CN109033537B - Calculation method and system for numerical simulation in rock-fill concrete pouring process - Google Patents
Calculation method and system for numerical simulation in rock-fill concrete pouring process Download PDFInfo
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Abstract
The embodiment of the invention provides a calculation method and a system for numerical simulation in a rockfill concrete pouring process, wherein the calculation method comprises the following steps: calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method. The calculation method and the system for numerical simulation of the rockfill concrete pouring process, provided by the embodiment of the invention, can accurately simulate the pouring process of the self-compacting concrete, not only can visually observe the flowing state of the self-compacting concrete in the rockfill pores, but also can know the final compacting state of the rockfill concrete, so that a large amount of labor cost, experimental cost and economic cost are saved, and the problem that the experimental method is difficult to observe on line is avoided.
Description
Technical Field
The embodiment of the invention relates to the technical field of rockfill concrete pouring, in particular to a calculation method and a system for numerical simulation in the rockfill concrete pouring process.
Background
The mass concrete plays an important role in modern engineering construction, particularly hydraulic and hydroelectric engineering construction. In China, the mass concrete poured in hydraulic and hydroelectric engineering is more than ten million cubes every year, and in addition, large-volume concrete is often adopted in ports, airport buildings, heavy machine foundations and the like. The rock-fill concrete is prepared by using a large amount of rock blocks (with a grain size of more than 30cm) to reduce the cement consumptionThereby effectively reducing the heat of hydration and reducing CO2The concrete has the characteristics of small shrinkage of a concrete structure, improved anti-cracking and anti-shearing capacity, high construction speed, low hydration heat, easy temperature control, high construction quality, low engineering cost and the like, so the concrete has wide application prospect and also meets the urgent need of vigorously popularizing a green low-carbon technology in China.
In the construction process of the rock-fill concrete, the stacking process and the final stacking shape of the rock-fill body have great influence on the mechanical property of the formed rock-fill concrete, but because the experiment cost is high and the shape and the style of the rock-fill body in the actual engineering are complex, the accurate experiment is difficult to be carried out to analyze the actual engineering, and the analysis and calculation of the stacking process of the rock-fill concrete rock-fill body by carrying out the numerical calculation method is a necessary trend. However, so far, how to accurately simulate and calculate the pouring construction process of the rock-fill concrete does not have any achievements and methods for reference.
Disclosure of Invention
Aiming at the problems in the prior art, the embodiment of the invention provides a calculation method and a system for numerical simulation in a rockfill concrete pouring process.
The embodiment of the invention provides a calculation method for numerical simulation in a rockfill concrete pouring process, which comprises the following steps: calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method.
The embodiment of the invention provides a calculation system for numerical simulation in a rockfill concrete pouring process, which comprises the following steps: the stacking analysis module is used for calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; and the pouring analysis module is used for calculating and analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks based on a smooth particle fluid dynamics (SPH) method after calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks.
The embodiment of the invention provides a calculation device for numerical simulation in a rockfill concrete pouring process, which comprises the following steps: at least one processor; and at least one memory communicatively coupled to the processor, wherein: the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the computing method.
Embodiments of the present invention provide a non-transitory computer-readable storage medium storing computer instructions that cause a computer to perform the above-described calculation method.
According to the calculation method and the system for numerical simulation of the rockfill concrete pouring process, provided by the embodiment of the invention, the finite element and discrete element coupling analysis method is set for mechanical analysis, so that the gradual stacking process of rockfill blocks under the stress action can be completely depicted, and the calculation result is more accurate. Through setting up the process of pouring and the final filling state of SPH method analysis self-compaction concrete in the final form of piling of heap stone, can accurately simulate the process of pouring of self-compaction concrete, not only can observe the mobile state of self-compaction concrete in the heap stone hole directly perceivedly, can also know the final closely knit state of heap stone concrete. The invention saves a large amount of labor cost, experiment cost and economic cost, and avoids the difficult problem that the experiment method is difficult to observe on line.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a flow chart of an embodiment of a calculation method for numerical simulation of a rock-fill concrete placement process of the present invention;
FIG. 2 is a block diagram of an embodiment of a computational system for numerical simulation of a rockfill concrete placement process according to the present invention;
fig. 3 is a schematic block diagram of a computing device for numerical simulation of a rockfill concrete pouring process in an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a flowchart of a calculation method of numerical simulation in a rock-fill concrete pouring process according to an embodiment of the present invention, as shown in fig. 1, including: s101, calculating and analyzing a stacking process and a final stacking form of a three-dimensional model of an initial state of a stacking block according to a finite element/discrete element coupling analysis method FEM/DEM; s102, after calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking block, calculating and analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking block based on a smooth particle fluid dynamics (SPH) method.
