Method and system for predicting dynamic growth factor of hybrid fiber reinforced geopolymer concrete

Abstract

The invention discloses a hybrid fiber reinforced geopolymer concrete dynamic growth factor prediction method and system, and relates to the technical field of composite materials, and the method comprises the steps: obtaining an initial peak stress growth factor based on the ratio of dynamic peak stress to quasi-static peak stress under a given strain rate; based on the ratio of the dynamic elastic modulus to the static elastic modulus, obtaining a dynamic increasing coefficient of the elastic modulus of the concrete; under the condition that the size of the static compression test piece is consistent with the size of the dynamic compression test piece, analyzing the influence of a fiber combination mode, a fiber type, a fiber mixing amount and a strain rate on the dynamic performance of the test piece; introducing fiber characteristic parameters to carry out secondary fitting on the initial peak stress growth factor to obtain a corrected peak stress growth factor; and fitting the dynamic increase coefficient of the elastic modulus of the concrete through a linear function to obtain a corrected elastic modulus increase factor and a critical strain rate. According to the method, the dynamic growth factor of the hybrid fiber reinforced geopolymer concrete can be accurately predicted, so that the impact resistance of the material is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and more particularly to a prediction method and system for a dynamic growth factor of hybrid fiber reinforced geopolymer concrete. Background Art

[0002] GPC materials contain pores and cracks, and the addition of fibers will increase the defects in the matrix. During the impact damage process, strain hardening behavior and damage softening behavior appear successively. Specifically, the dynamic stress-strain curve includes a linear elastic rise stage, a nonlinear elastic-plastic yield stage, and a nonlinear decline stage after the peak. The characteristics of each stage are as follows:

[0003] (1) In the linear elastic rising stage, stress increases linearly with the increase of strain. The initial slope of the dynamic stress-strain curve is the dynamic elastic modulus. At high strain rates, the slope of the elastic section is larger than that of the quasi-static section, that is, the dynamic elastic modulus is larger. This is mainly because rapid impact will cause rapid accumulation of energy inside the specimen, and at the same time, microcracks fail to expand in time, and the accumulated energy cannot be consumed in time;

[0004] (2) In the elastoplastic yield stage, the rate of stress increase decreases as the strain increases, which is manifested as a decreasing slope of the curve. In this stage, the cracks inside the concrete develop slowly as the strain gradually increases, the material exhibits obvious strain hardening behavior, and the material strength continues to increase until it reaches the peak of the stress-strain curve;

[0005] (3) The post-peak stress decreases nonlinearly with the increase of strain. Unlike the quasi-static stress-strain curve, the dynamic stress-strain curve is fuller after the peak. At this stage, the cracks inside the specimen develop rapidly, resulting in a sharp increase in strain, showing obvious damage softening behavior, and ultimately causing matrix damage. Crack expansion and fiber pullout or breakage consume impact energy, so the area under the stress-strain curve is larger when the fiber content is high.

[0006] For the same group of specimens, when the strain rate is low, the dynamic peak stress is first lower than the static peak stress. As the strain rate increases, the dynamic peak stress is much higher than the static peak stress. In other words, there is a critical strain rate during dynamic compression. When the impact strain rate exceeds the critical strain rate, GPC shows an obvious strain rate effect. Since the bonding effect between the geopolymer matrix and the fiber is better than that of ordinary concrete, the fiber can play a better bridging role when the matrix cracks. As the compressive strain increases, the matrix is ​​rapidly destroyed, causing more fibers to be pulled out or broken, thereby losing part of the bearing capacity.

[0007] Due to the expansion effect of fibers on concrete cracks, adding fibers can make the material carry more energy, thereby improving the strength of the material. Peak strain and ultimate strain are important parameters that characterize the deformation capacity of materials under dynamic loading, and are of great significance for evaluating the impact resistance of materials.

[0008] Therefore, how to accurately predict the dynamic growth factor of hybrid fiber reinforced geopolymer concrete and then obtain the impact resistance of the material is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0009] In view of this, the present invention provides a method and system for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, which solves the problems existing in the background technology.

