The Added Value of Infrared Thermography to Impact Damaging Assessment of Carbon Fibre Reinforced Composites

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 49-53
Author(s):  
Карломаньо ◽  
Giovanni Carlomagno ◽  
Монако ◽  
Ernesto Monako ◽  
Боффа ◽  
...  
Keyword(s):  
Composite Material ◽  
Infrared Thermography ◽  
Stacking Sequence ◽  
Impact Event ◽  
Imaging Device ◽  
Thermal Images ◽  
Impact Tests ◽  
Phase Images ◽  
Lock In ◽  
The Impact

Introduction. The weakness of composites to impact load is a well known problem. In particular, their impact damaging happens through complex mechanisms which are still not completely understood also because of the multitude of materials that can be created by changing: matrix, reinforcement and/or stacking sequence. It is enough to change the direction of a layer of fibres to have a new composite material. Once a new material is created, it is important to assess its performance under impact, or its impact resistance. The scope of this work is to show how advantageous may be to use infrared thermography to monitor impact tests, which are performed to ascertain the resistance-to-impact of a new composite material. Methods. Infrared thermography (IRT) and phased array ultrasonic testing (PAUT) are used. IRT is used with a twofold function: • on-line monitoring the impact event to visualize thermal signatures which bear the witness for the existence of any occurred damage; • non-destructive evaluation with lock-in thermography (LT) of the impacted specimens. Results. Some results are reported in terms of: • thermal images taken during impact tests on carbon/epoxy specimens; • phase images taken on the impacted specimens with lock-in thermography; • C-scan images taken with PAUT on the impacted surface of one specimen are compared with phase images obtained with lock-in thermography and also with thermal images taken during the impact. Discussion. Both LT and PAUT are effective in detecting the impact damage; LT is fast and more effective to map large surfaces, conversely PAUT is better to get information along the thickness especially in case of thick parts. Then, an integrated use of both techniques would be advantageous. However, they are characterized by some uncertainty in discriminating very thin delaminations when they are compared with the thermal signatures visualized during monitoring of the impact event, especially in presence of composites with complex stacking sequence. Conclusion. The obtained results show that, if the aim is to assess the performance under impact of composite materials for design purposes, monitoring the impact with an infrared imaging device appears to be the fastest and better solution.

scholarly journals The Contribution of Infrared Thermography to Impact Testing of Composite Materials†

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 29
Author(s):  
Carosena Meola
Keyword(s):  
Composite Materials ◽  
Infrared Thermography ◽  
Infrared Imaging ◽  
Impact Testing ◽  
Imaging Device ◽  
Impact Tests ◽  
Different Types ◽  
Infrared Cameras ◽  
The University ◽  
The Impact

This work wants to give an overview on information gathered at the University of Naples Federico II in the last ten years by monitoring the impact tests of composite materials with infrared thermography. Many tests have been carried out involving several different types of composites and different infrared cameras. The obtained results show that IRT can be advantageously used to both validate previously obtained data and to get new data that can be exploited for understanding more on the impact damaging of composite materials. This bears witness for the advantages of having an infrared imaging device within the testing instrumentation.

Detection of Wall-Thinning Defects in Nuclear Piping Components Using an Advanced Infrared Thermography Technique

2013 ◽  
Author(s):  
Jin Weon Kim ◽  
Kyung Won Yun ◽  
Hyun Chul Jung
Keyword(s):  
Thermal Conductivity ◽  
Infrared Thermography ◽  
High Thermal Conductivity ◽  
Detection Capability ◽  
Thermal Images ◽  
Wall Thinning ◽  
Phase Images ◽  
Lock In

An advanced infrared thermography (IRT) technique, known as lock-in mode IRT, has been developed and employed to improve the detection capability of defects in materials with high thermal conductivity. Lock-in mode IRT has been shown to provide better detection capability than conventional active IRT. Therefore, to investigate application of this technique to nuclear piping components, we conducted lock-in mode IRT tests on pipe specimens containing simulated wall-thinning defects. We obtained phase images of the wall-thinning defects and compared them with thermal images obtained from conventional active IRT tests. The results indicated that the ability to size the detected wall-thinning defects in piping components was improved by using lock-in mode IRT. The improvement was especially apparent when detecting short and narrow defects, and defects with slanted edges. However, the detection capability for shallow wall-thinning defects did not improve much when using lock-in mode IRT.

scholarly journals The Contribution of Infrared Thermography in the Characterization of Glass/Epoxy Laminates through Remote Sensing of Thermal-Stress Coupled Effects

Proceedings ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Carosena Meola ◽  
Simone Boccardi ◽  
Giovanni Maria Carlomagno
Keyword(s):  
Cantilever Beam ◽  
Mechanical Stresses ◽  
Material Behavior ◽  
Low Velocity Impact ◽  
Imaging Device ◽  
Temperature Variations ◽  
Thermal Images ◽  
Damage Initiation ◽  
Matrix Cracks ◽  
The Impact

