Effect of Core Architecture on Charpy Impact and Compression Properties of Tufted Sandwich Structural Composites

This study presents a novel sandwich structure that replaces the polypropylene (PP) foam core with a carbon fiber non-woven material in the tufting process and the liquid resin infusion (LRI) process. An experimental investigation was conducted into the flatwise compression properties and Charpy impact resistance of sandwich composites. The obtained results validate an enhancement to the mechanical properties due to the non-woven core and tufting yarns. Compared to samples with a pure foam core and samples without tufting threads, the compressive strength increased by 45% and 86%, respectively. The sample with a non-woven layer and tufting yarns had the highest Charpy absorbed energy (23.85 Kj/m2), which is approximately 66% higher than the samples without a non-woven layer and 90% higher than the samples without tufting yarns. Due to the buckling of the resin cylinders in the Z-direction that occurred in all of the different sandwich samples during the compression test, the classical buckling theory was adopted to analyze the differences between the results. The specific properties of the weight gains are discussed in this paper. The results show that the core layers have a negative effect on impact resistance. Nevertheless, the addition of tufting yarns presents an obvious benefit to all of the specific properties.

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Experimental investigation on tensile and Charpy impact behavior of Kevlar/S-glass/epoxy hybrid composite laminates

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0538 ◽

2017 ◽

Vol 37 (2) ◽

pp. 177-184 ◽

Cited By ~ 5

Author(s):

Ahmet Erkliğ ◽

Mehmet Bulut

Keyword(s):

Impact Strength ◽

Hybrid Composite ◽

Composite Laminates ◽

Glass Fibers ◽

Impact Resistance ◽

Charpy Impact ◽

Side Impact ◽

Impact Behavior ◽

Absorbed Energy ◽

Mixing Ratios

Abstract The aim of this study is to evaluate the effect of hybridizing Kevlar and glass fibers on the tensile and Charpy impact properties of their composites. Produced hybrid samples were designed as unbalanced and asymmetric structures in terms of different mixing ratios between woven Kevlar and S-glass fibers, and their tensile properties were determined using ASTM standards. A series of Charpy impact tests were performed to evaluate the amount of impact strength and absorbed energy by impacting each side of the hybrid composite samples. When the hybrid samples were impacted on the surface of the Kevlar side, they exhibited higher impact resistance compared with glass side impact. The resulting degree of hybridization effects showed that addition of Kevlar layers instead of glass layers contributed a significant increase in impact strength and absorbed energy of the overall composite laminate.

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Thermal Aging Behavior of Grade CF3M Cast Austenitic Stainless Steels

Volume 1A: Codes and Standards ◽

10.1115/pvp2017-65959 ◽

2017 ◽

Author(s):

Yasufumi Miura ◽

Takashi Sawabe ◽

Kiyoshi Betsuyaku ◽

Taku Arai

Keyword(s):

Fracture Toughness ◽

Stainless Steels ◽

Thermal Aging ◽

Impact Test ◽

Charpy Impact ◽

Charpy Impact Test ◽

Ferrite Phase ◽

Absorbed Energy ◽

Aging Conditions ◽

Charpy Absorbed Energy

In this study, CASSs which were thermally aged at 275–400°C for up to 30000 hrs were investigated using atom probe tomography, Charpy impact test, hardness test, and fracture toughness test in order to evaluate the effects of chemical composition and ferrite content on thermal aging embrittlement. Test materials were 4 types of statically casted grade CF3M stainless steels which are used in Japanese BWR plants. As a result of the tests, Charpy absorbed energy at room temperature of all thermal aging conditions were obtained. We also obtained the microstructural evolution in ferrite phase, hardness of ferrite phase, and J–R curves of several aging conditions. The fracture toughness and the Charpy absorbed energy of all materials aged at 275°C for up to 15000 hrs were approximately same as those of unaged materials. On the other hand, reduction of the fracture toughness and the Charpy absorbed energy were observed in the materials aged at 300°C, 320°C, 350°C and 400°C. For the Charpy impact test in this study, the absorbed energy of the material with highest molybdenum was lower than that of the material with highest ferrite content. After the tests, the fracture toughness estimation model for grade CF8M in NUREG/CR-4513 and the method in PVP2005-71528 (H3T model) were discussed in order to confirm the applicability of the prediction methods to CF3M.

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Effects of Mo segregation on Charpy absorbed energy in Ti-12Mo alloys

MATEC Web of Conferences ◽

10.1051/matecconf/202032111050 ◽

2020 ◽

Vol 321 ◽

pp. 11050

Author(s):

Satoshi Emura ◽

Xin Ji ◽

Xiaohua Min ◽

Koichi Tsuchiya

Keyword(s):

Room Temperature ◽

Tensile Elongation ◽

Solution Treatment ◽

Charpy Impact ◽

Transgranular Fracture ◽

Omega Phase ◽

Absorbed Energy ◽

Rolled Sample ◽

Heterogeneous Distribution ◽

Charpy Absorbed Energy

Beta phase stabilizing elements such as Mo have strong tendency to segregate. We have introduced swirly type segregation of Mo in Ti-12Mo (mass %) alloy through groove bar rolling. After solution treatment and low temperature aging, hard omega phase was precipitated heterogeneously, which improved the room temperature tensile elongation values without sacrificing tensile strength. In this study, the effect of Mo segregation and heterogeneous distribution of omega phase on Charpy absorbed energy was investigated in Ti-12Mo alloy. Samples with two types of segregation were prepared; namely, swirly segregation in bar rolled sample and layered segregation in plate rolled sample. For comparison, we have also prepared Ti-12Mo bar samples with lesser Mo segregation, through high temperature thermomechanical treatment. Charpy impact tests were carried out at room temperature, 373 K and 473 K, respectively, using the samples after aging to introduce isothermal omega-phase. The samples with the segregation exhibited higher Charpy absorbed energy, especially at higher temperature of 473 K, while the sample with the swirly segregation showed higher Charpy absorbed energy than that with the layered segregation. The sample with lesser Mo segregation exhibited brittle intergranular fracture surface after Charpy testing. On the contrary, samples with Mo segregation exhibited ductile transgranular fracture surfaces.

