A method and system for simulating acoustic-elastic coupling of a composite pile core pile and outer pile non-coaxial

Abstract

This invention discloses a method and system for simulating acoustic-structure interaction (ASI) between a composite pile core and an outer pile in a non-coaxial configuration, belonging to the field of intelligent pile foundation detection and numerical simulation. The method includes: establishing a finite element model comprising an acoustic emission group, a receiving group, a water area, the core pile, the outer pile, and the soil, and assigning corresponding physical and mechanical parameters to the acoustic and solid media; realizing the non-coaxial structure of the core pile and the outer pile through Boolean operations and rotational assembly; pre-setting a node set in the water area as acoustic excitation points and sound pressure response monitoring points; setting a dynamic explicit analysis step and corresponding time parameters, and dividing the mesh according to the element size principle of sound wave propagation; defining the interaction relationship based on the ASI principle, with Tie constraints applied to each medium interface; applying acoustic excitation and obtaining the sound pressure time history response at the receiving point. This invention realizes three-dimensional ASI propagation simulation of composite piles under non-coaxial conditions in a multi-medium water-solid environment, providing an effective means for ultrasonic CT detection and numerical analysis of heterogeneous pile structures.

Description

Technical Field

[0001] This invention discloses a method and system for acoustic-structure coupling simulation of non-coaxial composite core piles and outer piles, belonging to the field of intelligent pile foundation detection and numerical simulation. Background Technology

[0002] Composite piles, formed by inserting precast pipe piles (core piles) into cement-soil piles (outer piles), combine the advantages of high strength of pipe piles and large cross-section and high side friction of cement-soil piles. They can significantly control foundation settlement and deformation, and are therefore widely used in foundation reinforcement in coastal soft soil areas. During composite pile construction, the pipe piles need to be statically inserted into the cement-soil piles. Due to the homogeneity of the cement-soil and surrounding soil, as well as the influence of construction operations, varying degrees of non-coaxiality can occur between the pipe piles and the cement-soil piles. This introduces significant uncertainties into the pile foundation's bearing capacity and settlement control.

[0003] In recent years, Ultrasonic Computed Tomography (UCT) technology has been used for the internal structural inspection of composite piles. By acquiring multi-path ultrasonic travel times and reconstructing wave velocity distributions, differences in internal materials can be identified. In actual testing, the core pile is usually filled with water as an acoustic coupling medium to obtain stable ultrasonic signals. However, composite piles are typical heterogeneous transmedium systems consisting of a water column, a core pile, an outer pile, and surrounding soil. The water follows the acoustic wave equation, while the core pile and outer pile solids follow the elastic wave equation. Furthermore, the interfaces must satisfy the coupling conditions of stress and velocity, making the wave propagation process complex. Current technology lacks a three-dimensional simulation method that can accurately reflect the acoustic-solid coupling mechanism under non-coaxial structures, limiting the application of UCT in practical engineering.

[0004] Based on the above requirements, this invention proposes a method and system for simulating acoustic-structure interaction (AS / S) of non-coaxial composite pile core and outer pile. By jointly constructing the coupled wave equations of acoustics and elastic media, it achieves a realistic simulation of the propagation behavior of ultrasound in water columns, core piles, outer piles, and surrounding soil. This invention can comprehensively characterize the AS / S effect of non-coaxial composite piles, providing reliable numerical analysis and theoretical support for UCT (Unified Test-Temperature) detection, and has significant application prospects for improving the quality evaluation capabilities of composite piles and promoting intelligent pile foundation detection technology. Summary of the Invention

[0005] (a) Technical problems that need to be solved

[0006] The technical problem to be solved by the present invention is as follows: The present invention proposes a sound-structure coupling simulation method and system for non-coaxial composite pile core and outer pile, which can accurately simulate the propagation process of sound waves between water column, core pile, outer pile and surrounding soil and obtain the corresponding travel time, making up for the shortcomings of the prior art and having great significance for intelligent detection and numerical simulation of pile foundation.

[0007] (ii) Technical solutions to be adopted

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] First, this invention proposes a simulation method for acoustic-structure interaction of composite core piles and outer piles that are not coaxial, the steps of which are as follows:

[0010] Step 1: Create components based on Abaqus' preprocessing functions, including hollow core piles, water column inside the core piles, outer piles, and surrounding soil.