It should be noted that, due to the image of the scale effect in the physical model experiment, the object model experiment of the existing model scale cannot correctly reflect the strength of the real structure, and meanwhile, the prototype object model experiment is limited by the experiment conditions. The finite element method for simulating structural stress and deformation and the discrete element method for tracking block motion are combined to be called as a finite element/discrete element coupling analysis method FEM/DEM, the method keeps respective advantages of the finite element and the discrete element, can solve the problems of multi-body kinematics and failure mechanics, has the characteristics of a plurality of rock blocks, complex stress and deformation of the rock blocks along with stress change in the process of calculating the final stacking form of the rock blocks, adopts the finite element and discrete element coupling analysis method for mechanical analysis, can completely describe the gradual stacking process of the rock blocks under the stress action, and has more accurate calculation result.
The sph (smoothed Particle hydrodynamics) method is an abbreviation for smooth Particle hydrodynamics method, a meshless method that has evolved gradually over the last 20 years. The basic idea of the method is to describe a continuous fluid (or solid) by an interacting particle group, each particle carries various physical quantities including mass, velocity and the like, and the mechanical behavior of the whole system is obtained by solving the dynamic equation of the particle group and tracking the motion track of each particle. The embodiment of the invention uses an SPH method to simulate the pouring process of the self-compacting concrete in the rockfill and calculate the final flow state.
According to the calculation method for numerical simulation of the rockfill concrete pouring process, provided by the embodiment of the invention, the mechanical analysis is carried out by setting the finite element and discrete element coupling analysis method, the gradual stacking process of the rockfill under the stress action can be completely depicted, and the calculation result is more accurate. Through setting up the process of pouring and the final filling state of SPH method analysis self-compaction concrete in the final form of piling of heap stone, can accurately simulate the process of pouring of self-compaction concrete, not only can observe the mobile state of self-compaction concrete in the heap stone hole directly perceivedly, can also know the final closely knit state of heap stone concrete. The invention saves a large amount of labor cost, experiment cost and economic cost, and avoids the difficult problem that the experiment method is difficult to observe on line.
Based on the above embodiment, the calculating and analyzing stacking process and final stacking form of the three-dimensional model of the stacking stone initial state according to the finite element/discrete element coupling analysis method FEM/DEM further includes: and establishing a three-dimensional model of the initial state of the rock stacking block, wherein the rock stacking block comprises a plurality of block stone bodies.
Based on the above embodiment, the establishing of the three-dimensional model of the rock-fill block initial state specifically includes: establishing a three-dimensional model of the stacking block in an initial state according to predetermined parameters of the stacking block by using three-dimensional modeling software such as GID; or 3D scanning the external contour of the rock block body to form input data, inputting the input data into three-dimensional modeling software, and establishing a three-dimensional model of the initial state of the rock pile.
Since the size, type, number of stones required in each project or experiment are different, a three-dimensional model is built according to the actual parameters of the piled stones, and obviously a plurality of real parameters, such as hardness, size, density, etc. of the stones, need to be collected before building.
In the embodiment of the present invention, when the contour of the stone body is collected, a 3D scanner or a contour measuring instrument may be specifically used for scanning to obtain the contour parameters of the stone body, which is not specifically limited in the embodiment of the present invention.
The embodiment is beneficial to obtaining more accurate and real results when the finite element/discrete element coupling analysis method is used for analyzing the stacking process subsequently.