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Analysis of Statistical Scatter in Charpy Impact Toughness

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.2394 ◽

2014 ◽

Vol 783-786 ◽

pp. 2394-2399 ◽

Cited By ~ 5

Author(s):

Yasuhito Takashima ◽

Mitsuru Ohata ◽

Fumiyoshi Minami

Keyword(s):

Brittle Fracture ◽

Impact Toughness ◽

Weibull Distribution ◽

Shape Parameter ◽

Charpy Impact ◽

Numerical Results ◽

Statistical Distribution ◽

Absorbed Energy ◽

Charpy Impact Toughness ◽

Charpy Absorbed Energy

Charpy impact toughness values show large statistical scatter, particularly in the ductile-to-brittle transition temperature (DBTT) range. Although the statistical distribution of Charpy absorbed energy has not been clarified, critical values of the stress intensity factor, J-integral and crack-tip opening displacement (CTOD) at brittle fracture generally show the Weibull distribution with two or three parameters. This study proposes a brittle fracture model, based on the weakest link theory, for evaluating the scatter in Charpy absorbed energy KV. The numerical results show that the amplitude of the opening stress fields ahead of the V-notch at varying amounts of KV are uniquely characterized as the square of the applied load. With these numerical results, the Weibull shape parameter of the statistical distribution of KV is almost equal to 2. The proposed statistical model is verified through experimental results. It is found that the statistical distribution of KV is characterized by a two-parameter Weibull distribution with the shape parameter of 2 under the condition of pure brittle fracture.

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Effects of internal porosity and crystallographic texture on Charpy absorbed energy of electron beam melting titanium alloy (Ti-6Al-4V)

Materials Science and Engineering A ◽

10.1016/j.msea.2018.11.005 ◽

2019 ◽

Vol 742 ◽

pp. 269-277 ◽

Cited By ~ 14

Author(s):

Nikolas Hrabe ◽

Ryan White ◽

Enrico Lucon

Keyword(s):

Titanium Alloy ◽

Electron Beam ◽

Crystallographic Texture ◽

Electron Beam Melting ◽

Absorbed Energy ◽

Internal Porosity ◽

Charpy Absorbed Energy

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Effect of small steel-piece size on Charpy absorbed energy

Maintenance, Safety, Risk, Management and Life-Cycle Performance of Bridges ◽

10.1201/9781315189390-392 ◽

2018 ◽

pp. 2889-2893

Author(s):

D. Kitazume ◽

K. Ono ◽

K. Anami ◽

T. Iida

Keyword(s):

Absorbed Energy ◽

Piece Size ◽

Charpy Absorbed Energy ◽

Small Steel

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Prediction of Charpy Absorbed Energy of Steel for Welded Structure in Ductile-to-Brittle Fracture Transition Temperature Range

QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY ◽

10.2207/qjjws.38.103s ◽

2020 ◽

Vol 38 (2) ◽

pp. 103s-107s

Author(s):

Yasuhito TAKASHIMA ◽

Fumiyoshi MINAMI

Keyword(s):

Transition Temperature ◽

Brittle Fracture ◽

Absorbed Energy ◽

Temperature Range ◽

Fracture Transition ◽

Welded Structure ◽

Charpy Absorbed Energy

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Evaluation of sandwich panels with composite tube-reinforced foam core under bending and flatwise compression

Journal of Sandwich Structures & Materials ◽

10.1177/1099636218798161 ◽

2018 ◽

Vol 22 (2) ◽

pp. 480-493 ◽

Cited By ~ 1

Author(s):

Kenan Cinar

Keyword(s):

Thermal Conductivity ◽

Sandwich Structure ◽

Bending Stiffness ◽

Core Material ◽

Foam Core ◽

Compression Tests ◽

Composite Tubes ◽

Low Thermal Conductivity ◽

Compression Performance ◽

Compression Properties

In some applications such as roofs and walls, it is important to supply low thermal conductivity and high bending stiffness to structures. Generally, foam materials are preferred, which have low thermal conductivity. However, bending stiffness and compression properties of foam materials are low. In this study, composite tubes were inserted to the foam core material to improve the compression and bending properties of the sandwich structure. Vacuum infusion method was used to manufacture the sandwich structure. The bending and compression performance of the structures with and without composite tubes were compared. To measure the bending stiffness and compression properties of the structure, three-point bending and compression tests were conducted according to American Society for Testing and Materials (ASTM) standards. The manufacturing procedure can be easily automated and applied to large and complex shape panels. In addition, a parametric analysis was done to investigate the effect of the number of tubes and the diameter of the tubes on bending and compression stiffness of the structure. According to the test results, the samples including the composite tubes gave six times higher bending stiffness as compared to the samples without the composite tubes. As the diameter of the tubes increased the bending stiffness and the ultimate core shear strength increased. In addition, the structures including 14 mm diameter tubes had higher specific absorbed energy values under compression loading.

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