Ultra-high performance concrete regionalization performance evolution modeling method based on crack state

Abstract

The invention discloses an ultra-high performance concrete regionalization performance evolution modeling method based on a crack state, and belongs to the technical field of structural engineering and material modeling, and the method specifically comprises the following steps: S1, obtaining crack information of a component in a service or test state; s2, performing response area division on the component based on the crack information; s3, respectively endowing different areas with differentiated material constitutive models and degradation parameters; s4, establishing a component three-dimensional model in the finite element simulation platform, loading regionalized material parameters and boundary / load conditions, and executing nonlinear static analysis or quasi-static analysis; and S5, outputting a simulation result, and evaluating the performance evolution trend of the component in different crack states. The ultra-high performance concrete regionalization performance evolution modeling method based on the crack state has the advantages of being high in adaptability and differentiated in assignment, and the performance evolution process of a cracked structure can be simulated more accurately.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural engineering and material modeling, in particular to a crack state-based regionalized performance evolution modeling method for ultra-high performance concrete. BACKGROUND

[0002] Ultra-high performance concrete (UHPC) is a cement-based material with high strength, high toughness and high density, which has been widely used in flexural members of key parts such as bridges, tunnels, rail transit and high-rise buildings in recent years. In the actual service process, UHPC members inevitably produce cracks under the action of load, shrinkage, temperature and humidity cycles, and show an evolution process from micro-crack initiation (LOP) to main crack penetration (MOR). The existence of cracks not only changes the local mechanical response of the member, but also may induce interface slip, steel fiber pullout and regional degradation, which seriously affects 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 preset corrosion field variables, and simulate the overall response of the member through a unified material constitutive model, lacking fine division and constitutive difference assignment for the different response regions inside the member with formed cracks. Especially in the later stage of service when the structure has cracks, using a single constitutive model for simulation cannot effectively reflect the mechanical behavior differences between the main crack zone, the crack transition zone and the uncracked zone, resulting in magnified performance prediction errors. In addition, most existing modeling methods lack direct correlation with crack image data and structural response data obtained from tests or monitoring, and cannot achieve modeling driven based on the actual structure state. SUMMARY

[0004] The purpose of the present application is to provide a crack state-based regionalized performance evolution modeling method for ultra-high performance concrete, which has the characteristics of high adaptability and differentiated assignment, and can more accurately simulate the performance evolution process of the cracked structure.

[0005] To achieve the above purpose, the present application provides a crack state-based regionalized performance evolution modeling method for ultra-high performance concrete, which specifically comprises the following steps: S1, obtaining crack information of the member under service or test state; S2, dividing the response regions of the member based on the crack information; S3, assigning different regions with differentiated material constitutive models and degradation parameters; S4, establishing a three-dimensional model of the member in a finite element simulation platform, loading regionalized material parameters and boundary / load conditions, and performing nonlinear static analysis or quasi-static analysis; S5, outputting the simulation results and evaluating the performance evolution trend of the member under different crack states.

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

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

[0008] Preferably, in S3, the strain softening type tension constitutive or traction-separation model is used to represent the cracking and sliding behavior of the crack main control area; the multi-segment linear hardening-softening model is used to simulate the fiber bridging and microcrack development stage in the bridging transition area; and the linear elasticity or low damage model is used to maintain the structural stiffness continuity in the uncracked area.

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

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

[0011] Therefore, by using the above-mentioned regionalized performance evolution modeling method of ultra-high performance concrete based on crack state, the component can be divided into different response level regions according to the crack position, width and evolution path, and the differential constitutive parameter loading is implemented in the simulation model, so as to realize the service performance evolution simulation and damage trend prediction of the ultra-high performance concrete component under the condition that the crack state is known.

[0012] The technical solutions of the present application will be further described in detail below with the help of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the flow chart of the regionalized performance evolution modeling method of ultra-high performance concrete based on crack state of the present application. DETAILED DESCRIPTION

[0014] The technical solutions of the present application will be further described in detail below with the help of the drawings and examples.

