A Prediction Model of Concrete Fatigue Residual Strength

2012 ◽  
Vol 430-432 ◽  
pp. 1843-1846
Author(s):  
Xian Hong Meng ◽  
Yu Xian Zhang ◽  
Jing Hai Zhou
Keyword(s):  
Prediction Model ◽  
Residual Strength ◽  
Maximum Stress ◽  
Residual Life ◽  
Compressive Loading ◽  
Fatigue Loading ◽  
Number Of Cycles

A model of attenuation of residual strength with number of cycles has been founded .In this model the constant confined stress and maximum stress of fatigue loading are both considered. Based on the data of experiment, the coefficients of the model are determined. The model can be used to predict the residual life of specimen under biaxial compressive loading with constant confined stress.

Experimental Investigation on Residual Strength of Plain Concrete under Fatigue Biaxial Compression with Constant Confined Stress

2011 ◽  
Vol 261-263 ◽  
pp. 581-585
Author(s):  
X.H. Meng ◽  
W.W. Wang ◽  
J.H. Zhou ◽  
Yu Pu Song
Keyword(s):  
Experimental Investigation ◽  
Residual Strength ◽  
Maximum Stress ◽  
Residual Life ◽  
Compressive Loading ◽  
Plain Concrete ◽  
Fatigue Loading ◽  
Biaxial Compression ◽  
Number Of Cycles ◽  
Better Than

A model of attenuation of residual strength with number of cycles has been founded .In this model the constant confined stress and maximum stress of fatigue loading are both considered. 55 specimens of plain concrete are tested under biaxial compressive fatigue loading with constant confined stress. Based on the data of experiment, the coefficients of the model are determined. The residual strength attenuating curves are shown in the paper. The model can be used to predict the residual life of specimen under biaxial compressive loading with constant confined stress. The results of prediction show that the suggested method is better than the Miner rule.

scholarly journals Theoretical and Experimental Fatigue Strength Calculations of Lips Compensating Circumferential Backlash in Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 251
Author(s):  
Piotr Osiński ◽  
Grzegorz Chruścielski ◽  
Leszek Korusiewicz
Keyword(s):  
Maximum Stress ◽  
Theoretical Calculations ◽  
Fatigue Loading ◽  
Minimum Thickness ◽  
Bending Tests ◽  
External Gear Pumps ◽  
Gear Pumps ◽  
In Series ◽  
Number Of Cycles ◽  
Technical Solutions

This article presents theoretical and experimental calculations of the minimum thickness of a compensation lip used in external gear pumps. Pumps of this type are innovative technical solutions in which circumferential backlash (clearance) compensation is used to improve their volumetric and overall efficiency. However, constructing a prototype of such a pump requires long-lasting research, and the compensation lip is its key object, due to the fact that it is an element influenced by a notch and that it operates in unfavorable conditions of strong fatigue stresses. The theoretical calculations presented in this article are based on identifying maximum stress values in a fatigue cycle and on implementing the stress failure condition and the conditions related to the required value of the fatigue safety factor. The experimental research focuses on static bending tests of the lips as well as on the fatigue loading of the lips in series of tests at increasing stress values until lip failure due to fatigue. The tests allowed the minimum lip thickness to be found for the assumed number of fatigue cycles, which is 2.5 times the number of cycles used in wear margin tests.

Experimental Research on Residual Strength of Recycled Aggregate Concrete under Compressive Fatigue Loading

2010 ◽  
Vol 150-151 ◽  
pp. 1379-1382 ◽  
Author(s):  
Hong Bing Zhu ◽  
Xiu Li
Keyword(s):  
Probability Distribution ◽  
Experimental Research ◽  
Residual Strength ◽  
Functional Relation ◽  
Fatigue Loading ◽  
Strength Degradation ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Number Of Cycles

To investigate the residual strength degradation of recycled aggregate concrete under fatigue loading, experiments were conducted to determine the functional relation between residual strength and the number of cycles. Fifty 100mm ×100mm ×100mm specimens of recycled aggregate concrete were tested under uniaxial compressive fatigue loading. Based on probability distribution of the residual strength of concrete under fatigue loading, the P-R-N curves are obtained based on test data, the empirical expressions of the residual strength corresponding to the number of cycles were obtained. The curves can be used to predict the residual strength with reliability.

scholarly journals Research on Residual Strength Prediction Model of Corroded Pipeline Based on Improved PSO-BP

2021 ◽  
Vol 687 (1) ◽  
pp. 012007
Author(s):  
Li Tingke ◽  
Peng Yuanchun ◽  
Li Jiadi ◽  
Dulin ◽  
Lian Xingqin
Keyword(s):  
Prediction Model ◽  
Residual Strength ◽  
Strength Prediction ◽  
Improved Pso

A Study of Nozzles in Pressure Vessels under Pressure Fatigue Loading

1967 ◽  
Vol 182 (1) ◽  
pp. 657-684 ◽  
Author(s):  
J. Spence ◽  
W. B. Carlson
Keyword(s):  
Fatigue Life ◽  
Mild Steel ◽  
Pressure Vessel ◽  
Special Interest ◽  
Maximum Stress ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Pressure Vessels ◽  
Full Size

Nozzles in cylindrical vessels have been of special interest to designers for some time and have offered a field of activity for many research workers. This paper presents some static and fatigue tests on five designs of full size pressure vessel nozzles manufactured in two materials. Supporting and other published work is reviewed showing that on the basis of the same maximum stress mild steel vessels give the same fatigue life as low alloy vessels. When compared on the basis of current codes it is shown that mild steel vessels may have five to ten times the fatigue life of low alloy vessels unless special precautions are taken.