Based on the above embodiment, the calculating and analyzing the stacking process and the final stacking state of the three-dimensional model of the initial state of the stacking block, and the calculating and analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking state of the stacking block based on the smooth particle hydrodynamics SPH method further include: and establishing a self-compacting concrete model, wherein the self-compacting concrete model is a Bingham rheological model.
Specifically, the self-compacting concrete model is as follows:
wherein, tau0For yield strength, mupIs the plastic viscosity,. tau.is the shear stress; gamma is the shear strain rate.
Note that, the Bingham model (Bingham model): the buffer and the sliding block are connected in parallel and then connected in series with the spring to form a mechanical model reflecting viscosity, elasticity and plasticity rheological characteristics and processes of the rock soil.
Based on the above embodiment, the SPH method based on smooth particle hydrodynamics calculates and analyzes the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking block, and specifically includes: iteratively updating the density, position and speed of the fluid particles in the self-compacting concrete model one by one according to a time step based on an SPH (shortest Path fusion) method; the casting process and the final filling state of the self-compacting concrete in the final packing form of the lump of rock are analyzed based on the density, position and velocity of the fluid particles.
To further illustrate the functions and equations required by this embodiment, the SPH discrete form in this embodiment of the present invention is:
wherein, wherein: n is the total number of adjacent particles in the support domain; x is the number ofjIs the position of particle j; m isjAnd rhojRespectively the mass and density of the particle j; kernel function W (x-x)jH) is related to the distance between the particles and the smooth length h.
In this embodiment, the kernel function is selected as:
wherein d is a spatial dimension; h is the smooth length.
Wherein C is a normalization constant.
The state equation selected in this embodiment is:
wherein, B is used as initial pressure for limiting the maximum change amount of the density, and the invention takes
ρ0Is the initial density of the particle; gamma is a constant coefficient; c is artificial sound velocity, and for the consideration of numerical calculation stability and time step, a value much smaller than the real sound velocity is generally taken, and 10 times of the maximum flow velocity value of the flow field is generally taken, namely
H is the free liquid level height.
The displacement relationship of the particles is:
where r is the position vector of the particle point and u is the velocity vector of the particle.
The boundary processing method in the embodiment of the invention comprises the following steps: the solid-wall particles participate in the calculation of the governing equation, but their positions are fixed, and in the present invention the displacement is set to 0. The interaction between the boundary particles and the fluid particles can generally adopt the Lennard-Jones repulsive force method, that is, assuming that when the fluid particles are close enough to the solid wall, in order to prevent the inner fluid particles from flying across the solid wall boundary and causing computational collapse, the boundary particles exert a central repulsive force on the approaching fluid particles, and the magnitude of the repulsive force is determined by the mutual distance, the projection speed, the height position and the like. The free surface adopts an algorithm proposed by Koshizuka and the like to realize Dirichlet conditions, and the pressure value of particles at an interface is assigned to be 0 or a certain external pressure value.
Based on the above embodiment, the iteratively updating the density, the position, and the velocity of the fluid particles in the self-compacting concrete model one by one time step specifically includes: calculating the density change of the fluid particles one by one according to a continuity equation, capturing free surface particles and correcting the density of the free surface particles to obtain a density field of the self-compacting concrete model at each moment; updating the motion track of each fluid particle through a fluid particle displacement equation one by one time step to obtain the position of any fluid particle at each moment; and determining the pressure of any fluid particle through a state equation one by one according to the time step, calculating the acceleration generated by the external force based on the pressure of each fluid particle, and calculating the velocity field of each moment in the self-compacting concrete model through a momentum equation based on the acceleration.
It should be noted that the particle search employs a tree search method or an associated linked list search technique.
According to the calculation method for numerical simulation of the rockfill concrete pouring process, provided by the embodiment of the invention, the density, the position and the speed of the fluid particles in the self-compacting concrete model are updated iteratively by setting time step by time step, so that the rockfill concrete pouring process can be calculated accurately.
