Fatigue life of lugs under service loading - test results and predictions / Lebensdauer von Augenstäben bei Betriebsbelastung - Prüfungsergebnisse und Vorhersage / Durée de vie des oreilles dans charge de service - résultats d’essai et prédiction

1981 ◽  
Vol 23 (10) ◽  
pp. 344-348
Author(s):  
Alfred Buch ◽  
Abraham Berkovits
Keyword(s):  
Fatigue Life ◽  
Test Results ◽  
Loading Test ◽  
Service Loading

Study on the stiffness degradation in concrete continuous beam with externally prestressed CFRP tendons under fatigue loading

2021 ◽  
pp. 136943322199249
Author(s):  
Xing Li ◽  
Jiwen Zhang ◽  
Jun Cheng
Keyword(s):  
Fatigue Life ◽  
Fatigue Loading ◽  
Load Level ◽  
Fiber Reinforced Polymer ◽  
Stiffness Degradation ◽  
Test Results ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Practical Engineering ◽  
Good Agreement

This paper presents fatigue behaviors and the stiffness degradation law of concrete continuous beams with external prestressed carbon fiber-reinforced polymer (CFRP) tendons. Three specimens were tested under fatigue loading, and the influence of different load levels on the stiffness degradation and fatigue life were studied, and it was found that the stiffness degradation of three test specimens exhibited a three-stage change rule, namely rapid decrease, stable degradation, and sharp decline, but there are obvious differences in the rate and amplitude of stiffness degradation. The load level has a significant influence on the fatigue life of the test specimens. An analytical model with load level considered was proposed to calculate the residual stiffness and predict the stiffness degradation, which is in good agreement with the test results. The model of stiffness degradation presents a possible solution for practical engineering applications of concrete continuous beams with externally prestressed CFRP tendons subjected to different fatigue loadings.

scholarly journals Impact of Graphene Oxide on Zero Shear Viscosity, Fatigue Life and Low-Temperature Properties of Asphalt Binder

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3073
Author(s):  
Abbas Mukhtar Adnan ◽  
Chaofeng Lü ◽  
Xue Luo ◽  
Jinchang Wang
Keyword(s):  
Graphene Oxide ◽  
Fatigue Life ◽  
Low Temperature ◽  
Shear Viscosity ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Test Results ◽  
Zero Shear Viscosity ◽  
Modified Asphalt

This study has investigated the impact of graphene oxide (GO) in enhancing the performance properties of an asphalt binder. The control asphalt binder (60/70 PEN) was blended with GO in contents of 0%, 0.5%, 1%, 1.5%, 2%, and 2.5%. The permanent deformation behavior of the modified asphalt binders was evaluated based on the zero shear viscosity (ZSV) parameter through a steady shear test approach. Superpave fatigue test and the linear amplitude sweep (LAS) method were used to evaluate the fatigue behavior of the binders. A bending beam rheometer (BBR) test was conducted to evaluate the low-temperature cracking behavior. Furthermore, the storage stability of the binders was investigated using a separation test. The results of the ZSV test showed that GO considerably enhanced the steady shear viscosity and ZSV value, showing a significant contribution of the GO to the deformation resistance; moreover, GO modification changed the asphalt binder’s behavior from Newtonian to shear-thinning flow. A notable improvement in fatigue life was observed with the addition of GO to the binder based on the LAS test results and Superpave fatigue parameter. The BBR test results revealed that compared to the control asphalt, the GO-modified binders showed lower creep stiffness (S) and higher creep rate (m-value), indicating increased cracking resistance at low temperatures. Finally, the GO-modified asphalt binders exhibited good storage stability under high temperatures.

scholarly journals Analysis of the Correlation between the Static and Fatigue Test Results of the Interlayer Bondings of Asphalt Layers

2016 ◽  
Vol 62 (1) ◽  
pp. 83-98 ◽  
Author(s):  
A. Szydło ◽  
K. Malicki
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Mixture ◽  
Fatigue Tests ◽  
Test Results ◽  
Static Tests ◽  
Bonding State ◽  
Road Pavement ◽  
The Future ◽  
Pavement Structure

Abstract The bonding state of the asphalt layers in a road pavement structure significantly affects its fatigue life. These bondings, therefore, require detailed tests and optimization. In this paper, the analyses of the correlation between the results of laboratory static tests and the results of fatigue tests of asphalt mixture interlayer bondings were performed. The existence of the relationships between selected parameters was confirmed. In the future, the results of these analyses may allow for assessment of interlayer bondings’ fatigue life based on the results of quick and relatively easy static tests.

