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 A critical review of the influence of hydrogen on the mechanical properties of medium-strength steels

2013 ◽  
Vol 31 (3-6) ◽  
pp. 85-103 ◽  
Author(s):  
Qian Liu ◽  
Andrej Atrens
Keyword(s):  
Tensile Stress ◽  
Yield Stress ◽  
Stress Ratio ◽  
Ultimate Tensile Stress ◽  
Fatigue Properties ◽  
Lower Yield ◽  
Good Resistance ◽  
Microstructural Characteristics ◽  
Lower Yield Stress ◽  
Medium Strength

AbstractAs medium-strength steels are promising candidates for the hydrogen economy, it is important to understand their interaction with hydrogen. However, there are only a limited number of investigations on the behavior of medium-strength steels in hydrogen. The existing literature indicates that the influences of hydrogen on the tensile properties of medium-strength steels are mainly the following: (i) the steel can be hardened by hydrogen, as demonstrated by an increase in the yield stress or ultimate tensile stress; (ii) some steels can be embrittled by hydrogen, as revealed by lower yield stress or ultimate tensile stress; (iii) in most cases, these steels may experience hydrogen embrittlement (HE), as indicated by a reduction in ductility. The degree of HE mainly depends on the test conditions and the steel. The embrittlement can lead to catastrophic brittle fracture in service. The influence of hydrogen on the fatigue properties of medium-strength steels is dependent on many factors such as the stress ratio, temperature, yield stress of the steel, and test frequency. Generally, the hydrogen influence on fatigue limit is small, whereas hydrogen can accelerate the fatigue crack growth rate, leading to a shorter fatigue life. Inclusions are an important factor influencing the properties of medium-strength steels in the presence of hydrogen. However, it is not possible to predict the influence of hydrogen for any particular steel that has not been experimentally evaluated or to predict service performance. It is not known why similar steels can have different behavior, ranging from good resistance to significant embrittlement. A better understanding of the microstructural characteristics is needed.

Characterizing Static and Dynamic Mechanical Properties for Additive Manufactured ULTEM 9085 Used to Construct Flow Control Devices for Turbomachinery Applications

2018 ◽  
Author(s):  
Khang D. Pham ◽  
Walter F. O’Brien ◽  
Scott W. Case
Keyword(s):  
Fatigue Life ◽  
Tensile Stress ◽  
Complex Geometry ◽  
Weight Ratio ◽  
Ultimate Tensile Stress ◽  
Fatigue Properties ◽  
Dynamic Mechanical ◽  
Fused Deposition ◽  
R Ratio ◽  
Stress Levels

Extrusion additive manufacturing technologies may be utilized to fabricate complex geometry devices to control the flow distortions at the inlets of gas turbine engines. However, the success of these devices depends upon their ability to withstand the dynamic mechanical loads experienced in service. One such device is a StreamVane®. A current candidate material for StreamVane fabrication is ULTEM 9085 — a thermoplastic polymer material. ULTEM 9085 was selected as the material of choice for StreamVane production because of its high strength-to-weight ratio. In this study, quasi-static and cyclic fatigue tests were performed on ULTEM 9085 samples fabricated by fused deposition modeling. First, ASTM D638 tensile-tensile material tests were conducted on three different build orientations to verify the mechanical strength of ULTEM 9085 listed by Stratasys. The three different orientations that were tested were Orientation XZZ, Orientation XYZ, and Orientation ZXY with measured ultimate tensile strengths of 69.6 MPa, 56.3 MPa, and 37.6 MPa, respectively. Fatigue properties were investigated utilizing the procedure outlined in ASTM D7791. S-N curves were generated using data collected at stress levels of 80%, 60%, 30% and 20% of the ultimate tensile stress with an R-ratio of 0.1 for the build orientation XZY. Next, the modified Goodman approach was used to estimate the fully reversed (R = −1) fatigue life. The initial data suggested that the modified Goodman approach was very conservative. Therefore, four different stress levels of 25%, 20%, 15% and 10% of ultimate tensile stress were used to characterize the fully reversed fatigue properties. Because of the extreme conservatism of the modified Goodman model for this material, a simple phenomenological model was developed to estimate the fatigue life of ULTEM 9085 subjected to fatigue at different R-ratios. The calculated fatigue life using the model and the data collected for the fully reversed test correlated very well. The data from this investigation demonstrated that StreamVane designs using ULTEM 9085 are more than capable of withstanding the static and dynamic loads in currently planned turbomachinery applications.

