A digital twin method suitable for extrusion-drawing forming of an ultrahigh-strength steel shell

Abstract

The application discloses a digital twin method suitable for extrusion and drawing forming of an ultrahigh-strength steel shell, and the method comprises the following steps: based on the entity information digital twin modeling of the extrusion and drawing forming process of pre-pressing, reverse extrusion, positive extrusion and drawing, the process data and the digital twin model are realized in real time by using a data acquisition module, a data transmission module and an equipment monitoring module; and the material organization performance of the extrusion and drawing forming shell workpiece is predicted based on the digital twin model, and the forming process parameters are screened and optimized. The digital twin method suitable for the extrusion and drawing forming of the ultrahigh-strength steel shell can implement full-cycle real-time intelligent control on the forming process parameters, realizes the prediction and regulation of the target material organization, and has important significance for improving the length-diameter ratio of the formed shell, improving the forming quality and improving the production efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metal intelligent forming manufacturing, and particularly relates to a digital twin method suitable for extrusion and drawing forming of a super-high-strength steel shell. BACKGROUND

[0002] The super-high-strength steel shell is widely needed in the fields of aerospace, weapon equipment, etc., and the extrusion and forging forming of the super-high-strength steel shell is to forge and press the blank after forging by the way of free forging, and then to use a press to integrally extrude and form the shell forging in a special die. This production method saves raw materials, improves production efficiency and product quality, and is adopted by many domestic and foreign manufacturing enterprises. However, the extrusion stroke of the shell extrusion and forging is long, the temperature drops fast, if the heating temperature of the blank is not enough, cracking instability is prone to occur, and the extrusion force is too large to continue forming. If the heating temperature is too high, coarse recrystallized structure is formed, which leads to a large decrease in elongation of the product, and the forming quality cannot meet the use requirements. Therefore, it is urgent to introduce digital and intelligent means to monitor and control the forming manufacturing process, to realize accurate regulation and control of the material organization and performance, and to improve the quality stability and production efficiency.

[0003] The digital twin technology constructs a virtual model of a physical object in a virtual space through digital technology, integrates the real-time state of the simulated physical object based on different types of sensor data, sensor, operation history, etc., the simulation process is used as a mirror image of the physical production in the virtual space, for reflecting the whole life cycle process of the corresponding physical entity product, the state of the twin model and the physical object is compared, the deviation between them is analyzed, intervention and optimization are combined with the actual operation condition, and finally the feedback and control between the physical entity and the virtual model are realized. With the continuous intelligentization of manufacturing industry, the digital twin technology is gradually applied in the manufacturing industry, the combination of digital twin and product whole life cycle becomes an inevitable trend of the development of manufacturing industry, and has great application prospect in intelligent manufacturing.

[0004] Based on the digital twin technology, the digital twin method suitable for the extrusion and drawing forming of the super-high-strength steel shell is established by integrating the technical steps of process state data acquisition, digital twin modeling, macro and micro simulation, data mining optimization and equipment online control, the whole cycle real-time intelligent control of the forming process parameters is implemented, the prediction and regulation of the target material organization are realized, and it is of great significance to improve the length-diameter ratio of the shell, improve the forming quality and improve the production efficiency. SUMMARY

[0005] The application aims to provide a digital twin method suitable for the extrusion and drawing forming of an ultrahigh-strength steel shell, which collects the process state of the extrusion and drawing forming of the ultrahigh-strength steel shell online, combines a process system knowledge base and a digital twin database, processes the collected data online by using an optimization algorithm, controls the forming equipment in real time according to the optimized process parameters, and improves the organizational performance of the formed shell workpiece.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] A digital twin method suitable for the extrusion and drawing forming of an ultrahigh-strength steel shell, characterized in that it comprises an extrusion and drawing forming measurement and control system of the ultrahigh-strength steel shell and a digital twin platform. The data acquisition module in the measurement and control system acquires data of the process parameters in the extrusion and drawing forming process of the ultrahigh-strength steel shell, the data transmission module transmits the process parameter information to the digital twin platform, the digital twin platform comprises a database system, a forming simulation system, a microstructure prediction system, and a process optimization system, can optimize the forming process parameters online according to the reserves of the digital twin database, feed back the operation control instructions of the forming equipment, and implement real-time intelligent control of the extrusion and drawing forming of the ultrahigh-strength steel shell throughout the cycle through the equipment control module.

