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CN-121973371-A - Intelligent control system and method for dynamically adjusting prestress of composite material

CN121973371ACN 121973371 ACN121973371 ACN 121973371ACN-121973371-A

Abstract

The invention relates to the technical field of composite material forming processing, in particular to an intelligent control system and a method for dynamically adjusting the prestress of a composite material, wherein the system is designed according to an execution layer, a data processing layer and a decision layer in a layered manner, the execution layer comprises a layering belt, a prestress test table and a curing furnace, the test table adopts a fixed table top and a bottom plate which are arranged up and down, a left support roller assembly and a right support roller assembly are symmetrically arranged on two sides of the test table top, the bottom of the floating table top is provided with a height adjusting bolt, and the prestress adjustment module and a prestress induction module are matched to realize the prestress adjustment and control of the layering belt; the data processing layer completes signal conversion, and the decision layer generates an adjustment strategy through multi-algorithm fusion analysis. The method comprises five steps of preparation, initialization, data acquisition and processing, dynamic regulation and control and ending, and accurate dynamic regulation and control of the prestress in the whole curing process is realized based on a closed-loop process. The method solves the problem of member defects caused by residual stress, improves the forming precision and mechanical property, and is suitable for forming and processing high-end composite materials.

Inventors

  • LI XUELEI
  • TIAN HAOBIN
  • LI FANGFANG
  • ZENG WENLEI

Assignees

  • 上海第二工业大学

Dates

Publication Date
20260505
Application Date
20260123

Claims (10)

