Fatigue defect of layer steel fiber reinforced concrete

Liu

2014

KEM

This paper presents the results of a study on the fatigue damage of high strength concrete under uniaxial compression. Based on the experimental data, the change laws of fatigue strain and fatigue modulus are put forward. According to the experimental requests, the numerical value of fatigue strain and fatigue modulus when the fatigue failure of concrete occurs can be regarded as the criteria for fatigue failure of concrete. Then the paper presents a fatigue damage model. By reference to the concept about the damage variable defined by some scholars, the formula of the damage variable is proposed and the damage variable curves varying with recycle ratio (n%) are mapped. At last, the fitting curves of the damage variable varying with recycle ratio are proposed. The fitting effect is very good and the correlation coefficients are above 0.95.

Section: Fatigue Strainsupporting

confidence: 68%

Experimental Study on the Fatigue Damage of High Strength Concrete under Uniaxial Compression

Yin

Liu

2014

KEM

“…You [20] studied how the continuous gradient distribution of steel fibers will influence the mechanical properties of fiber-reinforced and cement-based materials. Ying-Bo and Zhe-Anda [21] studied fatigue defects in LSFRC and defined their degree. Huang used cubic polynomials to perform regression for the straincycle ratio equation and defect-cycle ratio equation, for which the correlation coefficient is close to 1.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Flexural Bearing Capacity and Failure Mode of Precast LSFRC Pavement Slab

Advances in Materials Science and Engineering

Ban

Luo

et al. 2022

To promote practical use of the top-and-bottom layered steel fiber reinforced concrete (LSFRC) plates, an appropriate constitutive model is selected using ABAQUS software to analyze the bearing capacity, failure pattern, and deformation of the LSFRC plates. An LSFRC plate model is established for the analysis and calculation. Meanwhile, a test was carried out to measure the bearing capacity of 10 LSFRC plates. The results show that, after going through the elastic stage, crack growth, and failure stage, when the maximum crack width reaches 0.1 mm, the load of the LSFRC plates can be used as the ultimate bearing load. When failure appears to be bending the LSFRC plates, the neutral axis will shift upwards, showing a pseudoplastic failure. There is a larger tensile stress area after the first crack appears at the bottom of the steel fiber concrete. The change before and after the maximum load is relatively gentle. After becoming plastic, the plate witnesses a rapid crack growth on its bottom. With similar results from the test and numerical simulation, small errors can be minimized by further analysis to provide a more accurate model for the subsequent bearing capacity analysis of the LSFRC plates.

“…Such polymers as poly(lactic acid)-poly(ethylene glycol) (PEG) copolymer and monolayer graphene oxide have been combined to modify superparamagnetic iron oxide nanoparticles as protein mass transfer carriers, polymer coating and application of surfactants in nanomaterials. [21][22][23][24][25][26][27][28] PEG has the advantages of environmental friendliness, non-toxicity, good lubricity and strong inhibition. 29,30 In addition, PEG could be a promising matrix for metacomposites with negative electromagnetic parameters.…”

Section: Introductionmentioning

confidence: 99%

Evaluation and application of poly(ethylene glycol) as lubricant in water‐based drilling fluid for horizontal well in Sulige Gas Field

Liu

Gao

et al. 2020

Polymer International

With the increasing amount of drilling of directional wells and large-displacement wells, high torque and high resistance have become critical problems. Therefore, high-performance and environment-friendly lubricants for water-based drilling fluid are urgently needed. In this paper, poly(ethylene glycol) 2000 (PEG) was used as a lubricant, and the lubricity, inhibition, compatibility and temperature resistance of the PEG lubricant were investigated. The results show that 0.1% (mass ratio) PEG in water-based drilling fluid can reduce the friction coefficient of mud cake by 44.5%. This PEG also has certain inhibition and temperature resistance. As PEG is used with other drilling fluid additives, the compatibility was good and the lubricity of drilling fluid can be improved effectively. The lubricating mechanism of PEG was explored and the results showed that the hydrophobic alkane chains in the PEG molecules were adsorbed on the surface of bentonite, forming a hydrophobic film on the friction surface, thereby forming a lubricating layer. Field application in Sulige Gas Field showed that the PEG lubricant has good lubricity and can meet the technical requirements of corresponding horizontal wells.