[0008] Further, the digital twin method suitable for the extrusion and drawing forming of the ultrahigh-strength steel shell is characterized in that the extrusion and drawing forming adopts a heating furnace to heat and keep the ultrahigh-strength steel blank workpiece, and adopts a multi-station extrusion and drawing forming equipment to realize the multi-station forming of the ultrahigh-strength steel shell, i.e. pre-pressing, reverse extrusion, positive extrusion, and drawing.

[0009] Further, the digital twin method suitable for the extrusion and drawing forming of the ultrahigh-strength steel shell is characterized in that the multi-station extrusion and drawing forming equipment uses one lower die and three punches for pressing, extruding, and drawing, is driven by a horizontal oil cylinder to move the slide horizontally, switches the upper die punches of different stations, and controls the movement of the die punches by the PLC control servo hydraulic system.

[0010] Further, the digital twin method suitable for the extrusion and drawing forming of the ultrahigh-strength steel shell is characterized in that the data acquisition module comprises a programmable logic controller (PLC), an electric thermocouple temperature sensor, an infrared temperature sensor, a temperature controller, and an equipment motion controller; the data transmission module comprises an Ethernet wired interface, a field data input and output control terminal, and a wireless controller for transmitting the collected temperature data and the operation information of the forming equipment, the operation information of the forming equipment includes the working time, the displacement and speed of the punch die under pressure, and other data information; and the equipment control module comprises a temperature controller and an equipment motion controller based on the PLC system.

[0011] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the database system manages the data information collected by the Internet of Things based on the MDC system software, the PDM system software manages the digital twin model library, the digital twin database, the process system database and the knowledge base; the forming simulation system is used for virtual entity modeling and process simulation in the production process based on the visual digital modeling software and the finite element software; the microstructure prediction system is used for microstructure performance prediction in the forming process based on the finite element software and the general mathematical software; and the process optimization system generates real-time control instructions of the forming equipment based on the data mining algorithm, the data reconstruction algorithm, the optimization algorithm and the PID control algorithm.

[0012] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the analog signals collected are converted into digital signals and transmitted to the field data input and output control terminal in a wired manner, the field data input and output control terminal communicates with the core switch through the wireless controller, and the collected data is transmitted to the computer workstation MDC system software.

[0013] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the temperature controller and the equipment motion controller based on the PLC system are connected to the field data input and output control terminal in an Ethernet wired manner, and then connected to the remote control terminal through the wireless controller to control the heating furnace temperature and the punch die motion by using the control program edited by the PID algorithm.

[0014] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the digital twin modeling objects include the profiling die, the extrusion die, the drawing die, the general die frame, the core die, the hydraulic system, the positioning mechanism, the guide mechanism and the multi-station sliding table; and the contents of the process simulation include the die motion, the die stress load, the plastic deformation, the temperature, the equivalent strain, the equivalent stress, the damage factor and the workpiece stability.

[0015] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the microstructure performance prediction method in the forming process is to predict the change of dislocation density in the forming process of the ultra-high strength steel based on the macro finite element of the material internal variable constitutive model, to transfer the boundary conditions of the finite element model to the cellular automaton model by using the grid re-division and re-mapping technology, and to visually predict the local microstructure grain size, phase change and recrystallization of the formed shell workpiece.

[0016] Further, the digital twin method suitable for the extrusion and drawing forming of the ultra-high strength steel shell is characterized in that: the data mining algorithm is based on a digital twin data reserve, and a mapping relationship between process parameters and organizational performance is established through a least square method and a linear regression mathematical optimization technique; the data reconstruction algorithm is based on a neural network model to perform three-dimensional reconstruction of a temperature field on the basis of temperature collection data; the online optimization algorithm realizes adaptive optimization design of the forming process parameters through BP neural network deep learning and a genetic algorithm, so as to ensure real-time control of the material organizational performance; and the PID control algorithm is used for real-time output of control instructions to a device controller, and an algorithm program is automatically edited and generated according to adaptive forming process parameters.

[0017] Compared with the prior art, the beneficial effects of the present application are that: the digital twin technology is used to establish a forming process digital twin model library, a database and a knowledge base, the digital mapping of the forming process parameters and the material organizational performance is realized through macro and micro simulation, the process parameters are optimized in real time according to the actual production process state, the running control instructions based on the optimization results of the process parameters are sent to the forming equipment online, the intelligent manufacturing of the ultra-high strength steel shell extrusion and drawing forming is realized, the length-diameter ratio of the formed shell is improved, the process system is optimized, the material organizational performance of the formed workpiece is improved, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a forming measurement and control system framework schematic diagram

[0019] Fig. 2 is a digital twin platform framework schematic diagram. DETAILED DESCRIPTION

[0020] In order to further understand the content of the present application, the following will be described in detail in conjunction with the drawings.

