Fatigue Behavior of 3D Braided Composites Containing an Open-Hole

The static and dynamic mechanical performances of notched and un-notched 3D braided composites were studied. The effect of longitudinal laid-in yarn was investigated in comparison with low braiding angle composites. The specimens were fatigue tested for up to millions of cycles, and the residual strength of the samples that survived millions of cycles was tested. The cross-section of the 3D braided specimens was observed after fatigue loading. It was found that the static and fatigue properties of low angle 3D braided behaved better than longitudinally reinforced 3D braided composites. For failure behavior, pure braids contain damage better and show less damage area than the braids with longitudinal yarns under fatigue loading. More cracks occurred in the 3D braided specimen with axial yarn cross-section along the longitudinal and transverse direction.

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Experimental Research on Low-Velocity Impact Properties of 3D Braided Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.1741 ◽

2010 ◽

Vol 97-101 ◽

pp. 1741-1744

Author(s):

Qi Jia ◽

Ya Nan Jiao

Keyword(s):

Three Dimensional ◽

Low Velocity Impact ◽

Braided Composites ◽

Low Velocity ◽

Impact Properties ◽

Damage Area ◽

3D Braided Composites ◽

Glass Fiber Reinforced ◽

Braiding Angle ◽

The Impact

This research dealt with the impact properties of glass fiber reinforced composites manufactured from different structures of three-dimensional braided preforms. Three different architectures of the braid structures, 4-Direction, 5-Direction and 6-Direction, were investigated together with three further various braiding angles of each architecture. The effect of architecture and braiding angle parameters upon the impact was examined. Damage morphology of the impacted materials was characterized. It has been found that the parameters affected the damage resistance and tolerance of composites evidently. 6-Directional composites showed higher impact toughness than the others with same braiding angle. Failure of the specimens with small damage area revealed the brittle characteristic of 3D braided composite.

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Prediction for Strength of 3D Braided Composites Based on Helix Geometry Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.387.64 ◽

2013 ◽

Vol 387 ◽

pp. 64-67

Author(s):

Li Li Jiang ◽

Xi Bin Wei ◽

Xun Liu ◽

Tao Zeng

Keyword(s):

Numerical Model ◽

Cross Section ◽

Present Model ◽

Experimental Results ◽

Micro Structure ◽

Braided Composites ◽

Geometry Model ◽

3D Braided Composites ◽

Braiding Angle ◽

Helix Geometry

A numerical model capable of calculating the strength of 3D braided composites is developed, based on the micro-structure of 3D four-directional braided composites and the assumption of the braiding yarn with a helix configuration and ellipse cross-section. The strength of 3D braided composites have been predicted through a finite multiphase element method (FMEM). Comparison was conducted for those from the present model and experiment. The results are in good agreements with the experimental results in the previous literature. The influences of braiding angle on the strength are also studied.

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Combined effects of sulfate attack under drying–wetting cycles and loading on the fatigue behavior of concrete

Advances in Structural Engineering ◽

10.1177/13694332211042774 ◽

2021 ◽

pp. 136943322110427

Author(s):

Ping Zhang ◽

Song Ren ◽

Yunfeng Zhao ◽

Le Wang ◽

Nengzeng Long ◽

...

Keyword(s):

Elastic Modulus ◽

Sodium Sulfate ◽

Fatigue Behavior ◽

Residual Deformation ◽

Fatigue Loading ◽

Damage Variable ◽

Fatigue Properties ◽

Sulfate Concentration ◽

Cycle Number ◽

Major Cycle

Concrete structures often undergo both fatigue loading and environmental impacts during their useful lifetime. This study aims to explore the fatigue properties of concrete subjected to sulfate attacks under drying–wetting cycles and loading. The coupled influences of major cycle number and sodium sulfate solution on the residual deformation, elastic modulus, and damage variable were investigated by uniaxial cyclic loading tests. Moreover, the phase composition of concrete samples was examined by X-ray diffraction. Results indicate that the concrete residual deformation and damage variable could be classified into initial and stable stages, while the elastic modulus fluctuated within a certain range. The fatigue strength of concrete was found to increase with an increase in the major cycle number and sodium sulfate concentration in the early stages, whereas the fatigue performance of concrete decreased as the major cycle number and sodium sulfate concentration increased in the later stage. The degree of influence of major cycle number and sodium sulfate concentration on the fatigue properties of concrete differed in each stage. These findings can contribute to understand the variation pattern of concrete properties in complicated environments and provide an important reference for associated construction projects.

