CFRT rigid weak and small sharp corner feature machining method and device, medium and equipment

Abstract

The invention discloses a CFRT rigid weak and small sharp corner feature machining method and device, a medium and equipment. The method comprises the steps that a small sharp corner area in CFRT is recognized; planning a cutting path and a cutting angle of the milling cutter based on the identified small sharp corner area; cutting parameters of the milling cutter in the cutting process are set; and based on the planned cutting path strength and cutting angle and the set cutting parameters, the CFRT rigidity weak and small sharp corner features are machined. The machining quality of the CFRT weak-rigidity small sharp corner can be improved.

Description

Technical Field

[0001] This application belongs to the field of composite material processing technology, specifically relating to a method, apparatus, medium, and equipment for processing rigid, weak, and sharp corner features of CFRT. Background Technology

[0002] Carbon fiber reinforced thermoplastic resin matrix composites (CFRT) are lightweight, high-strength, tough, heat-resistant, and recyclable. They also have irreplaceable manufacturing advantages over many thermosetting composites and high-performance alloy components (such as short molding cycle, low cost, repairability, and easy green manufacturing). CFRT has become the next strategic breakthrough for the transformation of aerospace equipment manufacturing models and the leapfrog improvement of performance.

[0003] Currently, thermoplastic composites (CFRTs) are mainly formed using two methods: near-net-shape forming and sheet metal subtractive forming, similar to metal parts. Compared to the near-net-shape forming method, which involves shaping surfaces, contours, and holes, sheet metal subtractive forming involves numerous complex features such as irregular curved surfaces, cavities, sharp corners, and support ribs. These complex structural features are typically machined using methods similar to those used for metal parts. However, due to the significant differences in the intrinsic properties of thermoplastic composites compared to metal materials, using the same toolpaths and parameters as for metal parts carries unpredictable quality risks. In particular, when machining the weak, sharp corner features of CFRTs, the poor structural rigidity and strength of the machined area mean that using the same toolpaths and parameters as for metal parts can lead to breakage of the small sharp corners due to cutting vibration and excessive cutting forces. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a method, apparatus, medium, and equipment for machining weak and sharp corner features of CFRT (Compact Fluid Reinforced Plastic) surfaces. This application aims to achieve stable and high-quality machining of weak and sharp corner features of CFRT surfaces.

[0005] To achieve the above objectives, this application provides the following technical solution: A method for machining rigid, weak, sharp-angle features in a CFRT (Criminal Fractured Relief Tool) includes: identifying small sharp-angle regions in the CFRT; planning the cutting path and cutting angle of a milling tool based on the identified small sharp-angle regions; setting the cutting parameters of the milling tool during the cutting process; and machining the rigid, weak, sharp-angle features of the CFRT based on the planned cutting path and cutting angle and the set cutting parameters.

[0006] Optionally, the identification of small sharp corner regions in CFRT includes: importing the CAD model of CFRT, automatically calculating the Gaussian curvature K and average curvature H of the CFRT surface based on the curvature analysis tool built into the CAD model to obtain candidate sharp corner regions of CFRT; and filtering the candidate sharp corner regions based on geometric features to obtain small sharp corner regions.

[0007] Optionally, the step of planning the cutting path and cutting angle of the milling tool based on the identified small sharp corner region includes: identifying weak and strong rigid regions within the small sharp corner region; planning the cutting trajectory of the milling tool based on the identified weak and strong rigid regions; and simultaneously adjusting the cutting angle of the milling tool during the planning of the cutting trajectory so that the cutting direction of the milling tool points towards the interior of the CFRT.

[0008] Optionally, the step of planning the cutting trajectory of the milling tool based on the identified weak and strong rigid regions includes: using the weak rigid region as the cutting start point and the strong rigid region as the cutting end point to form a machining path from weak rigidity to strong rigidity.

[0009] Optionally, setting the cutting parameters of the milling tool during the cutting process includes: setting the spindle speed of the milling tool; setting the depth of cut of the milling tool; setting the width of cut of the milling tool; obtaining the feed rate of the milling tool; and setting the cutting force of the milling tool based on the spindle speed, depth of cut, width of cut, and feed rate of the milling tool.

[0010] Optionally, the machining of the CFRT with weak rigidity and sharp corner features based on the planned cutting path and cutting angle and the set cutting parameters includes: integrating the set cutting parameters into the milling tool control system; monitoring the cutting vibration signal in real time; and detecting the CFRT after cutting.

