Crack state based modeling of regionalized performance evolution of ultra-high performance concrete

Abstract

The application discloses a crack-state-based modeling method for performance evolution of regionalization of ultra-high performance concrete, and belongs to the technical field of structural engineering and material modeling, and specifically comprises the following steps: S1, obtaining crack information of a component under a service or test state; S2, performing response region division on the component based on the crack information; S3, respectively assigning different material constitutive models and degradation parameters to different regions; S4, establishing a three-dimensional model of the component in a finite element simulation platform, loading regionalized material parameters and boundary / load conditions, and performing nonlinear static analysis or quasi-static analysis; and S5, outputting simulation results and evaluating performance evolution trends of the component under different crack states. The crack-state-based modeling method for performance evolution of regionalization of ultra-high performance concrete has the characteristics of high adaptability and differentiated assignment, and can more accurately simulate the performance evolution process of a cracked structure.

Description

Technical Field

[0001] This invention relates to the fields of structural engineering and materials modeling technology, and in particular to a method for regional performance evolution modeling of ultra-high performance concrete based on crack state. Background Technology

[0002] Ultra-high performance concrete (UHPC) is a cement-based material with high strength, high toughness, and high density, and has been widely used in flexural components of critical parts such as bridges, tunnels, rail transit, and high-rise buildings in recent years. During actual service, UHPC components inevitably develop cracks under load, shrinkage, and temperature and humidity cycles, exhibiting an evolutionary process from microcrack initiation (LOP) to main crack propagation (MOR). The presence of cracks not only alters the local mechanical response of the component but may also induce interface slip, steel fiber pull-out, and regional degradation, severely affecting the overall bending performance and service reliability of the structure.

[0003] Existing structural performance modeling methods are mostly based on the assumption of material homogeneity or pre-set corrosion field variables, simulating the overall response of components through a uniform material constitutive model. However, they lack fine-grained segmentation and constitutive differential assignment for regions of varying response within components with existing cracks. Especially in the later stages of service when cracks have already appeared, continuing to use a single constitutive model for simulation cannot effectively reflect the differences in mechanical behavior between the main crack zone, the crack transition zone, and the uncracked zone, leading to amplified performance prediction errors. Furthermore, most existing modeling methods lack a direct correlation with crack image data and structural response data obtained from experiments or monitoring, failing to achieve modeling driven by the actual structural state. Summary of the Invention

[0004] The purpose of this invention is to provide a regional performance evolution modeling method for ultra-high performance concrete based on crack state, which has the characteristics of high adaptability and differentiated value assignment, and can more accurately simulate the performance evolution process of cracked structures.

[0005] To achieve the above objectives, this invention provides a method for regional performance evolution modeling of ultra-high performance concrete based on crack state, specifically including the following steps: S1. Obtain crack information of components under service or testing conditions; S2. Divide the component into response regions based on crack information; S3. Assign differentiated material constitutive models and degradation parameters to different regions; S4. Establish a three-dimensional model of the component in the finite element simulation platform, load regionalized material parameters and boundary / load conditions, and perform nonlinear static analysis or quasi-static analysis. S5. Output simulation results and evaluate the performance evolution trend of components under different crack states.

[0006] Preferably, in S1, the main path of the crack, the cracked area and its boundary features are extracted by image processing or data analysis, and the crack status information of the component is collected. The crack information of the component includes crack length, width, distribution density and whether it is continuous.

[0007] Preferably, in S2, the component is divided into three types of regions based on a comprehensive judgment of crack width threshold, crack density, spatial distance, or damage distribution index: crack control zone, bridging transition zone, and uncracked zone. The crack control zone corresponds to the damage area where the main cracks are concentrated, the bridging transition zone is the transition layer between the control zone and the uncracked zone, and the uncracked zone is the part of the structure that has not yet been affected by cracks.

[0008] Preferably, in S3, the crack-controlled zone is represented by a strain-softening tensile constitutive model or a traction-separation model to represent its cracking and slip behavior; the bridging transition zone is simulated by a multi-segment linear hardening-softening model to simulate the fiber bridging and microcrack development stages; and the uncracked area is maintained by a linear elastic or low-damage model to maintain the structural stiffness continuity.

[0009] Preferably, the three-dimensional model of the component in S4 is constructed using solid elements or shell elements. Through sub-model or local coordinate mapping, the constitutive parameters corresponding to each region are loaded into the corresponding mesh region, and the loading boundary conditions, support types and simulation control parameters are set. The stress process of the structure is simulated by nonlinear static analysis or quasi-static analysis methods.

[0010] Preferably, the simulation results in S5 include the structural load-displacement response curve, the main crack propagation path diagram, the main crack length development curve, and the residual bearing capacity variation trend.

[0011] Therefore, the present invention adopts the above-mentioned regional performance evolution modeling method of ultra-high performance concrete based on crack state, which can divide the component into regions with different response levels according to the crack location, width and evolution path, and implement differentiated constitutive parameter loading in the simulation model, thereby realizing the simulation of service performance evolution and damage trend prediction of ultra-high performance concrete components under known crack state conditions.