Study of the low cycle fatigue of 12Cr18Ni10Ti steel based on fractal analysis and artificial intelligence approaches

2021 ◽  
Vol 87 (9) ◽  
pp. 59-67
Author(s):  
A. A. Khlybov ◽  
Yu. G. Kabaldin ◽  
M. S. Anosov ◽  
D. A. Ryabov ◽  
D. A. Shatagin
Keyword(s):  
Neural Network ◽  
Growth Rate ◽  
Fractal Dimension ◽  
Low Temperatures ◽  
Main Crack ◽  
Fatigue Loading ◽  
Wide Range ◽  
Lower Temperature ◽  
Number Of Cycles ◽  
Dimension Index

The evolution of the structure and assessment of the age limit of steel 12Cr18Ni10Ti upon fatigue loading is considered using neural network modeling and approaches of fractal analysis of the microstructure. An algorithm for processing images of the microstructures has been developed to improve their quality. An indicator of the fractal dimension of the image is used as a quantitative indicator for assessing the evolution of the microstructure of the surface metal layer. A quantitative assessment of the structures at different stress amplitudes is carried out in a wide range of low temperatures using the fractal dimension index. Correlation of the fractal dimension index with the run of the sample material is shown. The appearance of the main crack was observed in the range of 0.7 - 0.8 from the number of cycles to failure, after which the crack growth rate increased. At a lower temperature, the main crack is formed later, but further loading results in a higher crack growth rate. Formation of the secondary phases in austenitic steel at a lower temperature occurred at earlier stages than that at a temperature of t = +20°C, which led to hardening of the material. An artificial neural network (ANN) has been developed and trained for assessing structural changes in metal proceeding from the fractal dimensionality of the microstructure images at different stages of fatigue loading. The developed neural network made it possible to estimate with a sufficiently high accuracy the number of cycles before damage of the sample and the residual life of the material. Thus, the developed ANN can be used to assess the current state of the material in a wide range of low temperatures.

scholarly journals Bond Fatigue of TRC with Epoxy Impregnated Carbon Textiles

2019 ◽  
Vol 9 (10) ◽  
pp. 1980 ◽  
Author(s):  
Juliane Wagner ◽  
Manfred Curbach
Keyword(s):  
Cyclic Loading ◽  
Residual Strength ◽  
Negative Impact ◽  
Fatigue Behavior ◽  
Tensile Load ◽  
Textile Reinforced Concrete ◽  
Anchorage Length ◽  
Static Tests ◽  
Number Of Cycles ◽  
Bearing Behavior

For the economical construction of fatigue loaded structures with textile reinforced concrete (TRC), it is necessary to investigate the fatigue behavior of the materials. Since next to the tensile load-bearing behavior, the bond behavior of a material is crucial as well, the present paper deals with the bond fatigue of TRC with epoxy-impregnated carbon textiles. First, static tests are carried out to determine the sufficient anchorage length of the investigated material combination. Afterwards, the influence of cyclic loading on the necessary anchorage length, deformation, stiffness, and residual strength is investigated. The results of the cyclic tests are summarized in stress-number of cycles to failure (S-N) diagrams. In the end, it can be said that the cyclic loading has no negative impact on the necessary anchorage length. If specimens withstand the cyclic loading, there is no difference between their residual strength and the reference strength. The failure of specimens occurs only at high load levels, provided that the anchorage length is sufficient.

scholarly journals A Theory for the Effect of Mean Stress on Fatigue of Metals Under Combined Torsion and Axial Load or Bending

1959 ◽  
Vol 81 (4) ◽  
pp. 301-305 ◽  
Author(s):  
W. N. Findley
Keyword(s):  
Shear Stress ◽  
Axial Load ◽  
Maximum Stress ◽  
Influencing Factor ◽  
Shear Plane ◽  
Mean Stress ◽  
Cast Irons ◽  
Ductile Metals ◽  
Fatigue Data ◽  
Number Of Cycles

The concept that alternating shear stress is the primary cause of fatigue with the normal stress on the critical shear plane as an influencing factor has been developed for the case of mean (or static) stresses superimposed on combinations of torsion and axial load or bending. The influence of the maximum stress of the cycle of stress on the allowable alternating stress for a given number of cycles and on the orientation of the critical shear plane is explored. The predictions of the theory are consistent with the known trends of fatigue data both for ductile metals and cast irons. The theory explains the fact that the influence of mean stress is weak for torsion and stronger for bending of ductile metals, but strong for both torsion and bending of cast irons. As far as is known this is the first rational theory for the influence of mean stress.

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