Simulation analysis method, device, equipment and medium for stretching and shearing of ionomer material

Abstract

The invention discloses an ionomer material stretching and shearing simulation analysis method, device, equipment and medium, and relates to the technical field of molecular dynamics, under a regular ensemble, interaction force and a mechanical model are introduced to optimize an initial box of an ionomer model; introducing electrostatic interaction potential, monitoring the size change of the optimized box under the NPT ensemble, and determining the size of the box when the change is within a preset change range; monitoring whether the optimized box under the box size is in a balanced state or not, and if the optimized box is in the balanced state, continuing simulation under a regular ensemble to obtain an ionomer balanced melt; performing unbalanced stretching and unbalanced shearing on the ionomer equilibrium melt to obtain a stress tensor, coordinates in a strain process and coordinates in the stress tensor and strain process, and processing the coordinates to obtain the change condition of the ionomer equilibrium melt, so as to realize coarse-grained molecular dynamics simulation of the ionomer material under stretching and shearing. And the simulation analysis accuracy of stretching and shearing of the ionomer material is improved.

Description

Technical Field

[0001] The invention relates to the field of molecular dynamics technology, and in particular to a simulation analysis method, device, equipment and medium for stretching and shearing of ionomer materials. Background Art

[0002] Telechelic ionomers are associative polymers with ions connected by covalent bonds 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 gives this type of polymer unique mechanical and electrical properties, allowing it to be used in 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 lead to the inability to extrude from the extruder at a reasonable rate to produce useful products; and if it is extruded slowly, even if a 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 and it will be difficult to obtain the desired shape. On the contrary, if the viscosity is too low, the material cannot maintain its shape and cannot be used in practice. If the brittle toughness and mechanical strength of the ionomer material are adjusted by experimental trial and error to adjust the functional groups, counterion size and dielectric constant on the ionomer main chain, it will undoubtedly cause a waste of manpower and financial resources.

[0003] It can be seen from the above that how to achieve coarse-grained molecular dynamics simulation of the mechanics and microstructure of ionomer materials under tension and shear and improve the accuracy of simulation analysis of tension and shear of ionomer materials are problems to be solved in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention 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 mechanics and microstructure of ionomer materials under stretching and shearing, and improve the accuracy of simulation analysis of 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 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 molecular chain of the ionomer material;

[0007] Introducing the electrostatic interaction potential between ions, and monitoring the size change of the optimized box in real time under the NPT ensemble, and determining the size of the box when the size change is within a preset range of change;

[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 an equilibrium state, continuing the simulation under a canonical ensemble to obtain an ionomer equilibrium melt;

[0009] The ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain;

[0010] The stress tensors in different directions, the coordinates during the strain process, the stress tensors 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.

[0011] Optionally, the step of introducing the interaction force between bonded particles and the mechanical model to optimize the initial box including the ionomer model under the canonical ensemble includes:

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

[0013] Under the edge length and the canonical system, a FENE bond interaction or harmonic bond potential and a mechanical model between bonded particles 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.

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

[0015] The initial cutoff distance is modified, the electrostatic interaction potential between ions is introduced, and the dielectric constant parameters are set, and then the steps are run 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, 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:

[0017] Determine whether the size change of the optimized box is within a preset range, and if the size change is within the preset range, determine the box size;

[0018] 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;

[0019] 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.

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

[0021] The deform command with the option trate in the local area is used to perform non-equilibrium stretching on the ionomer equilibrium melt;

[0022] The ionomer equilibrium melt is subjected to nonequilibrium shearing using the deform command with the etrate option in the local context.

[0023] Optionally, the stress tensors in different directions, the coordinates during the strain process, the stress tensors 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, including:

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

[0025] The data analysis program is used to process stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain, and statistically simulate the microstructure information of the ionomer melt before strain and the changes in stress and chain conformation during stretching.

[0026] Optionally, 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:

[0027] 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.

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

[0029] An optimization module, used for optimizing the initial box including the ionomer model by introducing the interaction force between bonded particles and the mechanical model under the canonical ensemble, so as to obtain an optimized box; the ionomer model is a model obtained by modeling the main molecular chain of the ionomer material;

[0030] A size change monitoring module, used to introduce the electrostatic interaction potential between ions and perform real-time monitoring of the size change of the optimized box under the NPT ensemble, and determine the size of the box when the size change is within a preset change range;

[0031] An equilibrium state monitoring module is used to 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, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt.

