Methods, apparatuses, devices, and media for simulation analysis of ionomer material stretch and shear

Abstract

The application discloses a simulation analysis method, device and equipment of stretching and shearing of ionomer material and a medium, relates to the technical field of molecular dynamics, and under a canonical ensemble, an interaction force and a mechanical model are introduced to optimize an initial box of an ionomer model; an electrostatic interaction potential is introduced, and under an NPT ensemble, a change in a size of the optimized box is monitored; when the change is within a preset change range, the size of the box is determined; whether the optimized box under the size of the box is in an equilibrium state is monitored; if the box is in the equilibrium state, the canonical ensemble is changed to continue simulation, and an ionomer equilibrium melt is obtained; the ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing, and a stress tensor, coordinates in a stress tensor and a strain process and coordinates in the stress tensor and the strain process are obtained; the coordinates are processed, and a change of the ionomer equilibrium melt is obtained, a coarse-grained molecular dynamics simulation of the ionomer material under stretching and shearing is realized, and the simulation analysis accuracy of the ionomer material under stretching and shearing is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of molecular dynamics, in particular to a simulation analysis method, device, equipment and medium for stretching and shearing of ionomer materials. BACKGROUND

[0002] Telechelic ionomer is an associated polymer with covalent bonds connecting ions at both ends of the main chain. The polarity of the ions is much higher than that of the covalent main chain, which leads to the formation of ion aggregates. The reversible network structure formed by ion aggregates and polymer chains endows this kind of polymer with unique mechanical and electrical properties, so it can be used for battery separators, solid electrolytes, memory materials, packaging materials, etc. In actual processing, if the viscosity of the ionomer material is too high, it will be difficult to extrude from the extruder at a reasonable rate to produce useful products; if the extrusion rate is too slow, even if the normal shape can be extruded, it is too time-consuming and cannot be applied to actual production. If the extrusion rate is too fast, the melt will break, making it difficult to get the desired shape. Conversely, if the viscosity is too low, the material cannot maintain its shape and cannot be used in practice. If the adjustment of the brittleness and mechanical strength of the ionomer material is realized by constantly trying and error method on the functional groups on the ionomer main chain, the size and dielectric constant of the counter ions, it will undoubtedly cause waste of manpower and financial resources.

[0003] From the above, how to realize the coarse-grained molecular dynamics simulation of the mechanical properties and microstructure of ionomer materials under stretching and shearing, and improve the accuracy of the simulation analysis of the stretching and shearing of ionomer materials is a problem to be solved in the field. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a simulation analysis method, device, equipment and medium for stretching and shearing of ionomer materials, which can realize the coarse-grained molecular dynamics simulation of the mechanical properties and microstructure of ionomer materials under stretching and shearing, and improve the accuracy of the simulation analysis of the stretching and shearing of ionomer materials. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a simulation analysis method for stretching and shearing of ionomer materials, comprising:

[0006] Under the canonical ensemble, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model, to obtain an optimized box; the ionomer model is a model obtained by modeling the polymer main chain of the ionomer material;

[0007] The electrostatic interaction potential between ions is introduced, and the size change of the optimized box is monitored in real time under the NPT ensemble. When the size change is within a predetermined change range, the box size is determined;

[0008] monitoring whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in the equilibrium state, continuing to simulate under the canonical ensemble, so as to obtain an ionomer equilibrium melt;

[0009] respectively performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, so as to obtain stress tensors in different directions, coordinates of strain processes, stress tensors and coordinates of strain processes;

[0010] processing the stress tensors in different directions, the coordinates of strain processes, the stress tensors and the coordinates of strain processes, so as to obtain microstructure information of the ionomer equilibrium melt and changes of stress and chain conformation in a stretching process.

[0011] Optionally, the optimizing the initial box including the ionomer model under the canonical ensemble by introducing an interaction force between bonded particles and a mechanical model comprises:

[0012] setting an initial number density, and calculating an edge length of the initial box including the ionomer model based on the initial number density and a total number of particles;

[0013] under the edge length and the canonical system, introducing a FENE bond interaction or a Harmonic bond potential between the bonded particles, a mechanical model, and setting an initial cutoff distance, and optimizing the initial box including the ionomer model; the mechanical model comprises a non-bond interaction LJ potential function between particles.

[0014] Optionally, the introducing an electrostatic interaction potential between ions and monitoring a size change of the optimized box in real time under an NPT ensemble comprises:

[0015] modifying the initial cutoff distance, introducing the electrostatic interaction potential between ions, setting a dielectric constant parameter, and then running a step number under the NPT ensemble to monitor the size change of the optimized box in real time.

[0016] Optionally, when the size change is within a preset change range, the box size is determined; the monitoring whether the optimized box under the box size is in the equilibrium state, and if the optimized box under the box size is in the equilibrium state, the continuing to simulate under the canonical ensemble, so as to obtain the ionomer equilibrium melt comprises:

[0017] judging whether the size change of the optimized box is within the preset change range, and if the size change is within the preset change range, the box size is determined;

[0018] running the steps under the box size and canonical ensemble, and monitoring whether the energy change in the optimized box under the box size is in equilibrium; the energy change includes Coulomb potential and total potential energy;

[0019] if the energy change in the optimized box under the box size is in equilibrium, then continue to simulate under canonical ensemble, thereby obtaining an ionomer equilibrium melt.