[0010] In order to achieve the above object, the present invention provides the following technical solutions:

[0011] A method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete comprises the following steps:

[0012] Based on the ratio of the dynamic peak stress to the quasi-static peak stress at a given strain rate, the initial peak stress growth factor is obtained;

[0013] Based on the ratio of the dynamic elastic modulus to the static elastic modulus, the dynamic increase coefficient of the elastic modulus of concrete is obtained;

[0014] When the size of static compression specimens is the same as that of dynamic compression specimens, the effects of fiber combination, fiber type and dosage, and strain rate on the dynamic properties of the specimens are analyzed.

[0015] The fiber characteristic parameters are introduced to perform a quadratic fit on the initial peak stress growth factor to obtain the corrected peak stress growth factor.

[0016] The dynamic increase coefficient of the elastic modulus of concrete is fitted by a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

[0017] Alternatively, the initial peak stress growth factor can be predicted by:

[0018]

[0019] Where DIF f is the initial peak stress growth factor; is the dynamic strain rate, f d is the corresponding dynamic compressive strength; Is 30×10 -6 s -1 , f s is the quasi-static compressive strength.

[0020] Optionally, the prediction formula for the initial peak stress growth factor is applicable to the strain rate range of 30×10 -6 ~3×10 2 s -1 .

[0021] Optionally, the prediction formula for the dynamic increase coefficient of concrete elastic modulus is:

[0022]

[0023] Where: DIF E is the dynamic increase coefficient of elastic modulus, E d is the dynamic elastic modulus, E s is the static elastic modulus; is the dynamic strain rate, Is 30×10 -6 s -1 .

[0024] Optionally, the dynamic performance of the specimen is the peak stress growth factor, and the analysis results of the influence of fiber combination, fiber type and dosage, and strain rate on the peak stress growth factor are as follows:

[0025] Calculate the peak stress growth factor of different fiber combinations at different strain rates, with strain rates ranging from 45 to 220 s -1 When the strain rate changes between , the peak stress growth factors of different fiber combinations increase with the increase of strain rate and show a nonlinear relationship; the hydrophilicity of PVA fibers limits crack propagation by forming a curved surface at the crack tip, and the matrix containing PVA fibers is most sensitive to strain rate changes; excessive fiber addition introduces voids or forms agglomeration effects, reduces material uniformity, and increases strain sensitivity.

[0026] Optionally, the dynamic performance of the specimen is the elastic modulus growth factor, and the analysis results of the influence of fiber combination mode, fiber type and dosage, and strain rate on the elastic modulus growth factor are as follows:

[0027] The elastic modulus growth factor increases with the increase of strain rate and presents a linear relationship; when the strain rate is less than 85s -1 When the elastic modulus growth factor is less than 1, the strain rate exceeds 85s -1 When the strain rate is greater than 145s -1 When the elastic modulus growth factor exceeds the elastic modulus growth factor under the earthquake strain rate, the critical strain rate of the elastic modulus of geopolymer concrete is 145s -1 .

[0028] Optionally, obtain the corrected peak stress growth factor, specifically:

[0029] Introducing fiber characteristic parameters Perform quadratic fitting to obtain the peak stress growth factor prediction formula considering the strain rate and hybrid fiber characteristic value:

[0030]

[0031] in:

[0032] i=-0.028Λ H -0.0099Λ P -0.3114

[0033] j=-0.01Λ H -0.0312Λ P +1.3104

[0034] m=-0.025Λ H -0.0054Λ P -0.3114

[0035] n=0.0759Λ H +0.0309Λ P +1.3104

[0036] Where: DIF f ' is the corrected peak stress growth factor, is the quasi-static strain rate; L is the fiber length, d is the fiber diameter, V f is the volume content of the fiber; H is the fiber characteristic parameter of HS fiber, Λ P It is the fiber characteristic parameter of PVA fiber.

