A three-dimensional digital reconstruction and numerical simulation method for random slate samples

Abstract

The present invention discloses a three-dimensional digital reconstruction and numerical simulation method of a random slate sample, which includes: (S1) collecting statistical characteristics of foliation structures in slate slices and slate specimens through a polarizing microscope and a high-resolution camera; (S2) using the Monte Carlo method to batch generate random slate samples according to statistical characteristics; in the generation process of each random slate sample, a method of fusing a one-dimensional random field with a two-dimensional random field is used to realize the three-dimensional digital reconstruction of the multi-scale characteristics of the random slate sample; (S3) establishing a random finite element numerical model based on the three-dimensional digitally reconstructed random slate sample, which is used to predict the physical and mechanical properties and statistical characteristics of the slate sample. The method can generate random slate samples in batches, saving a lot of time and economic costs; the process of three-dimensional digital reconstruction of random slate samples in the patent method is simple and easy to operate.

Description

Technical Field

[0001] The invention relates to the field of geotechnical engineering, and in particular to a three-dimensional digital reconstruction and numerical simulation method of a random slate sample. Background Art

[0002] Slate is a natural geotechnical material with foliation structure, which consists of matrix and foliation planes. On the one hand, the matrix and foliation planes show multi-scale characteristics; on the other hand, the foliation structure has a certain randomness. The multi-scale characteristics and randomness of slate are important factors affecting its physical and mechanical properties. Therefore, the three-dimensional digital reconstruction of the multi-scale characteristics of random slate samples is of great significance for accurately predicting the physical and mechanical properties of slate.

[0003] The existing similar patent "A method and system for three-dimensional reconstruction of rock micro-defects" uses a laser scanner to perform a global scan of the rock sample to obtain the rock appearance feature point cloud data, thereby establishing the rock appearance three-dimensional structural framework; a CT scanner is used to scan the rock sample in layers to obtain the rock micro-defect image; then, the micro-defect image obtained by the CT scan is implanted into the three-dimensional structural framework to reconstruct the micro-defect rock sample. "Columnar jointed rock mass reconstruction method and columnar jointed rock mass reconstruction body" (2020), for columnar jointed rock mass, this method achieves the reconstruction of columnar jointed rock mass by tracing the inter-columnar joint surface. This method has limited accuracy and consumes a high time cost.

[0004] Existing patents mainly reconstruct rocks based on features such as micro-defects, but are unable to reconstruct the multi-scale foliation structural features of rocks, such as the foliation structural slate in this patent; existing patents require information collection from each rock sample through laser scanning, CT scanning, etc., which consumes a lot of manpower and material resources; the physical and mechanical properties of rock samples and their statistical characteristics usually require a large number of physical and mechanical tests, which consumes high time and economic costs.

[0005] Existing technologies make it difficult to three-dimensionally reconstruct slate samples with multi-scale characteristics and randomness, and are also unable to efficiently batch-generate slate samples. At the same time, the currently used methods require high time and economic costs. Summary of the invention

[0006] The purpose of the present invention is to provide a three-dimensional digital reconstruction and numerical simulation method for random slate samples. The method is based on random field theory, integrates two-dimensional random fields and one-dimensional random fields, performs three-dimensional digital reconstruction of slate with random foliation structural characteristics, and uses the three-dimensional digitally reconstructed random slate samples to establish a random finite element numerical model for predicting the physical and mechanical properties and statistical characteristics of the slate samples.

[0007] The technical solution of the present invention is a three-dimensional digital reconstruction and numerical simulation method of a random slate sample, which comprises:

[0008] (S1) Collect statistical characteristics of schistosity in slate slices and slate specimens by polarizing microscope and high-resolution camera;

[0009] (S2) using a Monte Carlo method to batch generate random slate samples according to statistical characteristics; in the process of generating each random slate sample, a one-dimensional random field is fused with a two-dimensional random field to achieve a three-dimensional digital reconstruction of multi-scale characteristics of the random slate sample;

[0010] (S3) A random finite element numerical model is established based on the three-dimensional digitally reconstructed random slate sample to predict the physical and mechanical properties and statistical characteristics of the slate sample.

[0011] A further improvement of the present invention is that in step (S1), a slate cross-section image is collected by a polarizing microscope, the angle of the schistosity plane is determined according to the image features, and the mean, variance and related distance of the schistosity plane thickness t are obtained.

[0012] A further improvement of the present invention is that in step (S1), a high-resolution camera is used to obtain an image of the slate specimen, and the mean, variance and related distance of the schistosity plane spacing d are obtained through the relationship between the image pixels and the actual size of the specimen.

[0013] The further improvement of the present invention is that the generation process of each random slate sample specifically includes: considering the schistosity plane spacing as a one-dimensional random field and the schistosity plane thickness as a two-dimensional random field; using the random field theory and the statistical parameters of the schistosity plane spacing to generate the spacing d of n+1 schistosity planes in the slate sample; i , where i is a positive integer less than n+1; and the random field theory is used to generate n+1 schistosity planes in sequence according to the statistical parameters of the schistosity plane thickness; finally, the n schistosity spacings and n+1 schistosity planes are merged together to generate a complete random slate sample.

[0014] A further improvement of the present invention is that the establishment process of each random finite element numerical model specifically includes the following steps: importing the random slate sample into the numerical software, dividing the matrix into solid units and bonding units without thickness, dividing the schistose surface into bonding units without thickness, and assigning the thickness of the schistose surface in the three-dimensional digitized sample to the bonding units of the schistose surface; applying boundary and load conditions to obtain the finite element numerical model.