  1. 1. An intelligent control system for dynamically adjusting prestress of a composite material, comprising: The system comprises an execution layer, a pre-stressing test bed, a layer-paving belt (1) and a curing furnace for providing a curing environment, wherein the pre-stressing test bed comprises a fixed table top (18) and a bottom plate (6) which are arranged up and down, a floating table top (2) is movably arranged on the fixed table top (18), a height adjusting bolt (22) is arranged at the bottom of the floating table top (2), a left supporting roller assembly (23) and a right supporting roller assembly (24) are symmetrically arranged at two sides of the fixed table top (18), one end of the layer-paving belt (1) is connected with the pre-stressing adjustment module through the left supporting roller assembly (23), and the other end of the layer-paving belt (1) is connected with the pre-stressing induction module (7) through the right supporting roller assembly (24) so as to realize pre-stressing adjustment and monitoring of the layer-paving belt (1) horizontally paved on the surface of the floating table top (2), and the layer-paving belt (1) is formed by paving prepreg materials on line and implanting a sensor; The system comprises a data processing layer, a tension and pressure sensor data acquisition unit and a data processing unit, wherein the data processing layer comprises an FBG demodulator and a tension and pressure sensor data acquisition unit, the FBG demodulator is used for demodulating optical signals related to stress and strain in the curing process of the layering belt (1) acquired by an FBG on-line sensor into digital data; The decision layer comprises a data receiving, storing and displaying unit, an artificial intelligent platform and an intelligent control strategy generating unit, wherein the data receiving, storing and displaying unit is used for receiving multidimensional digital monitoring data uploaded by the FBG demodulator and the pull pressure sensor data acquisition unit and realizing data visualization display, the artificial intelligent platform is coupled with multidimensional data and a process curve and judges a stress balance state through multi-algorithm fusion analysis, and the intelligent control strategy generating unit generates a prestress adjustment strategy according to an analysis result and converts the prestress adjustment strategy into a driving signal to be sent to the prestress adjustment module.
  2. 2. The intelligent control system for dynamically adjusting prestress of composite materials according to claim 1, wherein the prestress test bed further comprises a support column (5), a guide rail (12), a first sliding block (13), a first sliding block connecting plate (14), a second sliding block (21) and a second sliding block connecting plate (19), the support column (5) is arranged between the fixed table top (18) and the bottom plate (6), the guide rail (12) is fixed on the fixed table top (18), the first sliding block (13) and the second sliding block (21) are respectively and slidably connected to two end areas of the guide rail (12), the prestress adjusting module is connected with the first sliding block (13), and the prestress sensing module (7) is connected with the second sliding block (21).
  3. 3. The intelligent control system for dynamically adjusting the prestress of a composite material according to claim 2, wherein the prestress adjusting module comprises a prestress executing mechanism (9), a prestress applying plate (17) and a first composite material prepreg quick clamping mechanism (15), the prestress executing mechanism (9) and the first sliding block connecting plate (14) are respectively connected with the prestress applying plate (17), the first sliding block connecting plate (14) is fixedly connected with the first sliding block (13), and the first composite material prepreg quick clamping mechanism (15) is arranged on the first sliding block connecting plate (14) and used for fixing one end of the layering belt (1).
  4. 4. The intelligent control system for dynamically adjusting the prestress of a composite material according to claim 2, wherein the prestress sensing module (7) comprises a sensor fixing seat (10), a tension pressure sensor (11), a tension pressure sensor connecting plate (16) and a second composite material prepreg quick clamping mechanism (20), wherein the sensor fixing seat (10) is fixedly connected with the bottom plate (6), one end of the tension pressure sensor (11) is connected with the sensor fixing seat (10), the other end of the tension pressure sensor connecting plate is connected with the tension pressure sensor connecting plate (16), the tension pressure sensor connecting plate (16) is connected with the second slider connecting plate (19), the second slider connecting plate (19) is fixedly connected with the second slider (21), and the second composite material prepreg quick clamping mechanism (20) is arranged on the upper surface of the second slider connecting plate (19) and is used for fixing the other end of the laying belt (1).
  5. 5. An intelligent control system for dynamically adjusting the prestress of a composite material according to claim 1, characterized in that the height of a floating deck (2) can be fine-tuned by rotating the height adjusting bolts (22) to ensure a complete fitting of the decking strip (1) to the floating deck (2).
  6. 6. The intelligent control system for dynamically adjusting the prestress of a composite material according to claim 1, wherein the prestress test bed further comprises a heat insulation sealing unit (8), the heat insulation sealing unit (8) is arranged below the fixed table top (18) and is connected with the bottom plate (6), heat insulation cotton with changeable thickness is embedded in the heat insulation sealing unit, the thickness of the heat insulation cotton is matched with the curing temperature requirement of the layering belt (1) and is used for isolating the high temperature of the curing furnace and preventing components below the fixed table top (18) from being damaged by the high temperature.
  7. 7. The intelligent control system for dynamically adjusting prestress of composite material according to claim 1, wherein the left support roller assembly (23) and the right support roller assembly (24) are identical in structure and comprise support roller mounting seats (3) and support rollers (4), and the support rollers (4) are connected to the support roller mounting seats (3) through bearings and are used for reducing friction in the conveying process of the layering belt (1).
  8. 8. A control method of an intelligent control system for dynamically adjusting prestress of composite material based on any one of claims 1-7, comprising the steps of: S1, a preparation stage, namely paving and pasting composite material prepreg to form a paving belt (1), implanting FBG on-line sensors into the interior and the surface of the paving belt (1), clamping and fixing one end of the paving belt (1) on a first composite material prepreg quick clamping mechanism (15) through a left supporting roller assembly (23), clamping and fixing the other end of the paving belt on a second composite material prepreg quick clamping mechanism (20) through a right supporting roller assembly (24), and rotating a height adjusting bolt (22) to enable the paving belt (1) to be flatly attached to the surface of a floating table top (2); S2, in an initialization stage, according to the curing temperature requirement of the layering belt (1), selecting a heat-insulating cotton embedded heat-insulating sealing unit (8) with corresponding thickness and fixing the heat-insulating cotton embedded heat-insulating sealing unit on a bottom plate (6), transferring a prestress test bed to a temperature uniform area in a curing furnace, applying preset initial prestress to the layering belt (1) through a prestress adjusting module, and monitoring in real time through a tension pressure sensor (11) until a prestress value is stabilized in a preset range; S3, in the whole curing process, the FBG acquires stress-strain optical signals of the layering belt (1) in real time by an online sensor, and a pulling pressure sensor (11) acquires pulling pressure analog electrical signals of the layering belt (1) and temperature signals in a curing furnace by a temperature sensor; s4, a dynamic regulation stage, wherein the data receiving, storing and displaying unit stores and visually displays multidimensional digital data, the artificial intelligent platform invokes a preset algorithm, couples the digital data with a curing process curve, analyzes and judges the current stress balance state of the pavement belt (1), and if the stress state does not meet the preset requirement, the intelligent control strategy generating unit generates a targeted prestress regulation strategy, converts the targeted prestress regulation strategy into a driving signal and sends the driving signal to the prestress regulation module to control the prestress executing mechanism (9) to regulate the prestress of the pavement belt (1), and if the stress state meets the preset requirement, the current prestress parameter is maintained; And S5, ending the step of repeating the steps S3-S4 until the curing furnace completes the cooling process according to a preset process curve, and closing the curing furnace and each monitoring module to complete the curing and the prestress dynamic regulation of the laminated belt (1).
  9. 9. The intelligent control method for dynamically adjusting prestress of composite material according to claim 8, wherein in step S4, the artificial intelligent platform is integrated with at least two algorithms of CNN, SVM, random forest, particle swarm optimization, linear regression, decision tree, genetic algorithm.
  10. 10. The intelligent control method for dynamically adjusting the prestress of a composite material according to claim 8, wherein the prestress actuating mechanism (9) is a servo linear motor or a servo hydraulic cylinder.

