Effect of Intra-Ply Hybridization of Carbon-Aramid/Epoxy Laminates under Tension-Tension Fatigue Loading

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
B. Ruban Rajasekar ◽  
R. Asokan ◽  
C. Ramesh ◽  
V. Jamin Daniel Selvakumar ◽  
M. Dinesh
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Stress Ratio ◽  
Fatigue Loading ◽  
Fatigue Behaviour ◽  
Load Control ◽  
Elongation To Failure ◽  
Superior Mechanical Properties ◽  
Fibre Angle ◽  
Hybrid Carbon

The objective of the research is to investigate the fatigue life of intra-ply hybrid Carbon-Aramid laminate with Epoxy resin in on-axis and off-axis directions. Three different off-axis angles of 15, 30 and 45 degrees were considered for the present work. The intra-ply hybridization is used to combine the superior mechanical properties of Carbon fibre with excellent elongation-to-failure property of Aramid fibre in the same lamina. The fatigue test was performed using load control using a frequency of 5Hz. The fatigue behaviour was studied for Carbon/Epoxy, Aramid/Epoxy, Carbon-Aramid/Epoxy, Carbon-Aramid/Epoxy - 15, Carbon-Aramid/Epoxy - 30 and Carbon-Aramid/Epoxy - 45 with the stress ratio of R = 0.1. The ultimate tensile strength decreases progressively for Carbon/Epoxy, Carbon-Aramid/Epoxy, Aramid/Epoxy, Carbon-Aramid/Epoxy - 15, Carbon-Aramid/Epoxy - 30 and Carbon-Aramid/Epoxy - 45. The effect of off-axis loading indicates that the increase of fibre angle influences the decrease in tensile strength and fatigue life.

Effect of sulphate attack on the flexural fatigue behaviour of fly ash–based geopolymer concrete

2018 ◽  
Vol 53 (8) ◽  
pp. 711-718 ◽  
Author(s):  
Tao Long ◽  
Hongen Zhang ◽  
Yu Chen ◽  
Zhi Li ◽  
Jiageng Xu ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fly Ash ◽  
Damage Index ◽  
Fatigue Loading ◽  
Fatigue Behaviour ◽  
Distribution Model ◽  
Geopolymer Concrete ◽  
Sulphate Attack ◽  
Flexural Fatigue ◽  
Erosion Effect

In this work, the erosion effect of sulphate solution on the flexural fatigue behaviour of fly ash–based geopolymer concrete was investigated. Under cyclic bending loading, the effect of sulphate attack on the fatigue life of geopolymer concrete was analysed using the static flexural strength as the damage index. Results revealed that the fatigue life of geopolymer concrete after sulphate erosion was significantly reduced compared with uncorroded samples under the same fatigue loading condition. And the fatigue life of corroded/uncorroded geopolymer concrete can be approximately described by the two-parameter Weibull distribution model. Since the sulphate attack would increase the actual stress level of corroded geopolymer concrete, a fatigue equation considering the damage index was deduced to predict the fatigue life of geopolymer concrete after sulphate attack.

scholarly journals Fatigue behaviour of fibre-reinforced composite T-joints

2018 ◽  
Vol 165 ◽  
pp. 07004
Author(s):  
Ying Wang ◽  
Constantinos Soutis
Keyword(s):  
Fatigue Life ◽  
Testing Machine ◽  
Fatigue Loading ◽  
Maximum Load ◽  
Fatigue Behaviour ◽  
Control Mode ◽  
Static Properties ◽  
T Joints ◽  
Pull Out ◽  
Reinforced Composite

In this paper a study was carried out on the fatigue life of fibre-reinforced composite T-joints subjected to a tensile pull-out loading. The composite T-joints have been made of glass fabric infused with epoxy resin using a vacuum assisted resin transfer moulding technique. Methods such as the use of veil layers, tufting techniques and 3D weave have been employed to improve the interlaminar fracture toughness of the composite T-joints. All the tests were conducted in an Instron testing machine using a specially designed test fixture. Fatigue tests were performed in a load control mode with a stress ratio of R = σmin/σmax = 0.1. The cyclic loading pattern was a sinusoidal wave with a frequency of 6 Hz. The specimens were cycled at a series of constant maximum load values up to failure. Fatigue loads versus life data for each T-joint type were produced at various maximum applied loads. The 3D weave T-joints were found to have the best performance in both static and fatigue loading. Increasing the static properties increases fatigue life performance; the increasing rate in fatigue life is changed with the number of stress cycles. The location for the through-thickness reinforcement plays an important role in improving fatigue life of the Tjoints. Fatigue life is significantly improved if the web is reinforced in through-thickness direction. A finite element (FE) failure model was also created using ABAQUS to determine the location where delamination is initiated and its subsequent propagation.

scholarly journals Influence of porosity on the fatigue behaviour of additively fabricated TA6V alloys