[0032] A stretching and shearing module, used for performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, respectively, to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain;

[0033] The processing module is used to process the stress tensors in different directions, the coordinates during the strain process, 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 present application provides a simulation analysis method for stretching and shearing of ionomer materials, including introducing the interaction force between bonded particles and the mechanical model under the canonical ensemble to optimize the initial box including the ionomer model to obtain an optimized box; the ionomer model is a model obtained after modeling the main molecular chain of the ionomer material; introducing the electrostatic interaction potential between ions, and monitoring the size change of the optimized box in real time under the NPT ensemble, and determining the box size when the size change is within a preset change range; monitoring whether the optimized box under the box size is in equilibrium, if the optimized box under the box size is in equilibrium, then 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 respectively to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain; processing the stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain to obtain microstructure information of the ionomer equilibrium melt and changes in stress and chain conformation during stretching. In the canonical ensemble, the present application introduces the interaction force between bonded particles and the mechanical model to optimize the initial box including the ionomer model, introduces the electrostatic interaction potential between ions, and monitors the size change of the optimized box in real time under the NPT ensemble. When the optimized box is in equilibrium, the simulation is continued under the canonical ensemble to obtain the ionomer equilibrium melt. The present application optimizes the box including the ionomer molecular model based on the interaction force between bonded particles, the electrostatic interaction strength between ions that affects the mechanical properties of the ionomer, the size and other factors, and performs non-equilibrium stretching on the simulated ionomer equilibrium melt. and non-equilibrium shear, to achieve coarse-grained molecular dynamics simulation of the mechanics and microstructure of ionomer materials under tension and shear, and process the stress tensors in different directions, the coordinates during the strain process, the stress tensors and the coordinates during the strain process to obtain the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process. The microscopic aggregate clusters inside the ionomer are characterized by static structure factors, and the size changes of the main chain of ionomer molecules under tension and shear are simulated, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, which can improve the accuracy of the simulation analysis of the stretching and shearing of ionomer materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

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

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

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

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

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

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

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

[0047] Figure 8 A graph showing changes in stress / strain rate over time at different shear rates and changes in mean square gyration radius over shear for a sample disclosed in the present application;

[0048] Fig. 9 This is a schematic structural diagram of a simulation analysis device for stretching and shearing of ionomer materials disclosed in the present application;

[0049] Fig.10 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Telechelic ionomers are associative polymers with ions connected by covalent bonds 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 gives this type of polymer unique mechanical and electrical properties, allowing it to be used in 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 lead to the inability to extrude from the extruder at a reasonable rate to produce useful products; and if it is extruded slowly, even if a 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 and it will be difficult to obtain the desired shape. On the contrary, if the viscosity is too low, the material cannot maintain its shape and cannot be used in practice. If the brittle toughness and mechanical strength of the ionomer material are adjusted by experimental trial and error to adjust the functional groups, counterion size and dielectric constant on the ionomer main chain, it will undoubtedly cause a waste of manpower and financial resources. It can be seen from the above that how to achieve coarse-grained molecular dynamics simulation of the mechanics and microstructure of ionomer materials under tension and shear and improve the accuracy of simulation analysis of tension and shear of ionomer materials are problems to be solved in this field.

[0052] See also Figure 1 As shown, the embodiment of the present invention discloses a simulation analysis method for stretching and shearing of ionomer materials, which may specifically include:

[0053] Step S11: Under the canonical ensemble, the interaction force between 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 molecular chain of the ionomer material.

[0054] In this embodiment, the initial number density is set, and the side 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 side length and the canonical system, the FENE bond interaction or Harmonic bond potential and the mechanical model between the bonded particles are introduced, and the initial truncation distance is set, and the initial box including the ionomer model is optimized to obtain the optimized box; the mechanical model includes the LJ potential function of the non-bonded interaction between particles.

