Experimental and numerical investigations on seismic performance of RC bridge piers considering buckling and low-cycle fatigue of high-strength steel bars

The article presents the results of research on low cycle fatigue strength of laser welded joints vs. non-welded material of high-strength steel DOMEX 700 MC. The tests were performed under load controlled using the total strain amplitude ɛac. The operating principle of the special electro-mechanic fatigue testing equipment with a suitable clamping system was working on 35 Hz frequency. Fatigue life analysis was conducted based on the Manson-Coffin-Basquin equation, which made it possible to determine fatigue parameters. Studies have shown differences in the fatigue life of original specimens and laser welded joints analysed, where laser welded joints showed lower fatigue resistance. In this article a numerical analysis of stresses generated in bending fatigue specimens has been performed employing the commercially available FEM-program ADINA.

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Effect of anodic and cathodic processes on the low-cycle fatigue strength of high-strength steel subjected to a corrosive solution

Soviet Materials Science ◽

10.1007/bf00728697 ◽

1978 ◽

Vol 13 (6) ◽

pp. 671-672

Author(s):

G. V. Karpenko ◽

I. P. Pistun ◽

A. K. Litvin

Keyword(s):

Fatigue Strength ◽

High Strength Steel ◽

Low Cycle Fatigue ◽

High Strength ◽

Cycle Fatigue ◽

Corrosive Solution ◽

Cathodic Processes

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High-Strength Reinforcing Steel Bars: Low Cycle Fatigue Behavior Using RGB Methodology

International Journal of Concrete Structures and Materials ◽

10.1186/s40069-021-00474-9 ◽

2021 ◽

Vol 15 (1) ◽

Author(s):

Jorge E. Egger ◽

Fabian R. Rojas ◽

Leonardo M. Massone

Keyword(s):

Fatigue Life ◽

Strain Amplitude ◽

Low Cycle Fatigue ◽

High Strength ◽

Image Correlation ◽

Total Strain ◽

Total Strain Amplitude ◽

Reinforcing Steel ◽

Cycle Fatigue ◽

Steel Bars

AbstractLow cycle fatigue life of high-strength reinforcing steel bars (ASTM A706 Grade 80), using photogrammetry by RGB methodology is evaluated. Fatigue tests are performed on specimens under constant axial displacement with total strain amplitudes ranging from 0.01 to 0.05. The experimental observations indicate that buckling of high-strength reinforcing bars results in a damaging degradation of their fatigue life performance as the slenderness ratio increases, including an early rebar failure as the total strain amplitude increases since it achieves the plastic range faster. In addition to this, the results show that the ratio of the ultimate tensile strength to yield strength satisfies the minimum of 1.25 specified in ASTM A706 for reinforcement. On the other hand, the RGB methodology indicates that the axial strains measured by photogrammetry provide more accurate data since the registered results by the traditional experimental setup do not detect second-order effects, such as slippage or lengthening of the specimens within the clamps. Moreover, the RGB filter is faster than digital image correlation (DIC) because the RGB methodology requires a fewer computational cost than DIC algorithms. The RGB methodology allows to reduce the total strain amplitude up to 45% compared to the results obtained by the traditional setup. Finally, models relating total strain amplitude with half-cycles to failure and total strain amplitude with total energy dissipated for multiple slenderness ratios (L/d of 5, 10, and 15) are obtained.

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