[0020] Optionally, the non-equilibrium stretching and non-equilibrium shearing of the ionomer equilibrium melt respectively, comprises:

[0021] non-equilibrium stretching of the ionomer equilibrium melt by using the deform command with the local option of trate;

[0022] non-equilibrium shearing of the ionomer equilibrium melt by using the deform command with the local option of etrate.

[0023] Optionally, the processing of the stress tensor in different directions, the coordinates in the strain process, the stress tensor and the coordinates in the strain process to obtain the microstructure information of the ionomer equilibrium melt and the stress and chain conformation change in the stretching process, comprises:

[0024] writing a data analysis program based on a program writing language; the program writing language includes Fortran language;

[0025] processing the stress tensor in different directions, the coordinates in the strain process, the stress tensor and the coordinates in the strain process by using the data analysis program, and statistically simulating the microstructure information of the ionomer melt before the strain and the stress and chain conformation change in the stretching process.

[0026] Optionally, after obtaining the microstructure information of the ionomer equilibrium melt and the stress and chain conformation change in the stretching process, further comprising:

[0027] visualizing the microstructure information of the ionomer equilibrium melt and the stress and chain conformation change in the stretching process by using a preset visualization software; the visualization software includes Ovito.

[0028] In a second aspect, the present application discloses a simulation analysis device for ionomer material stretching and shearing, comprising:

[0029] an optimization module, configured to introduce interaction forces between bonded particles and a mechanical model to optimize an initial box including an ionomer model under canonical ensemble, to obtain an optimized box; the ionomer model is a model obtained after modeling a main chain of an ionomer material;

[0030] A size change monitoring module is used to introduce the electrostatic interaction potential between ions and monitor the size change of the optimized box in real time under the NPT ensemble. When the size change is within a preset range, the box size is determined;

[0031] an equilibrium state monitoring module, for monitoring whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in an equilibrium state, continuing the simulation under the canonical ensemble to obtain an ionomer equilibrium melt;

[0032] a stretching and shearing module, configured to perform non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, respectively, to obtain stress tensors in different directions, coordinates during the strain process, and stress tensors and coordinates during the strain process;

[0033] The processing module is used to process the stress tensors in different directions, the coordinates during the strain process, and the stress tensors and the coordinates during the strain process to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process.

[0034] In a third aspect, the present application discloses an electronic device, comprising:

[0035] Memory, used to store computer programs;

[0036] A processor is used to execute the computer program to implement the aforementioned simulation analysis method for stretching and shearing of ionomer materials.

[0037] In a fourth aspect, the present application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the aforementioned disclosed method for simulating and analyzing the stretching and shearing of ionomer materials are implemented.

[0038] It can be seen that the application provides a simulation analysis method for stretching and shearing of ionomer material, comprising: under a canonical ensemble, introducing interaction force between bonded particles and a mechanical model to optimize an initial box comprising an ionomer model to obtain an optimized box; the ionomer model is a model obtained after modeling a polymer main chain of ionomer material; introducing an electrostatic interaction potential between ions, and monitoring size change of the optimized box in real time under an NPT ensemble, when the size change is within a preset change range, the box size is determined; monitoring whether the optimized box under the box size is in an equilibrium state, if the optimized box under the box size is in the equilibrium state, continuing to simulate under the canonical ensemble, so as to obtain an ionomer equilibrium melt; respectively performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt to obtain stress tensors in different directions, coordinates in a stress process, stress tensors and coordinates in a strain process; processing the stress tensors in different directions, the coordinates in the stress process, the stress tensors and the coordinates in the strain process to obtain microstructure information of the ionomer equilibrium melt and change conditions of stress and chain conformation in a stretching process. In the application, the initial box comprising the ionomer model is optimized under the canonical ensemble by introducing the interaction force between the bonded particles and the mechanical model, the electrostatic interaction potential between the ions is introduced, the size change of the optimized box is monitored in real time under the NPT ensemble, when the optimized box is in the equilibrium state, the simulation is continued under the canonical ensemble, so as to obtain the ionomer equilibrium melt. The application optimizes the box comprising the ionomer molecular model from the interaction force between the bonded particles, the electrostatic interaction strength between the ions affecting the mechanical properties of the ionomer, the size and other factors, optimizes the ionomer equilibrium melt simulated by respectively performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, realizes coarse-grained molecular dynamics simulation of the ionomer material under the mechanical and microstructure corresponding to stretching and shearing, processes the stress tensors in different directions, the coordinates in the stress process, the stress tensors and the coordinates in the strain process, and obtains the microstructure information of the ionomer equilibrium melt and the change conditions of stress and chain conformation in the stretching process. The microaggregates in the ionomer are characterized by a static structure factor, and the size change of the ionomer molecular main chain under stretching and shearing is simulated, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, and the accuracy of simulation analysis of stretching and shearing of the ionomer material can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0040] Figure 1 A flow chart of a simulation analysis method for stretching and shearing of a ionomer material disclosed in the present application;