[0011] Step 2: Create the component properties using Abaqus' preprocessing capabilities. The hollow core pile, the water column within the core pile, the outer pile, and the surrounding soil are all solid and homogeneous; water is the acoustic medium, and the rest are solid media.

[0012] Step 3: Assemble the created hollow core pile, the water column inside the core pile, the outer pile, and the surrounding soil. Using the rotation instance function in the assembly, rotate the core pile of the acoustic emission source counterclockwise by 1° around the vertex center, and rotate the outer pile counterclockwise by 3° around the vertex center. Use Boolean methods to cut the surrounding soil, forming the soil around the pile with the excavated space.

[0013] Step 4: Set the analysis step. The analysis step uses dynamic display, with a time step of 0.002s, a maximum time increment step of 1E-0.7, a time scaling factor of 10, a linear volume parameter of 0.5, and a quadratic volume viscosity parameter of 1.0.

[0014] Step 5: Regarding element type selection, the water column uses an eight-node three-dimensional acoustic linear solid element (AC3D8R) with reduced integral and hourglass control. The core pile uses a hexahedral solid element (C3D8R) with reduced integral. The cement-soil piles in the receiving signal group have a relatively regular shape and also use hexahedral solid elements (C3D8R). However, in the acoustic excitation group, due to the non-coaxial nature of the composite piles and the complex geometry of the outer piles and surrounding soil with irregular curved surfaces, it is necessary to combine hexahedral (C3D8R) and tetrahedral (C3D4) elements for mesh generation.

[0015] Step 6: The grid units of the hollow core pile, the water column inside the core pile, the outer pile, and the surrounding soil are planted according to the edges;

[0016] Step 7: Tie constraints are used to simulate acoustic-structure interaction at the contact surfaces of the water column-core pile interface, the core pile-outer pile interface, and the outer pile-soil interface.

[0017] Step 8: In the water column of the launch group, an acoustic excitation point is set up every 0.1m in the form of a node set. The acoustic excitation type is inward volume acceleration, and the analysis step is dynamic display.

[0018] Step 9: When submitting the job, the job type is full analysis, using 8 processors for parallel memory, the number of domains is 8, the precision of Abaqus / Explicit is both-analysis only, and the precision of node variable output is single precision.

[0019] Step 10: Output the results of the numerical simulation and obtain the sound pressure time domain diagram based on the history monitoring of the sound receiving point.

[0020] Furthermore, in step 1 of this invention, there are two core piles, two outer piles, and two water column components, which are respectively an acoustic emission group and an acoustic receiving group. There is one soil element surrounding the pile.

[0021] Furthermore, in step 2 of this invention, the soil around the pile of the component needs to be set with different attributes in different areas to simulate the characteristic that the wave velocity in the soil gradually increases with depth.

[0022] Furthermore, in step 2 of this invention, the relationship between the elastic modulus, Poisson's ratio, density, and wave velocity of the core pile, outer pile, and surrounding soil needs to satisfy formula (1):

[0023] (1)

[0024] In the formula, For the velocity of sound waves in a solid, For Young's modulus, The density of the solid. It is Poisson's ratio.

[0025] Furthermore, in step 2 of this invention, the water column is considered an incompressible or weakly compressible medium, and the sound wave propagates in the water as a longitudinal compressive wave. The relationship between its wave velocity, bulk modulus, and density needs to satisfy:

[0026] (2)

[0027] In the formula, The velocity of sound waves in the fluid. Bulk modulus The density of the fluid.

[0028] Furthermore, during the assembly process in step 3 of this invention, the outer pile of the acoustic emission assembly and the surrounding soil need to be cut using a Boolean method before assembly.

[0029] Furthermore, in step 5 of this invention, to avoid numerical dispersion caused by excessively coarse mesh division and to ensure accurate waveform propagation, the mesh cell size needs to meet the following requirements:

[0030] (3)

[0031] In the formula, This is the maximum size of the grid. This is a coefficient related to accuracy, typically between 10 and 20. The center frequency is 30kHz. The speed of sound waves.

