An Evaluation of the Effects of Stacking Sequence and Thickness on the Fatigue Life of Quasi-Isotropic Graphite/Epoxy Laminates

Abstract The study elucidated the relationship between the stacking sequence and physical properties, by investigating mechanical properties, fatigue life and the morphology, after fatigue fracture of carbon fiber/epoxy composites. The results show that the unidirectional carbon fiber laminate has the maximum tensile stress. Moreover, the laminate with ±45° plies can improve the tensile strain. The fatigue life of all specimens was shorter than 103 cycles under high cyclic stress level, and longer than 106 cycles under low cyclic stress level. Laminates with [908]s stacking sequence had the shortest fatigue life under high and low cyclic stress, while the unidirectional carbon fiber laminate had the highest fatigue life. A number of fatigue damage models, including delaminating, matrix cracking and fiber failure, have been identified by scanning electron microscopy (SEM). The SEM micrographs showed that the morphology on the cross section, after fatigue fracture, was significantly correlated to the stacking sequence.

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Influence of the Stacking Sequence and Load Direction on the Fatigue Behaviour of Quasi-isotropic Graphite/Peek Laminates

Composite Structures 5 ◽

10.1007/978-94-009-1125-3_40 ◽

1989 ◽

pp. 671-677

Author(s):

B. Picasso ◽

P. Priolo

Keyword(s):

Fatigue Behaviour ◽

Stacking Sequence ◽

Load Direction ◽

Isotropic Graphite

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High Resolution Study of Polytypism: Application to SiC and Au3 Mn

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055540 ◽

1982 ◽

Vol 40 ◽

pp. 540-541

Author(s):

G. Van Tendeloo ◽

J. Van Landuyt ◽

S. Amelinckx

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Stacking Sequence ◽

X Ray ◽

Powerful Technique ◽

Resolution Study ◽

The Ideal

Polytypism has been studied for a number of years and a wide variety of stacking sequences has been detected and analysed. SiC is the prototype material in this respect; see e.g. Electron microscopy under high resolution conditions when combined with x-ray measurements is a very powerful technique to elucidate the correct stacking sequence or to study polytype transformations and deviations from the ideal stacking sequence.

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Defect structures of Nb1+αS2 sulfidation scales

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012059x ◽

1992 ◽

Vol 50 (1) ◽

pp. 38-39

Author(s):

Chuxin Zhou ◽

L. W. Hobbs

Keyword(s):

Stacking Faults ◽

Rhombohedral Structure ◽

Stacking Sequence ◽

Defect Structures ◽

X Ray Diffraction ◽

X Ray ◽

Plane Normal ◽

Lower Case ◽

Sulfur Layer ◽

Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

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Long term effect of power system unbalance on the corrosion fatigue life expenditure of low pressure turbine blades

IEE Proceedings - Science Measurement and Technology ◽

10.1049/ip-smt:20000423 ◽

2000 ◽

Vol 147 (5) ◽

pp. 229-236 ◽

Cited By ~ 14

Author(s):

T.-P. Tsao ◽

C.-H. Lin

Keyword(s):

Fatigue Life ◽

Power System ◽

Corrosion Fatigue ◽

Turbine Blades ◽

Low Pressure ◽

Term Effect ◽

Low Pressure Turbine ◽

Long Term Effect

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Fatigue Life of Superelastic Springs for an Anterior Cruciate Ligament Prosthesis

Journal de Physique IV (Proceedings) ◽

10.1051/jp4/1995581223 ◽

1995 ◽

Vol 05 (C8) ◽

pp. C8-1223-C8-1228

Author(s):

N. Hagemeister ◽

L'H. Yahia ◽

E. Weynant ◽

T. Lours

Keyword(s):

Anterior Cruciate Ligament ◽

Fatigue Life ◽

Cruciate Ligament ◽

Anterior Cruciate ◽

Ligament Prosthesis

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Modification of MnS inclusion by tellurium in 38MnVS6 micro-alloyed steel

Metallurgical Research & Technology ◽

10.1051/metal/2020066 ◽

2020 ◽

Vol 117 (6) ◽

pp. 615

Author(s):

Ping Shen ◽

Lei Zhou ◽

Qiankun Yang ◽

Zhiqi Zeng ◽

Kenan Ai ◽

...

Keyword(s):

Fatigue Life ◽

Aspect Ratio ◽

Strong Influence ◽

Experimental Results ◽

Alloyed Steel ◽

Equivalent Diameter ◽

Small Aspect Ratio ◽

Steel Quality ◽

Eds Analysis ◽

Micro Alloyed Steel

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.

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