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Investigation of the fatigue behavior of thermoplastic composites by load increase tests

Journal of Composite Materials ◽

10.1177/0021998320954524 ◽

2020 ◽

pp. 002199832095452

Author(s):

Andreas Baumann ◽

Sebastian Backe ◽

Joachim Hausmann

Keyword(s):

Fatigue Behavior ◽

Numerical Data ◽

Fatigue Loading ◽

Polyamide 6 ◽

Heat Emission ◽

Thermoplastic Composites ◽

Failure Behavior ◽

Glass Fiber Reinforced ◽

The Matrix ◽

Load Increase

Fatigue is one major load case in many structures for transport applications. New materials often lack the necessary data base for a fast application in cyclic loaded components due to time consuming testing series. The aim of this study is the evaluation of the load increase test as method to determine a possible fatigue limit of glass fiber reinforced polyamide 6. Under the working hypothesis that cracks are the main contributors for heat emission, the results show that the investigated material exhibits a different behavior in comparison to thermosets. Instead of crack formation experimental and numerical data indicate that the matrix relaxes under fatigue loading. This relaxation could potentially lead to crack prevention but might also result in the observed sudden failure behavior of the material. These findings suggest a totally different behavior of thermoplastic composites under fatigue loading.

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Research on Fabricating Technology of Three Dimensional Integrated Braided Composite I Beam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.136.59 ◽

2010 ◽

Vol 136 ◽

pp. 59-63 ◽

Cited By ~ 1

Author(s):

X.Y. Pei ◽

Jia Lu Li

Keyword(s):

Cross Section ◽

High Performance ◽

Research Result ◽

Three Dimensional ◽

Void Content ◽

Braided Composites ◽

Braided Composite ◽

Transfer Molding ◽

3D Braided Composites

In this paper the fabricating technology of three dimensional (3D) integrated braided composite I beam is researched, including: braiding technology of 3D braided I beam preform, the orientation of fiber-tow in the I beam preform, the optimizing of process parameters of resin transfer molding (RTM) for 3D braided composite I beam, and the design of mould for consolidation of composite I beam. The quality of 3D braided composites is good analyzed by ultrasonic A-scan, void content calculation and microscope observation. The research result will provide a good way for designing and fabricating high performance 3D integrated braided composite components with irregular cross section.

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Effect of UV Ageing on the fatigue life of bulk polyethylene

MATEC Web of Conferences ◽

10.1051/matecconf/201816508002 ◽

2018 ◽

Vol 165 ◽

pp. 08002 ◽

Cited By ~ 1

Author(s):

Hamza Lamnii ◽

Moussa Nait-Abdelaziz ◽

Georges Ayoub ◽

Jean-Michel Gloaguen ◽

Ulrich Maschke ◽

...

Keyword(s):

Fatigue Life ◽

Uv Irradiation ◽

Chemical Structure ◽

Fatigue Behavior ◽

Crystalline Polymer ◽

Fatigue Loading ◽

Chain Scission ◽

Fatigue Tests ◽

Fatigue Properties ◽

Irradiation Effect

Polymers operating in various weathering conditions must be assessed for lifetime performance. Particularly, ultraviolet (UV) radiations alters the chemical structure and therefore affect the mechanical and fatigue properties. The UV irradiation alters the polymer chemical structure, which results into a degradation of the mechanical and fatigue behavior of the polymer. The polymer properties degradation due to UV irradiation is the result of a competitive process of chain scission versus post-crosslinking. Although few studied investigated the effect of UV irradiation on the mechanical behaviour of thermoplastics, fewer examined the UV irradiation effect on the fatigue life of polymers. This study focuses on investigating the effect of UV irradiation on the fatigue properties of bulk semi-crystalline polymer; the low density Polyethylene (LDPE). Tensile specimens were exposed to different dose values of UV irradiation then subjected to fatigue loading. The fatigue tests were achieved under constant stress amplitude at a frequency of 1Hz. The results show an important decrease of the fatigue limit with increasing absorbed UV irradiation dose.