[0032] Furthermore, the principle described in formula (3) of this invention will result in the model having tens of millions of mesh elements. In order to avoid computational crash, the size of the finite element model is reduced by a factor of 10.

[0033] Furthermore, in step 6 of this invention, the unit sizes of the grids for the core pile and water column are 0.004m and 0.002m respectively; the unit sizes of the grids for the outer pile acoustic emission group and receiving group are 0.006~0.009m and 0.004m respectively; and the unit sizes of the grids for the soil around the pile are 0.009~0.07m.

[0034] Furthermore, the acoustic-structure coupling principle in step 7 of this invention is to couple the elastic wave equation of the solid medium and the acoustic wave equation of the fluid medium through the continuity of the normal velocity and the stress balance condition at the interface. The specific principle is as follows:

[0035] S701, Equation governing elastic waves in solids:

[0036] (4)

[0037] S702, Equation of sound pressure wave in fluid:

[0038] (5)

[0039] S703, Acoustic-solid interface coupling conditions:

[0040] (1) Normal velocity continuity:

[0041] (6)

[0042] (2) Normal stress equilibrium condition:

[0043] (7)

[0044] (3) Tangential stress is 0:

[0045] (8)

[0046] In the formula, For solid displacement, For stress, For solid density, For fluid sound pressure, For the speed of sound in fluid, For the displacement of solid particles, For fluid particle displacement, The interface normal unit vector, For solid stress, For time, This is the tangential stress.

[0047] Furthermore, in step 8 of this invention, the acoustic excitation point and acoustic receiving point are respectively arranged in the water columns of the transmitting and receiving sources, existing in the form of a node set. The excitation point is set as the acoustic acceleration within the volume, and the acoustic receiving point is set for sound pressure history monitoring. The acoustic excitation signal is as follows:

[0048] (9)

[0049] In the formula, The waveform amplitude, The center frequency is 30kHz. Time, in seconds. This represents the number of individual audio frequencies, set to 10.

[0050] Secondly, this invention proposes a non-coaxial acoustic-structure coupling simulation system for composite core piles and outer piles, including a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the method steps proposed in this invention.

[0051] (III) The technical effects to be achieved

[0052] Compared with the prior art, the beneficial effects of the present invention are:

[0053] (1) The acoustic-structure coupling three-dimensional simulation model established in this invention realizes for the first time the simulation of sound wave propagation across media (water column-core pile-outer pile-soil). This fills the current technical gap in cross-media acoustic-structure coupling three-dimensional simulation, provides important technical reference and theoretical support for related fields, and demonstrates its extremely high practical value and innovation.

[0054] (2) The acoustic-structure interaction simulation method for composite core pile-outer pile in non-coaxial state proposed in this invention involves extremely complex surface geometry modeling and mesh generation techniques. This achievement not only provides solid technical support and accurate theoretical basis for intelligent detection technology of pile foundation ultrasonic CT, but more importantly, it provides innovative technical ideas and methodological references for complex surface mesh generation and high-performance finite element model establishment in the field of numerical simulation. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the ultrasonic CT simulation steps of a non-coaxial acoustic-structure coupling simulation method for composite pile core and outer pile provided as an example of the present invention.

[0056] Figure 2 This is a schematic diagram of the acoustic-solid coupling simulation of the present invention;

[0057] In the diagram: 1 is the sound excitation point; 2 is the sound receiving point; 3 is the Zhuangzhou soil; 4 is the water column inside the core pile; 5 is the core pile; 6 is the outer pile; 7 is the sound wave ray path.

[0058] Figure 3 This is a time-domain diagram of the emitted signal at the acoustic excitation point of the present invention.

[0059] Figure 4 This is a time-domain diagram of the sound pressure at the 14 receiving points of the present invention (0.1m from the transmitting point). Detailed Implementation

[0060] To make the objectives and implementation schemes of the present invention clearer, the implementation schemes of the present invention will be described more specifically and completely below in conjunction with specific embodiments. The embodiments described are only some, not all, of the embodiments of the present invention. It should be understood that the specific embodiments described below are for illustrative purposes only and are not intended to limit the scope of the present invention. Other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0061] This invention proposes a simulation method and system for acoustic-structure interaction (ASI) of composite pile core and outer pile in a non-coaxial state. Based on Abaqus numerical simulation software, a complex surface model and a three-dimensional cross-medium ASI numerical simulation method are established for the non-coaxial state of the core and outer pile. This invention fills a current technological gap and has important reference value and innovation for intelligent monitoring and numerical simulation of ultrasonic CT.

