Residual stress regulation and control method for multi-field multi-parameter coupling of carbon fiber composite material laminated plate

Abstract

The invention provides a multi-field and multi-parameter coupled residual stress regulation and control method for a carbon fiber composite laminated plate. The method is suitable for preparing a molded anisotropic and thin-wall carbon fiber composite material and a product of the carbon fiber composite material. The method comprises seven single-multi-condition coupling forms such as a high-low temperature field and a load field, and multiple parameters of the load field comprise the vibration frequency f, the excitation force F and the clamping point position P on the platform. The multiple parameters of the temperature field comprise any node from the cryogenic temperature Tc (-196 DEG C) to the high temperature Th (220 DEG C), the heating rate hr, the cooling rate cr and the like. Vibration process parameters can be inserted into a global high-low temperature time axis at will, and a mechanism that complex regulation and control process coupling acts on materials and products is achieved. By means of the method, full-field residual stress regulation and control of the carbon fiber composite material and deformation control of the product can be achieved, the comprehensive performance of the product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of residual stress regulation of carbon fiber composite laminates, and in particular to a multi-field and multi-parameter coupled residual stress regulation method for laminates. Background Art

[0002] Carbon fiber composites are widely used in advanced manufacturing fields such as aerospace, electronics, and automobiles. However, during the curing process, due to the mismatch of thermal expansion coefficients between the fiber and the matrix, the different angles of ply-lamination, the material and the mold, and the complex manufacturing process coupled with multiple field parameters such as "heating-insulation-cooling + high pressure", the internal components of the composite material will produce uneven residual stress fields inside the material in order to maintain their own balance. Their existence greatly reduces the strength and precision of the composite material, and may induce problems such as matrix microcracks, interface debonding, and overall deformation and warping, affecting the quality and service life of the composite material and its products.

[0003] Therefore, for carbon fiber composite materials and their laminates with the best preparation process and performance properties, the residual stress control method of commonly used isotropic materials is transplanted to anisotropic carbon fiber composite materials. The residual stress is controlled by coupling multiple field parameters such as deep cooling-heating-vibration to homogenize the residual stress distribution between fiber-matrix and layer-layer. Their generation and reproduction are controlled earlier and actively, so that the materials and products have the advantages of good mechanical properties and stability. It also lays a methodological foundation for the high-quality, high-precision and high-efficiency application of composite materials and their products in the aerospace field. Summary of the invention

[0004] The purpose of the present invention is to regulate the problems of uneven residual stress distribution between fibers and matrices of carbon fiber composite materials, uneven deformation between layers, and deformation exceeding the use requirements. A multi-field and multi-parameter coupling residual stress regulation method for carbon fiber composite laminates is proposed.

[0005] In order to solve the above technical problems, the present invention provides a multi-field and multi-parameter coupled residual stress control method for laminated plates, comprising the following steps:

[0006] (1) First, carbon fiber laminates with different angle laying configurations are selected. The angle laying configurations include UDL [θ1 / … / θ1]s or MDL [θ1 / θ2 / θ3… / θ i ]s, where the fiber angle arrangement and total number of layers can be set and modified according to actual needs;

[0007] (2) The initial residual stress RS and deformation d of the composite laminate specimens of the fixed process batch are tested and analyzed. No less than 3 groups of parallel tests should be carried out under each condition, and the average value σ0 is taken as the control group of basic data;

[0008] (3) Setting a multi-parameter load field, including whether the specimen is clamped c, platform vibration frequency f, exciter eccentricity angle θ, excitation force F, clamping point position P on the platform, and other parameters. Such vibration parameters can be used to realize the research on vibration aging process control;

[0009] (4) Setting a multi-parameter temperature field, including the high temperature heating rate hr, the high temperature aging temperature Th, the deep cooling rate cr, the deep cooling aging temperature Tc, and whether to air cool ac after the process is completed;

[0010] (5) Using the process parameters in (4) and (5) above, multi-field coupling mode control is performed, including vibration aging VSR-#1, high temperature aging TSR-#2, low temperature aging CSR-#3, cold and hot aging CTSR-#4, hot vibration aging TVSR-#5, cold and hot aging CTSR-#6 and cold-heat-vibration coupled aging CTVSR-#7;

[0011] (6) Detect the residual stress distribution and deformation of the specimen after multiple process parameters are adjusted, and make records under each parameter, which are recorded as σ according to the process type. #1 -σ #7 ;

[0012] (7) Analyze the effect after regulation and compare it with the initial (before regulation) data. Analyze the efficiency η after regulation by using the method of fixed parameter setting and the method of comparing different process forms;

[0013]

[0014] Where η is the regulated elimination rate, σ i is the residual stress of different process configurations, and σ0 is the magnitude of the initial residual stress.

[0015] (8) Through a series of processes such as detection and analysis of the above steps (1) to (7), the residual stress control process research of carbon fiber laminates with different configurations can be met.

[0016] The beneficial effects of the present invention are as follows: the invention can meet the requirements of all-round and multi-parameter residual stress control research after carbon fiber composite laminates are prepared under different thicknesses and different angle laying configuration processes. The method can complete the pre-detection, control and analysis of materials with high quality and high efficiency, making up for the shortcomings of cumbersome process methods and uncertain parameters. It not only provides method support for designers, but also shortens the manufacturing cycle and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a technical flow chart of a multi-field and multi-parameter coupled residual stress control method for carbon fiber composite laminates;

[0018] Figure 2 Methods for selecting vibration platform points and setting the eccentric angle of the vibrator;

[0019] Figure 3 is the frequency and acceleration distribution at each point and eccentricity angle;

[0020] Figure 4 Parameter setting method for high and low temperature field loads;

[0021] Figure 5 This is the result of the gradient residual stress distribution of the composite material along the layer depth. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings and embodiments. However, the protection scope of the present invention is not limited by the specific implementation methods, and it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all implementation cases.

