scholarly journals Performance of Repaired Concrete under Cyclic Flexural Loading

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1363
Author(s):  
Boyu Wang ◽  
Rishi Gupta
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Endurance Limit ◽  
Failure Criteria ◽  
Future Research ◽  
Cycle Fatigue ◽  
Loading Test ◽  
Repair Mortar ◽  
Fatigue Endurance ◽  
Test Process

There is limited research reported on the effect of cyclic loading on cement-based repair materials as conducting such tests is time consuming. To overcome this issue, this study utilized a novel loading regime consisting of cycle groups with increasing stress amplitude to accelerate the test process. The Palmgren-Minder rule was used to estimate the fatigue life of repaired specimens. Specimens repaired with Mix M (cementitious repair mortar), which was estimated to have the highest 2-million-cycle fatigue endurance limit (77.4%), showed the longest fatigue life (95,991 cycles) during the cyclic loading test, the highest slant, and splitting bond strength among all repair mixes. The estimated two-million cycle fatigue endurance limit of Mix S (70.8%) was very similar to that was reported in literature (71%) using the traditional loading method. This study confirms the usefulness of Palmgren-Minder rule on estimating the fatigue life of repaired specimens. Additionally, the use of the novel loading regime showed the benefit of shortening the test process while producing results similar to those from using traditional loading methods. To improve the prediction accuracy, future research is required to modify the failure criteria to accommodate specimens that may not fail even when the average flexural strength is met.

Fatigue Behavior of Aerospace Al-Cu, Al-Li and Al-Mg-Si Sheet Alloys

2015 ◽  
Vol 1099 ◽  
pp. 1-8
Author(s):  
Nikolaos D. Alexopoulos ◽  
Vangelis Migklis ◽  
Stavros K. Kourkoulis ◽  
Zaira Marioli-Riga
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Endurance Limit ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Constant Amplitude ◽  
6Xxx Series ◽  
Fatigue Endurance

In the present work, an experimental study was performed to characterize and analyze the tensile and constant amplitude fatigue mechanical behavior of several aluminum alloys, namely 2024 (Al-Cu), 2198 (Al-Li) and 6156 (Al-Mg-Si). Al-Li alloy was found to be superior of 2024 in the high cycle fatigue and fatigue endurance limit regimes, especially when considering specific mechanical properties. Alloy 6156 was found to have superior constant amplitude fatigue performance that the respective 6xxx series alloys; more than 15% higher endurance limit was noticed against 6061 and almost 30% higher than 6082. Alloy 6156 presented only a marginal increase in fatigue life for the HCF regime.

Fatigue Performance of Concrete with Pre-Cracks in Tension-Compression Cycles

2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Compression Cycle

A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

Low-cycle fatigue life and plasticity mechanisms of a Fe−15Mn−10Cr−8Ni−4Si seismic damping alloy under cyclic loading at various temperatures

2021 ◽  
Vol 220 ◽  
pp. 117267
Author(s):  
Takahiro Sawaguchi ◽  
Ilya Nikulin ◽  
Kazuyuki Ogawa ◽  
Susumu Takamori ◽  
Fumiyoshi Yoshinaka ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Seismic Damping

Fatigue Tests on Specimens Containing Skew Holes

1976 ◽  
Vol 18 (6) ◽  
pp. 287-291 ◽  
Author(s):  
I. Ficenec ◽  
G. Craggs ◽  
B. N. Cole
Keyword(s):  
Fatigue Life ◽  
Endurance Limit ◽  
Fatigue Crack Initiation ◽  
Major Axis ◽  
Fatigue Tests ◽  
Minor Axis ◽  
Skew Angle ◽  
Cross Sectional ◽  
Skew Angles ◽  
Fatigue Endurance

The fatigue life of uniaxial fatigue specimens containing a skew hole is investigated. Contrary to expectation, fatigue life and fatigue endurance limit show no discernible change for vertical skew angles up to 45 when stress is calculated using the gross cross-sectional area. The point of fatigue crack initiation moves from the tip of the minor axis of the ellipse towards the tip of the major axis as skew angle increases.