[0021] 35CrMnSiA ultra-high strength steel is used as the shell forming material, the shell forming process includes pre-pressing type → reverse extrusion → positive extrusion → drawing, the above-mentioned multi-process forming is realized by using a multi-station extrusion and drawing forming equipment, the equipment uses one lower die and three punches for pressing, extrusion and drawing, the horizontal cylinder pushes the slide table to move horizontally, the upper die punches of different stations are switched, and the die punch movement is controlled by the PLC control servo hydraulic system. The ultra-high strength steel blank is heated and kept warm by the heating furnace before pre-pressing forming. After pre-pressing, the process piece is heated, and the reverse extrusion is completed in one heating; the process piece is heated again, and the positive extrusion and drawing are continuously completed in one heating.

[0022] Based on the multi-process forming process of the ultra-high strength steel shell extrusion and drawing, the digital twin method of the ultra-high strength steel shell extrusion and drawing forming is composed of a measurement and control system ( Figure 1 ) and a digital twin platform ( Figure 2 ).

[0023] The temperature in the heating furnace and the heating time are collected by the thermocouple temperature sensor and the temperature controller, the multi-point temperature data of the surface of the forming process mold and the workpiece blank are collected by the distributed infrared temperature sensor, the mold working time, the displacement of the pressing, and the pressing speed are collected by the motion controller, the temperature sensor and the equipment controller are collected by the PLC acquisition device, and the analog signals collected are converted into digital signals and transmitted to the field data input / output terminal. Then, the collected data are transmitted into the MDC system software in the computer workstation through the communication with the core switch by the wireless controller, for managing the data information collected by the Internet of Things.

[0024] The PDM system software is used to manage the digital twin model library, the digital twin database, the process system database, and the knowledge base. The digital twin modeling is performed on the compression mold, the extrusion mold, the drawing and stretching mold, the general mold frame, the core mold, the hydraulic system, the positioning mechanism, the guide mechanism, and the multi-station sliding table based on the visual digital modeling software, to construct the digital twin model library. The finite element model with embedded internal variable material constitutive is used to simulate the multi-process forming process of the ultra-high strength steel shell pre-compression → reverse extrusion → positive extrusion → drawing, to simulate the mold movement, to predict the mold stress load, the process piece deformation, the temperature field, the equivalent strain, the equivalent stress, the damage factor, and the workpiece stability. The macro-scale numerical simulation dislocation density prediction results are synchronously transmitted to the micro-scale simulation model through the cross-scale boundary condition mapping and grid re-division and re-mapping technology. The cellular automata method is used to simulate and predict the local area grain size, recrystallization, phase change, and other microstructure evolution, to realize the visualization prediction of the local microstructure of the formed workpiece. The macro and micro simulation results are saved to the digital twin database managed by the PDM system software. Based on the reserved data of the digital twin database, the least squares and linear regression mathematical optimization technology are used to mine the twin data, to establish the digital mapping relationship between the extrusion and drawing forming process parameters of the ultra-high strength steel shell and the microstructure performance; the temperature collection data of the extrusion and drawing forming of the ultra-high strength steel shell are processed, the three-dimensional temperature field is reconstructed online through the neural network model, the average grain size of the material organization is less than 25 microns, the recrystallization degree is greater than 95%, the residual austenite is less than 5%, the maximum damage factor is less than 0.5, and the instability phenomenon does not occur as the forming optimization target. The BP neural network deep learning and genetic algorithm are used to realize the online design and optimization of the forming process parameters, to ensure the real-time control of the process parameters for the target material organization performance, and the PID control algorithm is used to automatically edit and generate the control instruction program of the forming equipment controller according to the optimized forming process parameters.

[0025] In the forming process, the equipment feedback optimization control command generated by the digital twin platform is received through the wireless controller, and then input to the temperature controller and motion controller based on the PLC system through the field data input and output control terminal in a wired manner, to realize real-time control of the heat treatment furnace and multi-station extrusion drawing forming equipment, and realize the intelligent forming manufacturing of ultra-high strength steel shell extrusion drawing based on digital twin technology.

