Effect of Impact Modifiers on Strength and Fracture Toughness of CFRPs

The aim of this work is to study the effect of core-shell rubbers on the mechanical properties of CFRPs.For the preparation of composites, two types of resins were used, a three-component Araldite resin (resin-hardener-accelerator system in proportions of 100-90-0,5 by weight respectively), and MX 156, which contains 25 % core-shell elastomers and 75 % Araldite resin. Depending on the mechanical test, two types of carbon fibre fabrics (UD C415, G0926) are used with corresponding number of layers. The composites were prepared by vacuum infusion and cut to the appropriate dimensions by water-cutting. They were tested for mechanical performance, by bending, shearing, tensile, impact and fracture toughness tests, to compare the properties of CSR-containing composites and reference CFRPs. Fracture analysis of specimens was performed by scanning electron microscopy (SEM). The results exhibited a 50% increase in impact strength while the energy absorbed during the fracture toughness test was 4 times greater on specimens with CSR than reference.

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Fracture Behavior of Natural Fiber Reinforced Biopolymer Matrix Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.1189 ◽

2008 ◽

Vol 47-50 ◽

pp. 1189-1192

Author(s):

Y. Yusliza ◽

A. Zuraida ◽

Iis Sopyan

Keyword(s):

Fracture Toughness ◽

Mechanical Performance ◽

Natural Fiber ◽

Mechanical Test ◽

Industrial Applications ◽

Morphological Observation ◽

Fiber Reinforced ◽

Pull Out ◽

Cotton Fibres ◽

The Impact

The attention in natural fiber reinforced biopolymer composite materials has been rapidly growing both in terms of industrial applications and basic research. This study was addressed to the investigation of the impact properties and fracture behaviour of biodegradable composites made from egg albumen reinforced by natural cotton fibres. The albumen-cotton composites have been fabricated by hands lay-up technique at varied volume fiber fraction from 2, 4, 6, 8, and 10 vol.% cotton. The specimens were cured at room temperature for a fixed time of 14 days to ensure the specimens are fully dried and harden, before being subjected to mechanical test. The cotton fibres have contributed in a significant improvement in fracture toughness of the composites. The obtained impact strength varied from 15.0 to 19.0 kJ/m2, and the fracture toughness varied from 0.7177 to 0.9453 J depending on vol.% cotton, with the optimum mechanical performance was obtained at 6 vol.% cotton. Morphological observation using SEM revealed that most of the fabricated specimens failed due to fiber breakage, pull out, and void growth.

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A Comparative Study on the Mechanical Properties of Clay Modified Epoxy Adhesive by Using Different Clay Types

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.780.43 ◽

2018 ◽

Vol 780 ◽

pp. 43-47

Author(s):

Siti Norasmah Surip ◽

A.H. Ismail

Keyword(s):

Mechanical Properties ◽

New World ◽

Mechanical Performance ◽

Mechanical Test ◽

Epoxy Adhesive ◽

Advanced Materials ◽

Clay Particles ◽

Tensile Impact ◽

Micron Size ◽

Modified Epoxy

In this new world, polymer nanocomposites have developed to be one of the latest evolutionary steps in the polymer technology, besides showing a great deal to become the most versatile industrial advanced materials. In comparison with conventional composites, nanocomposites demonstrate significantly higher levels of mechanical performance with less content of particles. Thus, this study was carried out to investigate the effect of nano& micron size of clay particles to mechanical properties of epoxy adhesive. Three types of mechanical test were performed; tensile, impact and shear test. The result shows that the tensile strength was increase by using micron clay while shear and impact strength was increase by using nanoclay. The dispersion of clay in the epoxy adhesive is very important because it will affect the mechanical properties of epoxy adhesive itself. The function of clay to enhance the properties of epoxy adhesive is more effective when the clay is well dispersed. FESEM shows that the nanoclay was well dispersed in the epoxy adhesive while micron sized clay was partially intercalated.

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The effect of nano- and micron-scale filler modified epoxy matrix on glass-fiber reinforced polymer insulator component behavior

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/14644207211000775 ◽

2021 ◽

pp. 146442072110007

Author(s):

Iurii Burda ◽

Michel Barbezat ◽

Andreas J Brunner

Keyword(s):