[0015] The beneficial effects of the present invention are as follows: based on the image data collected in the laboratory, combined with the multi-scale foliation structure of the slate, the patent adopts random field theory to batch generate random slate samples, and establishes a random finite element model, so as to predict the random physical and mechanical properties of the slate; by batch generating random slate samples, the time cost and economic cost spent by laboratory staff in making samples are saved; the process of three-dimensional digital reconstruction of random slate samples by the method of the patent is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the three-dimensional digital reconstruction and numerical simulation method of random slate specimens;

[0017] Figure 2 It is a slate specimen and its schematic diagram;

[0018] Figure 3 It is a random slate specimen reconstructed in three dimensions;

[0019] Figure 4 It is a random finite element numerical model of a random slate specimen. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, this embodiment provides a three-dimensional digital reconstruction and numerical simulation method of a random slate sample, which includes:

[0021] (S1) Statistical features of schistosity in slate slices collected using a polarizing microscope and a high-resolution camera.

[0022] Specifically, Figure 2 As shown, in this step, the slate section image is collected by a polarizing microscope, the angle of the schistosity plane is determined according to the image characteristics, and the statistical parameters such as the mean, variance and related distance of the schistosity plane thickness t are obtained. The image of the slate specimen is obtained by a high-resolution camera, and the statistical parameters such as the mean, variance and related distance of the schistosity plane spacing d are obtained through the relationship between the image pixels and the actual size of the specimen.

[0023] (S2) A Monte Carlo method is used to batch generate random slate samples according to statistical characteristics. In the process of generating each random slate sample, a one-dimensional random field is fused with a two-dimensional random field to achieve a three-dimensional digital reconstruction of the multi-scale characteristics of the random slate sample.

[0024] In this embodiment, the generation process of each random slate sample specifically includes: considering the schistosity plane spacing as a one-dimensional random field, and considering the schistosity plane thickness as a two-dimensional random field; using the random field theory and the statistical parameters of the schistosity plane spacing to generate the spacing d of n+1 schistosity planes in the slate sample. i, where i is a positive integer less than n+1; and the random field theory is used to generate n+1 schistosity planes in sequence according to the statistical parameters of the schistosity plane thickness; finally, the n schistosity spacings (one-dimensional random field) and n+1 schistosity planes (two-dimensional random field) are fused together to generate a complete random slate sample. The generated random slate sample is as follows Figure 3 shown.

[0025] (S3) A random finite element numerical model is established based on the three-dimensional digitally reconstructed random slate sample to predict the physical and mechanical properties and statistical characteristics of the slate sample.

[0026] In this step, a random finite element numerical model is established for each random slate sample generated in step (S2). The process of establishing each random finite element numerical model specifically includes the following steps: importing the random slate sample into the commercial numerical software ABAQUS, dividing the matrix into solid units and bonding units without thickness, dividing the schistose planes into bonding units without thickness, and assigning the thickness of the schistose planes in the three-dimensional digital sample to the bonding units of the schistose planes through the subroutine VUSDFLD; applying boundary and load conditions, the finite element numerical model can be obtained. Repeating the above process can obtain a batch of random finite element models. The random finite element model is as follows: Figure 4 As shown, Figure 4 a is a random finite element model, Figure 4 b is the solid unit of the matrix, Figure 4 c is the bonding unit in the matrix.

[0027] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A three-dimensional digital reconstruction and numerical simulation method for random slate samples, characterized in that The following steps are involved: (S1) Collect statistical characteristics of schistosity in slate slices and slate specimens by polarizing microscope and high-resolution camera; (S2) using a Monte Carlo method to batch generate random slate samples according to statistical characteristics; in the process of generating each random slate sample, a one-dimensional random field is fused with a two-dimensional random field to achieve a three-dimensional digital reconstruction of multi-scale characteristics of the random slate sample; (S3) establishing a random finite element numerical model based on the three-dimensional digitally reconstructed random slate sample to predict the physical and mechanical properties and statistical characteristics of the slate sample; In step (S1), a slate cross-section image is collected by a polarizing microscope, the angle of the schistosity plane is determined according to the image features, and the mean, variance and related distance of the schistosity plane thickness t are obtained; In step (S1), a high-resolution camera is used to obtain an image of the slate specimen, and the mean, variance and correlation distance of the schistosity plane spacing d are obtained through the relationship between the image pixels and the actual size of the specimen; The generation process of each random slate sample specifically includes: considering the schistosity plane spacing as a one-dimensional random field, and considering the schistosity plane thickness as a two-dimensional random field.

2. The method for three-dimensional digital reconstruction and numerical simulation of a random slate sample according to claim 1, characterized in that: In the process of generating each random slate sample, the random field theory and the statistical parameters of the schistosity plane spacing are used to generate the spacing d of n+1 schistosity planes. i , where i is a positive integer less than n+1; and the random field theory is used to generate n+1 schistosity planes in sequence according to the statistical parameters of the schistosity plane thickness; finally, the n schistosity spacings and n+1 schistosity planes are merged together to generate a complete random slate sample.

3. The method for three-dimensional digital reconstruction and numerical simulation of a random slate sample according to claim 2, characterized in that: The establishment process of each random finite element numerical model specifically includes the following steps: importing the random slate sample into the numerical software, dividing the matrix into solid units and bonding units without thickness, dividing the schistose surface into bonding units without thickness, and assigning the thickness of the schistose surface in the three-dimensional digital sample to the bonding unit of the schistose surface; applying boundary and load conditions, the finite element numerical model can be obtained.

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