[0055] The present invention changes the electrostatic interaction strength between telechelic ionomers by changing the dielectric constants of anions and cations in the model while keeping the length of the coarse-grained polymer main chain and the number of ions at the end of the telechelic ionomer chain unchanged. Figure 2As shown, the red particles are neutral particles, the blue particles are anions, and the yellow particles are cations. The construction process of the ionomer model is as follows: first, 48 neutral particles connected by covalent bonds are constructed, and then a particle is connected at both ends with the same covalent bond, and the types of these two particles are distinguished from the previous 48 particles. In addition, two free particles are selected, and the types are distinguished from the two particles on the main chain. Adding 500 polymer chains in this way corresponds to 1000 terminal ions and 1000 free ions. These 1000 terminal ions correspond to anionic functional groups (for example: carboxylate, sulfonate, etc.), and 1000 cations can be analogously corresponding to Na+ (sodium ion), K+ (potassium ion), Cs+ (cesium ion), etc. This model coarse-grains the ionomer polymer material into a polymer chain connected by a single rigid sphere and a single rigid sphere that moves freely, and adjusts the strength of the internal association network of the ionomer material by changing the interaction strength between anions and cations and the size of the cations. All particle information, bond information, dihedral information, and initial velocity information are written in Python. You can also use Material Studio software to build the initial model, and you can also use the create_box, create_atoms, regin and other instructions in LAMMPS (Large-scale Atomic / Molecular Massively ParallelSimulator) software to build the model.

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

[0057] Step S12: introducing the electrostatic interaction potential between ions, and monitoring the size change of the optimized box in real time under the NPT ensemble, and determining the box size when the size change is within a preset range.

[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. Then, the steps are run under the NPT ensemble, and the size change of the optimized box is monitored in real time. When the size change is within the preset range of change, the box size is determined.

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

[0060] Step S13: monitoring 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, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt.

[0061] In this embodiment, it is determined whether the size change of the optimized box is within a preset range of change. If the size change is within the preset range of change, 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 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.

[0062] On the basis of step S12, the average size of the area with relatively stable box size is taken as the box size of this step, and then on this basis, an appropriate number of steps are run in the NVT ensemble. During the simulation, the energy changes such as the Coulomb potential and the total potential energy in the system are monitored. When each energy tends to be stable, it means that the system has reached an equilibrium state. At this time, the simulation result obtained is an ionomer equilibrium melt.

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

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

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

[0066] Step S15: Processing the stress tensors in different directions, the coordinates during the strain process, 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.

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

[0068] In this embodiment, a data analysis program is written in Fortran language, and statistical simulation is performed to obtain stress tensors in different directions, coordinates during strain, stress tensors, and coordinates during strain. The data analysis program is used to process stress tensors in different directions, coordinates during strain, stress tensors, and coordinates during strain. In addition to using Fortran language to write the calculation program, it can also be written in Python, C / C++, and other programming languages. For the static structure factor and mean square gyration radius, the compute command in 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 using the data analysis program includes:

[0069] The static structure factor is calculated for the equilibrium melt using the following formula:

[0070] ;

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

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

[0073] ;

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

[0075] After obtaining the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during stretching, the preset visualization software is used to visualize the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during stretching, presenting the changes in the molecular main chain structure and ionic cluster morphology of the ionomer main chain in equilibrium, stretching, and shearing; in addition, in addition to using Ovito software for visualization, VMD software or Python programming language can also be used for drawing.

[0076] Taking the stretching / shearing simulation of ionomer melts with the same electrostatic interaction strength and the same cation size as an example, the simulation process is as follows: Figure 3 As shown, (1) determine the telechelic ionomer model with different electrostatic interaction strengths: in this model, each polymer chain is composed of 50 particles, with a total of 500 polymers, corresponding to 1000 free cations, and each chain has anions at both ends; (2) remove unreasonable structures in the custom initial structure: set the initial number density to 0.001, introduce the FENE bond interaction between bonded particles and the LJ potential function of non-bonded interaction between particles, set the cutoff distance to 1.12246, ensure that the non-bonded interaction between particles in the system is only repulsive, and run an appropriate number of steps to eliminate unreasonable structures in the system; (3) obtain the size of the ionomer equilibrium melt box: following the result of the previous step, set the cutoff distance of non-bonded interaction to 2.5, ensure that there is an attractive effect when the particle distance 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 an appropriate number of steps under the NPT ensemble, monitor the size change of the simulation box during the process, and run an appropriate number of steps again when the size change is relatively small; (4) fully relax the ionomer melt under the NVT ensemble to obtain an equilibrium melt. The static structure factors of the ions in the equilibrium melt of the ionomer under different electrostatic interaction strengths are as follows: Figure 4As shown: the average size of the area with relatively stable box size in the previous step is used as the simulation box size of this step, and then on this basis, an appropriate number of steps are run in the NVT ensemble. During the process, the energy changes such as Coulomb potential and total potential energy in the system are monitored. When each energy tends to be stable, it means that the system has reached equilibrium. The simulation result obtained at this time is the equilibrium melt of the ionomer; (5) Non-equilibrium stretching is performed on the equilibrium melt with different electrostatic interaction strengths; (6) Non-equilibrium shear is performed on the equilibrium melt with different electrostatic interaction strengths; (7) Data analysis of the results: The data analysis program is written in Fortran language to calculate the static structure factor of the ion for the obtained equilibrium melt. The microstructure information of the ionomer melt before strain and the changes in stress and chain conformation during stretching / shearing are obtained by statistical simulation; (8) The changes in the molecular main chain structure and ion cluster morphology of the ionomer main chain with different electrostatic interaction strengths at equilibrium, stretching, and shearing are presented using Ovito software. The polymer melt in the ionomer simulation box is shown as follows: Figure 5 The ion cluster structure of the simulated ionomer equilibrium melt is shown in Figure 6 shown.