[0012] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0013] Figure 1 This is a flowchart of the regional performance evolution modeling method for ultra-high performance concrete based on crack state, as proposed in this invention. Detailed Implementation

[0014] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0016] Example 1 like Figure 1 As shown, this invention provides a method for regional performance evolution modeling of ultra-high performance concrete based on crack state, specifically including the following steps: S1. Obtain crack information of components under service or testing conditions; The main path, cracked area, and boundary features of the cracks are extracted through image processing or data analysis. Crack status information of the component is collected, including parameters such as crack length, width, distribution density, and whether it is continuous. Image recognition includes crack edge extraction and crack width field generation. Experimental data includes key cutoff points corresponding to the proportional limit (LOP) and failure limit (MOR).

[0017] S2. Divide the component into response regions based on crack information; The structural components are classified into three zones based on a comprehensive assessment of crack width threshold, crack density, spatial distance, or damage distribution indicators: crack-controlled zone, bridging transition zone, and uncracked zone. These zones are labeled with tags. The crack-controlled zone corresponds to the damaged area where the main cracks are concentrated; the bridging transition zone is the transition layer between the crack-controlled zone and the uncracked zone; and the uncracked zone is the portion of the structure not yet affected by cracks.

[0018] S3. Assign differentiated material constitutive models and degradation parameters to different regions; The crack-controlling region is represented by a strain-softening tensile constitutive model or a traction-separation model to depict its cracking and slip behavior; the bridging transition region is simulated using a multi-segment linear hardening-softening model to model the fiber bridging and microcrack development stages; and the uncracked region is maintained by a linear elastic or low-damage model to preserve the structural stiffness continuity. Transition zones are set between different regions to achieve parameter smoothing and avoid abrupt changes in the simulation process.

[0019] S4. Establish a three-dimensional model of the component in the finite element simulation platform, load regionalized material parameters and boundary / load conditions, and perform nonlinear static analysis or quasi-static analysis. The simulation platform includes, but is not limited to, ABAQUS and COMSOL platforms. Component models can be selected as beams, slabs, walls, or node structures. Region parameters are loaded through sub-model partitioning or local material property control. The 3D component model is constructed using solid or shell elements. Constitutive parameters corresponding to each region are loaded into the corresponding mesh region through sub-modeling or local coordinate mapping. Loading boundary conditions, support types, and simulation control parameters are set. Nonlinear static analysis or quasi-static analysis methods are used to simulate the structural stress process.

[0020] S5. Output simulation results and evaluate the performance evolution trend of components under different crack states; The simulation results include the structural load-displacement response curve, the main crack propagation path diagram, the main crack length development curve, and the residual bearing capacity variation trend.

[0021] Therefore, the present invention adopts the above-mentioned regional performance evolution modeling method of ultra-high performance concrete based on crack state, which can divide the component into regions with different response levels according to the crack location, width and evolution path, and implement differentiated constitutive parameter loading in the simulation model, thereby realizing the simulation of service performance evolution and damage trend prediction of ultra-high performance concrete components under known crack state conditions.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for regional performance evolution modeling of ultra-high performance concrete based on crack state, characterized in that: Specifically, the following steps are included: S1. Obtain crack information of components under service or testing conditions; The main path, cracked area and boundary features of the crack are extracted by image processing or data analysis, and the crack status information of the component is collected. The crack information of the component includes crack length, width, distribution density and whether it is continuous. S2. Divide the component into response regions based on crack information; The components are divided into three categories based on a comprehensive judgment of crack width threshold, crack density, spatial distance or damage distribution index: crack control zone, bridging transition zone and uncracked zone. The crack control zone corresponds to the damage area where the main cracks are concentrated, the bridging transition zone is the transition layer between the control zone and the uncracked zone, and the uncracked zone is the part of the structure that has not yet been affected by cracks. S3. Assign differentiated material constitutive models and degradation parameters to different regions; The crack-controlled zone is represented by a strain-softening tensile constitutive model or a traction-separation model to indicate its cracking and slip behavior; the bridging transition zone is simulated by a multi-segment linear hardening-softening model to simulate the fiber bridging and microcrack development stages; the uncracked area is maintained by a linear elastic or low-damage model to maintain the structural stiffness continuity, and the parameters are smoothed by setting transition zones between different areas. S4. Establish a three-dimensional model of the component in the finite element simulation platform, load regionalized material parameters and boundary / load conditions, and perform nonlinear static analysis or quasi-static analysis. The three-dimensional model of the component is constructed using solid or shell elements. Constitutive parameters corresponding to each region are loaded into the corresponding mesh region through sub-model or local coordinate mapping. Loading boundary conditions, support types and simulation control parameters are set, and nonlinear static analysis or quasi-static analysis methods are used to simulate the stress process of the structure. S5. Output simulation results and evaluate the performance evolution trend of components under different crack states.

2. The method for regional performance evolution modeling of ultra-high performance concrete based on crack state according to claim 1, characterized in that: The simulation results in S5 include the structural load-displacement response curve, the main crack propagation path diagram, the main crack length development curve, and the residual bearing capacity variation trend.

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