Based on the above embodiment, the calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to the finite element/discrete element coupling analysis method FEM/DEM specifically includes: obtaining the continuous medium mechanical behavior of each rock block in the three-dimensional model of the stacking initial state of the rock blocks according to a finite element analysis (FEM); obtaining the mechanical behavior of a non-continuous medium among the rock masses in the three-dimensional model of the initial state of the rock pile according to a discrete element analysis (DEM); and substituting the continuous medium mechanical behaviors and the non-continuous medium mechanical behaviors of all the rock masses into a dynamic balance equation of the three-dimensional model of the initial state of the rock pile to obtain the stacking process and the final stacking form.
It should be noted that Finite Element Analysis (FEA) is a method of simulating a real physical system (geometric and load conditions) by using mathematical approximation. With simple and interactive elements, a finite number of unknowns can be used to approximate a real system of infinite unknowns. It considers the solution domain as consisting of many small interconnected subdomains called finite elements, assuming a suitable approximate solution for each element, and then deducing the overall satisfaction conditions for solving this domain, to arrive at a solution to the problem.
Continuous media mechanics (continuous media) is a branch of physics, the mechanics of handling the macroscopic properties of so-called "continuous media," including solids and fluids. Such as conservation of mass, theorems of momentum and angular momentum, conservation of energy, etc. Continuous medium mechanics considers that the space occupied by an actual fluid or solid can be viewed approximately as being continuously filled with "particles" (i.e., groups of molecules that are sufficiently large on a microscopic scale and sufficiently small on a macroscopic scale) without voids. The particles have macroscopic physical quantities (such as mass, velocity, pressure, temperature, etc.) that satisfy all physical laws that should be followed, such as the laws of mass conservation, newtonian law of motion, law of energy conservation, law of thermodynamics, and transport properties such as diffusion, viscosity, and thermal conduction. This assumption neglects the specific microstructure of a substance (microstructure studies on solids fall into the category of condensed state physics), and expresses macroscopic physical quantities (such as mass, degree, pressure, etc.) with a set of partial differential equations.
The discrete element analysis method is a numerical simulation method specially used for solving the problem of the discontinuous medium. The method treats the rockfill mass as consisting of discrete rock bodies and joints between the rock bodies, allowing the rock bodies to translate, rotate and deform, while the joints can be compressed, separated or slid. Thus, the heap of rocks is considered to be a discrete medium of discontinuity. The inner part of the block can have large displacement, rotation and sliding and even separation of the block, thereby being capable of more truly simulating the nonlinear large deformation characteristic in the rock pile.
The general solution process of the discrete element method is as follows: dispersing the solved space into a discrete element unit array, and connecting two adjacent units by using reasonable connecting elements according to an actual problem; the relative displacement between the units is a basic variable, and normal and tangential acting forces between the two units can be obtained according to the relationship between the force and the relative displacement; the acting force of the unit and other units in all directions and the external force caused by the action of other physical fields on the unit are used for solving resultant force and resultant moment, and the acceleration of the unit can be solved according to the Newton's second law of motion; it is time integrated to obtain the velocity and displacement of the cell. So as to obtain the physical quantities of the speed, the acceleration, the angular speed, the linear displacement, the rotation angle and the like of all the units at any time.
On the basis of the above embodiments, this embodiment further describes a specific process for obtaining the continuous medium mechanical behavior of each rock mass in the three-dimensional model of the initial state of the rock mass according to the finite element analysis FEM.
In particular, the continuous medium mechanical behavior comprises: the internal force vector caused by the node deformation of the grid cell, the external force vector of the node of the grid cell and the quality matrix.
Correspondingly, the obtaining of the continuous medium mechanical behavior of each stone body in the three-dimensional model according to the finite element analysis method specifically comprises the following steps:
and carrying out mesh division on the three-dimensional model of the rock-fill block in the initial state to obtain a finite element model consisting of mesh units.
And obtaining the internal force vector according to the grid unit volume, the standard function and the Cauchy stress tensor.