[0015] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the meanings as commonly understood by one of ordinary skill in the art to which the present application pertains. The terms "first", "second", and similar terms are used herein to distinguish one element from another, and are not necessarily used in a sequence or to denote importance or quantity. The terms "comprise", "comprising", "include", "including" and the like are used herein to mean including but not limited to. The terms "connected", "coupled", "linking" or the like are not limited to a physical or mechanical connection or linkage to either be direct or indirect and can include an electrical connection, whether direct or indirect.

[0016] Embodiment one As shown in the figure, the present application provides a crack state-based regional performance evolution modeling method for ultra-high performance concrete, which specifically comprises the following steps: Figure 1 S1, obtaining crack information of the component under service or test state; The crack main path, cracking area and boundary characteristics are extracted through image processing or data analysis to collect the crack state information of the component. The crack information of the component includes crack length, width, distribution density and whether it is through or not. Image recognition includes crack edge extraction and crack width field generation. Test data includes key points corresponding to proportional limit (LOP) and failure limit (MOR). S2, response region division of the component based on crack information;

[0017] The component is divided into three regions of crack main control area, bridge transition area and uncracked area according to the comprehensive judgment of crack width threshold, crack density, spatial distance or damage distribution index. The region type is labeled in the form of label. The crack main control area corresponds to the damage area where the main cracks are concentrated. The bridge transition area is the transition layer between the main control area and the uncracked area. The uncracked area is the part of the structure that has not been affected by cracks. S3, differentiating material constitutive model and degradation parameters for different regions;

[0018] The strain softening type tension constitutive or traction-separation model is used in the crack main control area to represent its cracking and sliding behavior. The multi-segment linear hardening-softening model is used in the bridge transition area to simulate the fiber bridging and microcrack development stage. The linear elasticity or low damage model is used in the uncracked area to maintain the continuity of structural stiffness. The transition zone is set between different regions to realize parameter smoothing and avoid simulation process mutation.

[0019] ​S4. Establish a three-dimensional model of the component in the finite element simulation platform, load the 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, COMSOL platform, the component model can be selected from a beam, a plate, a wall body or a node structure, and the regional parameters are loaded through submodel division or local material attribute control. The three-dimensional model of the component is constructed by solid elements or shell elements, the corresponding constitutive parameters of each region are loaded to the corresponding grid region through submodel or local coordinate mapping, the boundary conditions, support types and simulation control parameters are set, and the stress process of the structure is simulated by using nonlinear static analysis or quasi-static analysis method.

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

[0021] Therefore, by using the above-mentioned regionalized performance evolution modeling method of ultra-high performance concrete based on crack state, the component can be divided into different response level regions according to the crack position, width and evolution path, and the differential constitutive parameter loading is implemented in the simulation model, so that the service performance evolution simulation and damage trend prediction of the ultra-high performance concrete component under the condition that the crack state is known can be realized.

[0022] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

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; 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.

2. The method for regional performance evolution modeling of ultra-high performance concrete based on crack state according to claim 1, characterized in that: In S1, the main path of the crack, the cracked area and its boundary features are extracted through image processing or data analysis. The crack status information of the component is collected, including the crack length, width, distribution density and whether it is continuous.

3. The method for regional performance evolution modeling of ultra-high performance concrete based on crack state according to claim 1, characterized in that: In S2, components are 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.

4. The method for regional performance evolution modeling of ultra-high performance concrete based on crack state according to claim 1, characterized in that: 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.

5. The method for regional performance evolution modeling of ultra-high performance concrete based on crack state according to claim 1, characterized in that: In S4, the three-dimensional model of the component is constructed using solid or shell elements. Through sub-model or local coordinate mapping, the constitutive parameters of 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 using nonlinear static analysis or quasi-static analysis methods.

6. 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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