Description

Intelligent control system and method for dynamically adjusting prestress of composite material Technical Field The invention relates to the technical field of composite material molding processing, in particular to an intelligent control system and method for dynamically adjusting prestress of a composite material. The method is particularly suitable for accurately regulating and controlling the residual stress in the curing process of the carbon fiber reinforced polymer composite material, and belongs to the technical field of intelligent equipment for molding the composite material. Background The carbon fiber reinforced polymer composite material has excellent performances such as high specific strength, high specific modulus, corrosion resistance and the like, and is widely applied to high-end fields such as aerospace, rail transit, new energy and the like. The traditional solidification process of the carbon fiber reinforced polymer composite product comprises the links of heating, heat preservation, cooling and the like. In the early gel stage of curing, the interface between the resin and the fiber is not completely formed, so that the residual stress is difficult to accumulate obviously, and even in the later stage of curing reaction, the viscoelastic characteristic of the resin can relieve the residual stress generated in the curing process to a certain extent through the stress relaxation effect because the reaction process is in a high-temperature environment. However, in the final cooling stage of the curing process, the composite material undergoes a transition from a high temperature state to a room temperature environment, and due to the chemical shrinkage of the resin and the mismatch of the thermal expansion coefficients between the fibers and the matrix material, residual stress is often induced in the composite material, so that the degradation of the overall mechanical property and the structural efficiency of the material is caused, the performance and the reliability of the carbon fiber composite material are affected, deformation, warping and even cracking of the component are also caused, and the component is scrapped when serious. To mitigate these adverse effects, the residual stresses may be reduced in the prior art by optimizing curing process parameters, utilizing low temperature curing resin systems and fiber pre-stressing techniques, and the like. The fiber pre-stretching technology has the advantages that a certain initial strain field is formed in the composite material structure, the strain difference plays a role in compensating, warp or bending deformation generated in the solidification stage is counteracted after the pre-stress is released, and the fiber pre-stretching technology is considered as a preferable choice for improving the performance of the polymer matrix composite material, and can effectively adjust the stress level in the material, so that the mechanical performance of the material is improved. However, the existing fiber pre-stressing technology is to apply constant tension to the continuous carbon fiber before the composite material is solidified and maintain the continuous carbon fiber in the whole solidification process, and the method ignores the evolution rule of the residual stress, namely, the residual stress generated in the composite material is different in magnitude and different in action form in different solidification stages, and only constant pre-stressing is applied, so that the stress state in the composite material cannot be accurately regulated, and the fiber pre-stressing technology is restricted to play a larger action effect. Meanwhile, the existing test bed has the problems of disordered component marking, unreasonable layout of the supporting roller assembly, indistinguishable prestress adjustment and induction module, improper heat insulation structure position and the like, so that uneven tension transmission, low detection precision and easily damaged components due to high temperature are caused, the accuracy of prestress adjustment and control and the stability of the device are further influenced, and the molding quality and the industrialized application value of the composite material are restricted. Therefore, a new solution is needed to solve the above technical problems. Disclosure of Invention The invention aims to solve the problems of the prior art, and provides an intelligent control system and method for dynamically adjusting the prestress of a composite material, which are used for solving the problems of performance degradation and component defects caused by residual stress in the solidification and cooling stage of the composite material, and overcoming the defects of insufficient regulation precision and stability caused by the fact that the constant tension in the prior art cannot be adapted to dynamic change of stress and the layout and protection of a test bed are unreasonable. The above purpose is realiz