Fracture Toughness ◽

Compressive Strength ◽

Glass Fiber ◽

Epoxy Matrix ◽

Ternary Systems ◽

Fiber Reinforced Polymer ◽

Core Shell ◽

Glass Fiber Reinforced Polymer ◽

Reinforced Polymer ◽

Glass Fiber Reinforced

Glass-fiber reinforced polymer (GFRP) composite rods with epoxy matrix filled with electrically nonconducting particles find widespread use in high-voltage electrical insulator applications. The service loads require a range of different, minimum material property values, e.g. toughness, tensile, or compressive strength, but also component-specific performance, e.g. pull-out friction of surface crimped metal fittings or electric breakdown strength. The contribution discusses selected examples of the effects of different particle filler types on the properties of filled epoxy resin as well as on the behavior of GFRP rods with such a matrix. In all investigated systems CaCO3 was used as micron-sized filler, complemented by different amounts of either nanosilica or core-shell rubber (binary filler), or by both, nanosilica and core-shell rubber (ternary filler). With ternary filler combinations at a content of 36 wt%, fracture toughness GIC was improved in nanocomposite epoxy plates and in GFRP rods by 60% and 100%, respectively compared to a matrix with 20 wt% CaCO3 (used as reference system). The glass transition temperature Tg for some ternary systems dropped from 160 °C (for neat epoxy), to approximately 140 °C, the maximum allowed drop in Tg in view of requirements from further processing steps of the electrically insulating components. The ternary fillers yield transfer of the improvements of fracture properties from epoxy nanocomposite plates into the GFRP rods beyond that of the system with CaCO3 filler only. Compressive strength of the GFRP rods was improved by about 20% only for the binary nanosilica and CaCO3 filler, and was not significantly enhanced with the ternary systems. That combination, however, did not yield improvements in toughness beyond the CaCO3-filled nanocomposite plates and rods. With the range of filler types and contents investigated here, it was hence not possible to simultaneously optimize both, fracture toughness and compressive strength of the GFRP insulator rods.

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Effect of toughened polyamide-coated carbon fiber fabric on the mechanical performance and fracture toughness of CFRP

Journal of Composite Materials ◽

10.1177/0021998321999458 ◽

2021 ◽

pp. 002199832199945

Author(s):

Jong H Eun ◽

Bo K Choi ◽

Sun M Sung ◽

Min S Kim ◽

Joon S Lee

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Photoelectron Spectroscopy ◽

Mechanical Performance ◽

Epoxy Composites ◽

Scanning Calorimetry ◽

Internal Damage ◽

Impact Tests ◽

Flexural Tests ◽

The Impact

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.

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Precise Instrumentation and Stabilization of Interlaminar Fracture Toughness Test on CFRP by Long Gage Strain Measurement.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.65.1405 ◽

1999 ◽

Vol 65 (634) ◽

pp. 1405-1411

Author(s):

Kouichi KATSURA ◽

Kiyoshi TANAKA ◽

Kenji AONO

Keyword(s):

Fracture Toughness ◽

Strain Measurement ◽

Fracture Toughness Test ◽

Interlaminar Fracture Toughness ◽

Interlaminar Fracture ◽

Toughness Test

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Experimental Investigation on Relative Crack Length For Fracture Toughness of Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.1524 ◽

2010 ◽

Vol 146-147 ◽

pp. 1524-1528 ◽

Cited By ~ 3

Author(s):

Xue Zhi Wang ◽

Zong Chao Xu ◽

Zhong Bi ◽

Hao Wang

Keyword(s):

Fracture Toughness ◽

Experimental Investigation ◽

Crack Length ◽

Fracture Toughness Test ◽

Test Results ◽

Toughness Test ◽

Wedge Splitting Test ◽

Splitting Test ◽

Wedge Splitting

The wedge splitting test specimens with three series of different relative crack length were used to study the influences of relative crack length on the fracture toughness of common concrete. The suitable formulation for fracture toughness of concrete with different relative crack length was gotten on comparing between fracture toughness test results and computation results of the model developed from Hu formula.

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IMPACT FRACTURE TOUGHNESS TEST OF CERAMIC REINFORCED METALS

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:19913108 ◽

1991 ◽

Vol 01 (C3) ◽

pp. C3-769-C3-774 ◽

Cited By ~ 1

Author(s):

S. TAKAHASHI ◽

K. KISHIMOTO ◽

S. AOKI

Keyword(s):

Fracture Toughness ◽

Impact Fracture ◽

Fracture Toughness Test ◽

Toughness Test

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Dynamic Fracture Toughness Testing for Welding Part of Nuclear Piping Using Normalization Data Reduction Technique

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.306-308.73 ◽

2006 ◽

Vol 306-308 ◽

pp. 73-78

Author(s):

Yong Huh ◽

Hyung Ick Kim ◽

Chang Sung Seok

Keyword(s):

Fracture Toughness ◽

Dynamic Fracture ◽

Data Reduction ◽

Dynamic Test ◽

Dynamic Fracture Toughness ◽

Reduction Technique ◽

Fracture Toughness Test ◽

Static Test ◽

Welding Part ◽

Data Reduction Technique

In this study, we performed the static test of nuclear piping materials by the unloading compliance method and the normalization data reduction technique and obtained two fracture resistance curves (J-R curves). The two curves were similar, which proves that the normalization data reduction technique can be adopted in the static test. Then we performed the dynamic fracture toughness test for welding part of nuclear piping. The J-R curves were obtained from the dynamic test by the normalization data reduction technique and were compared to those of the static test results.

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