materials ◽

Optical Fiber ◽

Polymer Composite ◽

Static Loading ◽

Mechanical Characteristics ◽

Fiber Optic ◽

Fiber Optic Sensors ◽

Polymer Composite Materials ◽

Physicomechanical Characteristics ◽

Physical And Mechanical Characteristics

Currently, developments of the so-called Smart-constructions are relevant as they enable a real-time monitoring of changes in required values. Smart designs are widely used in the construction, automotive and aerospace industries. Technologies of creating products from polymer composite materials make it possible to introduce various sensors directly into the structure of a material, thereby create systems monitoring the state of structures. The most recommended for such implementation are fiber-optic sensors, which have a number of advantages over other sensors (luminescent, strain gauge, piezoelectric ones). However, when introducing the fiber-optic sensors, there is a number of difficulties, which are primarily associated with fragility of the optical fiber and lead to the breakdown of fiber-optic lines. As a result, it is necessary to develop a Smart-layer that will protect the optical fiber leads and will not significantly change the physical and mechanical characteristics. This paper aims to determine the stiffness and strength characteristics of samples made of polymer composite materials: reference samples, samples with embedded fiber-optic sensors, samples with embedded Smart-layers. In this work, a Smart-layer is understood as a coating that protects the fiber-optic sensors at the stage of implementation into a structure. The paper considers the following configurations of the Smart-layer: polymer reinforced mesh, polyamide and polyurethane layer. We analyzed and compared the influence of the embedded optical fiber and various configurations of the Smart-layer in the composite structure on the physicomechanical characteristics of the samples obtained under quasi-static loading (tension, compression, and interlayer shear). For a more detailed analysis of using the fiber-optic sensors and various configurations of the Smart-layer, the corresponding loads were simulated to assess their mechanical behavior. Based on the obtained physical and mechanical characteristics, a specific configuration of the Smart-layer was selected and justified for further researches.

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Fiber Optic Sensors for Damage Detection in Composite Materials

ASME 1997 Turbo Asia Conference ◽

10.1115/97-aa-067 ◽

1997 ◽

Author(s):

Anand Asundi

Keyword(s):

Composite Materials ◽

Damage Detection ◽

Monitoring System ◽

Fiber Optic ◽

Fiber Optic Sensors ◽

Design Rules ◽

Interferometric Sensors ◽

On Line ◽

Proper Design

An absence of proper design rules has limited the application of composite materials to specific areas. However, within these application areas there is still a need to regular monitor the component resulting in significant downtime and loss of revenue. To overcome this it is proposed to have an on-line monitoring system capable of global checking of the component. Fiber optic polarimetric sensors are chosen in this study to globally characterize the health of a component. Polarimetric sensors have better sensitivity than intensity sensors and at the same time are more rugged than interferometric sensors. In this study, the effect of debonds and fiber breakages are investigated in composite bend specimens.

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