Mechanical stresses of materials are generally coupled with temperature variations and then, monitoring such variations can help gaining information about the material behavior under the applied loads. This can be accomplished with an infrared imaging device, which can be advantageously exploited to sense the thermal radiation associated with mechanical stresses and to obtain a legible explicative temperature map. In the present paper, glass/epoxy is used as material case study to show that thermal signatures visualized during the load application can be decoded into knowledge, which can contribute to the material characterization. In particular, glass/epoxy specimens are subjected to three types of tests: cantilever beam alternate bending, quasi-static bending and low velocity impact. Thermal images are acquired in time sequence during each test and after post-processed and analyzed. It is possible to get data about the damage initiation and its evolution under either quasi-static bending, or impact. In particular, a cute analysis of thermal images supplies information about damage types (matrix cracks, or fibers breakage) and extension of delamination, as well of the impact duration and the time to reach peak contact force. It is also possible to well depict the harmonic cantilever beam oscillations through the associated small temperature variations.

scholarly journals Lock-In Thermography and Ultrasonic Testing of Impacted Basalt Fibers Reinforced Thermoplastic Matrix Composites

2019 ◽  
Vol 9 (15) ◽  
pp. 3025 ◽  
Author(s):  
Boccardi ◽  
Boffa ◽  
Carlomagno ◽  
Core ◽  
Meola ◽  
...  
Keyword(s):  
Composite Material ◽  
Ultrasonic Testing ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Matrix Composites ◽  
Basalt Fibers ◽  
Low Velocity ◽  
Destructive Testing ◽  
Impact Tests ◽  
Lock In

Basalt fibers are receiving increasing consideration because they seem to be adequate as reinforcement of composites and to comply with the environmental safeguard rules. However, many factors affect the performance of composite material, demanding specific testing; one may be performance assessment under impact tests. The attention of the present work is focused on the detection of impact damage in basalt-based composites with two non-destructive testing techniques: lock-in thermography (LT) and ultrasonic testing (UT). Two different types of materials are considered which both include basalt fibers as reinforcement but two different matrices: Polyamide and polypropylene. Polypropylene is used either pure or modified with the addition of a coupling agent; the latter improves the fiber/matrix interface strength, giving in practice, a material of different characteristics. Specimens are first subjected to low-velocity impact tests and then non-destructively examined with the two above mentioned techniques. The obtained results are analyzed and compared to highlight the advantages and limitations of the two techniques to detect impact damage in basalt-based composites. Both techniques seem effective for the inspection of polyamide/basalt composite; in particular, there is a general agreement between results. Conversely, UT seems not suitable for the inspection of polypropylene/basalt composites because of their superficial porosity, while lock-in thermography is effective also for this type of composite material.

scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 203
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Impact Test ◽  
Carbon Fiber Composites ◽  
Internal Defects ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Fibers Orientation ◽  
Lock In ◽  
The Impact

With the increasing use of carbon fiber reinforced plastics in various fields, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For the non-contact evaluation of internal defects, the lock-in infrared thermography was proposed to investigate the defects in the composites subjected to the compression after impact test (CAI). The drop-weight impact test was conducted to study the impact behavior of the composites according to fibers orientation for composite fabricated using unidirectional (UD) carbon fiber prepregs. Using CAI tests, the residual compressive strengths were determined, and the damage modes were detected using a thermal camera. The results of the drop weight impact tests showed that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. The specimens with 0°/90° and +45°/−45° fibers orientation exhibited more than 90% of the impact energy absorption and good impact resistance. Furthermore, the specimens that underwent the impact tests were subjected to compressive test simultaneously with the lock-in thermography defects detection. The results showed that internal delamination, fibers splitting, and broken fibers occurred. The temperature differences in the residual compression tests were not significant.

Effect of Continuous Micro Reinforcement and Processing Parameters on the Low-Velocity Impact Behaviour of Polymer Composite Materials

2019 ◽  
Vol 56 (2) ◽  
pp. 382-387
Author(s):  
Raluca Maier ◽  
Andrei Mandoc ◽  
Alexandru Paraschiv ◽  
Marcel Istrate
Keyword(s):  
Processing Parameters ◽  
Woven Fabrics ◽  
Low Velocity Impact ◽  
Stacking Sequence ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
Ductility Index ◽  
Impact Tests ◽  
The Impact

Low velocity impact tests were conducted on quasi-isotropic [�45/0/90o]xs laminates under drop weight impact from 0.7m, corresponding to a 30J energy. In this respect modified epoxy blends reinforced with carbon and Kevlar woven fabrics laminates were developed using autoclave technology. The four configurations developed for low velocity impact tests aimed at investigating several aspects like: the effect of fiber type, stacking sequence and mainly technological processing parameters, on the impact performances. The recorded Load-Time curves were plotted and visual inspection, high resolution laser scanner were used to observe the fracture characteristics of the impacted composite laminates. The results obtained showed that for tested configurations, both stacking sequence and processing parameters directly linked to fiber volume fraction, have a strong effect on the impact performances. The amount of absorbed energy, ductility index was calculated for each configuration under study. The results obtained showed that hybrid configuration exhibits lower stiffness and damage initiation energy amount when compared to carbon reinforced configurations. Nevertheless, their damage propagation energy amount and ductility index was the uppermost. This behaviour was already reported previously [1] and is partially attributed to the higher elastic energy absorption of carbon fibers that delays the propagation of delamination, and fiber breakage. Lower tenacity obtained on hybrid laminates was attributed to both lack of resin local rinse saturate and to the intrinsic anisotropy of para-aramid fibers.

scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

2020 ◽  
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
and Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Carbon Fiber Composites ◽  
Compression Tests ◽  
Internal Defects ◽  
Finite Elements Analysis ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Lock In ◽  
The Impact

.With the increasing use of carbon fiber reinforced plastics in various area, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For non-contact evaluation of internal defects, we proposed lock-in infrared thermography to investigate orientation angles after a compression test. We also conducted a drop-weight impact test to study the behaviour of the composites after impact according the fibers orientation for composite fabricated using unidirectional carbon fiber prepregs. Using CAI tests, we determined the residual compressive strength and confirmed the damage modes using a thermal camera. The results of the drop weight impact tests show that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. In contrast, the specimens oriented in of 0°/90° and +45°/–45° directions transferred more than 90% of the impact energy back to the impactor because of the lamination of fibers in the orthogonal directions. Furthermore, the specimens that underwent complete damage in the impact tests were subjected to the lock-in method and showed internal delamination and cut fibers. With the finite elements analysis, the damage of each ply could be observed. Moreover, the temperature differences in the residual compression tests were not significant.

The Added Value of Infrared Thermography to Assess the Impact Performance of Composites

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Simone Boccardi ◽  
Natalino D. Boffa ◽  
Giovanni M. Carlomagno ◽  
Carosena Meola ◽  
Fabrizio Ricci ◽  
...  
Keyword(s):  
Composite Materials ◽  
Nondestructive Evaluation ◽  
Infrared Thermography ◽  
Added Value ◽  
Manufacturing Defects ◽  
Impact Performance ◽  
Before And After ◽  
New Material ◽  
Lock In ◽  
The Impact

Composite materials are becoming ever more popular in an increasing number of applications. This because of their many advantages, amongst others the possibility to create a new material of given characteristics in a quite simple way by changing either the type of matrix, or reinforcement, and/or rearranging the reinforcement in a different way. Of course, once a new material is created, it is necessary to characterize it to verify its suitability for a specific exploitation. In this context, infrared thermography (IRT) represents a viable means since it is noncontact, nonintrusive, and can be used either for nondestructive evaluation to detect manufacturing defects, or fatigue-induced degradation, or else for monitoring the inline response to applied loads. In this work, IRT is used to investigate different types of composite materials, which involve carbon fibers embedded in a thermoset matrix and either glass or jute fibers embedded in a thermoplastic matrix, which may be neat, or modified by the addition of a percentage of a specific compatibilizing agent. IRT is used with a twofold function. First, for nondestructive evaluation, with the lock-in technique, before and after loading to either assure absence of manufacturing defects, or discover the damage caused by the loads. Second, for visualization of thermal effects, which develop when the material is subjected to impact. The obtained results show that it is possible to follow inline what happens to the material (bending, delamination, and eventual failure) under impact and get information, which may be valuable to deepen the complex impact damaging mechanisms of composites.

scholarly journals A New Approach for Design Optimization and Parametric Analysis of Symmetric Compound Parabolic Concentrator for Photovoltaic Applications

2021 ◽  
Vol 13 (9) ◽  
pp. 4606
Author(s):  
Faisal Masood ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Javed Akhter ◽  
Mohammad Azad Alam
Keyword(s):  
Parametric Analysis ◽  
Concentration Ratio ◽  
Synergistic Effects ◽  
Geometric Optimization ◽  
Design Parameters ◽  
Imaging Device ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
Half Angle ◽  
The Impact

A compound parabolic concentrator (CPC) is a non-imaging device generally used in PV, thermal, or PV/thermal hybrid systems for the concentration of solar radiation on the target surface. This paper presents the geometric design, statistical modeling, parametric analysis, and geometric optimization of a two-dimensional low concentration symmetric compound parabolic concentrator for potential use in building-integrated and rooftop photovoltaic applications. The CPC was initially designed for a concentration ratio of “2×” and an acceptance half-angle of 30°. A MATLAB code was developed in house to provoke the CPC reflector’s profile. The height, aperture width, and concentration ratios were computed for different acceptance half-angles and receiver widths. The interdependence of optical concentration ratio and acceptance half-angle was demonstrated for a wide span of acceptance half-angles. The impact of the truncation ratio on the geometric parameters was investigated to identify the optimum truncation position. The profile of truncated CPC for different truncation positions was compared with full CPC. A detailed statistical analysis was performed to analyze the synergistic effects of independent design parameters on the responses using the response surface modeling approach. A set of optimized design parameters was obtained by establishing specified optimization criteria. A 50% truncated CPC with an acceptance half-angle of 21.58° and receiver width of 193.98 mm resulted in optimum geometric dimensions.

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