Tensile and Bending Strength Analysis of Ramie Fiber and Woven Ramie Reinforced Epoxy Composite

Abstract The paper presents the validation procedure of the model used in the analysis of the composite blade for the rotor of the ILX-27 rotorcraft, designed and manufactured in the Institute of Aviation, by means of numerical analyses and tests of composite elements. Numerical analysis using finite element method and experimental studies of three research objects made of basic materials comprising the blade structure – carbon-epoxy laminate, glass-epoxy composite made of roving and foam filler – were carried out. The elements were in the form of four-point bent beams, and for comparison of the results the deflection arrow values in the middle of the beam and axial deformations on the upper and lower surfaces were selected. The procedure allowed to adjust the discrete model to real objects and to verify and correct the material data used in the strength analysis of the designed blade.

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Ramie fiber reinforced composites with flame retardant structure design: flammability, smoke suppression, and mechanical properties

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0221 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Chenkai Zhu ◽

Lei Nie ◽

Xiaofei Yan ◽

Jiawei Li ◽

Dongming Qi

Keyword(s):

Shear Strength ◽

Iron Oxide ◽

Heat Release ◽

Flame Retardant ◽

Interlaminar Shear Strength ◽

Smoke Suppression ◽

Strength Analysis ◽

Ramie Fiber ◽

Composite Surface ◽

Interlaminar Shear

Abstract In this work, the structure of composite was designed as Core Stack and Surface Stack, which was treated with the expandable graphite (EG) and metal oxides such as iron oxide (IO), hydroxyapatite (HA), and aluminum tri-hydroxide (ATH). The mechanical performance of composites was characterized via flexural performance and interlaminar shear strength analysis. The flame retardance and smoke suppression of composite was explored in detail by LOI, UL-94, and cone calorimeter test. The findings presented that flexural properties of composites were observed to decrease due to delamination of surface stack, whilst no significant effect on interlaminar shear strength. In comparison with control composite, the loading of metal oxide into composite Surface Stack led to the reduction of peak heat release rate, total heat release, and fire growth index effectively. Moreover, the remarkable decrease in total smoke production could be observed due to the addition of iron oxide and the flame retardant mechanism was discussed. This study was the preliminary exploration of composite with flame retardant design which could be potential solution to improve flame retardancy and smoke suppression of composite with better mechanical structure preservation.

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Knitted Meshes for Reinforcing Building Composites

Fibres and Textiles in Eastern Europe ◽

10.5604/01.3001.0013.1826 ◽

2019 ◽

Vol 27 (4(136)) ◽

pp. 102-111

Author(s):

Zbigniew Mikołajczyk ◽

Katarzyna Pieklak ◽

Aleksandra Roszak

Keyword(s):

Concrete Beam ◽

Bending Strength ◽

Relative Elongation ◽

Testing Machine ◽

Strength Analysis ◽

Knitted Fabrics ◽

Three Point Bending ◽

Concrete Mass ◽

Frp Composites ◽

Technical Textiles

Modern technical textiles, including knitted fabrics, are widely used in the construction industry. Regarding textiles in concrete reinforcement, methods based on shredded fibres, meshes, reinforcing mats, woven textiles and knitted DOStapes are frequently used as underlays of concrete constructions. Textiles are also used in the reinforcement of fibrous FRP composites. The research presented focused on producing composites made of MapeiMapefill concrete mass with reinforcement in the form of three variants of knitted meshes made of 228 tex polyamide threads, polypropylene threads of 6.3 tex and 203 tex glass threads, as well as identification of their mechanical properties. The mesh variant made of glass fibre is especially noteworthy, as its strength is more than three times higher than that of polyamide meshes. At the same time, a very small relative elongation of 3% is observed for this variant of knitted fabric, which is a desired property regarding the comparatively low stretching extension of concrete. In the process of making the composites, the adhesion of the concrete mass to the surface of the threads was analyzed. For this purpose, a "Sopro HE449" type agent was used. Composite beams were subjected to a three-point bending strength analysis on a testing machine. The results of strength measurements of the composites obtained prove that those with glass fibres demonstrate a threefold increase in strength compared to the original concrete beam.

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Differences in Tensile and Bending Strength for Knoop-Cracked Lead Zirconate Titanate Specimens

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.2000.tb01254.x ◽

2004 ◽

Vol 83 (3) ◽

pp. 669-671 ◽

Cited By ~ 3

Author(s):

Theo Fett ◽

Dietrich Munz ◽

Gerhard Thun

Keyword(s):

Lead Zirconate Titanate ◽

Bending Strength ◽

Lead Zirconate ◽

Zirconate Titanate ◽

Tensile And Bending Strength

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Modelling and bending strength analysis of cylindrical gears with arcuate tooth trace

Australian Journal of Mechanical Engineering ◽

10.7158/m13-068.2015.13.2 ◽

2015 ◽

Vol 13 (2) ◽

pp. 77-86 ◽

Cited By ~ 1

Author(s):

F Jia ◽

L Hou ◽

Y Wei ◽

B Li ◽

Y You

Keyword(s):

Bending Strength ◽

Strength Analysis ◽

Cylindrical Gears

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Strength Analysis and Stress-Strain Deformation Behavior of 3 mol% Y-TZP and 21 wt.% Al2O3-3 mol% Y-TZP

Materials ◽

10.3390/ma14143903 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3903

Author(s):

Liliya Vladislavova ◽

Tomasz Smolorz ◽

Nina Orlovskaya ◽

Mykola Lugovy ◽

Michael J. Reece ◽

...