Strengthening of reinforced concrete corbels with GFRP overlays

2011 ◽  
Vol 18 (1-2) ◽  
pp. 69-77 ◽  
Author(s):  
Sevket Ozden ◽  
Hilal Meydanli Atalay
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Ratio ◽  
Fiber Reinforced Polymer ◽  
Peak Performance ◽  
Test Results ◽  
Loading Test ◽  
Load Bearing Capacity ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Normal Strength

AbstractThe strength and post-peak performance of reinforced concrete corbels, strengthened with epoxy bonded glass fiber reinforced polymer (GFRP) overlays, were experimentally investigated. The test variables were the corbel shear span to depth ratio, corbel main reinforcement ratio, and the number and orientation of the GFRP fibers. In total, 24 normal strength concrete, one-third scale, corbel specimens, without hoop reinforcement, were tested to failure under quasi-static gravity loading. Test results revealed that GFRP overlays can easily be used for the enhancement of corbel load bearing capacity, depending on the fiber orientation. The main reinforcement ratio and the number of GFRP plies were found to be the two main variables affecting the level of strength gain in the corbel specimens.

Estimation of Seismic Energy Dissipation for Steel Slit Shear Walls Considering Out-of-Plane Buckling

2021 ◽  
Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Thickness Ratio ◽  
Design Parameters ◽  
Test Results ◽  
Loading Test ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Energy Dissipation Capacity

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.

High-cycle fatigue tests of pretensioned concrete beams

PCI Journal ◽  
2022 ◽  
Vol 67 (1) ◽  
Author(s):  
Jörn Remitz ◽  
Martin Empelmann
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Design Methods ◽  
Test Results ◽  
Cycle Fatigue ◽  
Pretensioned Concrete ◽  
Current Design

Pretensioned concrete beams are widely used as bridge girders for simply supported bridges. Understanding the fatigue behavior of such beams is very important for design and construction to prevent fatigue failure. The fatigue behavior of pretensioned concrete beams is mainly influenced by the fatigue of the prestressing strands. The evaluation of previous test results from the literature indicated a reduced fatigue life in the long-life region compared with current design methods and specifications. Therefore, nine additional high-cycle fatigue tests were conducted on pretensioned concrete beams with strand stress ranges of about 100 MPa (14.5 ksi). The test results confirmed that current design methods and specifications overestimate the fatigue life of embedded strands in pretensioned concrete beams.

Influence of loading rate on the capacity of a model pile in clay

1995 ◽  
Vol 32 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Robert G. Horvath
Keyword(s):  
Loading Rate ◽  
Axial Loading ◽  
Displacement Transducer ◽  
Test Methods ◽  
Point Load ◽  
Test Results ◽  
Loading Test ◽  
Normal Loading ◽  
Model Pile ◽  
Rate Of Loading

Loading tests were carried out on a model pile embedded in clay to examine the influence of rate of loading on the capacity of the pile. The pile was loaded to failure using constant rate of penetration (CRP), quick maintained loading (QML), and quick continuous loading (QCL) methods of loading. The QCL test models the Statnamic loading test, which has been recently developed in Canada. The CRP tests were used as a reference, and the results were normalized using the CRP test results. The durations of the QML and QCL tests varied from approximately 0.1 s to 17 min, which are significantly faster than normal loading rates. Applied loads and point load were measured using load cells, and top displacement was measured using a displacement transducer. The test results showed an increase in pile capacity with increased rate of loading. Damping was found to be significant for the QCL tests (duration = 0.1 s) and negligible for the QML tests (duration ≥ 10 s). Correcting the results of the QCL tests for damping, using the equilibrium point method developed for Statnamic testing, greatly improved the correlation of the QCL and QML test results. Key words : model piles, axial loading, loading rate, clay, laboratory study, test methods.

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