[0023] like Figure 1 The figure shows a technical flow chart of a multi-field and multi-parameter coupled residual stress control method for a carbon fiber composite laminate; the specific steps include:

[0024] Step (1): First, select carbon fiber laminates with different angle laying configurations, including UDL [θ1 / … / θ1]s or MDL [θ1 / θ2 / θ3… / θ i ]s, where the fiber angle arrangement and total number of layers can be set and modified according to actual needs;

[0025] Step (2): using the composite laminate selected in step (1), using blank materials from a fixed curing process batch, and processing them into test pieces of the same size, and testing and analyzing the initial residual stress RS and deformation d. No less than 3 groups of parallel tests should be carried out under each condition, and the average value σ0 is taken as the control group of basic data;

[0026] Step (3): Further, Figure 2 As shown, a multi-parameter load field is set. This includes whether the specimen is clamped c, the rotation speed causes the platform vibration frequency f to change, the exciter eccentricity angle θ = 5° / 10° / 20° / 30°..., the induced exciting force F changes, the clamping point position P on the platform (123 on the left, 456 in the middle, 789 on the right), and a series of other parameters. Through the coupling of such vibration parameters, the vibration aging process control research can be realized;

[0027] Intuitive, such as Figure 3 As shown, the characteristic curves and corresponding resonance peak positions of the clamping point P, eccentric angle θ, frequency f and acceleration a collected in the above step (3) are shown. Figure 3 Several forms of .

[0028] Step (4): Figure 4 As shown, a multi-parameter temperature field is set, which includes the high temperature heating rate hr, high temperature aging temperature Th, deep cooling cooling rate cr, deep cooling aging temperature Tc, whether to air cool ac after the process is completed, and the combination form includes full thermal aging, full deep cooling aging, hot and cold cycle aging and vibration aging parameters inserted in any insulation time period node in the middle.

[0029] Step (5): using the process parameters in (4) and (5) above, multi-field coupling mode control is performed, including vibration aging VSR-#1, high temperature aging TSR-#2, low temperature aging CSR-#3, cold and hot aging CTSR-#4, hot vibration aging TVSR-#5, cold and hot aging CTSR-#6 and cold-heat-vibration coupled aging CTVSR-#7;

[0030] Step (6): Detect the residual stress distribution and deformation of the specimen after multiple process parameters are adjusted, and make records under each parameter, which are recorded as σ according to the process type. #1 -σ #7 The residual stress collected in three directions is shown in Figure (5).

[0031] Step (7): Analyze the effect after regulation and compare it with the initial (before regulation) data. Analyze the efficiency η after regulation by using the method of fixed parameter setting and the method of comparing different process forms;

[0032]

[0033] Where η is the regulated elimination rate, σ i is the residual stress of different process configurations, and σ0 is the magnitude of the initial residual stress.

[0034] Step (8): Through a series of processes such as detection and analysis of the above steps (1) to (7), the residual stress control process research of carbon fiber laminates with different configurations can be met.

[0035] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that some local modifications or changes may be made without departing from the principles and basic features of the present invention, all of which fall within the scope of protection of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is determined by the appended claims. The present invention does not involve parts that are identical to the prior art or can be implemented using the prior art.

Claims

1. A multi-field and multi-parameter coupled residual stress control method for carbon fiber composite laminates. Mainly includes: Specimens with different laying angles, configurations and numbers of layers were selected to detect the initial deformation and residual stress distribution state under the selected process batch, and multi-parameter load field, temperature field and coupled regulation experiments were carried out. The deformation and stress field after all parameters were regulated were detected, and the effect after regulation was analyzed.

2. The multi-parameter coupling residual stress control method proposed in claim 1 is characterized in that: The following steps are involved: (1) First, carbon fiber laminates with different angle laying configurations are selected, and the angle laying configurations include UDL [θ1 / … / θ1]s or MDL [θ1 / θ2 / θ3… / θi]s, where the fiber angle arrangement and the total number of layers can be set and modified according to actual needs; (2) The initial residual stress RS and deformation d of the composite laminate specimens of the fixed process batch are tested and analyzed. No less than 3 groups of parallel tests should be carried out under each condition, and the average value σ0 is taken as the control group of basic data; (3) Setting a multi-parameter load field, including whether the specimen is clamped c, platform vibration frequency f, exciter eccentricity angle θ, exciting force F, clamping position P on the platform and other parameters. Such vibration parameters can be used to realize the research on vibration aging process control; (4) Setting a multi-parameter temperature field, including the high temperature heating rate hr, the high temperature aging temperature Th, the deep cooling rate cr, the deep cooling aging temperature Tc, and whether to air cool ac after the process is completed; (5) Using the process parameters in (4) and (5) above, multi-field coupling mode control is performed, including vibration aging VSR-#1, high temperature aging TSR-#2, low temperature aging CSR-#3, cold and hot aging CTSR-#4, hot vibration aging TVSR-#5, cold and hot aging CTSR-#6 and cold-heat-vibration coupled aging CTVSR-#7; (6) Detect the residual stress distribution and deformation of the specimen after multiple process parameters are adjusted, and make records of each parameter, which are recorded as σ#1-σ#7 according to the process type; (7) Analyze the effects after regulation and compare with the initial (pre-regulation) data. According to the method of fixed parameter setting and the method of comparing different process forms, the efficiency η after regulation is analyzed; Where η is the regulated elimination rate, is the residual stress of different process configurations, and is the initial residual stress. (8) Through a series of processes such as detection and analysis of the above steps (1) to (7), the residual stress control process research of carbon fiber laminates with different configurations can be met.

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