[0041] Figure 2 A model diagram of a claw-shaped ionomer main chain structure and neutralized cations disclosed in the present application;

[0042] Figure 3 A stretching / shearing simulation flow chart of an ionomer melt disclosed in the present application;

[0043] Figure 4 An example diagram of an ion static structure factor in an ionomer equilibrium melt under different electrostatic interaction strengths disclosed in the present application;

[0044] Figure 5 A polymer melt diagram in an ionomer simulation box disclosed in the present application;

[0045] Figure 6 An ion cluster structure diagram of an ionomer equilibrium melt disclosed in the present application;

[0046] Figure 7 A stress-strain curve of a sample under different stretching rates and a change of a mean square radius of gyration with stretching diagram disclosed in the present application;

[0047] Figure 8 A stress / strain rate change with time of a sample under different shearing rates and a change of a mean square radius of gyration with shearing diagram disclosed in the present application;

[0048] Figure 9 A structure schematic diagram of a simulation analysis device for stretching and shearing of an ionomer material disclosed in the present application;

[0049] Figure 10 A structure diagram of an electronic device provided in the present application. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application.

[0051] Telechelic ionomer is an associated polymer with covalent bonds at both ends of the main chain. The polarity of the ion is much higher than that of the covalent main chain, which leads to the formation of ion aggregates. The reversible network structure formed by the ion aggregates and the polymer chain endows this kind of polymer with unique mechanical and electrical properties, so it can be used for battery separators, solid electrolytes, memory materials, packaging materials, etc. In the actual processing process, if the viscosity of the ionomer material is too high, it will be difficult to extrude from the extruder at a reasonable rate to produce useful products; if the extrusion speed is too slow, even if the normal shape can be extruded, it is too time-consuming and cannot be applied to actual production. If the extrusion rate is too fast, the melt will be broken, and the desired shape cannot be obtained. Conversely, if the viscosity is too low, the material cannot maintain the shape and cannot be practically applied. If the adjustment of the brittleness and mechanical strength of the ionomer material is realized by constantly trying and error method on the functional groups on the main chain of the ionomer, the size and dielectric constant of the counter ion, it will undoubtedly cause waste of manpower and financial resources. As can be seen from the above, how to realize the coarse-grained molecular dynamics simulation of the mechanical properties and microstructure of the ionomer material under tension and shear, and improve the accuracy of the simulation analysis of the tension and shear of the ionomer material is a problem to be solved in the field.

[0052] Reference Figure 1 As shown in the drawings, the embodiment of the present application discloses a simulation analysis method for tension and shear of ionomer material, which can specifically include:

[0053] Step S11: under the canonical ensemble, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model to obtain the optimized box; the ionomer model is a model obtained by modeling the polymer main chain of the ionomer material.

[0054] In this embodiment, the initial number density is set, and the edge length of the initial box including the ionomer model is calculated based on the initial number density and the total number of particles; under the edge length and the canonical system, the FENE bond interaction or the harmonic bond potential between the bonded particles is introduced, the mechanical model is set, and the initial cutoff distance is set to optimize the initial box including the ionomer model to obtain the optimized box; the mechanical model includes the LJ potential function of non-bonded interaction between particles.

[0055] On the basis of the coarse-grained length of the polymer main chain and the unchanged number of ions at the end of the telechelic ionomer chain, the change of the electrostatic interaction strength between the ions of the telechelic ionomer is realized by changing the dielectric constant of the anion and the cation in the model. The model of the telechelic ionomer main chain structure and the neutralized cation is as shown in Figure 2As shown, the red particles are neutral particles, the blue particles are anions, and the yellow particles are cations, and the construction process of the ionomer model is as follows: first, 48 neutral particles connected by covalent bonds are constructed, and then one particle is connected to each end by the same covalent bond, and the types of the two particles are distinguished from the previous 48 particles. In addition, two free particles are selected, and the types of the two particles are distinguished from the two particles on the main chain. In this way, 500 polymer chains are added, corresponding to 1000 terminal ions and 1000 free ions. The 1000 terminal ions correspond to anion functional groups (for example: such as carboxylate, sulfonate, etc.), and the 1000 cations can be analogized to Na+ (sodium ion), K+ (potassium ion), Cs+ (cesium ion), etc. The model coarsely grinds the ionomer polymer material into polymer chains connected by single rigid spheres and single rigid spheres moving freely, and controls the strength of the associated network inside the ionomer material by changing the interaction strength between the anions and cations and the size of the cations. All particle information, bond information, dihedral angle information, and initial velocity information are written in python; the initial model can also be constructed using Material Studio software, and the model can also be constructed using the create_box, create_atoms, regin, and other instructions in the LAMMPS (Large-scale Atomic / Molecular Massively Parallel Simulator) software.

[0056] In this embodiment, the initial number density is set to 0.001, the side length of the initial box is calculated by the total number of particles, and under the NVT (regular) system, the FENE bond interaction or Harmonic bond potential between the bonded particles and the non-bonding interaction LJ potential function between the particles are introduced, the initial cutoff distance is set to 1.12246, and the non-bonding interaction between the particles in the system is only repulsive force. Run the appropriate number of steps to eliminate unreasonable structures in the system.