And obtaining the quality matrix according to the volume of the grid unit when the grid unit is not deformed, the density corresponding to the volume of the grid unit when the grid unit is not deformed and the standard function.
And obtaining the external force vector according to the physical force, the surface force and the unit surface area of the stone body.
Further, the internal force vector is calculated as:
wherein V represents the unit volume, N is the standard form function, and T is the Cauchy stress tensor.
The node external force vector is calculated according to the following formula:
wherein b represents physical strength, t represents surface strength, and S is unit surface area.
The quality matrix is calculated as follows:
wherein, V0Volume of the cell when undeformed, p0Is represented by the formula V0The corresponding density.
On the basis of the above embodiments, this embodiment further describes a specific process for obtaining the mechanical behavior of the non-continuous medium between the rock masses in the three-dimensional model of the stacking rock initial state according to the discrete element analysis DEM.
Specifically, the mechanical behavior of the non-continuous medium comprises: contact force between the stone bodies.
Correspondingly, the method for obtaining the mechanical behavior of the non-continuous medium between the rock masses in the three-dimensional model according to the discrete element analysis method specifically comprises the following steps:
the contact body and the target body in the three-dimensional model are obtained through a non-binary tree search contact algorithm (the contact judgment method adopts the non-binary tree search contact algorithm proposed by Munjiza and Andrews, namely, an efficient NBS algorithm, the algorithm occupies a small memory, and can realize rapid contact search among units under the condition that the unit sizes of the blocks are similar).
Obtaining a contact body and a target body in the three-dimensional model through a non-binary tree search contact algorithm;
according to the formula:
obtaining a normal contact force between the contact body and the target body; wherein, betacAnd betatRespectively representing the contact body and the target body, m and n respectively representing the limited number of cells for the discrete contact body and the target body,
denotes a contact potential, S denotes a boundary of the mutually embedded portions, and n denotes an outer normal direction vector of the boundary.
According to the formula:
obtaining a tangential contact force between the contact body and the target body; wherein k istIs tangential stiffness, ηtAs a tangential viscous damping coefficient, dtAnd vtRespectively, tangential relative displacement and relative velocity.
If it is judged that
Then the formula is re-established according to the coulomb friction law
Calculating the tangential contact force.
And taking the vector sum of the normal contact force and the tangential contact force as the contact force.
On the basis of the above embodiment, the finite element discrete form of the dynamic balance equation of the rock-fill block initial state three-dimensional model is:
x＝X+u；
wherein M, C represent mass matrix and damping matrix, respectively, fintRepresenting the internal force vector, f, caused by deformationcIndicating contact force, fextRepresenting all external force vectors except for the contact force,
and
respectively representing the acceleration and the speed of the finite element node, wherein X is the initial position vector of the finite element node, and u is the displacement vector of the finite element node.
As a preferred embodiment, the calculation method for numerical simulation of the rockfill concrete pouring process in the embodiment of the present invention specifically includes:
and establishing a three-dimensional model of the initial state of the rock stacking block, wherein the rock stacking block comprises a plurality of block stone bodies.
And calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM.
Inputting the final stacking form of the three-dimensional model of the rock-fill block initial state in a boundary form, and establishing a self-compacting concrete model, wherein the self-compacting concrete model is a Bingham rheological model.
Based on the smooth particle fluid dynamics (SPH) method, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed.
According to the embodiment of the invention, Paraview software is used as post-processing software to process the calculation result. It should be noted that the Paraview software is a mature software for processing numerical calculation results, and mainly analyzes the visualization processing of the rock-filled concrete pouring process, the analysis of the velocity field and the stress field, and the display of the final pouring state memory compactness.
Establishing a three-dimensional model of an initial state of a rock stacking block, wherein the rock stacking block comprises a plurality of block stone bodies, and the method specifically comprises the following steps: establishing a three-dimensional model of the rock stacking block in an initial state by using three-dimensional modeling software according to predetermined parameters of the rock stacking block; or 3D scanning the external contour of the rock block body to form input data, inputting the input data into three-dimensional modeling software, and establishing a three-dimensional model of the initial state of the rock pile.