Fatigue Behavior of Impacted Plain-Weave Glass/Epoxy Composites under Tensile Fatigue Loading

2005 ◽  
Vol 297-300 ◽  
pp. 1291-1296 ◽  
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Fatigue Life ◽  
Impact Damage ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Behavior ◽  
Plain Weave ◽  
The Impact

The goals of this paper are to identify the impact damage behavior of plain-weave E-glass/epoxy composites and predict the fatigue life of the composites with impact-induced damage under constant amplitude loading. To identify these behaviors, the low velocity impact and fatigue after impact tests are performed for glass/epoxy composites having two types of fiber orientations. The impact damage behavior is dependent on the fiber orientation of the composites. The fatigue life of the impacted composites can be identified through the prediction model, which was proposed on the carbon/epoxy laminates by authors regardless of fiber orientations.

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.

A Master S-N Curve Representation of Subsea Umbilical Tube Weld Fatigue Data

2010 ◽  
Author(s):  
Pingsha Dong ◽  
Xinhua Yang
Keyword(s):  
Stress Ratio ◽  
Correction Term ◽  
Fatigue Loading ◽  
Nominal Stress ◽  
Stress Range ◽  
Fatigue Data ◽  
Range Parameter ◽  
Weld Fatigue ◽  
Curve Representation ◽  
The One

In this paper, some of the available duplex and super-duplex stainless steel umbilical tube fatigue data are analyzed using an equivalent nominal stress range parameter, which shares a great deal of similarity to the one used in the 2007 ASME Div 2 Code. The proposed fatigue parameter consists of nominal stress range, a size correction term RTt with RT being the tube radius and t being tube wall thickness, and a stress ratio term (1 − R) with R being applied stress ratio. With it, the available girth weld fatigue test data are shown to collapse into a narrow band. The equivalent nominal stress range parameter is also shown to be effective in correlating seam weld data collected from seam-welded umbilicals, but with a different slope in log-log based S-N plot. Coiling/uncoiling low-cycle effects can be addressed by introducing a pseudo elastic nominal stress definition. Miner’s rule can be used to combine both coiling/uncoiling effects with subsequent high-cycle fatigue loading.

High-Temperature Fatigue Properties of Single Crystal Superalloys in Air and Hydrogen

2004 ◽  
Vol 126 (3) ◽  
pp. 590-603 ◽  
Author(s):  
N. K. Arakere
Keyword(s):  
Fatigue Life ◽  
Single Crystal ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Turbine Blades ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Fatigue Data ◽  
Blade Tip ◽  
Pressure Hydrogen

Hot section components in high-performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys such as PWA1480, PWA1484, CMSX-4, and Rene N-4 as these materials provide superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over their polycrystalline counterparts. Fatigue failures in PWA1480 single crystal nickel-base superalloy turbine blades used in the space shuttle main engine fuel turbopump are discussed. During testing many turbine blades experienced stage II noncrystallographic fatigue cracks with multiple origins at the core leading edge radius and extending down the airfoil span along the core surface. The longer cracks transitioned from stage II fatigue to crystallographic stage I fatigue propagation, on octahedral planes. An investigation of crack depths on the population of blades as a function of secondary crystallographic orientation (β) revealed that for β=45+/−15 deg tip cracks arrested after some growth or did not initiate at all. Finite element analysis of stress response at the blade tip, as a function of primary and secondary crystal orientation, revealed that there are preferential β orientations for which crack growth is minimized at the blade tip. To assess blade fatigue life and durability extensive testing of uniaxial single crystal specimens with different orientations has been tested over a wide temperature range in air and hydrogen. A detailed analysis of the experimentally determined low cycle fatigue properties for PWA1480 and SC 7-14-6 single crystal materials as a function of specimen crystallographic orientation is presented at high temperature (75°F–1800°F) in high-pressure hydrogen and air. Fatigue failure parameters are investigated for low cycle fatigue data of single crystal material based on the shear stress amplitudes on the 24 octahedral and 6 cube slip systems for FCC single crystals. The max shear stress amplitude [Δτmax] on the slip planes reduces the scatter in the low cycle fatigue data and is found to be a good fatigue damage parameter, especially at elevated temperatures. The parameter Δτmax did not characterize the room temperature low cycle fatigue data in high-pressure hydrogen well because of the noncrystallographic eutectic failure mechanism activated by hydrogen at room temperature. Fatigue life equations are developed for various temperature ranges and environmental conditions based on power-law curve fits of the failure parameter with low cycle fatigue test data. These curve fits can be used for assessing blade fatigue life.