[0057] Step S12: Introduce the electrostatic interaction potential between ions, and monitor the size change of the optimized box in real time under the NPT system, and when the size change is within the preset change range, the box size is determined.

[0058] In this embodiment, the initial cutoff distance is modified, the electrostatic interaction potential between ions is introduced, and the dielectric constant parameter is set, and then the number of steps is run under the NPT system, the size change of the optimized box is monitored in real time, and when the size change is within the preset change range, the box size is determined.

[0059] On the basis of step S11, the initial cutoff distance is modified, and the cutoff distance of non-bonding interaction is set to 2.5 to ensure that the particle distance is between 1.12246 and 2.5, and there is an attractive effect. At the same time, the electrostatic interaction potential between ions is introduced, and the long-range electrostatic interaction potential is set according to the particle label (neutral particles are 1, anions are 2, and cations are 3) between 2-2, 2-3, and 3-3, and the cutoff distance is 6.5. The dielectric constant parameter in LAMMPS is set to 0-10. Then, a suitable number of steps is run under the NPT ensemble, and the size change of the simulation box is monitored during the simulation. When the relative change amplitude of the size is small (i.e., when the size change is within a preset change range), a suitable number of steps is run.

[0060] Step S13: Monitor whether the optimized box under the box size is in an equilibrium state. If the optimized box under the box size is in an equilibrium state, continue to simulate under the canonical ensemble, thereby obtaining an ionomer equilibrium melt.

[0061] In this embodiment, it is determined whether the size change of the optimized box is within a preset change range. If the size change is within the preset change range, the box size is determined. The number of steps is run under the box size and the canonical ensemble, and it is monitored whether the energy change in the optimized box under the box size is in an equilibrium state. The energy change includes the Coulomb potential and the total potential energy. If the energy change in the optimized box under the box size is in an equilibrium state, continue to simulate under the canonical ensemble, thereby obtaining an ionomer equilibrium melt.

[0062] On the basis of step S12, the average size of the region with a stable box size is taken as the box size of this step. Then, a suitable number of steps is run under the NVT ensemble on this basis, and the Coulomb potential, total potential energy, and other energy changes in the system are monitored during the simulation. When the energies tend to be stable, it means that the system reaches an equilibrium state. At this time, the simulation result obtained is an ionomer equilibrium melt.

[0063] Step S14: Perform non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt to obtain the stress tensor in different directions, the coordinates in the strain process, the stress tensor, and the coordinates in the strain process.

[0064] In this embodiment, the deform command with the local option trate is used to perform non-equilibrium stretching on the ionomer equilibrium melt, and the deform command with the local option etrate is used to perform non-equilibrium shearing on the ionomer equilibrium melt, to obtain the stress tensor in different directions, the coordinates in the strain process, the stress tensor, and the coordinates in the strain process.

[0065] Specifically, the simulated equilibrium state melt of the ionomer is subjected to non-equilibrium stretching, and the deform command with the trate option in LAMMPS is used to output the stress tensor in different directions and the coordinates during the strain process during the stretching process; the simulated equilibrium state melt of the ionomer is subjected to non-equilibrium shearing, and the deform command with the etrate option in LAMMPS is used to output the stress tensor in different directions and the coordinates during the strain process during the shearing process. In addition, stretching can also be realized through the end velocity.

[0066] Step S15: processing the stress tensor in different directions, the coordinates during the strain process, the stress tensor and the coordinates during the strain process to obtain the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation during the stretching process.

[0067] In this embodiment, the data analysis program is written based on a program writing language; the program writing language includes Fortran language; the data analysis program is used to process the stress tensor in different directions, the coordinates during the strain process, the stress tensor and the coordinates during the strain process, and the microstructure information of the ionomer melt before the strain and the change of stress and chain conformation during the stretching process are simulated and counted, and then the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation during the stretching process are visualized by using a preset visualization software; the visualization software includes Ovito.

[0068] In this embodiment, the data analysis program is written by using Fortran language, and the stress tensor in different directions, the coordinates during the strain process, the stress tensor and the coordinates during the strain process are simulated and counted by using the data analysis program; in addition to using Fortran language to write the calculation program, Python, C / C++ and other programming languages can also be used for writing, and for the static structure factor and the mean square radius of gyration, the compute instruction in the LAMMPS software can also be used for calculation, or the calculation module provided by the visualization software Ovito can be used for analysis. The process of processing by using the data analysis program includes:

[0069] The static structure factor is calculated for the equilibrium state melt, and the calculation formula is as follows:

[0070] ;

[0071] wherein q is a wave vector, and is the particle coordinate, and N is the total number of particles.

[0072] Stress in the stretching process and shear process Plot the change with strain. Calculate the mean square radius of gyration of the ionomer main chain in the equilibrium state and in the process of strain, the calculation formula is as follows:

[0073] ;

[0074] Wherein, N is the total number of polymer chains, M is the total number of particles of each polymer chain, and The jth particle of the ith chain and the mass center coordinate of the ith chain are respectively.