According to a finite element/discrete element coupling analysis method FEM/DEM, calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state, specifically comprising the following steps: obtaining the continuous medium mechanical behavior of each rock block in the three-dimensional model of the stacking initial state of the rock blocks according to a finite element analysis (FEM); obtaining the mechanical behavior of a non-continuous medium among the rock masses in the three-dimensional model of the initial state of the rock pile according to a discrete element analysis (DEM); and substituting the continuous medium mechanical behaviors and the non-continuous medium mechanical behaviors of all the rock masses into a dynamic balance equation of the three-dimensional model of the initial state of the rock pile to obtain the stacking process and the final stacking form.
Based on the smooth particle fluid dynamics SPH method, the method calculates and analyzes the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking block, and specifically comprises the following steps: iteratively updating the density, position and speed of the fluid particles in the self-compacting concrete model one by one according to a time step based on an SPH (shortest Path fusion) method; the casting process and the final filling state of the self-compacting concrete in the final packing form of the lump of rock are analyzed based on the density, position and velocity of the fluid particles.
Based on the above embodiments, fig. 2 is a block diagram of a computing system for numerical simulation of rockfill concrete pouring process according to an embodiment of the present invention, as shown in fig. 2, including: the stacking analysis module 201 is used for calculating and analyzing the stacking process and the final stacking form of the stacking stone initial state three-dimensional model according to a finite element/discrete element coupling analysis method FEM/DEM; and the pouring analysis module 202 is configured to calculate and analyze a pouring process and a final filling state of the self-compacting concrete in the final stacking form of the stacking block based on a Smooth Particle Hydrodynamics (SPH) method after calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking block.
The short message distribution system of the embodiment of the invention can be used for executing the technical scheme of the calculation method embodiment of the numerical simulation in the rockfill concrete pouring process shown in fig. 1, and the realization principle and the technical effect are similar, and are not repeated here.
Based on the above embodiment, fig. 3 is a schematic block diagram of a computing device for numerical simulation of a rockfill concrete pouring process in an embodiment of the present invention. Referring to fig. 3, an embodiment of the present invention provides a computing apparatus for numerical simulation of a rockfill concrete pouring process, including: a processor (processor)310, a communication Interface (communication Interface)320, a memory (memory)330 and a bus 340, wherein the processor 310, the communication Interface 320 and the memory 330 complete communication with each other through the bus 340. The processor 310 may call logic instructions in the memory 330 to perform methods comprising: calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method.
An embodiment of the present invention discloses a computer program product, which includes a computer program stored on a non-transitory computer readable storage medium, the computer program includes program instructions, and when the program instructions are executed by a computer, the computer can execute the computing method provided by the above method embodiments, for example, the computer program includes: calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method.
Based on the foregoing embodiments, an embodiment of the present invention provides a non-transitory computer-readable storage medium, which stores computer instructions, where the computer instructions cause the computer to execute the computing method provided by the foregoing method embodiments, for example, the method includes: calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM; after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method.
Those of ordinary skill in the art will understand that: the implementation of the above-described apparatus embodiments or method embodiments is merely illustrative, wherein the processor and the memory may or may not be physically separate components, i.e. may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a usb disk, a removable hard disk, a ROM/RAM, a magnetic disk, an optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute the method according to the embodiments or some parts of the embodiments.