[0077] Taking the stretching / shearing simulation of ionomer melts with different cation sizes and the same electrostatic interaction strength as an example, the specific simulation process is as follows: (1) Construct an ionomer model. In this model, each polymer chain is composed of 50 particles, and there are a total of 500 polymers, corresponding to 1000 free cations. The two ends of each chain are anions. The size of the cation is set to 0.5 times, 1.0 times, and 1.5 times that of the anion. The electrostatic interaction strength between ions is set to be consistent, such as 0.5, 5.0, etc.; (2) Set the initial number density to 0.001, and calculate the edge of the initial box through the total number of particles. long, under this box length, using the NVT ensemble, introduce the FENE bond interaction between bonded particles and the LJ potential of non-bonded interaction between particles, set the cutoff distance to 1.12246, ensure that the non-bonded interaction between particles in the system is only repulsive, and run an appropriate number of steps to eliminate the unreasonable structure in the system; (3) Following the result of the previous step, set the cutoff distance of non-bonded interaction to 2.5, ensure that there is an attractive effect when the particle distance 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 an appropriate number of steps under the NPT ensemble, monitor the size changes of the simulation box during the process, and run an appropriate number of steps when the size changes relatively little; (4) Use the average size of the area where the box size is relatively stable in the previous step as the simulation box size of this step, and then run an appropriate number of steps in the NVT ensemble on this basis, monitor the energy changes such as Coulomb potential and total potential energy in the system during the process. When each energy tends to be stable, it means that the system has reached an equilibrium state. The simulation result obtained at this time is an ionomer equilibrium melt; (5) Perform non-equilibrium stretching on equilibrium melts with different electrostatic interaction strengths; (6) Perform non-equilibrium shearing on equilibrium melts with different electrostatic interaction strengths; (7) Use Fortran language to write a data analysis program to calculate the static structure factor of the ion for the equilibrium melt. The microstructural information of the ionomer melt before strain and the changes in stress and chain conformation during stretching / shearing obtained by statistical simulation, the stress-strain curves of the samples at different stretching rates and the changes in the mean square gyration radius with stretching are shown in the figure. Figure 7 As shown in Figure 2, the stress / strain rate of the sample at different shear rates changes with time and the mean square gyration radius changes with shear. Figure 8 As shown, Figure 7 is the change trend of stress-strain curve and mean square gyration radius of ionomer melt when the stretching rate is 0.001 and 0.0001, Figure 8 It is the stress-strain curve and the changing trend of the mean square gyration radius of the ionomer melt at different shear rates; (8) It visualizes the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process.

[0078] It can be seen that the present application can simulate the nonlinear stretching of ionomer melts with the same ion electrostatic interaction and different counterion sizes, and can also simulate the nonlinear stretching of ionomer melts with different ion electrostatic interactions and the same counterion size.

[0079] In this embodiment, under the canonical ensemble, the interaction force between 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 after modeling the main molecular 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, and when the size change is within a preset range of change, the box size is determined; it is monitored whether the optimized box under the box size is in equilibrium, and if the optimized box under the box size is in equilibrium, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt; the ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain; the stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain are processed to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during stretching. In the canonical ensemble, the present application introduces the interaction force between bonded particles and the mechanical model to optimize the initial box including the ionomer model, introduces the electrostatic interaction potential between ions, and monitors the size change of the optimized box in real time under the NPT ensemble. When the optimized box is in equilibrium, the simulation is continued under the canonical ensemble to obtain the ionomer equilibrium melt. The present application optimizes the box including the ionomer molecular model based on the interaction force between bonded particles, the electrostatic interaction strength between ions that affects the mechanical properties of the ionomer, the size and other factors, and performs non-equilibrium stretching on the simulated ionomer equilibrium melt. and non-equilibrium shear, to achieve coarse-grained molecular dynamics simulation of the mechanics and microstructure of ionomer materials under tension and shear, and process the stress tensors in different directions, the coordinates during the strain process, the stress tensors and the coordinates during the strain process to obtain the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process. The microscopic aggregate clusters inside the ionomer are characterized by static structure factors, and the size changes of the main chain of ionomer molecules under tension and shear are simulated, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, which can improve the accuracy of the simulation analysis of the stretching and shearing of ionomer materials.