scholarly journals Study on Fatigue Characteristics of Carbonation Erosion Prestressed Hollow Slabs in Whole Life Cycle

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yuanxun Zheng ◽  
Kuan Li ◽  
Mengen Ji ◽  
Ehsan Moshtagh
Keyword(s):  
Life Cycle ◽  
Fatigue Life ◽  
Carbon Fiber ◽  
Steel Plate ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Hollow Beam ◽  
Whole Life Cycle ◽  
Life Cycle Failure

In this paper, the whole life cycle (failure-reinforcement-failure) durability and related fatigue properties of prestressed hollow beam under carbonation erosion environment were studied. According to a 20 m hollow slab beam, the model of prestressed hollow beam was designed and made, and the durability and fatigue tests for the whole life cycle of prestressed hollow beam were carried out. The results showed that the compressive strength and elastic modulus of the specimens increased by about 20% under the action of carbonization erosion. With the increase of fatigue loading cycles, the crack occurrence and development speed of carbonized erosion components were greater than those of healthy components, and the fatigue life decreased sharply from 3 million cycles to 50,000 cycles. Pasting carbon fiber and steel plate had better reinforcement effect on the damaged prestressed plate beam and could help improving the fatigue life of the reinforced component. Comparing the reinforcement of different strengthening methods, it is found that the steel-plate-reinforced components have better mechanical properties and antifatigue attenuation characteristics than the carbon-fiber-reinforced ones. The research results have important theoretical value for improving the durability of structure and prolonging its service life.

Residual Fatigue Properties of a 2024-T351 Aluminium Alloy from the Teardown of AIRBUS A320 Wing Panels after Service

2014 ◽  
Vol 891-892 ◽  
pp. 621-626 ◽  
Author(s):  
Fabien Billy ◽  
Gilbert Hénaff ◽  
Guillaume Benoit ◽  
Sjoerd van der Veen
Keyword(s):  
Fatigue Life ◽  
Aluminium Alloy ◽  
End Of Life ◽  
Fatigue Resistance ◽  
Fatigue Properties ◽  
Fracture Surfaces ◽  
Fatigue Data ◽  
Residual Fatigue

This paper reports on investigations on the residual fatigue resistance of a 2024 aluminium alloy of an A320 aircraft at the end of life. The fatigue data (S-N and da/dN curves) are compared with data obtained on a pristine alloy using a similar procedure. The results are analysed on the basis of fracture surfaces observations and of AFGROW fatigue life computations.

scholarly journals Thermo-mechanical fatigue damage behavior for Ni-based superalloy under multiaxial loading

2018 ◽  
Vol 165 ◽  
pp. 19002
Author(s):  
Dao-Hang Li ◽  
De-Guang Shang
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Tensile Stress ◽  
Fatigue Damage ◽  
Mechanical Strain ◽  
Creep Damage ◽  
Fatigue Loading ◽  
Shear Stresses ◽  
Damage Behavior ◽  
Von Mises

The fatigue damage behavior was experimentally investigated in different axial-torsional thermo-mechanical loading conditions for Ni-based superalloy GH4169. The strain controlled tests were carried out with the same von Mises equivalent mechanical strain amplitude of 0.8% in the temperature range from 360°C to 650°C. The results show that the fatigue life is drastically reduced when the axial mechanical strain and the temperature are in-phase, which can be due to that the creep damage is induced by the tensile stress at high temperature. Moreover, the fatigue life is further decreased when the axial mechanical strain and the shear strain are out-of-phase, which can be attributed to that the non-proportional hardening can increase the creep and the oxidation damages. Furthermore, the tensile stress is crucial to the nucleation of creep cavities at high temperature compared with the shear stress. The tensile and shear stresses all can increase the creep damage under fatigue loading at high temperature. In addition, the oxidation damage can be induced during cyclic loading at high temperature, and it can be increased by the tensile mean stress caused in non-isothermal loading.

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.

Sign in / Sign up

Export Citation Format

Share Document