Effects of stabilization patterns on the static and fatigue behavior of glass fiber non-crimp fabric composites

2019 ◽  
Vol 53 (25) ◽  
pp. 3589-3598
Author(s):  
Sana Ullah Nasir ◽  
Asim Shahzad
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Glass Fiber ◽  
Volume Fraction ◽  
Fatigue Behavior ◽  
Experimental Studies ◽  
Tensile Modulus ◽  
Fatigue Properties ◽  
Fabric Composites ◽  
Static Tensile

Experimental studies have been conducted to evaluate static tensile and tension–tension fatigue response of unidirectional glass fiber non-crimp fabric composites subject to seven different stabilization patterns (two multiaxial and five uniaxial stabilizing yarns). The effect of stabilization patterns on non-crimp fabric is crucial as they produce different mesoscale bundle shapes and bundle volume fractions which may affect the static and fatigue properties of non-crimp fabric composites. The studies show that tensile modulus and fatigue life decline with increasing amount of uniaxial stabilizations. Different stabilizations with different bundle shapes influence the final composite properties through various factors than just the volume fraction. The multiaxial stabilizations with higher static tensile strength have shorter fatigue life as compared to uniaxial stabilizations with lower tensile strength. As the areal weight of stabilizing yarns increases, fatigue life decreases at all stress levels which show the deleterious effects of stabilizations on the fatigue behavior of composites. Areal weight and orientation of stabilizing yarns should be optimally selected for the anticipated performance of the non-crimp fabric composites.

Factors that Affect the Fatigue Life of Rubber: A Literature Survey

2004 ◽  
Vol 77 (3) ◽  
pp. 391-412 ◽  
Author(s):  
W. V. Mars ◽  
A. Fatemi
Keyword(s):  
Fatigue Life ◽  
Volume Fraction ◽  
Mechanical Load ◽  
Fatigue Behavior ◽  
Fatigue Properties ◽  
Loading Waveform ◽  
Constitutive Response ◽  
Short And Long Term

Abstract Many factors are known to influence the mechanical fatigue life of rubber components. Four major categories of factors are reviewed here: the effects of mechanical loading history, environmental effects, effects of rubber formulation, and effects due to dissipative aspects of the constitutive response of rubber. For each category, primary factors are described, and existing literature is presented and reviewed. Rubber's fatigue behavior is extremely sensitive to both the maximum and minimum cyclic load limits. Other aspects of the mechanical load history are also discussed, including the effects of static loaded periods (“annealing”), load sequence, multiaxiality, frequency, and loading waveform. Environmental factors can affect both the short and long term fatigue behavior of rubber. The effects of temperature, oxygen, ozone, and static electrical charges are reviewed. A great range of behavior is available by proper manipulation of formulation and processing variables. Effects of elastomer type, filler type and volume fraction, antidegradants, curatives, and vulcanization are discussed. The role of dissipative constitutive behavior in the improvement of fatigue properties of rubber is also reviewed. Four distinct dissipative mechanisms are identified, and their effects on fatigue behavior are described.

The effects of nano-silica/nano-alumina on fatigue behavior of glass fiber-reinforced epoxy composites

2016 ◽  
Vol 51 (12) ◽  
pp. 1667-1679 ◽  
Author(s):  
A Fathy ◽  
A Shaker ◽  
M Abdel Hamid ◽  
AA Megahed
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Glass Fiber ◽  
Silica Nanoparticles ◽  
Epoxy Composite ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Alumina Nanoparticles ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

This paper presents an experimental and statistical study of the fatigue behavior of unidirectional glass fiber-reinforced epoxy composite rods manufactured using pultrusion technique and modified with nanoparticles of alumina (Al2O3) and silica (SiO2) at four different weight fractions (0.5, 1.0, 2.0 and 3.0 wt.%). Tensile test was performed to investigate the influence of nanoparticles. Addition of alumina nanoparticles up to 3 wt.% increases the tensile strength by 54.76% over the pure glass fiber-reinforced epoxy specimen. For silica nanoparticles, there is an increase in the tensile strength of 31.29% for the content of 0.5 wt.% over the pure glass fiber-reinforced epoxy specimen. As the silica nanoparticles’ content increases over 0.5 wt.%, there is a decrease in the tensile strength. Rotating bending fatigue tests have been conducted at five different stress levels. Fatigue life of glass fiber-reinforced epoxy composite rods modified with alumina nanoparticles increases as the content of the nanoparticles increases. The effect of adding silica nanoparticles on the fatigue life of glass fiber-reinforced epoxy composite rods is relatively insignificant with a small improvement in the content of 0.5 wt.% silica above the pure glass fiber-reinforced epoxy specimens. Two-parameter Weibull distribution function was used to statistically analyze the fatigue life data.