[0075] After obtaining the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process, the preset visualization software is used to visualize the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process, and the change of the molecular main chain structure of the ionomer main chain in the equilibrium state, stretching and shearing and the ion cluster morphology is presented; in addition, in addition to using Ovito software for visualization, VMD software or Python programming language can also be used for plotting.

[0076] Taking the stretching / shearing simulation of ionomer melt with different same electrostatic interaction strength and same cation size as an example, the simulation process is as shown in Figure 3 (1) Determine the telechelic ionomer model with different electrostatic interaction strength: in this model, each polymer chain is composed of 50 particles, a total of 500 polymer chains, corresponding to 1000 free cations, and the chain ends of each chain are anions respectively; (2) remove unreasonable structure in the self-defined initial structure: set the initial number density to 0.001, introduce the FENE bond interaction between the bonded particles and the non-bonding interaction LJ potential function between the particles, set the cutoff distance to 1.12246, ensure that the non-bonding interaction between the particles in the system only has repulsive force, and run appropriate number of steps to eliminate unreasonable structure in the system; (3) get the ionomer equilibrium melt box size: based on the result of the above step, set the non-bonding interaction cutoff distance to 2.5, ensure that there is an attractive force when the distance between particles is between 1.12246 and 2.5, and at the same time introduce the electrostatic interaction potential between ions, the dielectric constant parameter in LAMMPS can be set to 0-10. Then run appropriate number of steps under NPT ensemble, monitor the size change of the simulation box during the process, and run appropriate number of steps when the relative change amplitude of the size is small; (4) make the ionomer melt fully relax under NVT ensemble to obtain the equilibrium melt, the static structure factor of ions in the ionomer equilibrium melt under different electrostatic interaction strength is as shown in Figure 4: The average size of the stable region of the box size in the previous step is used as the simulation box size of this step, and then a suitable number of NVT ensemble runs are performed on this basis, monitoring the changes in the Coulomb potential, total potential energy and other energies in the system during the process. When the energies tend to be stable, it means that the system has reached an equilibrium state, and the simulation results obtained at this time are the equilibrium melt of the ionomer; (5) Non-equilibrium stretching of the equilibrium melt of different electrostatic interaction strengths; (6) Non-equilibrium shear of the equilibrium melt of different electrostatic interaction strengths; (7) Data analysis of the results: using Fortran language to write data analysis program, calculating the static structure factor of the ions of the equilibrium melt obtained. The microstructure information of the ionomer melt before strain and the changes of stress and chain conformation during the stretching / shearing process are obtained by statistical simulation; (8) Using Ovito software to present the changes of the molecular backbone structure and ion cluster morphology of the ionomer main chain under equilibrium, stretching and shearing at different electrostatic interaction strengths. The polymer melt in the ionomer simulation box is as shown in Figure 5 The ion cluster structure of the ionomer equilibrium melt obtained by simulation is as shown in Figure 6 .

[0077] The stretching / shearing simulation of ionomer melt with different cation size and same electrostatic interaction strength is taken as an example, and the specific simulation process is as follows, (1) constructing ionomer model, in this model, each polymer chain is composed of 50 particles, a total of 500 polymer chains, corresponding to 1000 free cations, the size of each chain is set to be 0.5 times, 1.0 times and 1.5 times of that of anion, and the electrostatic interaction strength between ions is set to be consistent, for example, 0.5, 5.0 and other values; (2) setting the initial number density as 0.001, calculating the initial box length by the total number of particles, introducing the FENE bond interaction between the bonded particles and the non-bonded interaction LJ potential between the particles in the NVT ensemble under the box length, setting the cutoff distance as 1.12246 to ensure that the non-bonded interaction between the particles in the system only has repulsive force, and running appropriate number of steps to eliminate unreasonable structure in the system; (3) based on the result of the above step, setting the cutoff distance of non-bonded interaction as 2.5 to ensure that the particles have attractive force when the distance is between 1.12246 and 2.5, and at the same time introducing the electrostatic interaction potential between ions, the dielectric constant parameter in LAMMPS can be set as 0-10. Then running appropriate number of steps in the NPT ensemble, monitoring the size change of the simulation box during the process, and running appropriate number of steps when the relative size change is small; (4) using the average size of the box size in the stable region of the above step as the simulation box size of this step, and then running appropriate number of steps in the NVT ensemble based on this, monitoring the change of Coulomb potential, total potential energy and other energy in the system during the process, and when the energies tend to be stable, it means that the system reaches the equilibrium state, and the simulation result obtained at this time is the equilibrium melt of ionomer; (5) non-equilibrium stretching of the equilibrium melt with different electrostatic interaction strengths; (6) non-equilibrium shearing of the equilibrium melt with different electrostatic interaction strengths; (7) using Fortran language to write data analysis program to calculate the static structure factor of ions in the equilibrium melt. The microstructure information of ionomer melt before strain and the change of stress and chain conformation during stretching / shearing are obtained by statistical simulation, the stress-strain curves of samples at different stretching rates and the change of mean square radius of gyration with stretching are shown in Figure 7 , the change of stress / strain rate with time and the change of mean square radius of gyration with shearing of samples at different shearing rates are shown in Figure 8 , Figure 7 is the stress-strain curve and the change trend of mean square radius of gyration of ionomer melt at stretching rates of 0.001 and 0.0001, Figure 8 is the stress-strain curve and the change trend of mean square radius of gyration of ionomer melt at different shearing rates; (8) visualizing the microstructure information of ionomer equilibrium melt and the change of stress and chain conformation during stretching.