[0037] A prediction system for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, using any of the above-mentioned prediction methods for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, comprising:

[0038] A first initial value calculation module is used to obtain an initial peak stress growth factor according to a ratio of a dynamic peak stress to a quasi-static peak stress at a given strain rate;

[0039] The second initial value calculation module is used to obtain the dynamic increase coefficient of the concrete elastic modulus according to the ratio of the dynamic elastic modulus to the static elastic modulus;

[0040] The analysis module is used to analyze the influence of fiber combination mode, fiber type and dosage, and strain rate on the dynamic performance of the specimen when the size of the static compression specimen is consistent with that of the dynamic compression specimen;

[0041] The first optimization module is used to perform a secondary fitting on the initial peak stress growth factor by introducing fiber characteristic parameters to obtain a corrected peak stress growth factor;

[0042] The second optimization module is used to fit the dynamic increase coefficient of the elastic modulus of concrete through a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

[0043] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a method and system for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, which can accurately predict the dynamic growth factor of hybrid fiber reinforced geopolymer concrete and then evaluate the impact resistance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0045] Figure 1 A schematic flow chart of a method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete provided by the present invention;

[0046] Figure 2 A schematic diagram of the dynamic peak stress of each group of test pieces at different strain rates provided by the present invention;

[0047] Figure 3 The present invention provides The linear function of Comparison chart of power function fitting effects;

[0048] Figure 4 The DIF provided by the present invention E Schematic diagram of the change with strain rate. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The embodiment of the present invention discloses a method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, such as Figure 1 As shown, the following steps are included:

[0051] Based on the ratio of the dynamic peak stress to the quasi-static peak stress at a given strain rate, the initial peak stress growth factor is obtained;

[0052] Based on the ratio of the dynamic elastic modulus to the static elastic modulus, the dynamic increase coefficient of the elastic modulus of concrete is obtained;

[0053] When the size of static compression specimens is the same as that of dynamic compression specimens, the effects of fiber combination, fiber type and dosage, and strain rate on the dynamic properties of the specimens are analyzed.

[0054] The fiber characteristic parameters are introduced to perform a quadratic fit on the initial peak stress growth factor to obtain the corrected peak stress growth factor.

[0055] The dynamic increase coefficient of the elastic modulus of concrete is fitted by a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

[0056] In this embodiment, the peak stress can be directly obtained as the dynamic peak stress through the dynamic stress-strain curve, such as Figure 2 As shown. At a lower strain rate, most specimens are not damaged. The strength at this time can only reflect the response of the specimen to the dynamic compression energy, and the fiber reinforcement effect cannot be judged based on the dynamic strength at a low strain rate: when a high strain rate is reached, all specimens are damaged. The dynamic strength at this time can reflect the difference in reinforcement effects of different fiber types and fiber dosages. The following conclusions are drawn:

[0057] (1) In general, the strength of geopolymer concrete increases with the increase of strain rate, regardless of whether it is mixed with fibers or not, showing its sensitivity to strain rate. However, the strength of geopolymer concrete decreases at 220 s. -1 When the intensity decreases;

[0058] (2) Geopolymer concrete with steel fiber alone can withstand high strain rate impact better than geopolymer concrete with PVA fiber alone; geopolymer concrete with MS fiber alone has higher dynamic strength than geopolymer concrete with HS fiber alone;

[0059] (3) At lower strain rates, geopolymer concrete with PVA fibers alone is more sensitive to strain rate than that with steel fibers alone. At higher strain rates, geopolymer concrete mixed with PVA and steel fibers exhibits higher dynamic peak stress than that with single fibers, indicating that the combination of PVA fibers and steel fibers can significantly improve the dynamic compressive capacity of geopolymer concrete, and the combination of PVA+MS has a better effect.

[0060] (4) When mixing PVA fiber and MS fiber, there is an optimal fiber dosage combination. Excessive dosage of either fiber may reduce the dynamic strength of the matrix. The recommended combination is 0.55% PVA fiber and 1.0% MS fiber.

[0061] Peak strain and ultimate strain are important parameters that characterize the deformation capacity of materials under dynamic loading and are of great significance for evaluating the impact resistance of materials.

[0062] Peak stress growth factor (DIF f ) is a dimensionless quantity, defined as the ratio of the dynamic peak stress to the quasi-static peak stress at a given strain rate, and is often used to evaluate the strain rate sensitivity of a material. Based on the CEB-FIP Model Code for Concrete Structures, the prediction formula for the initial peak stress growth factor is given as:

[0063]

[0064] Where DIF f is the initial peak stress growth factor; is the dynamic strain rate, f d is the corresponding dynamic compressive strength; Is 30×10 -6 s -1 , f s is the quasi-static compressive strength. The prediction formula for the initial peak stress growth factor is applicable to the strain rate range of 30×10 -6 ~3×10 2 s -1 .