[0011] This application also provides a machining device for rigid, weak, sharp-corner features of a CFRT (Criminal Fractured Relief Tool). The device includes: an identification module for identifying small sharp-corner regions in the CFRT; a planning module for planning the cutting path and cutting angle of a milling tool based on the identified small sharp-corner regions; a parameter setting module for setting the cutting parameters of the milling tool during the cutting process; and a machining module for machining the rigid, weak, sharp-corner features of the CFRT based on the planned cutting path and cutting angle and the set cutting parameters.

[0012] This application also provides a storage medium including instructions that, when executed on a computer, cause the computer to perform the method as described in the preceding claim.

[0013] This application also provides an electronic device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method as described in any of the preceding claims.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: Based on the rigidity characteristics of the weakly rigid small-angle structure, this application formulates a tool path from weak to strong rigidity and a tool swing angle strategy with the cutting force direction pointing inward to the part. At the same time, it formulates a principle for determining cutting parameters under multi-dimensional constraints such as resonance mode, surface quality, and material failure. By combining the practical application of tool path, tool swing angle, and cutting parameters, stable and high-quality machining of CFRT weakly rigid small-angle structures is achieved. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a method for machining rigid, weak, sharp corner features in CFRT, provided in one embodiment of this application. Figure 2 This is a structural schematic diagram of a thermoplastic CF / PEEK part provided in another embodiment of this application; Figure 3 This is a schematic diagram of the tool path provided in another embodiment of this application; Figure 4 This is a schematic diagram of a first-order resonance provided in another embodiment of this application; Figure 5 This is a schematic diagram of second-order resonance provided in another embodiment of this application; Figure 6 This is a schematic diagram of the first twenty modal analysis results provided in another embodiment of this application; Figure 7 This is a schematic diagram of the process of forming the cutting width provided in another embodiment of this application. Detailed Implementation

[0016] Specific embodiments of this application will now be described in detail with reference to the accompanying drawings. While specific embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0017] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0018] To facilitate understanding of the embodiments of this application, the following will provide further explanation and description with reference to the accompanying drawings and specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of this application.

[0019] Figure 1 This is a flowchart illustrating a method for processing rigid, weak, sharp-corner regions of CFRT according to an embodiment of this application. Figure 1 As shown, the method includes the following steps: S100: Identifies small sharp-angled regions in CFRT; S200: Plans the cutting path and cutting angle of the milling tool based on the identified small sharp corner areas; S300: Sets the cutting parameters of the milling tool during the cutting process; S400: Machining of rigid, weak, sharp-angled features of CFRT based on the planned cutting path, cutting angle, and set cutting parameters.

[0020] In another exemplary embodiment, step S100, identifying the small sharp-angle region in the CFRT, includes the following steps: S101: Import the CAD model of CFRT and automatically calculate the Gaussian curvature K and average curvature H of the CFRT surface based on the curvature analysis tool built into the CAD model to obtain candidate sharp corner regions of CFRT. In this step, this application specifies that when the curvature of a certain region of the CFRT surface is calculated... K absolute value (For example =0.5mm -1 )and ( =0.3mm -1 When the condition is met, the region is marked as a candidate sharp corner region for CFRT.

[0021] S102: Filter candidate sharp corner regions based on geometric features to obtain small sharp corner regions.

[0022] In this step, this application defines a candidate sharp corner region as a small sharp corner region when the apex angle of the candidate sharp corner region is less than 15° and the minimum thickness is less than 5mm. It should be noted that this dual size threshold is set based on mechanical principles and process experiments. The angle condition constrains its geometric sharpness, and the thickness condition constrains its resistance to deformation.

[0023] In another exemplary embodiment, step S200, planning the cutting path and cutting angle of the milling tool based on the identified small sharp-angle region, includes the following steps: S201: Identify weak and strong rigid regions within small, sharp-angled areas; In this step, the distinction between weak and strong rigidity regions is based on local resistance to deformation. Weak rigidity regions refer to geometrically abrupt areas in CFRT, such as sharp corners and thin-walled edges (e.g., within the outermost 5mm of a sharp corner). These areas exhibit significantly larger deformation under unit load (e.g., deformation > 0.1mm / N), making them prone to severe vibration and material failure under cutting forces, and thus high-risk areas for machining breakage. Strong rigidity regions, on the other hand, refer to stable support areas in CFRT near the workpiece matrix or fixture (e.g., the root of sharp corner ribs, thick sections, within 10mm of the inner side of the sharp corner connecting to the matrix). These areas possess strong resistance to deformation (e.g., deformation < 0.05mm / N), providing mechanical support for the cutting process.