2018 ◽  
Vol 165 ◽  
pp. 02008 ◽  
Author(s):  
Viet-Duc Le ◽  
Etienne Pessard ◽  
Franck Morel ◽  
François Edy
Keyword(s):  
Fatigue Life ◽  
Additive Manufacturing ◽  
Fatigue Strength ◽  
Pore Size ◽  
Selective Laser Melting ◽  
Fatigue Loading ◽  
Fatigue Behaviour ◽  
Laser Melting ◽  
Experimental Campaign ◽  
Porosity Fraction

This work is focused on the influence of porosity when dealing with the fatigue behaviour of the TA6V alloys fabricated by the selective laser melting (SLM) process. The presence of porosity is one of the major issue facing additive manufacturing (AM) of metallic components subjected to fatigue loading. In order to study the effect of porosity on the fatigue behaviour, a vast experimental campaign has been undertaken. These materials are fabricated by the SLM process with different building directions (horizontal, vertical and diagonal) thanks to which specimen batches with different pore sizes are obtained. It is observed that despite a low porosity fraction (around 0.01%), the influence of pores on the fatigue strength of the materials is pronounced. A mapping approach is presented, which links the applied stress, the pore size and the fatigue life. This approach makes it possible to accurately characterize the effect of the porosity size, and also to construct Kitagawa-Takahashi diagrams from S-N data.

Fatigue Behaviour of GFRP Reinforced Beams

2021 ◽  
Vol 322 ◽  
pp. 163-169
Author(s):  
Ondřej Januš ◽  
Frantisek Girgle ◽  
Vojtěch Kostiha ◽  
Jan Prokeš ◽  
Petr Štěpánek
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Life ◽  
Concrete Slab ◽  
Fatigue Loading ◽  
Maximum Load ◽  
Fatigue Behaviour ◽  
Constant Load ◽  
Reinforced Concrete Slab ◽  
Reinforced Beams ◽  
Constant Load Amplitude

This article deals with the influence of fatigue loading on the behaviour of GFRP (Glass Fibre Reinforced Polymers) reinforced concrete elements. The aim of the experimental programme is to quantify the effect of fatigue loading on the mechanical properties of GFRP reinforced beams subjected to flexure. The proposed element was a beam simulating the cut-out part of a reinforced concrete slab directly subjected to traffic loading. The dimensions and the amount of reinforcement were adjusted regarding the possibilities of the testing laboratory and to ensure the repeatability of the test. Two different fatigue loading schemes were experimentally verified: a) a constant load amplitude, b) a gradually increasing amplitude. The applied fatigue load with a constant amplitude was designed to achieve a fatigue life of the element ≥ 2×106 cycles. In the case of fatigue loading with an increasing amplitude, the load was increased every 50,000 cycles by 5% of the maximum load in the cycle. The resulting fatigue life was compared to the expected fatigue life determined according to Miner's rule on linear fatigue summation.

Damage Mechanics and Critical Plane Approach to Multiaxial Fatigue

2013 ◽  
Vol 592-593 ◽  
pp. 239-245
Author(s):  
Roberto Brighenti ◽  
Andrea Carpinteri
Keyword(s):  
Fatigue Life ◽  
Damage Mechanics ◽  
Crack Nucleation ◽  
Fatigue Loading ◽  
Fatigue Behaviour ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
Scalar Damage Parameter

The mechanical behaviour of structural components subjected to multiaxial fatigue loading is very important in modern design. Several approaches have been introduced in recent decades to analyse this problem. The so-called critical plane approach, based on the stresses acting on the plane where the crack nucleation is expected to occur, is widely used. This criterion can give us a fatigue damage measurement, which can be used to evaluate fatigue life. On the other hand, fatigue life under general multiaxial stress histories can also be assessed by applying the damage accumulation method. In such a method, a scalar damage parameter is quantified through the damage increments which develop during the fatigue process up to the critical damage value corresponding to the final failure of the structures. The damage increment approach to fatigue has recently been discussed and connected to the classical crack propagation approach. In the present paper, the interpretation of the critical plane approach based on the continuum damage mechanics concepts is examined. In particular, the physical meaning of the critical plane approach is shown, that is, such an approach can be interpreted as a damage method which takes into account the scalar damage parameter evaluated along preferential directions. Finally, the fatigue behaviour of a metallic material under multiaxial cyclic load histories is analysed through the two above approaches.

Fatigue Life of Arenga Pinnata/Epoxy Composites

2015 ◽  
Vol 1102 ◽  
pp. 103-106 ◽  
Author(s):  
Abdul Hakim Abdullah ◽  
Muhd Faiz Mat
Keyword(s):  
Fatigue Life ◽  
Tensile Stress ◽  
Tensile Test ◽  
Stress Ratio ◽  
Fatigue Loading ◽  
Ultimate Tensile Stress ◽  
Epoxy Composites ◽  
Fatigue Properties ◽  
Material Fatigue ◽  
Fatigue Data

In this study, fatigue properties of unidirectional Arenga Pinnata fibre reinforced epoxy composites have been investigated under tension-tension fatigue loading. Composites were made at 25% by Arenga Pinnata fibre weight contents using hand lay-out technique. Tensile test was performed prior fatigue loading evaluation. The composites where then were cycled between 90%, 80%, 70% measured from ultimate tensile stress (UTS), with 10 Hz of frequency and stress ratio of R at 0.1. Tensile results indicated that the composites resist to deformation and this reaction denotes that the composites are a brittle material. Fatigue life of composite was improving as the cycled stress decreases. The fatigue resistance were calculated by employing analytical expression and compared with relevant fatigue data.