[0078] Therefore, the application can simulate the nonlinear stretching of ionomer melt with the same ionic electrostatic interaction and different counterion sizes, or simulate the nonlinear stretching of ionomer melt with different ionic electrostatic interactions and the same counterion size.

[0079] In the embodiment, under the canonical ensemble, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model to obtain an optimized box; the ionomer model is a model obtained by modeling the main chain of the ionomer material; the electrostatic interaction potential between ions is introduced, and the size change of the optimized box is monitored in real time under the NPT ensemble; when the size change is within a preset change range, the box size is determined; whether the optimized box under the box size is in an equilibrium state is monitored; if the optimized box under the box size is in the equilibrium state, the simulation under the canonical ensemble is continued, so as to obtain an ionomer equilibrium melt; the ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain the stress tensor in different directions, the coordinates in the stress and strain processes, and the coordinates in the strain process; and the stress tensor in different directions, the coordinates in the stress and strain processes, and the coordinates in the strain process are processed to obtain the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process. In the application, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model under the canonical ensemble, the electrostatic interaction potential between ions is introduced, the size change of the optimized box is monitored in real time under the NPT ensemble, and when the optimized box is in the equilibrium state, the simulation under the canonical ensemble is continued, so as to obtain the ionomer equilibrium melt. The application optimizes the box including the ionomer model from the interaction force between the bonded particles, the electrostatic interaction strength between the ions affecting the mechanical properties of the ionomer, the size and other factors, optimizes the ionomer equilibrium melt simulated by the ionomer model, and subjects the ionomer equilibrium melt to non-equilibrium stretching and non-equilibrium shearing, so as to realize the coarse-grained molecular dynamics simulation of the mechanical properties and the corresponding microstructure of the ionomer material under stretching and shearing, process the stress tensor in different directions, the coordinates in the stress and strain processes, and the coordinates in the strain process, obtain the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process, characterize the microaggregates in the ionomer by the static structure factor, and simulate the size change of the ionomer main chain under stretching and shearing, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, and improve the accuracy of the simulation analysis of the stretching and shearing of the ionomer material.

[0080] Referring to Figure 9 As shown in the drawings, the embodiment of the application discloses a simulation analysis device for ionomer material stretching and shearing, which can specifically include:

[0081] An optimization module 11 is used to optimize the initial box including the ionomer model by introducing the interaction force between bonded particles and the mechanical model under the canonical ensemble to obtain an optimized box; the ionomer model is a model obtained by modeling the main molecular chain of the ionomer material;

[0082] A size change monitoring module 12 is used to introduce the electrostatic interaction potential between ions and monitor the size change of the optimized box in real time under the NPT ensemble. When the size change is within a preset range, the box size is determined;

[0083] an equilibrium state monitoring module 13, configured to monitor whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in an equilibrium state, continue the simulation under the canonical ensemble to obtain an ionomer equilibrium melt;

[0084] a stretching and shearing module 14 for performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, respectively, to obtain stress tensors in different directions, coordinates during the strain process, and stress tensors and coordinates during the strain process;

[0085] The processing module 15 is used to process the stress tensors in different directions, the coordinates during the strain process, and the stress tensors and the coordinates during the strain process to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process.

[0086] In the embodiment, under the canonical ensemble, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model to obtain an optimized box; the ionomer model is a model obtained by modeling the main chain of the ionomer material; the electrostatic interaction potential between ions is introduced, and the size change of the optimized box is monitored in real time under the NPT ensemble; when the size change is within a preset change range, the box size is determined; whether the optimized box under the box size is in an equilibrium state is monitored; if the optimized box under the box size is in the equilibrium state, the simulation under the canonical ensemble is continued, so as to obtain an ionomer equilibrium melt; the ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain the stress tensor in different directions, the coordinates in the stress and strain process, and the coordinates in the strain process; and the stress tensor in different directions, the coordinates in the stress and strain process, and the coordinates in the strain process are processed to obtain the microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process. In the application, under the canonical ensemble, the interaction force between the bonded particles and the mechanical model are introduced to optimize the initial box including the ionomer model, the electrostatic interaction potential between ions is introduced, and the size change of the optimized box is monitored in real time under the NPT ensemble; when the optimized box is in the equilibrium state, the simulation under the canonical ensemble is continued, so as to obtain an ionomer equilibrium melt. The application optimizes the box including the ionomer model from the interaction force between the bonded particles, the electrostatic interaction strength between the ions affecting the mechanical properties of the ionomer, the size and other factors, optimizes the ionomer equilibrium melt simulated by the ionomer model, and realizes the coarse-grained molecular dynamics simulation of the mechanical properties and the corresponding microstructure of the ionomer material under stretching and shearing by subjecting the ionomer equilibrium melt to non-equilibrium stretching and non-equilibrium shearing. The microstructure information of the ionomer equilibrium melt and the change of stress and chain conformation in the stretching process are obtained by processing the stress tensor in different directions, the coordinates in the stress and strain process, and the coordinates in the strain process. The microaggregates in the ionomer are characterized by the static structure factor, and the size change of the ionomer main chain under stretching and shearing is simulated, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, and the accuracy of the simulation analysis of the stretching and shearing of the ionomer material can be improved.