[0080] See also Fig. 9 As shown, the embodiment of the present invention discloses a simulation analysis device for stretching and shearing of ionomer materials, which may specifically include:

[0081] The optimization module 11 is used to optimize the initial box including the ionomer model by introducing the interaction force between the 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 to monitor the size change of the optimized box in real time under the NPT ensemble, and to determine the size of the box when the size change is within a preset range of change;

[0083] An equilibrium state monitoring module 13 is used to 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, the simulation is continued 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 strain, stress tensors, and coordinates during strain;

[0085] The processing module 15 is used to process the stress tensors in different directions, the coordinates during the strain process, 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 this embodiment, under the canonical ensemble, the interaction force between 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 after modeling the main molecular 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, and when the size change is within a preset range of change, the box size is determined; it is monitored whether the optimized box under the box size is in equilibrium, and if the optimized box under the box size is in equilibrium, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt; the ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain; the stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain are processed to obtain the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during stretching. In the canonical ensemble, the present application introduces the interaction force between bonded particles and the mechanical model to optimize the initial box including the ionomer model, introduces the electrostatic interaction potential between ions, and monitors the size change of the optimized box in real time under the NPT ensemble. When the optimized box is in equilibrium, the simulation is continued under the canonical ensemble to obtain the ionomer equilibrium melt. The present application optimizes the box including the ionomer molecular model based on the interaction force between bonded particles, the electrostatic interaction strength between ions that affects the mechanical properties of the ionomer, the size and other factors, and performs non-equilibrium stretching on the simulated ionomer equilibrium melt. and non-equilibrium shear, to achieve coarse-grained molecular dynamics simulation of the mechanics and microstructure of ionomer materials under tension and shear, and process the stress tensors in different directions, the coordinates during the strain process, the stress tensors and the coordinates during the strain process to obtain the microstructural information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process. The microscopic aggregate clusters inside the ionomer are characterized by static structure factors, and the size changes of the main chain of ionomer molecules under tension and shear are simulated, so as to explain the mechanism behind the stress response of the ionomer material under different flow fields, which can improve the accuracy of the simulation analysis of the stretching and shearing of ionomer materials.

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

[0088] A side length calculation module, used for setting an initial number density and calculating a side length of an initial box including an ionomer model based on the initial number density and a total number of particles;

[0089] The initial box optimization module is used to introduce FENE bond interaction or Harmonic bond potential and mechanical model between bonded particles under the edge length and the regular system, and set the initial cutoff distance to optimize the initial box including the ionomer model; the mechanical model includes the LJ potential function of non-bonded interaction between particles.

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

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

[0092] In some specific embodiments, the balance state monitoring module 13 may specifically include:

[0093] A box size determination module, used 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, used for running 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;

[0095] The simulation module is used for continuing the simulation under the canonical ensemble if the energy change in the optimized box under the box size is in a balanced state, so as to obtain an ionomer equilibrium melt.

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

[0097] The non-equilibrium stretching module is used to perform non-equilibrium stretching on the ionomer equilibrium melt using the deform command with the trate option in the local box;

[0098] The non-equilibrium shear module is used to perform non-equilibrium shear on ionomer equilibrium melts using the deform command with the option etrate in the local.

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

[0100] A program writing module, used for writing a data analysis program based on a program writing language; the program writing language includes Fortran language;

[0101] The statistical module is used to process the stress tensors in different directions, the coordinates during the strain process, the stress tensors and the coordinates during the strain process using the data analysis program, and statistically simulate the microstructure information of the ionomer melt before strain and the changes in stress and chain conformation during the stretching process.

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

[0103] The visualization module is used to visualize the microstructure information of the ionomer equilibrium melt and the changes in stress and chain conformation during the stretching process using preset visualization software; the visualization software includes Ovito.