[0062] The present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the simplified process diagrams used in the drawings are not intended to limit the actual product. The present invention provides a method and system for acoustic-structure interaction simulation of a composite core pile and an outer pile that are not coaxial.

[0063] Example: This invention provides a simulation method for acoustic-structure interaction of composite core piles and outer piles that are not coaxial, specifically including the following steps:

[0064] Step 1: Create components based on Abaqus' preprocessing capabilities, including core piles (tube piles), outer piles (cement-soil piles), water columns, and surrounding soil. For example... Figure 2 As shown, the core pile is 1.8m long, with an inner diameter of 0.021m and an outer diameter of 0.04m; the outer pile is 1.5m long, with an inner diameter of 0.04m and an outer diameter of 0.08m; the soil around the pile is a cylinder with a diameter of 0.5m and a length of 2m; the water column is a cylinder with a diameter of 0.021m and a length of 1.8m.

[0065] Step 2: Create component properties using Abaqus' preprocessing capabilities. The core pile, water column, outer pile, and surrounding soil are all solid and homogeneous; water is the acoustic medium, and the rest are solid media. The material elastic modulus and Poisson's ratio are shown in Table 1.

[0066] The relationship between the elastic modulus, Poisson's ratio, density, and wave velocity of the core pile, outer pile, and surrounding soil must satisfy formula (1):

[0067] (1)

[0068] In the formula, For the velocity of sound waves in a solid, For Young's modulus, The density of the solid. It is Poisson's ratio.

[0069] S202. A water column is considered an incompressible or weakly compressible medium. Sound waves propagate in water as longitudinal compression waves. The relationship between its wave velocity, bulk modulus, and density must satisfy the following:

[0070] (2)

[0071] In the formula, The velocity of sound waves in the fluid. Bulk modulus The density of the fluid.

[0072] Step 3: Assemble the created core pile, water column, outer pile, and surrounding soil. Using the rotation instance function in the assembly, rotate the core pile of the acoustic emission source counterclockwise by 1° around the vertex center, and rotate the cement-soil pile counterclockwise by 3° around the vertex center. Use Boolean methods to cut the soil, forming the soil with the excavated space.

[0073] Step 4: Set the analysis step. The analysis step uses dynamic display, with a time step of 0.002s, a maximum time increment step of 1E-0.7, a time scaling factor of 10, a linear volume parameter of 0.5, and a quadratic volume viscosity parameter of 1.0.

[0074] Step 5: Regarding element type selection, the water column uses an eight-node three-dimensional acoustic linear solid element (AC3D8R) with reduced integral and hourglass control. The core uses a hexahedral solid element (C3D8R) with reduced integral. The outer pile in the receiving signal group has a relatively regular shape and also uses a hexahedral solid element (C3D8R). However, in the acoustic excitation group, due to the non-coaxial nature of the composite piles, the geometry of the outer soil piles and the surrounding soil is more complex and has irregular curved surfaces. Therefore, it is necessary to combine hexahedral (C3D8R) and tetrahedral (C3D4) elements for mesh generation. The specific mesh generation method and model parameters are shown in Table 1;

[0075]

[0076] Step 6: During mesh generation, to avoid excessively coarse meshes that could lead to numerical dispersion and to ensure accurate waveform propagation, the mesh cell size must meet the following requirements:

[0077] (3)

[0078] In the formula, This is the maximum size of the grid. This is a coefficient related to accuracy, typically between 10 and 20. The center frequency is 30kHz. The speed of sound waves.

[0079] The unit sizes for the S601, core pile, and water column grids, arranged according to edge type, are 0.004m and 0.002m, respectively; the unit sizes for the external pile acoustic emission and receiving groups, arranged according to edge type, are 0.006~0.009m and 0.004m, respectively; and the unit sizes for the surrounding soil grids, arranged according to edge type, are 0.009~0.07m.