scholarly journals Tensile Fatigue Behaviour of Polyester and Vinyl Ester Based Gfrp Laminates – a Comparative Evaluation

2020 ◽  
Author(s):  
Wahid Ferdous ◽  
Allan Manalo ◽  
Peng Yu ◽  
Choman Salih ◽  
Rajab Abousnina ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Failure Mode ◽  
Applied Stress ◽  
Environmental Conditions ◽  
Vinyl Ester ◽  
Stress Ratio ◽  
Fatigue Behaviour ◽  
Unique Contribution ◽  
Tensile Fatigue ◽  
Fatigue Model

Fatigue loading is critical to fibre reinforced polymer composites due to their anisotropic and heterogenous nature. This study investigated the tensile fatigue behaviour of polyester and vinyl ester based GFRP laminates to understand the critical aspects of failure mode and fatigue life under cyclic loading. GFRP laminates with two different resin systems (polyester and vinyl ester), two different stress ratios (0.1 and 0.5) and two different environmental conditions (air and water) were investigated at an applied stress of 80%, 60% and 40% of the ultimate capacity. Based on the investigated parameters (i.e., resin types, stress ratio, environmental conditioning and maximum applied stress), a fatigue model was proposed. Results show that the resin system plays a great role in fatigue failure mode while the stress ratio and environmental condition significantly affect the tensile fatigue life of GFRP laminates. The types of resin used in GFRP laminates and environmental conditions as input parameter in the proposed fatigue model is a unique contribution.

Weibull Analysis of the Effect of Modified Aging Treatments on Fatigue Life of Cast Aluminium Alloy 354

2013 ◽  
Vol 800 ◽  
pp. 356-360 ◽  
Author(s):  
Salil Sainis ◽  
Aakarshit Kalra ◽  
G. Dinesh Babu ◽  
M. Nageswara Rao
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Ultimate Tensile Strength ◽  
Aluminium Alloy ◽  
Artificial Aging ◽  
Aging Treatment ◽  
Fatigue Loading ◽  
Weibull Analysis ◽  
Compressor Wheel ◽  
Cast Aluminium

Cast aluminium alloy 354 has extensive applications in the automobile industry. Due to its attractive combination of mechanical properties and excellent castability, it is being used in production of automobile components like the compressor wheel for turbochargers. Performance of this component under fatigue loading conditions is a critical issue. The present study explores the possibility of improving the fatigue life of the component by bringing in process changes (i) adopting a two-step aging treatment in place of the normally used single step aging treatment (ii) adopting a lower artificial aging temperature (171°C) instead of the temperature normally used for artificial aging (188°C) while performing T61 treatment. In all cases Weibull analysis of fatigue test results was carried out. Weibull analysis of Ultimate Tensile Strength (UTS) values obtained after artificial aging at 171°C and 188°C was also carried out. Among the four variants of two-step aging treatment carried out, the one consisting of 100°C for 5 hours followed by 170°C for 5 hours was found to have the best characteristic fatigue life for the components. The modified T61 treatment where aging was carried out at 171°C instead of the normally used 188°C yielded better characteristic fatigue life as well as better Ultimate Tensile Strength (UTS).

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.

Uniaxial Ratcheting and Low-Cycle Fatigue Failure of U75V Rail Steel

2016 ◽  
Vol 853 ◽  
pp. 246-250 ◽  
Author(s):  
Tao Fang ◽  
Qian Hua Kan ◽  
Guo Zheng Kang ◽  
Wen Yi Yan
Keyword(s):  
Fatigue Life ◽  
Strain Amplitude ◽  
Stress Ratio ◽  
Stress Amplitude ◽  
Rail Steel ◽  
Low Cycle Fatigue ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Ratcheting Strain ◽  
Cyclic Straining

Experiments on U75V rail steel were carried out to investigate the cyclic feature, ratcheting behavior and low-cycle fatigue under both strain- and stress-controlled loadings at room temperature. It was found that U75V rail steel shows strain amplitude dependent cyclic softening feature, i.e., the responded stress amplitude under strain-controlled decreases with the increasing number of cycles and reaches a stable value after about 20th cycle. Ratcheting strain increases with an increasing stress amplitude and mean stress, except for stress ratio, and the ratcheting strain in failure also increases with an increasing stress amplitude, mean stress and stress ratio. The low-cycle fatigue lives under cyclic straining decrease linearly with an increasing strain amplitude, the fatigue lives under cyclic stressing decrease with an increasing mean stress except for zero mean stress, and decrease with an increasing stress amplitude. Ratcheting behavior with a high mean stress reduces fatigue life of rail steel by comparing fatigue lives under stress cycling with those under strain cycling. Research findings are helpful to evaluate fatigue life of U75V rail steel in the railways with passenger and freight traffic.

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