According to the calculation method and the system for numerical simulation of the rockfill concrete pouring process, provided by the embodiment of the invention, the finite element and discrete element coupling analysis method is set for mechanical analysis, so that the gradual stacking process of rockfill blocks under the stress action can be completely depicted, and the calculation result is more accurate. Through setting up the process of pouring and the final filling state of SPH method analysis self-compaction concrete in the final form of piling of heap stone, can accurately simulate the process of pouring of self-compaction concrete, not only can observe the mobile state of self-compaction concrete in the heap stone hole directly perceivedly, can also know the final closely knit state of heap stone concrete. The invention saves a large amount of labor cost, experiment cost and economic cost, and avoids the difficult problem that the experiment method is difficult to observe on line. The density, the position and the speed of the fluid particles in the self-compacting concrete model are updated iteratively by setting time step by time step, so that the pouring process of the rock-fill concrete can be calculated accurately.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (7)
1. A calculation method for numerical simulation in a rockfill concrete pouring process is characterized by comprising the following steps:
calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM;
after the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks are calculated and analyzed, the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks are calculated and analyzed based on a smooth particle fluid dynamics (SPH) method;
iteratively updating the density, the position and the speed of fluid particles in the self-compacting concrete model one by one according to a time step based on an SPH (shortest path H) method;
analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks based on the density, the position and the speed of the fluid particles;
wherein, the iteratively updating the density, the position and the speed of the fluid particles in the self-compacting concrete model one by one time step specifically comprises:
calculating the density change of the fluid particles one by one according to a continuity equation, capturing free surface particles and correcting the density of the free surface particles to obtain a density field of the self-compacting concrete model at each moment;
updating the motion track of each fluid particle through a fluid particle displacement equation one by one time step to obtain the position of any fluid particle at each moment;
determining the pressure of any fluid particle through a state equation one by one according to the time step, calculating the acceleration generated by the external force based on the pressure of each fluid particle, and calculating the velocity field of each moment in the self-compacting concrete model through a momentum equation based on the acceleration;
the method for calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to the finite element/discrete element coupling analysis method FEM/DEM specifically comprises the following steps:
obtaining the continuous medium mechanical behavior of each rock block in the three-dimensional model of the stacking initial state of the rock blocks according to a finite element analysis (FEM);
obtaining the mechanical behavior of a non-continuous medium among the rock masses in the three-dimensional model of the initial state of the rock pile according to a discrete element analysis (DEM);
substituting the continuous medium mechanical behaviors and the non-continuous medium mechanical behaviors of all the rock masses into a dynamic balance equation of the three-dimensional model of the initial state of the rock mass pile to obtain the stacking process and the final stacking form;
the continuous medium mechanical behavior comprises: an internal force vector caused by node deformation of the grid unit, an external force vector of the node of the grid unit and a mass matrix;
the method for obtaining the continuous medium mechanical behavior of each block stone body in the three-dimensional model according to the finite element analysis method specifically comprises the following steps:
carrying out mesh division on the three-dimensional model of the rock-fill block in the initial state to obtain a finite element model consisting of mesh units;
obtaining the internal force vector according to the grid unit volume, the standard type function and the Cauchy stress tensor;
obtaining the quality matrix according to the volume of the grid unit when the grid unit is not deformed, the density corresponding to the volume of the grid unit when the grid unit is not deformed and the standard function;
obtaining the external force vector according to the physical strength, the surface force and the unit surface area of the stone body;
the mechanical behavior of the non-continuous medium comprises: contact force between the stone bodies;
the method for obtaining the mechanical behavior of the non-continuous medium between the rock masses in the three-dimensional model according to the discrete element analysis method specifically comprises the following steps:
obtaining a contact body and a target body in the three-dimensional model through a non-binary tree search contact algorithm;
and taking the vector sum of the normal contact force and the tangential contact force as the contact force.
2. The method according to claim 1, wherein the step of computationally analyzing the stacking process and the final stacking shape of the three-dimensional model of the stacking blocks in the initial state according to the finite element/discrete element coupling analysis method FEM/DEM further comprises:
and establishing a three-dimensional model of the initial state of the rock stacking block, wherein the rock stacking block comprises a plurality of block stone bodies.
3. The method of claim 1, wherein the step of computationally analyzing the stacking process and the final stacking state of the three-dimensional model of the initial state of the stacking blocks, and the step of computationally analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking state of the stacking blocks based on the Smooth Particle Hydrodynamics (SPH) method further comprises:
and establishing a self-compacting concrete model, wherein the self-compacting concrete model is a Bingham rheological model.