[0087] In some specific embodiments, the optimization module 11 can specifically include:

[0088] The edge length calculation module is configured to set an initial number density and calculate the edge length of the initial box including the ionomer model based on the initial number density and the total number of particles.

[0089] An initial box optimization module is configured to introduce FENE bond interaction or a harmonic bond potential into the initial box under the side length and the canonical system, set an initial cutoff distance, and optimize the initial box including a model of ionomer.

[0090] In some embodiments, the size change monitoring module 12 can specifically include:

[0091] A modification module is configured to modify the initial cutoff distance, introduce an electrostatic interaction potential between ions, set a dielectric constant parameter, and then run a number of steps under the NPT ensemble to monitor the size change of the optimized box in real time.

[0092] In some embodiments, the equilibrium state monitoring module 13 can specifically include:

[0093] A box size determination module is configured to determine whether the size change of the optimized box is within a preset change range, and if the size change is within the preset change range, determine the box size.

[0094] An energy change monitoring module is configured to run a number of steps under the box size and the canonical ensemble, and monitor whether the energy change in the optimized box under the box size is in an equilibrium state; the energy change includes a Coulomb potential and a total potential energy.

[0095] A simulation module is configured to continue simulation under the canonical ensemble if the energy change in the optimized box under the box size is in the equilibrium state, thereby obtaining an ionomer equilibrium melt.

[0096] In some embodiments, the stretching and shearing module 14 can specifically include:

[0097] A non-equilibrium stretching module is configured to perform non-equilibrium stretching on the ionomer equilibrium melt by using a deform command with a local center option of trate.

[0098] A non-equilibrium shearing module is configured to perform non-equilibrium shearing on the ionomer equilibrium melt by using a deform command with a local center option of etrate.

[0099] In some embodiments, the processing module 15 can specifically include:

[0100] A program writing module is configured to write a data analysis program based on a program writing language; the program writing language includes a Fortran language.

[0101] A statistical module is configured to process the stress tensor in different directions, the coordinates of the strain process, the stress tensor and the coordinates of the strain process by using the data analysis program, and statistically simulate the microstructure information of the ionomer melt before the strain and the change of the stress and chain conformation in the stretching process.

[0102] In some specific embodiments, the processing module 15 can specifically include:

[0103] A visualization module is configured to visualize the microstructure information of the ionomer equilibrium melt and the change of the stress and chain conformation in the stretching process by using a preset visualization software; the visualization software includes Ovito.

[0104] Figure 10 A structural schematic diagram of an electronic device is provided in the embodiments of the present application. The electronic device 20 can specifically include at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25 and a communication bus 26. The memory 22 is configured to store a computer program, and the processor 21 is configured to load and execute the computer program to implement the related steps in the simulation analysis method for ionomer material stretching and shearing performed by the electronic device disclosed in any of the foregoing embodiments.

[0105] In the embodiments, the power supply 23 is configured to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol followed by the communication interface 24 can be any communication protocol applicable to the technical solutions of the present application, which is not specifically limited herein; the input / output interface 25 is configured to obtain external input data or output data to the outside world, and the specific interface type can be selected according to the specific application needs, which is not specifically limited herein.

[0106] In addition, the memory 22 as a carrier for resource storage can be a read-only memory, a random access memory, a magnetic disk or an optical disk, etc., and the resources stored thereon include an operating system 221, a computer program 222 and data 223, etc., and the storage mode can be temporary storage or permanent storage.

[0107] The operating system 221 is used to manage and control the various hardware devices and computer programs 222 on the electronic device 20, and to implement the operations and processes of the processor 21 on the data 223 in the memory 22, and can be Windows, Unix, Linux, etc. The computer programs 222 can further include computer programs for performing other specific work in addition to the computer programs for performing the simulation analysis method of the stretching and shearing of the coagulant material disclosed in any of the embodiments described above. The data 223 can include data received from external devices transmitted by the simulation analysis device for the stretching and shearing of the coagulant material, data collected by the input and output interface 25, etc.

[0108] The steps of the methods or algorithms described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in random access memory (RAM), flash memory, read-only memory (ROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0109] Further, the embodiments of the present application also disclose a computer readable storage medium, wherein the storage medium stores a computer program, and the computer program is loaded and executed by a processor to implement the simulation analysis method of the stretching and shearing of the coagulant material disclosed in any of the embodiments described above.

[0110] Finally, it should be noted that, in this document, the terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or device. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of additional identical elements in the process, method, article or device that includes the element.

