Prospects to separately estimate temperature and duration of a thermal pre-load on a polymer matrix composite

Eibl, Sebastian; Wolfrum, Johannes

doi:10.1177/0021998312460714

Cited by 13 publications

(24 citation statements)

References 22 publications

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“…The residual interlaminar shear strength of the investigated composite “8552/IM7” decreases continuously with duration and temperature of conditioning, starting from 80 MPa as reported in . Specimens with interlaminar shear strength lower than ca.…”

Section: Resultssupporting

confidence: 60%

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Quantification of a thermal pre‐load on polymer matrix composites by the degradation and colour change of polyurethane top coats

Eibl

2016

Materialwissenschaft Werkst

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This work provides techniques to separately determine temperature (90-340°C) and duration (1 minute to 240 days) of a thermal pre-load as well as residual strength of polymer matrix composites on basis of the degradation of the top-coat. Infrared spectroscopy and colorimetry characterizing binder degradation and colour changes of polyurethane top-coats were used to provide a non-destructive in-service method to quantify incipient heat damage. A multivariate (chemometric) analysis of infrared and colorimetric data was performed. The precision of the calculated values for duration and temperature of the thermal pre-load as well as residual strength for specimen with unknown thermal history is slightly better for the infraredspectroscopic analysis. Deviation of the calculated temperature is less than 10°C. However, the sole analysis of colorimetric data allows a separate evaluation of these parameters. Limitations of the techniques are identified.

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Section: Resultssupporting

confidence: 60%

“…In principal, a certain thermal damage may be achieved by a short thermal load at high temperature or a longer load at lower temperature. In order to separately determine time and temperature at least three different independent indicators are necessary . These indicators ideally represent degradation processes with different velocities.…”

Section: Resultsmentioning

confidence: 99%

Quantification of a thermal pre‐load on polymer matrix composites by the degradation and colour change of polyurethane top coats

Eibl

2016

Materialwissenschaft Werkst

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“…A detailed description of this method and attribution of the IR bands for 8552/IM7 is given in the literature. 2,18,21,27,29…”

Section: Resultsmentioning

confidence: 99%

Damage initiation of thermally degraded carbon composites in tension

Wolfrum¹,

Quan²,

Maier³

et al. 2018

Journal of Composite Materials

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This study focuses on exploring the initial failure of thermally degraded carbon fibre-reinforced polymers. It is the aim of this study to provide deep insight into the damage development and propagation as well as to understand failure mechanisms of thermally degraded composites. Carbon fibre-reinforced polymer panels with different fibre orientations are exposed to heat above maximum operational temperature (up to 200 ℃) for various durations (up to ca. 200 days). Thermal degradation of the material is characterized by scanning electron microscopy and infrared spectroscopy. The onset of the failure in tension is determined by acoustic emission analysis. The results show that the development and propagation of cracks depend on the level of thermal degradation and the fibre orientation relative to the applied load. With increasing thermal degradation, transverse matrix cracking, as the prevailing initiating failure mode, is replaced by crack initiation and propagation in the damaged outermost ply independent of its fibre orientation. Severe thermal matrix degradation is limited to this area, as characterized by infrared spectroscopy. With increasing thermal degradation of the polymer matrix, the onset of crack initiation and propagation is shifted to lower strains. The effects of damage initiation on fracture behaviour are discussed.

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“…Structural parts that may be exposed to external heat source, lightening impact, or hot engine exhaust gases. The thermal treatment of CFRP may result in debonding of fiber and resin due to degradation of the interphase, delamination, formation of cracks, and the degradation of the polymer matrix [1]. Thermal degradation of the polymer matrix can be detected by the intensity ratio of infrared (IR) bands at 1510 cm −1 characteristic for the epoxy resin [1].…”

Section: Introductionmentioning

confidence: 99%

“…The thermal treatment of CFRP may result in debonding of fiber and resin due to degradation of the interphase, delamination, formation of cracks, and the degradation of the polymer matrix [1]. Thermal degradation of the polymer matrix can be detected by the intensity ratio of infrared (IR) bands at 1510 cm −1 characteristic for the epoxy resin [1]. As it was shown by Heckner et al [2] when the degradation occurs in an environment with oxygen, a thermo-oxidative degradation occurs.…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Non-Destructive Study of CFRP Adhesive Bonds Subjected to Pre-Bond Thermal Treatment and De-Icing Fluid Contamination

et al. 2018

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Abstract:Composite materials are commonly used in many branches of industry. One of the effective methods to join the carbon fibre reinforced polymer (CFRP) parts includes the use of adhesives. There is a search on effective methods for quality assurance of bonded parts. In the research here reported the influence of surface pre-bond modification on the adhesive bonds of CFRP plates has been analyzed. Adherends surface modifications, to include defects affecting the bonding quality, were obtained through surface thermal treatment, surface contamination with de-icing fluid and a combination of both the previously described treatments. Characterization of bonded joints was performed by means of mechanical testing, ultrasounds and electromechanical impedance (EMI) measurements. The study here proposed has also the aim to evaluate the ability of different destructive and non-destructive techniques to assess the quality of the bonds. While mechanical tests were strongly affected by the surface modifications, results obtained ultrasound and EMI test have demonstrate only a limited ability of these techniques to differentiate between the different samples. In fact, ultrasounds did not show any changes in the bondline, due to pre-bond modifications. However, this technique was able to detect delamination in CFRP for one of the samples thermally treated at 280 • C. Electromechanical impedance (EMI) measurements showed similar behavior as mechanical tests for samples thermally treated at 260 • C and 280 • C, and for the sample whose surface modification was made with a combination of thermally and de-icing fluid treatments.

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Prospects to separately estimate temperature and duration of a thermal pre-load on a polymer matrix composite

Cited by 13 publications

References 22 publications

Quantification of a thermal pre‐load on polymer matrix composites by the degradation and colour change of polyurethane top coats

Quantification of a thermal pre‐load on polymer matrix composites by the degradation and colour change of polyurethane top coats

Damage initiation of thermally degraded carbon composites in tension

Mechanical and Non-Destructive Study of CFRP Adhesive Bonds Subjected to Pre-Bond Thermal Treatment and De-Icing Fluid Contamination

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