Claims

1. A digital twin method suitable for extrusion-draw forming of ultra-high strength steel shell, characterized in that: A measurement and control system and a digital twin platform for extrusion and drawing forming of an ultra-high-strength steel shell are provided. The extrusion and drawing forming is based on a multi-station extrusion and drawing forming device to realize multi-station forming of an ultra-high-strength steel shell, including pre-pressing, reverse extrusion, positive extrusion and drawing, and based on a heating furnace to heat and keep the ultra-high-strength steel shell workpiece blank. The forming measurement and control system includes a data acquisition module, a data transmission module and a device control module, and is used for collecting and controlling the process state information of the extrusion and drawing forming of the ultra-high-strength steel shell. The digital twin platform includes a database system, a forming simulation system, a microstructure prediction system and a process optimization system, that is, through digital twin modeling, macro and micro visualization virtual simulation, mining and optimization of digital twin data, online intelligent control of the extrusion and drawing forming device of the ultra-high-strength steel shell is realized.

2. The digital twin method for extrusion-drawing forming of a shell of ultra-high strength steel according to claim 1, characterized in that: The multi-station extrusion and drawing forming device uses one lower die and three punches for pressing, extruding and drawing, and is driven by a horizontal oil cylinder to move the slide horizontally, switches the upper die punches of different stations, and controls the movement of the die punches by a PLC control servo hydraulic system.

3. The digital twin method for the extrusion and drawing forming of the ultra-high-strength steel shell according to claim 1, wherein the data acquisition module includes a programmable logic controller (PLC), an electric thermocouple temperature sensor, an infrared temperature sensor, a temperature controller and a device motion controller; the data transmission module includes an Ethernet wired interface, a field data input / output control terminal and a wireless controller for transmitting the collected temperature data and the operation information of the forming device, and the operation information of the forming device includes working time, punch die displacement and displacement speed; and the device control module includes a temperature controller and a device motion controller based on the PLC system.

4. The digital twin method for extrusion and drawing forming of ultra-high strength steel shell according to claim 1, characterized in that: the database system manages the data information collected by the Internet of Things based on the MDC system software, the PDM system software manages the digital twin model library, the digital twin database, the process system database and the knowledge base; the forming simulation system is used for virtual entity modeling and process simulation in the production process based on the visual digital modeling software and the finite element software. The microstructure prediction system is based on finite element software and general mathematical software for microstructure performance prediction in the forming process. The process optimization system is based on data mining algorithms, data reconstruction algorithms, optimization algorithms and PID control algorithms to generate real-time control instructions for the forming device.

5. The digital twin method for the extrusion and drawing forming of the ultra-high-strength steel shell according to claim 3, wherein the data acquisition module is mounted with the temperature sensor, the temperature controller and the device motion controller, converts the collected analog signals into digital signals and transmits them to the field data input / output control terminal, the field data input / output control terminal communicates with the core switch through the wireless controller, and the collected data is transmitted to the computer workstation MDC system software.

6. The digital twin method for the extrusion and drawing forming of the ultra-high-strength steel shell according to claim 3, wherein the temperature controller and the device motion controller based on the PLC system are connected to the field data input / output control terminal through the Ethernet wired interface, and are connected to the remote control terminal through the wireless controller to control the temperature of the heating furnace and the movement of the punch die according to the control program edited by the PID algorithm.

7. The digital twin method for the extrusion and drawing forming of an ultra-high strength steel shell according to claim 4, characterized in that the objects of the digital twin modeling include the compression die, the extrusion die, the drawing die, the universal die holder, the core die, the hydraulic system, the positioning mechanism, the guide mechanism, and the multi-station sliding table; and the content of the process simulation includes die movement, die stress load, process part deformation, temperature, equivalent strain, equivalent stress, damage factor, and workpiece stability.

8. The digital twin method for the extrusion and drawing forming of an ultra-high strength steel shell according to claim 4, characterized in that the microstructure and performance prediction method for the forming process is a macro finite element prediction of the change of dislocation density in the forming process of ultra-high strength steel based on a material internal variable constitutive model, a grid re-partitioning and remapping technology is used to transfer the boundary conditions of the finite element model to the cellular automaton model, and the local microstructure grain size, phase change, and recrystallization of the formed shell workpiece are visualized and predicted.

9. The digital twin method for the extrusion and drawing forming of an ultra-high strength steel shell according to claim 4, characterized in that the data mining algorithm is based on a digital twin data reserve, a mapping relationship between process parameters and microstructure and performance is established through least squares and linear regression mathematical optimization techniques; the data reconstruction algorithm is based on a neural network model to perform three-dimensional reconstruction of the temperature field from temperature acquisition data; the optimization algorithm is to realize adaptive optimization design of the forming process parameters through BP neural network deep learning and genetic algorithm, to ensure real-time control of the material microstructure and performance; and the PID control algorithm is used to output control instructions to the equipment controller in real time, and to automatically edit and generate algorithm programs according to the adaptive forming process parameters.

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