Application of the Dissipated Energy Concept in Fatigue Endurance Limit Testing

2005 ◽  
Vol 1929 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Shihui Shen ◽  
Samuel H. Carpenter
Keyword(s):  
Fatigue Life ◽  
Endurance Limit ◽  
Fatigue Behavior ◽  
Testing Procedure ◽  
Dissipated Energy ◽  
Long Time ◽  
Loading Modes ◽  
Damage Condition ◽  
Fatigue Endurance ◽  
Unique Relationship

A fatigue endurance limit has been postulated to exist in hot-mix asphalt pavement performance. It cannot be observed and studied with the use of traditional phenomenological approaches as seen by the totally different fatigue behavior at low strain–damage levels close to the fatigue endurance limit. The ratio of dissipated energy change succeeds in defining and investigating the existence of a fatigue endurance limit with a unique relationship between plateau value (PV) and fatigue life (Nf), regardless of strain–damage levels, mixture types, loading modes, and other testing conditions. To determine a fatigue endurance limit requires an extraordinarily long time to conduct testing. This paper applied the PV to the study of a fatigue endurance limit to validate a shortened laboratory testing procedure. Statistical analysis shows that the shortened test can predict the PV with sufficient accuracy. By applying the validated relationship between PV and Nf, the extremely long fatigue life under low strain–damage condition can be predicted without performing millions of loading cycles.

Experimental analysis of constant-amplitude fatigue properties in 6156 (Al-Mg-Si) sheet aluminum alloy

2018 ◽  
Vol 53 (8) ◽  
pp. 676-686
Author(s):  
Nikolaos D Alexopoulos ◽  
Evangelos Migklis ◽  
Dimitrios Myriounis
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Work Hardening ◽  
Endurance Limit ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Constant Amplitude ◽  
The Matrix ◽  
Fatigue Endurance

Fatigue mechanical behavior of wrought aluminum alloy (Al-Mg-Si) 6156 at T4 temper is experimentally investigated. Constant-amplitude fatigue tests, at fixed stress ratio R = 0.1, were carried out, and the respective stress–life diagram was constructed and compared against the competitive 6xxx aluminum alloys, for example, 6082 and 6061. Fatigue endurance limit of AA6156 was found to be approximately 155 ± 5 MPa, that is, almost 30% below yield stress Rp of the material. AA6156 presents almost 50% higher fatigue life in the high-cycle fatigue area and approximately 20% higher fatigue endurance limit, when compared with other 6xxx series aluminum alloys. Significant work hardening was induced due to fatigue and was experimentally validated by the measurements of residual stiffness of fatigue loops as well as of absorbed energy per fatigue loop. Work-hardening exponent was essentially decreased by almost 25% from the first fatigue cycles and up to 10% of fatigue life. Fracture surfaces of specimens loaded at applied stresses close to fatigue endurance limit exhibited signs of coarse voids due to the formed precipitates at the matrix. The fracture mechanism was a mixture of transgranunal and intergranular fracture for the fatigue specimens tested at higher applied fatigue loadings.

Low Cycle Fatigue Life Prediction of Ti-6Al-4V Titanium Alloy under Multi-Axial Non Proportional Cyclic Loading

2013 ◽  
Vol 668 ◽  
pp. 814-817
Author(s):  
Rui Feng Wang ◽  
You Tang Li ◽  
Hu Ping An
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Low Cycle Fatigue ◽  
Testing Machine ◽  
Equivalent Strain ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Plane Method ◽  
Torsional Strain ◽  
Method Model

A series multi-axial tension and torsion low cycle fatigue life experiments of Ti-6Al-4V alloy were conducted on the MTS tension and torsion joint testing machine, in which the torsional strain control and non proportional cyclic loading method under the loading paths of circular, rectangular, square, oval and diamond were successively used. The experimental results are compared and analyzed with the results that calculated by the equivalent strain model, the energy method model and the critical plane method model. The results show that the critical plane method is the accurate prediction model to predict the multi-axial low cycle fatigue life of Ti-6Al-4V alloy.

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