[0065] CEB-FIP Specification for DIF f The calculation instructions only indicate that the average compressive strength is used for calculation, but the size of the static and dynamic compression specimens is not specified. In the prior art, the static strength used to calculate DIF is usually derived from conventional quasi-static compression tests, so the specimen shape used to obtain the static strength is often different from that used in dynamic tests. There is an obvious size effect on the static compressive strength of concrete materials, that is, the larger the specimen size, the lower the measured compressive strength. Therefore, using a larger static compression specimen size may result in a calculated DIF. f The value is high, and the difference is more obvious under high strain rate conditions. This example aims to analyze the effects of fiber combination, fiber type and dosage, and strain rate on the dynamic performance of GPC and make a horizontal comparison between groups. Therefore, when the static specimens and dynamic specimens are consistent between groups, the DIF f The comparison is reasonable.

[0066] In this embodiment, the dynamic performance of the specimen is the peak stress growth factor, and the analysis results of the influence of the fiber combination mode, fiber type and dosage, and strain rate on the peak stress growth factor are specifically as follows:

[0067] Calculate the peak stress growth factor of different fiber combinations at different strain rates, with strain rates ranging from 45 to 220 s -1 When the strain rate changes between , the peak stress growth factors of different fiber combinations increase with the increase of strain rate and show a nonlinear relationship; the hydrophilicity of PVA fibers limits crack propagation by forming a curved surface at the crack tip, and the matrix containing PVA fibers is most sensitive to strain rate changes; excessive fiber addition introduces voids or forms agglomeration effects, reduces material uniformity, and increases strain sensitivity.

[0068] In the prior art, DIF f The formula usually uses Linear function form, a few use However, the DIF of the present invention f and It is not an obvious linear relationship, and the power function fitting is more accurate. in Perform nonlinear fitting. Since the data trends are very close, The power of is set to a constant value, and the global optimal solution for finding the same p value for each group is 0.399325, which is approximately 0.4. The fitting parameters are shown in Table 1.

[0069] Table 1 The fitting parameters of

[0070]

[0071]

[0072] The strain rate is 10 -5 s -1 to 10 -3 s -1 When the DIF f and The linear correlation is good. Taking the typical group as an example, The linear function of The power function fitting effect of Figure 3 As shown, the strain rate is 10 -5 s -1 to 10 - 3 s -1When the prediction trends of the two functions are between , the prediction trends of the two functions are very close. Therefore, the DIF under quasi-static and seismic strain rate in this embodiment f Can be used uniformly The power function prediction of -5 s -1 to 10 -3 s -1 Under the strain rate, the global optimal solution of p value is -0.126874, which is approximately -0.127. The fitting parameters are shown in Table 2.

[0073] Table 2 The fitting parameters of

[0074] Group i j <![CDATA[R 2 ]]> Group i j <![CDATA[R 2 ]]> C -0.311489 1.310430 0.999033 P -0.567303 1.562494 0.994011 H -0.494597 1.491795 0.997316 M -0.511417 1.521973 0.965510 H10P4 -0.688532 1.705611 0.950945 M10P4 -0.469897 1.460975 0.970661 H10P55 -0.421979 1.421519 0.999901 M10P55 -0.385921 1.377124 0.958252 H10P7 -0.700333 1.704562 0.996952 M10P7 -0.574425 1.560660 0.954066 H5P55 -0.806335 1.828146 0.942197 M5P55 -0.619877 1.627547 0.987327 H15P55 -0.978633 1.966749 0.987786 M15P55 -0.488732 1.466853 0.856137

[0075] The differences in parameters m, n, i, and j are caused by fibers, so the fiber characteristic parameters Perform quadratic fitting to obtain the peak stress growth factor prediction formula considering the strain rate and hybrid fiber characteristic value:

[0076]

[0077] in:

[0078] i=-0.028Λ H -0.0099Λ P -0.3114

[0079] j=-0.01Λ H -0.0312Λ P +1.3104

[0080] m=-0.025Λ H -0.0054Λ P -0.3114

[0081] n=0.0759Λ H +0.0309Λ P +1.3104

[0082] Where: DIF f ' is the corrected peak stress growth factor, is the quasi-static strain rate; L is the fiber length, d is the fiber diameter, V f is the volume content of the fiber; H is the fiber characteristic parameter of HS fiber, Λ P It is the fiber characteristic parameter of PVA fiber.