Keyword(s):

Elastic Deformation ◽

Deformation Behavior ◽

Ceramic Composite ◽

Bending Strength ◽

Domain Switching ◽

Small Deviation ◽

Strength Analysis ◽

Stress Strain ◽

Linear Elastic ◽

Four Point Bending

The mechanical behavior of 3 mol% Y2O3-ZrO2 ceramic and 21 wt.% Al2O3-3 mol% Y2O3-ZrO2 ceramic composite with submicron grain size was studied. Mechanical properties, such as hardness, Young’s modulus, four-point bending strength, and fracture toughness of both materials were measured. Linear stress-strain deformation behavior of both 3 mol% Y2O3-ZrO2 and 21 wt.% Al2O3-3 mol% Y2O3-ZrO2 was observed in flexure, both at room temperature and at 400 °C. A small deviation from linear elastic deformation was detected in 21 wt.% Al2O3-3 mol% Y2O3-ZrO2 ceramic composite when loaded above a stress of 1500 MPa. Therefore, it was concluded that only elastic deformation occurred at low stresses upon loading, which exclude the presence of domain switching in zirconia upon bending under the loading conditions of this study.

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Glide analysis and bone strength tests indicate powered flight capabilities in hatchling pterosaurs

10.7287/peerj.preprints.3216 ◽

2017 ◽

Author(s):

Mark P Witton ◽

Elizabeth Martin-Silverstone ◽

Darren Naish

Keyword(s):

Growth Rate ◽

Body Weight ◽

Bone Strength ◽

Bending Strength ◽

Skeletal Development ◽

Maximum Size ◽

Strength Analysis ◽

Life Stages ◽

Strength Tests ◽

Very High

Pterosaur embryos and ‘hatchling’ specimens show a surprising level of skeletal development including well-ossified skeletons and large wings. This has prompted interpretations of pterosaurs as being flight-capable from the earliest ontogenetic stages, contrasting them against the majority of other flying animals, living or extinct. Though popular, this hypothesis is not universally accepted. Some authors propose that pterosaurs only became flight capable once they reached 50% of maximum size, explaining a slowing of growth rate in later ontogeny as metabolic resources were diverted into an energy-demanding form of locomotion. We investigated these hypotheses through glide performance and wing bone strength analysis on hatchling-grade specimens of two pterosaurs, Pterodaustro guinazui and Sinopterus dongi. We found that hatchling pterosaurs were excellent gliders, but with a wing ecomorphology more comparable to powered fliers than obligate gliders. Bone strength analysis shows that hatchling pterosaur wing bones are structurally identical to those of larger pterosaurs and – because of their very low body masses – their bending strength relative to body weight is very high, comparable to or exceeding the greatest values estimated for larger, more mature pterosaurs. Hatchling pterosaurs are thus as mechanically adapted to powered flight stresses as other pterosaurs, if not moreso. Together with our glide tests, this result supports interpretations of hatchling pterosaurs as flight-capable. Size differences between pterosaur hatchlings and larger members of their species dictate differences in wing ecomorphology and flight capabilities at different life stages, which might have bearing on pterosaur ontogenetic niching.

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Reinforcement of epoxy polymers with hydride-silylated fumed silica

Himia Fizika ta Tehnologia Poverhni ◽

10.15407/hftp11.04.484 ◽

2020 ◽

Vol 11 (4) ◽

pp. 484-491

Author(s):

P. O. Kuzema ◽

◽

D. L. Starokadomsky ◽

O. O. Tkachenko ◽

V. A. Tertykh ◽

...

Keyword(s):

Fumed Silica ◽

Bending Strength ◽

Epoxy Composite ◽

Spectrophotometric Analysis ◽

Silicon Hydride ◽

Compression Tests ◽

Epoxy Polymers ◽

Functional Capabilities ◽

Bending Modulus ◽

Reinforcing Filler

Fumed silica (FS) is widely used in numerous fields of application, the plastics industry being one of the most significance, where FS has proved to be successful as an efficient thickening, thixotropic, and anti-settling agent, as well as reinforcing filler. Chemical modification of silica surface enlarges its functional capabilities. In particular, silica with grafted silicon hydride groups was found to be active in the processes of hydrosilylation of alkene and alkyne bonds in monomers during their polymerization, resulting in the formation of reinforced polymeric composites. Recently, specific epoxy resins have gained significance, and FS was found to be useful, particularly as rheological additive. The aim of this study was to evaluate the efficiency of hydride-silylated FS (HFS) as a potentially active reinforcing component for epoxy-based polymers. The activation energy for hydrosilylation of olefins is higher than that for ring-opening polymerization of epoxides, therefore, one may expect the latter process with participation of ≡SiH groups to proceed more readily. HFS was obtained via FS treatment with triethoxysilane. The presence of grafted silicon hydride groups was confirmed by means of IR spectroscopy, and their concentration measured by titrimetric and spectrophotometric analysis was found to be about 0.4 mmol/g. FS-epoxy and HFS-epoxy composites were prepared by the corresponding filler introduction (2 wt. % loading) into the mixture of epoxy monomer and amine hardener. The resulted materials after curing were subject to compression, bending, and adhesion tests. Compression tests revealed that filling with FS and HFS reduced the compressive strength by 10%, however, HFS-epoxy composite was found to possess an increased by 20 % Young’s modulus for compression as compared to that for the unfilled epoxy polymer. Upon this, 2 wt. % loading with silicas keeps the ductility of the polymer. Also, silica-containing epoxy polymers showed an improved bending strength and bending modulus, the former being two times higher for HFS-epoxy composite than that for the unfilled polymer. The adhesion to steel was found to increase by more than 2 times upon filling with silicas, HFS-epoxy composite being also superior as compared to the FS-epoxy one. Thus, preliminary results indicate that fumed silica with grafted silicon hydride groups shows promise as active reinforcing filler for epoxy polymers.

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