[0104] Fig.10 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 20 may 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 used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the simulation analysis method of ionomer material stretching and shearing performed by the electronic device disclosed in any of the aforementioned embodiments.

[0105] In this embodiment, the power supply 23 is used 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 the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

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

[0107] The operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20, so as to realize the operation and processing of the data 223 in the memory 22 by the processor 21, which can be Windows, Unix, Linux, etc. In addition to including a computer program that can be used to complete the simulation analysis method of ionomer material stretching and shearing performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can also further include a computer program that can be used to complete other specific tasks. In addition to including data transmitted from an external device received by the simulation analysis device for stretching and shearing of ionomer materials, the data 223 can also include data collected by its own input and output interface 25, etc.

[0108] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0109] Furthermore, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored. When the computer program is loaded and executed by a processor, the steps of the simulation analysis method for stretching and shearing of ionomer materials disclosed in any of the aforementioned embodiments are implemented.

[0110] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used 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 "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0111] The above is a detailed introduction to the simulation analysis method, device, equipment and storage medium for stretching and shearing of ionomer materials provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A simulation analysis method for stretching and shearing of ionomer materials, characterized in that: include: Under the canonical ensemble, the interaction force between 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 molecular chain of the ionomer material; Introducing the electrostatic interaction potential between ions, and monitoring the size change of the optimized box in real time under the NPT ensemble, and determining the size of the box when the size change is within a preset range of change; 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; The ionomer equilibrium melt is subjected to non-equilibrium stretching and non-equilibrium shearing respectively to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain; The stress tensors in different directions, the coordinates during the strain process, the stress tensors 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: The method of optimizing the initial box including the ionomer model by introducing the interaction force between bonded particles and the mechanical model under the canonical ensemble includes: Setting an initial number density, and calculating a side length of an initial box including an ionomer model based on the initial number density and a total number of particles; Under the edge length and the canonical system, a FENE bond interaction or harmonic bond potential and a mechanical model between bonded particles 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.

3. The simulation analysis method of ionomer material stretching and shearing according to claim 1, characterized in that: 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, including: The initial cutoff distance is modified, the electrostatic interaction potential between ions is introduced, and the dielectric constant parameters are set, and then the steps are run under the NPT ensemble to monitor the size change of the optimized box in real time.

4. 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 change range, the box size is determined; whether the optimized box under the box size is in an equilibrium state is monitored, and if the optimized box under the box size is in an equilibrium state, the simulation is continued under a canonical ensemble to obtain an ionomer equilibrium melt, including: Determine whether the size change of the optimized box is within a preset range, and if the size change is within the preset range, determine 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.

5. 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 deform command with the option trate in the local area is used to perform non-equilibrium stretching on the ionomer equilibrium melt; The ionomer equilibrium melt is subjected to nonequilibrium shearing using the deform command with the etrate option in the local context.

6. The simulation analysis method of ionomer material stretching and shearing according to claim 1, characterized in that: The stress tensors in different directions, the coordinates during the strain process, the stress tensors 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, including: 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, coordinates during strain, stress tensors and coordinates during strain, and statistically simulate the microstructure information of the ionomer melt before strain and the changes in stress and chain conformation during stretching.

7. The simulation analysis method for stretching and shearing of ionomer materials according to any one of claims 1 to 6, 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.

8. A simulation analysis device for stretching and shearing of ionomer materials, characterized in that: include: An optimization module, used for optimizing the initial box including the ionomer model by introducing the interaction force between bonded particles and the mechanical model under the canonical ensemble, so as to obtain an optimized box; the ionomer model is a model obtained by modeling the main molecular chain of the ionomer material; A size change monitoring module, used to introduce the electrostatic interaction potential between ions and perform real-time monitoring of the size change of the optimized box under the NPT ensemble, and determine the size of the box when the size change is within a preset change range; An equilibrium state monitoring module is used to 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, the simulation is continued under the canonical ensemble to obtain an ionomer equilibrium melt. A stretching and shearing module, used for performing non-equilibrium stretching and non-equilibrium shearing on the ionomer equilibrium melt, respectively, to obtain stress tensors in different directions, coordinates during strain, stress tensors and coordinates during strain; The processing module is used to process the stress tensors in different directions, the coordinates during the strain process, 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.

9. 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 as claimed in any one of claims 1 to 7.

10. 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 as claimed in any one of claims 1 to 7 is implemented.

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