[0083] Due to the complexity of the dynamic elastic modulus changing with strain rate, it is usually difficult to directly give the exact relationship between the elastic modulus and the strain rate, but the secant elastic modulus growth factor can be predicted by the formula. According to the CEB-FIP specification, the prediction formula for the dynamic increase coefficient of the concrete elastic modulus is:

[0084]

[0085] Where: DIF E is the dynamic increase coefficient of elastic modulus, E d is the dynamic elastic modulus, E s is the static elastic modulus; is the dynamic strain rate, Is 30×10 -6 s -1 .

[0086] like Figure 4 As shown, draw DIF E The relationship between the strain rate and the strain rate shows that the formula based on the CEB-FIP specification cannot correctly estimate the DIF of GPC E , and it cannot reflect the effect of added fiber on DIF E The impact of Figure 4 It can be seen that DIF E It increases with the increase of strain rate and presents a linear relationship. The formula fitting coefficient is shown in Table 3. Adding steel fiber can increase DIF E The strain rate sensitivity of DIF increases with the increase of fiber content. E The strain rate sensitivity of the H15P55 group and the M15P55 group is also significantly increased. It can be seen from the values ​​of parameter k in Table 3 that in the two blending series, the DIF E The strain rate sensitivity is the largest, and the combination of PVA and HS has a higher strain rate sensitivity. The strain rate is less than 85s -1 When DIF E The value is less than 1, and the strain rate exceeds 85s -1 When DIF E The value is greater than 1; when the strain rate is greater than 145s -1 When DIF E The value of exceeds the elastic modulus growth factor under seismic strain rate. This indicates that the elastic modulus of geopolymer concrete increases more significantly at high strain rates, and the critical strain rate is 145s -1 .

[0087] Table 3 Fitting coefficients

[0088] Group k a <![CDATA[R 2 ]]> Group k a <![CDATA[R 2 ]]> C 0.0065 0.4797 0.9118 P 0.0054 0.5677 0.8853 H 0.0045 0.5811 0.9573 M 0.0046 0.5971 0.9291 H10P4 0.0046 0.6117 0.9907 M10P4 0.0053 0.6262 0.9834 H10P55 0.0057 0.5266 0.9952 M10P55 0.0046 0.6411 0.9988 H10P7 0.0065 0.4432 0.9909 M10P7 0.0067 0.4523 0.9759 H5P55 0.0063 0.5219 0.9861 M5P55 0.0053 0.038 0.9913 H15P55 0.0103 0.2503 0.9949 M15P55 0.0088 0.4168 0.978

[0089] and Figure 1 Corresponding to the method described above, the embodiment of the present invention also provides a prediction system for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, which is used to Figure 1 The specific implementation of the method in the embodiment of the present invention is a prediction system for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, which can be applied to computer terminals or various mobile devices, and specifically includes:

[0090] A first initial value calculation module is used to obtain an initial peak stress growth factor according to a ratio of a dynamic peak stress to a quasi-static peak stress at a given strain rate;

[0091] The second initial value calculation module is used to obtain the dynamic increase coefficient of the concrete elastic modulus according to the ratio of the dynamic elastic modulus to the static elastic modulus;

[0092] The analysis module is used to analyze the influence of fiber combination mode, fiber type and dosage, and strain rate on the dynamic performance of the specimen when the size of the static compression specimen is consistent with that of the dynamic compression specimen;

[0093] The first optimization module is used to perform a secondary fitting on the initial peak stress growth factor by introducing fiber characteristic parameters to obtain a corrected peak stress growth factor;

[0094] The second optimization module is used to fit the dynamic increase coefficient of the elastic modulus of concrete through a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

[0095] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0096] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, characterized in that: The following steps are involved: Based on the ratio of the dynamic peak stress to the quasi-static peak stress at a given strain rate, the initial peak stress growth factor is obtained; Based on the ratio of the dynamic elastic modulus to the static elastic modulus, the dynamic increase coefficient of the elastic modulus of concrete is obtained; When the size of static compression specimens is the same as that of dynamic compression specimens, the effects of fiber combination, fiber type and dosage, and strain rate on the dynamic properties of the specimens are analyzed. The fiber characteristic parameters are introduced to perform a quadratic fit on the initial peak stress growth factor to obtain the corrected peak stress growth factor. The dynamic increase coefficient of the elastic modulus of concrete is fitted by a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

2. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 1, characterized in that: The prediction formula for the initial peak stress growth factor is: Where DIF f is the initial peak stress growth factor; is the dynamic strain rate, f d is the corresponding dynamic compressive strength; Is 30×10 -6 s -1 , f s is the quasi-static compressive strength.

3. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 2, characterized in that: The prediction formula of the initial peak stress growth factor is applicable to the strain rate range of 30×10 -6 ~3×10 2 s -1 .

4. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 1, characterized in that: The prediction formula for the dynamic increase coefficient of concrete elastic modulus is: Where: DIF E is the dynamic increase coefficient of elastic modulus, E d is the dynamic elastic modulus, E s is the static elastic modulus; is the dynamic strain rate, Is 30×10 -6 s -1 .

5. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 1, characterized in that: The dynamic performance of the specimen is the peak stress growth factor. The analysis results of the influence of fiber combination, fiber type and dosage, and strain rate on the peak stress growth factor are as follows: Calculate the peak stress growth factor of different fiber combinations at different strain rates, with strain rates ranging from 45 to 220 s -1 When the strain rate changes between , the peak stress growth factors of different fiber combinations increase with the increase of strain rate and show a nonlinear relationship; the hydrophilicity of PVA fibers limits crack propagation by forming a curved surface at the crack tip, and the matrix containing PVA fibers is most sensitive to strain rate changes; excessive fiber addition introduces voids or forms agglomeration effects, reduces material uniformity, and increases strain sensitivity.

6. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 1, characterized in that: The dynamic performance of the specimen is the elastic modulus growth factor. The analysis results of the influence of fiber combination, fiber type and dosage, and strain rate on the elastic modulus growth factor are as follows: The elastic modulus growth factor increases with the increase of strain rate and presents a linear relationship; when the strain rate is less than 85s -1 When the elastic modulus growth factor is less than 1, the strain rate exceeds 85s -1 When the strain rate is greater than 145s -1 When the elastic modulus growth factor exceeds the elastic modulus growth factor under the earthquake strain rate, the critical strain rate of the elastic modulus of geopolymer concrete is 145s -1 .

7. The method for predicting the dynamic growth factor of hybrid fiber reinforced geopolymer concrete according to claim 1, characterized in that: Obtain the corrected peak stress growth factor, specifically: Introducing fiber characteristic parameters Perform quadratic fitting to obtain the peak stress growth factor prediction formula considering the strain rate and hybrid fiber characteristic value: in: i=-0.028Λ H -0.0099L P -0.3114 j=-0.01Λ H -0.0312L P +1.3104 m=-0.025Λ H -0.0054L P -0.3114 n=0.0759Λ H +0.0309L P +1.3104 Where: DIF f ' is the corrected peak stress growth factor, is the quasi-static strain rate, L is the fiber length, d is the fiber diameter, V f is the volume content of the fiber; H is the fiber characteristic parameter of HS fiber, Λ P It is the fiber characteristic parameter of PVA fiber.

8. A prediction system for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete, using the prediction method for the dynamic growth factor of hybrid fiber reinforced geopolymer concrete as claimed in any one of claims 1 to 7, characterized in that: include: A first initial value calculation module is used to obtain an initial peak stress growth factor according to a ratio of a dynamic peak stress to a quasi-static peak stress at a given strain rate; The second initial value calculation module is used to obtain the dynamic increase coefficient of the concrete elastic modulus according to the ratio of the dynamic elastic modulus to the static elastic modulus; The analysis module is used to analyze the influence of fiber combination mode, fiber type and dosage, and strain rate on the dynamic performance of the specimen when the size of the static compression specimen is consistent with that of the dynamic compression specimen; The first optimization module is used to perform a secondary fitting on the initial peak stress growth factor by introducing fiber characteristic parameters to obtain a corrected peak stress growth factor; The second optimization module is used to fit the dynamic increase coefficient of the elastic modulus of concrete through a linear function to obtain the corrected elastic modulus growth factor and critical strain rate.

Images