Preparation and fatigue behavior of graphene-based aerogel/epoxy nanocomposites

2021 ◽  
Vol 63 (2) ◽  
pp. 163-168
Author(s):  
Ali Kordi ◽  
Saeed Adib Nazari ◽  
Ali Emam ◽  
Mohammad Najafi ◽  
Maryam Ghasabzadeh Saryazdi
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Maximum Stress ◽  
Epoxy Polymer ◽  
Fatigue Behavior ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Substantial Improvement ◽  
Neat Epoxy ◽  
Porous Nanoparticles

Abstract In this research, the effect of adding graphene-based aerogel ((G)A) nanoparticles on the tensile and fatigue behavior of the epoxy polymer was investigated. Specimens of nanocomposites were prepared by adding 0.05, 0.1, 0.2, 0.5, 1, and 2 wt.-% (G)A nanoparticles to the epoxy polymer. Tensile tests revealed that the 0.1 wt.-% graphene-based aerogel/epoxy ((G)A/E) nanocomposites had the highest increase in tensile strength with 19 % growth compared to neat epoxy. Also, the tensile modulus increased by 15 % in the 0.5 wt.-% (G)A/E nanocomposites. A substantial improvement in fatigue life of the epoxy polymer was observed on adding 0.1 wt.-% (G)A nanoparticles. For instance, the fatigue life of (G)A/E nanocomposites improved by 236 % at a maximum stress of 35 MPa compared to the neat epoxy. Fractography in failure analysis of the test samples showed that the placement of (G)A porous nanoparticles on the epoxy polymer with crack twist or crack tilt prevent the formation of large and catastrophic cracks, resulting in delaying the fatigue failure.

scholarly journals Fatigue Modeling and Numerical Analysis of Re-Filling Probe Hole of Friction Stir Spot Welded Joints in Aluminum Alloys

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Element Model ◽  
Plastic Strain Amplitude ◽  
Friction Stir ◽  
Probe Hole ◽  
Good Agreement

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.

scholarly journals Quantitative Analysis of Inclusion Engineering on the Fatigue Property Improvement of Bearing Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Chao Gu ◽  
Min Wang ◽  
Yanping Bao ◽  
Fuming Wang ◽  
Junhe Lian
Keyword(s):  
Fatigue Life ◽  
Quantitative Analysis ◽  
Critical Size ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Fatigue Property ◽  
Bearing Steel ◽  
Fatigue Properties ◽  
Bearing Steels ◽  
Inclusion Distribution

The fatigue property is significantly affected by the inner inclusions in steel. Due to the inhomogeneity of inclusion distribution in the micro-scale, it is not straightforward to quantify the effect of inclusions on fatigue behavior. Various investigations have been performed to correlate the inclusion characteristics, such as inclusion fraction, size, and composition, with fatigue life. However, these studies are generally based on vast types of steels and even for a similar steel grade, the alloy concept and microstructure information can still be of non-negligible difference. For a quantitative analysis of the fatigue life improvement with respect to the inclusion engineering, a systematic and carefully designed study is still needed to explore the engineering dimensions of inclusions. Therefore, in this study, three types of bearing steels with inclusions of the same types, but different sizes and amounts, were produced with 50 kg hot state experiments. The following forging and heat treatment procedures were kept consistent to ensure that the only controlled variable is inclusion. The fatigue properties were compared and the inclusions that triggered the fatigue cracks were analyzed to deduce the critical sizes of inclusions in terms of fatigue failure. The results show that the critical sizes of different inclusion types vary in bearing steels. The critical size of the spinel is 8.5 μm and the critical size of the calcium aluminate is 13.5 μm under the fatigue stress of 1200 MPa. In addition, with the increase of the cleanliness of bearing steels, the improvement of fatigue properties will reach saturation. Under this condition, further increasing of the cleanliness of the bearing steel will not contribute to the improvement of fatigue property for the investigated alloy and process design.

scholarly journals Mechanical Properties of Oil Palm Shell Composites

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
J. Sahari ◽  
M. A. Maleque
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Oil Palm ◽  
Volume Fraction ◽  
Unsaturated Polyester ◽  
Tensile Modulus ◽  
Sem Analysis ◽  
Palm Shell ◽  
Pull Out ◽  
Oil Palm Shell

The mechanical properties of oil palm shell (OPS) composites were investigated with different volume fraction of OPS such as 0%, 10%, 20%, and 30% using unsaturated polyester (UPE) as a matrix. The results presented that the tensile strength and tensile modulus of the UPE/OPS composites increased as the OPS loading increased. The highest tensile modulus of UPE/OPS was obtained at 30 vol% of OPS with the value of 8.50 GPa. The tensile strength of the composites was 1.15, 1.17, and 1.18 times higher than the pure UPE matrix for 10, 20, and 30 vol% of OPS, respectively. The FTIR spectra showed the change of functional group of composites with different volume fractions of OPS. SEM analysis shows the filler pull-out present in the composites which proved the poor filler-matrix interfacial bonding.