4. The calculation method according to claim 2, wherein the establishing of the three-dimensional model of the stacking block initial state specifically comprises:
establishing a three-dimensional model of the rock stacking block in an initial state by using three-dimensional modeling software according to predetermined parameters of the rock stacking block; or,
and 3D scanning the outline of the rock mass body to form input data, inputting the input data into three-dimensional modeling software, and establishing a three-dimensional model of the rock mass in the initial state.
5. A computing system for numerical simulation of a rockfill concrete placement process, comprising:
the stacking analysis module is used for calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to a finite element/discrete element coupling analysis method FEM/DEM;
the pouring analysis module is used for calculating and analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks based on a smooth particle fluid dynamics (SPH) method after calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the initial state of the stacking blocks;
iteratively updating the density, the position and the speed of fluid particles in the self-compacting concrete model one by one according to a time step based on an SPH (shortest path H) method;
analyzing the pouring process and the final filling state of the self-compacting concrete in the final stacking form of the stacking blocks based on the density, the position and the speed of the fluid particles;
wherein, the iteratively updating the density, the position and the speed of the fluid particles in the self-compacting concrete model one by one time step specifically comprises:
calculating the density change of the fluid particles one by one according to a continuity equation, capturing free surface particles and correcting the density of the free surface particles to obtain a density field of the self-compacting concrete model at each moment;
updating the motion track of each fluid particle through a fluid particle displacement equation one by one time step to obtain the position of any fluid particle at each moment;
determining the pressure of any fluid particle through a state equation one by one according to the time step, calculating the acceleration generated by the external force based on the pressure of each fluid particle, and calculating the velocity field of each moment in the self-compacting concrete model through a momentum equation based on the acceleration;
the method for calculating and analyzing the stacking process and the final stacking form of the three-dimensional model of the stacking stone initial state according to the finite element/discrete element coupling analysis method FEM/DEM specifically comprises the following steps:
obtaining the continuous medium mechanical behavior of each rock block in the three-dimensional model of the stacking initial state of the rock blocks according to a finite element analysis (FEM);
obtaining the mechanical behavior of a non-continuous medium among the rock masses in the three-dimensional model of the initial state of the rock pile according to a discrete element analysis (DEM);
substituting the continuous medium mechanical behaviors and the non-continuous medium mechanical behaviors of all the rock masses into a dynamic balance equation of the three-dimensional model of the initial state of the rock mass pile to obtain the stacking process and the final stacking form;
the continuous medium mechanical behavior comprises: an internal force vector caused by node deformation of the grid unit, an external force vector of the node of the grid unit and a mass matrix;
the method for obtaining the continuous medium mechanical behavior of each block stone body in the three-dimensional model according to the finite element analysis method specifically comprises the following steps:
carrying out mesh division on the three-dimensional model of the rock-fill block in the initial state to obtain a finite element model consisting of mesh units;
obtaining the internal force vector according to the grid unit volume, the standard type function and the Cauchy stress tensor;
obtaining the quality matrix according to the volume of the grid unit when the grid unit is not deformed, the density corresponding to the volume of the grid unit when the grid unit is not deformed and the standard function;
obtaining the external force vector according to the physical strength, the surface force and the unit surface area of the stone body;
the mechanical behavior of the non-continuous medium comprises: contact force between the stone bodies;
the method for obtaining the mechanical behavior of the non-continuous medium between the rock masses in the three-dimensional model according to the discrete element analysis method specifically comprises the following steps:
obtaining a contact body and a target body in the three-dimensional model through a non-binary tree search contact algorithm;
and taking the vector sum of the normal contact force and the tangential contact force as the contact force.
6. A computing device for numerical simulation of a rockfill concrete placement process, comprising:
at least one processor; and
at least one memory communicatively coupled to the processor, wherein:
the memory stores program instructions executable by the processor, the processor being capable of performing the computing method of any of claims 1 to 4 when invoked by the program instructions.
7. A non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the computing method of any one of claims 1 to 4.
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| CN111666699B (en) * | 2020-04-30 | 2023-06-02 | 山东大学 | Rock mass engineering trans-scale simulation calculation method based on REV full-area coverage |
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