[0111] The simulation analysis method, device, equipment and storage medium for the stretching and shearing of the ionomer material provided by the application are described in detail, the principles and implementation manners of the application are described by using specific examples, and the above description of the examples is only used to help understand the method of the application and the core idea thereof; meanwhile, for those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the application, and the above description of the specification should not be understood as a limitation on the application.

Claims

1. A simulation analysis method for stretching and shearing of ionomer materials, characterized in that: include: Under a canonical ensemble, an interaction force between bonded particles and a mechanical model are introduced to optimize an initial box including an ionomer model to obtain an optimized box, including: setting an initial number density, and calculating a side length of the initial box including the ionomer model based on the initial number density and the total number of particles; under the side length and the canonical ensemble, a FENE bond interaction or a harmonic bond potential between bonded particles and a mechanical model are introduced, and an initial cutoff distance is set to optimize the initial box including the ionomer model; the mechanical model includes an LJ potential function of non-bonded interaction between particles; the ionomer model is a model obtained by modeling the main molecular chain of the ionomer material; Introducing an electrostatic interaction potential between ions and monitoring the size change of the optimized box in real time under the NPT ensemble, including: modifying the initial cutoff distance, introducing the electrostatic interaction potential between ions, and setting a dielectric constant parameter, then running the number of steps under the NPT ensemble and monitoring the size change of the optimized box in real time; when the size change is within a preset change range, determining the box size; monitoring whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in an equilibrium state, continuing the simulation under the canonical ensemble to obtain an ionomer equilibrium melt; performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt to obtain stress tensors in different directions and coordinates during the strain process; The stress tensors in different directions and the coordinates during the strain process are processed to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process.

2. The simulation analysis method of ionomer material stretching and shearing according to claim 1, characterized in that: When the size change is within a preset range, determining the box size; monitoring whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in an equilibrium state, continuing the simulation under a canonical ensemble to obtain an ionomer equilibrium melt, including: Determining whether the size change of the optimized box is within a preset range, and if so, determining the box size; Running the number of steps under the box size and canonical ensemble, and monitoring whether the energy change in the optimized box under the box size is in a balanced state; the energy change includes Coulomb potential and total potential energy; If the energy change in the optimized box under the box size is in a balanced state, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt.

3. The simulation analysis method of ionomer material stretching and shearing according to claim 1, characterized in that: The step of subjecting the ionomer equilibrium melt to non-equilibrium stretching and non-equilibrium shearing respectively comprises: The ionomer equilibrium melt was subjected to non-equilibrium stretching using the deform command with the trate option in the local context. The equilibrium melt of the ionomer is subjected to nonequilibrium shearing using the deform command with the etrate option in the local context.

4. The simulation analysis method of ionomer material stretching and shearing according to claim 1, characterized in that: The processing of the stress tensors in different directions and the coordinates during the strain process to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process includes: Writing a data analysis program based on a programming language; the programming language includes Fortran; The data analysis program is used to process stress tensors in different directions and coordinates during the strain process, and statistically simulate the microstructure information of the ionomer equilibrium melt before strain and the changes in stress and chain conformation during the stretching process.

5. The simulation analysis method for stretching and shearing of ionomer materials according to any one of claims 1 to 4, characterized in that: After obtaining the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process, the method further includes: The microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process are visualized using preset visualization software; the visualization software includes Ovito.

6. A simulation analysis device for stretching and shearing of ionomer materials, characterized in that: include: An optimization module is used to optimize an initial box including an ionomer model by introducing an interaction force between bonded particles and a mechanical model under a canonical ensemble to obtain an optimized box, including: setting an initial number density and calculating a side length of the initial box including the ionomer model based on the initial number density and the total number of particles; introducing a FENE bond interaction or a harmonic bond potential between bonded particles and a mechanical model under the side length and the canonical ensemble, and setting an initial cutoff distance to optimize the initial box including the ionomer model; the mechanical model includes an LJ potential function for non-bonded interactions between particles; and the ionomer model is a model obtained by modeling the main molecular chain of the ionomer material. A size change monitoring module is used to introduce the electrostatic interaction potential between ions and monitor the size change of the optimized box in real time under the NPT ensemble, including: modifying the initial cutoff distance, introducing the electrostatic interaction potential between ions, and setting the dielectric constant parameter, and then running the number of steps under the NPT ensemble to monitor the size change of the optimized box in real time; when the size change is within a preset change range, determining the box size; an equilibrium state monitoring module, for monitoring whether the optimized box under the box size is in an equilibrium state, and if the optimized box under the box size is in an equilibrium state, continuing the simulation under the canonical ensemble to obtain an ionomer equilibrium melt; a stretching and shearing module, configured to perform non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, respectively, to obtain stress tensors in different directions and coordinates during the strain process; The processing module is used to process the stress tensors in different directions and the coordinates during the strain process to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process.

7. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the simulation analysis method for stretching and shearing of ionomer materials according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that Used to store a computer program; wherein, when the computer program is executed by a processor, the simulation analysis method for stretching and shearing of ionomer materials according to any one of claims 1 to 5 is implemented.

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