Experiment Investigation on Mechanical Property of Glass Fiber Reinforced Concrete

2014 ◽  
Vol 915-916 ◽  
pp. 784-787
Author(s):  
Yan Lv
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Volume Fraction ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Glass Fiber Reinforced

Based on the mechanical properties experiment of the glass fiber reinforced concrete with 0%0.6%0.8% and 1% glass fiber volume fraction, the mechanics property such as tensile strength, compressive strength, flexural strength and flexural elasticity modulus are analyzed and compared with the plain concrete when the kinds of fiber content changes. The research results show that the effect of tensile strength and flexural strength can be improved to some extent, which also can serve as a reference or basis for further improvement and development the theory and application of the glass fiber reinforced concrete.

scholarly journals Effect of Microstructure on Fatigue Properties of Several Ti-Alloys for Aerospace Application

2020 ◽  
Vol 321 ◽  
pp. 04015
Author(s):  
A. El-Chaikh ◽  
A. Danzig ◽  
D. Muenter
Keyword(s):  
Heat Treatment ◽  
Cross Sections ◽  
Volume Fraction ◽  
Fatigue Behavior ◽  
Slight Modification ◽  
Fatigue Properties ◽  
Ti Alloys ◽  
Wide Range ◽  
Flight Controls ◽  
Electron Microscopes

A wide range of available Ti-alloys is used at Liebherr-Aerospace Lindenberg GmbH for several aeronautical applications in flight controls and landing gear systems. For these applications, the mechanical properties of conventionally manufactured Ti-alloys (α+β, near β) as well as additive manufactured Ti-alloy were optimized. Modification of the heat treatment parameters of a near-β titanium alloy leads to optimization of the hardening process of large cross-sections. This modification allows the adjustment of an optimum volume fraction of the primary α-phase resulting in enhancing of the elongation, fracture toughness and fatigue properties. For a fatigue critical forging part from (α+β)-alloy a slight modification of the chemical composition combined with an additional heat treatment step during the forging process was performed. The adjusted microstructure of the modified process exhibits better fatigue behavior when compared to the conventional microstructure. Ti6Al4V parts produced by Additive Manufacturing, printed with optimized parameters and followed by heat treatment will result in reasonable fatigue properties in all printing directions, reducing the anisotropy of the printed parts. These improvements bring Liebherr-Aerospace Lindenberg GmbH in the position to adapt the used titanium alloys for the needs in a wide range. For the evaluation of the microstructure, light and scanning electron microscopes were used. Furthermore a model described in the “Metallic Materials Properties Development and Standardization” (MMPDS) was modified and used for the evaluation of the fatigue results.

Damage and fatigue analysis of AA7050-T7451 plate with cold expanded hole based on a micro-void evolution model

2019 ◽  
Vol 54 (2) ◽  
pp. 105-115
Author(s):  
Fengmei Xue ◽  
Fuguo Li ◽  
Xiaolei Cui
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Complex Stress ◽  
Evolution Model ◽  
Fatigue Properties ◽  
Strengthening Effect ◽  
Void Evolution ◽  
Cold Worked ◽  
Three Dimensional Finite Element

The ultimate tensile strength and fatigue life of plate with cold worked hole under high loading are always key designing parameters in engineering field. In this article, different cold expanded degrees (ranging from 1.69% to 11.11%) are applied to plate specimens with a central hole, made of 7050-T7451 aluminum alloy. The damage and fatigue properties are investigated by the three-dimensional finite element method with a user subroutine embedded into a void evolution model under complex stress states. The damage analysis indicates that plastic damage becomes critical when the cold expanded degree is larger than 7.14%, which does not suit for further service due to the loss of toughness. The cold expanded degree of 5.26% is identified as the best. It can be found that the fatigue life improves with the increased cold expanded degree. The small cold expanded degree leads to poor strengthening effect because of lacking sufficient residual stress, while large cold expanded degree makes micro-cracks emerge, which is beneficial to the increase in strengthening. All these results prove that the numerical analysis can accurately predict fatigue behavior of AA7050-T7451 plate based on our proposed approach, which is expected to be a powerful method in engineering field.

scholarly journals Effect of UV Ageing on the fatigue life of bulk polyethylene

2018 ◽  
Vol 165 ◽  
pp. 08002 ◽  
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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