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Damage Assessment of Similar Martensitic Welds Under Creep, Fatigue and Creep-Fatigue Loading

Volume 6: Materials and Fabrication ◽

10.1115/pvp2020-21497 ◽

2020 ◽

Author(s):

Thorben Bender ◽

Andreas Klenk ◽

Stefan Weihe

Keyword(s):

Base Metal ◽

Fatigue Behavior ◽

Base Material ◽

Fatigue Loading ◽

Design Guidelines ◽

Failure Behavior ◽

Martensitic Steels ◽

Viscoplastic Material ◽

Local Strains ◽

Creep Fatigue

Abstract For the assessment of welds under high-temperature conditions in the creep or creep-fatigue regimes, the knowledge on the damage location and its temporal evolution are of high importance. The failure behavior of similar welds of ferritic-martensitic steels in the creep regime is well known. For creep-fatigue loading, the behavior of welds is still subject to research but it seems that the heat affected zone (HAZ) limits the lifetime of welded components as well. This local failure behavior is not reflected in design guidelines using weld reduction factors or in typical assessment approaches. The evaluation of local strains and stresses in the HAZ is unavoidable. For the improvement of design and inspection guidelines, a more detailed consideration of weld behavior is of interest. In this paper, an overview of current developments in the assessment of welds under creep, fatigue, and creep-fatigue loading conditions is given. An assessment approach for creep damage and failure, including the prediction of rupture time and location, is presented. The assessment is based on numerical analyses considering the different behavior of base material and HAZ represented by three different subzones. The approach is validated with the simulation of a uniaxial cross weld, creep crack, and component tests. Whereas the creep behavior of the HAZ compared to base metal is quite well known, there is only little knowledge of their fatigue behavior. Using a set of fatigue tests on HAZ, base metal specimens and cross weld specimens, the influence of fatigue and creep-fatigue loading on the lifetime and failure location of a weld will be discussed. For the numerical simulations, a viscoplastic material law of Chaboche type is used and an evaluation of the local strains in the HAZ allows an attempt to explain the observed failure locations.

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Effect of SiO2 and Al2O3 Hybrid Nano Materials on Fatigue Behavior for Laminated Composite Materials Used to Manufacture Artificial Socket Prostheses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1039.493 ◽

2021 ◽

Vol 1039 ◽

pp. 493-509

Author(s):

Nesreen Dakhel ◽

Ameer A. Kadhim ◽

Rasha Hayder Al-Khayat ◽

Muhannad Al-Waily

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Experimental Work ◽

Numerical Technique ◽

Fatigue Behavior ◽

Laminated Composite ◽

Fatigue Loading ◽

Maximum Error ◽

Fatigue Properties ◽

Materials Used

Most artificial socket prostheses are applied to fatigue load; therefore, more failure of socket prostheses occur due to fatigue loading. Then, it was necessary to improve the fatigue characterizations of composite materials used to manufacture the artificial socket prostheses by using hybrid nanomaterials, with different types and amounts. So, this work suggested mixing two nanomaterials types to improve the mechanical and fatigue properties of composite materials. Therefore, the experimental work used to manufacture tensile and fatigue samples of composite with different nanoweight fraction effects, in addition to calculating the mechanical properties and fatigue behavior for its composite. There, strength and modulus of elasticity, in addition to, fatigue strength and life evaluating of composite with different nanomaterials mixing. Also, the numerical technique by using the finite element method is used to calculate fatigue life and strength of composite materials. Also, comparison fatigue results were calculated by experimental work with fatigue results evaluated by numerical technique to give the discrepancy for results evaluation. Hence, the comparison of results showed good agreement for the technique used to evaluate the fatigue behavior of composite materials with the nanoeffect, where, the maximum error did not exceed (11.86%). Finally, the results have shown that the reinforcement by mixing two Nanomaterial types lead to improvement in the mechanical properties and fatigue behavior to more than (35%) and increasing the mechanical properties and fatigue behavior to (10%) more than the increase of properties and fatigue characterizations reinforcement by one Nanomaterial type.

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