A Concrete Fatigue Deformation Evolution Model Based on Weibull Equation

Abstract

The invention discloses a concrete fatigue deformation evolution model based on Weibull equation. In the ever-growing field of modern civil engineering, the fatigue performance of concrete materials has become one of the focuses. How to accurately characterize the fatigue performance evolution of concrete and predict the fatigue life of concrete has become an important issue in the field of engineering construction. The model provided by the invention can be used to characterize the deformation evolution law of concrete under compression, tension and bending fatigue loads. It has the advantages of various applicable load forms, simple expression, easy to use, and high precision. In the process of use, the amount of calculation can be greatly reduced, and only the number of fatigue load cycles needs to be measured n and the first n The deformation corresponding to a certain stress in one cycle ε These two fatigue parameters can simplify detection equipment. The above model can provide important technical support for the whole process of engineering design, construction, inspection and maintenance.

Description

Technical field

[0001] The present invention belongs to the technical field of concrete fatigue deformation evolution model. Background technique

[0002] Since the 19th century Portland cement, concrete has been widely used in the field of transportation, construction, water conservancy, ocean and other engineering, and is the largest material for engineering construction. At the beginning of the 20th century, with the construction and development of reinforced concrete bridges, related research on fatigue performance of concrete materials was also gradually carried out. In the 21st century, with the construction of large infrastructure such as highways, high-speed railways, ultra-high-rise buildings, special dams, cross-sea bridges, marine platforms, and concrete structures faced a recycling load, alternating environment, etc., more complicated, strict Service conditions. On the other hand, further development of concrete structural design theory and high-strength concrete prom...

Examples

Embodiment 1

[0023] This example uses the literature "Holmen J o.fatigue of concrete by constant andvariable amplitude loading" [j] .aci special publication, 1982, 75: 71-110. "Fig.11" concrete compression fatigue sample D22 fatigue Deformation results. The maximum deformed ε of the sample under the action of compressed fatigue loading s , Residual deformation ε p Evolution law figure 1 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s Directly obtained from the literature, residual deformation ε p Calculated from the fatigue deformation result from the literature.

[0024] according to figure 1 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = 0.09582, proportional parameter λ s = 0.11497, shape parameter k s = 3.16309. Thereby, the following fatigue deformation evolution model can be obtained:

[0025] N / N f = 1-exp (- (ε) s -0.09582) / 0.11497) 3.16309 ), (r 2 = 0.9971)

[0026] according to figure...

Embodiment 2

[0030] This example uses the literature "CHEN X, Bu J, FAN X, et al.effect of loading frequency stress level limited, custom ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,) "Fig.8C" concrete stretched fatigue sample S = 0.85 Test Data fatigue deformation results. The maximum deformed ε under the action of stretching fatigue loading s , Residual deformation ε p Evolution law figure 2 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s And residual deformation ε p All are obtained directly from the literature.

[0031] according to figure 2 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = 38.21874, proportional parameter λs = 66.41625, shape parameter K s = 11.44255. Thereby, the following fatigue deformation evolution model can be obtained:

[0032] N / N f = 1-exp (- (ε) s -38.21874 / 66.41625) 11.44255 ), (r 2 = 0.9769)

[0033] according to figure 2 The residual defor...

Embodiment 3

[0037] This embodiment employs document "Liu W, Xu S, Li H.Flexural fatigue damage model ofultra-high toughness cementitious composites on base of continuum damagemechanics [J] .International Journal of Damage Mechanics, 2014,23 (7): 949-963 "Fig.3a" fiber concrete curved fatigue sample S0.80 fatigue deformation results. The maximum deformed ε of the sample under bending fatigue load s , Residual deformation ε p Evolution law image 3 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s Directly obtained from the literature, residual deformation ε p Calculated from the fatigue deformation result from the literature.

[0038] according to image 3 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = -2.27807, proportional parameter λ s = 4.85335, shape parameter K s = 9.28728. Thereby, the following fatigue deformation evolution model can be obtained:

[0039] N / N f = 1-exp (- (ε) s +2.27807) / 4.8...

Technical field

[0001] The present invention belongs to the technical field of concrete fatigue deformation evolution model. Background technique

[0002] Since the 19th century Portland cement, concrete has been widely used in the field of transportation, construction, water conservancy, ocean and other engineering, and is the largest material for engineering construction. At the beginning of the 20th century, with the construction and development of reinforced concrete bridges, related research on fatigue performance of concrete materials was also gradually carried out. In the 21st century, with the construction of large infrastructure such as highways, high-speed railways, ultra-high-rise buildings, special dams, cross-sea bridges, marine platforms, and concrete structures faced a recycling load, alternating environment, etc., more complicated, strict Service conditions. On the other hand, further development of concrete structural design theory and high-strength concrete prom...

Examples

Embodiment 1

[0023] This example uses the literature "Holmen J o.fatigue of concrete by constant andvariable amplitude loading" [j] .aci special publication, 1982, 75: 71-110. "Fig.11" concrete compression fatigue sample D22 fatigue Deformation results. The maximum deformed ε of the sample under the action of compressed fatigue loading s , Residual deformation ε p Evolution law figure 1 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s Directly obtained from the literature, residual deformation ε p Calculated from the fatigue deformation result from the literature.

[0024] according to figure 1 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = 0.09582, proportional parameter λ s = 0.11497, shape parameter k s = 3.16309. Thereby, the following fatigue deformation evolution model can be obtained:

[0025] N / N f = 1-exp (- (ε) s -0.09582) / 0.11497) 3.16309 ), (r 2 = 0.9971)

[0026] according to figure...

Embodiment 2

[0030] This example uses the literature "CHEN X, Bu J, FAN X, et al.effect of loading frequency stress level limited, custom ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,) "Fig.8C" concrete stretched fatigue sample S = 0.85 Test Data fatigue deformation results. The maximum deformed ε under the action of stretching fatigue loading s , Residual deformation ε p Evolution law figure 2 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s And residual deformation ε p All are obtained directly from the literature.

[0031] according to figure 2 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = 38.21874, proportional parameter λs = 66.41625, shape parameter K s = 11.44255. Thereby, the following fatigue deformation evolution model can be obtained:

[0032] N / N f = 1-exp (- (ε) s -38.21874 / 66.41625) 11.44255 ), (r 2 = 0.9769)

[0033] according to figure 2 The residual defor...

Embodiment 3

[0037] This embodiment employs document "Liu W, Xu S, Li H.Flexural fatigue damage model ofultra-high toughness cementitious composites on base of continuum damagemechanics [J] .International Journal of Damage Mechanics, 2014,23 (7): 949-963 "Fig.3a" fiber concrete curved fatigue sample S0.80 fatigue deformation results. The maximum deformed ε of the sample under bending fatigue load s , Residual deformation ε p Evolution law image 3 Indicated. It should be noted that the maximum deformed ε of the fatigue sample s Directly obtained from the literature, residual deformation ε p Calculated from the fatigue deformation result from the literature.

[0038] according to image 3 The maximum deformed ε shown s The experimental value, by fitting, location parameters ε can be obtained s0 = -2.27807, proportional parameter λ s = 4.85335, shape parameter K s = 9.28728. Thereby, the following fatigue deformation evolution model can be obtained:

[0039] N / N f = 1-exp (- (ε) s +2.27807) / 4.8...

Images