[0080] Step 7: Tie constraints are used to simulate acoustic-structure interaction at the contact surfaces of the water column-core pile interface, the core pile-outer pile interface, and the outer pile-surrounding soil interface. The constraint method is surface-to-surface, and the primary plane mesh must be coarser than the secondary plane mesh.

[0081] S701. The conditions for acoustic-structure coupling are the continuity of the normal velocity at the interface and the stress balance condition, which couple the elastic wave equation of the solid medium and the acoustic wave equation of the fluid medium. The governing equation for elastic waves in a solid is:

[0082] (4)

[0083] S702, Equation of sound pressure wave in fluid:

[0084] (5)

[0085] S703, Acoustic-solid interface coupling conditions:

[0086] (1) Normal velocity continuity:

[0087] (6)

[0088] (2) Normal stress equilibrium condition:

[0089] (7)

[0090] (3) Tangential stress is 0:

[0091] (8)

[0092] In the formula, For solid displacement, For stress, For solid density, For fluid sound pressure, For the speed of sound in fluid, For the displacement of solid particles, For fluid particle displacement, The interface normal unit vector, For solid stress, For time, This is the tangential stress.

[0093] Step 8: Within the water column of the launching group, an acoustic excitation point is set up every 0.1m in a node set manner. The acoustic excitation type is inward volumetric acceleration, and the analysis step is dynamic display. The amplitude formula of the acoustic excitation signal is as follows; for specific signal output, see... Figure 3 :

[0094] (9)

[0095] In the formula, The waveform amplitude, The center frequency is 30kHz. Time, in seconds. This represents the number of individual audio frequencies, set to 10.

[0096] Step 9: When submitting the job, the job type is full analysis, using 8 processors for parallel memory, the number of domains is 8, the precision of Abaqus / Explicit is both-analysis only, and the precision of node variable output is single precision.

[0097] Step 10: Output the results of the numerical simulation, obtaining the sound pressure time-domain graph based on the history monitoring of the sound receiving point. For example... Figure 4 As shown, taking a 1m acoustic emission point as an example, there are a total of 14 received signals;

[0098] This invention proposes a non-coaxial acoustic-structure coupling simulation system for composite pile core and outer pile, including a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the method steps proposed in this invention.

[0099] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0100] In the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0101] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A method for acoustic-structure interaction simulation of non-coaxial composite core piles and outer piles, characterized in that, The steps are as follows: Step 1: Create components based on Abaqus' preprocessing capabilities, including hollow core piles, the water column inside the core pile, the outer pile, and the surrounding soil. Step 2: Create the properties of the component based on Abaqus' preprocessing function. The core pile, outer pile, and surrounding soil are all solid homogeneous, water is the acoustic medium, and the rest are solid media. Step 3: Assemble the created core pile, water column, outer pile, and surrounding soil components. Using the rotation instance function in the assembly, rotate the core pile of the acoustic emission source counterclockwise by 1° around the vertex center and the outer pile counterclockwise by 3° around the vertex center. Use Boolean method to cut the soil to form the soil with the excavated space. Step 4: Set the analysis step. The analysis step uses dynamic display, with a time step of 0.002s, a maximum time increment step of 1E-0.7, a time scaling factor of 10, a linear volume parameter of 0.5, and a quadratic volume viscosity parameter of 1.

0. Step 5: In terms of element type selection, the water column uses the eight-node three-dimensional acoustic linear solid element AC3D8R with reduced integral and hourglass control, the core pile uses the hexahedral solid element C3D8R with reduced integral, the cement-soil pile in the receiving signal group has a relatively regular shape, and also uses the hexahedral solid element C3D8R, while in the acoustic excitation group, due to the non-coaxial situation of the composite pile, the geometry of the outer pile soil and the surrounding soil is relatively complex and has irregular curved surfaces, so C3D8R and C3D4 are used for meshing. Step 6: The core piles, water columns, outer piles, and surrounding soil grid units are planted according to their edges; Step 7: Tie constraints are used to simulate acoustic-structure interaction at the contact surfaces of the water column-core pile interface, the core pile-outer pile interface, and the outer pile-soil interface. Step 8: In the water column of the launch group, an acoustic excitation point is set up every 0.1m in the form of a node set. The acoustic excitation type is inward volume acceleration, and the analysis step is dynamic display. Step 9: When submitting the job, the job type is Full Analysis, using 8 processors for parallel memory operation, the number of domains is 8, the precision of Abaqus / Explicit is both-analysis only, and the precision of node variable output is single precision. Step 10: Output the results of the numerical simulation and obtain the sound pressure time domain diagram based on the history monitoring of the sound receiving point.

2. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, Step 1: There are two core piles, two outer piles, and two water column components, which are the acoustic emission group and the acoustic reception group, respectively. There is one soil component.

3. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, Step 2 involves creating soil components that require setting attributes for different zones to simulate the characteristic of wave velocity gradually increasing with depth in the soil on site.

4. The acoustic-structure interaction simulation method for non-coaxial composite core pile and outer pile according to claim 1, characterized in that, Step 2: The relationship between the elastic modulus, Poisson's ratio, density, and wave velocity of the core pile, outer pile, and soil must satisfy the following formula: (1) In the formula, For the velocity of sound waves in a solid, For Young's modulus, The density of the solid. It is Poisson's ratio.

5. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, In step 2, the water column is considered an incompressible or weakly compressible medium. Sound waves propagate in the water as longitudinal compressive waves, and the relationship between their wave velocity, bulk modulus, and density must satisfy the following: (2) In the formula, The velocity of sound waves in the fluid. Bulk modulus The density of the fluid.

6. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, During step 3 assembly, the outer piles of the acoustic emission assembly and the surrounding soil need to be cut using Boolean method before assembly.

7. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, Step 5: To avoid numerical dispersion caused by excessively coarse meshing and to ensure accurate waveform propagation, the mesh cell size needs to meet the following requirements: (3) In the formula, This is the maximum size of the grid. This is a coefficient related to accuracy, typically between 10 and 20. The center frequency is 30kHz. The speed of sound waves.

8. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, In step 5, the unit sizes of the grid for the core pile and water column are 0.004m and 0.002m respectively, according to the edge layout; the unit sizes of the grid for the external pile acoustic emission group and receiving group are 0.006~0.009m and 0.004m respectively, according to the edge layout; and the unit size of the grid for the soil around the pile is 0.009~0.07m.

9. The acoustic-structure interaction simulation method for non-coaxial composite core piles and outer piles according to claim 1, characterized in that, Satisfying the principle described in formula (3) will result in the model having tens of millions of mesh elements. To avoid computational crashes, the size of the finite element model is reduced by a factor of 10.

10. The acoustic-structure interaction simulation method for non-coaxial composite core pile and outer pile according to claim 1, characterized in that, The acoustic excitation point and acoustic receiving point in step 7 are respectively arranged in the water columns of the transmitting and receiving sources, existing in the form of a node set. The excitation point is set as the acoustic acceleration in the volume, and the acoustic receiving point is set as the sound pressure history monitoring point. The acoustic excitation signal is as follows: (4) In the formula, The waveform amplitude, The center frequency is 30kHz. Time, in seconds. This represents the number of individual audio frequencies, set to 10.

11. The acoustic-structure interaction simulation method for non-coaxial composite core pile and outer pile according to claim 1, characterized in that, The acoustic-structure interaction principle in step 6 is to couple the elastic wave equation of the solid medium and the acoustic wave equation of the fluid medium through the continuity of the normal velocity and the stress balance condition at the interface. The specific principle is as follows: Elastic wave governing equation in solids: (5) The equation for the sound pressure wave of a fluid: (6) Acoustic-solid interface coupling conditions: (1) Normal velocity continuity: (7) (2) Normal stress equilibrium condition: (8) (3) Tangential stress is 0: (9) In the formula, For solid displacement, For stress, For solid density, For fluid sound pressure, For the speed of sound in fluid, For the displacement of solid particles, For fluid particle displacement, The interface normal unit vector, For solid stress, For time, This is the tangential stress.

12. A simulation system for acoustic-structure interaction of a composite core pile and an outer pile that are not coaxial, comprising a processor and a memory, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the acoustic-structure coupling simulation method for non-coaxial composite pile core and outer pile as described in any one of claims 1 to 11.

Images