[0024] It should be noted that the weak rigid region is the amplification source of cutting vibration (similar to the free end of a cantilever beam), while the strong rigid region is the stress dissipation anchor point (similar to the fixed end). The "weak → strong" trajectory can transmit the cutting force from the weak rigid region to the strong rigid region, thereby preventing the weak rigid region from being tensile and broken.

[0025] Specifically, based on the small sharp corner region, the local deformation resistance of each part in this region is first evaluated by combining finite element modal analysis or simplified mechanical model. Areas with geometrical abrupt changes and lack of support, such as the ends of sharp corners and thin-walled edges (e.g., within the outermost 5mm of the sharp corner), are identified as "weakly rigid regions." Their typical characteristics include large deformation under unit load (e.g., >0.1mm / N), low dynamic stiffness, and a tendency to generate significant vibration and stress concentration under cutting forces, similar to the free end of a cantilever beam, making them high-risk areas for material tearing and edge breakage. Meanwhile, transition sections near the main body of the part, the root of the ribs, or the clamping area of ​​the fixture (e.g., within the inner 10mm range connecting to the base) are also considered "weakly rigid regions." The area within which the material is located is identified as a "high-rigidity region." This region has sufficient structural support, small deformation under unit load (e.g., <0.05mm / N), and stable dynamic response. It can serve as an anchor point for stress transfer, similar to the fixed end of a cantilever beam. Through this identification method based on geometric-mechanical coupling, sub-regions with different rigidity levels are clearly distinguished. This guides toolpath planning to follow a "from weak to strong" machining sequence, allowing cutting forces to be gradually transferred from the fragile tip to the stable substrate. The high-rigidity region absorbs vibration energy and provides reverse support, effectively suppressing chatter and tensile stress concentration during machining. This significantly reduces the risk of small-angle breakage and improves machining integrity and surface quality.

[0026] S202: Plan the cutting trajectory of the milling tool based on the identified weak and strong rigid regions; In this step, the core principle of planning the milling tool cutting trajectory in this application is to follow the machining sequence from weak to strong, that is, to take the weak rigid region as the cutting start point and the strong rigid region as the cutting end point, forming a machining path of "weak rigidity → strong rigidity". The specific planning process is as follows: The starting point of the cutting path should be set at the weakest point, such as the end or edge of a small sharp corner. These areas, lacking support, are like the free end of a cantilever beam, making them highly susceptible to vibration, deformation, and even material tearing or breakage under cutting forces. The ending point of the cutting path should be set near the main body of the part, the root of ribs, or the fixture support area, where rigidity is higher. These areas, like the fixed end of a cantilever beam, provide good mechanical support and resistance to deformation. The planned tool path direction should be clearly defined as moving from the tip of the sharp corner (weak area) towards the interior of the part or the base material (strong area). For example, when machining an outward-extending sharp corner, the tool should start from the tip of the corner and gradually advance towards the main body of the part.

[0027] The cutting trajectory planning method described above identifies weak and strong rigid regions within a small sharp corner area and forces a "weak to strong" tool path (i.e., starting from a weak rigid region such as the end of the sharp corner and advancing towards a strong rigid region such as the part matrix). This effectively achieves the orderly transmission of cutting force along the tool path from the weak region to the support region. By using the strong rigid region as a mechanical anchor point to absorb vibration and provide dynamic support, it avoids defects such as material tearing and edge breakage caused by tension or vibration amplification in the weak rigid region during the cutting process. This improves machining stability and surface quality and is suitable for high-precision and high-reliability machining of rigid, weak, and sharp corner features such as CFRT.

[0028] S203: During the planning of the cutting trajectory, the cutting angle of the milling tool is adjusted so that the cutting direction of the milling tool points inward to the CFRT.

[0029] In this step, after completing the cutting path planning from weak to strong, the cutting angle of the milling tool is dynamically adjusted based on the local geometric normal and tangent vectors of key points on the path (such as the start point, end point, and curvature change points) to ensure that its cutting direction always points towards the interior of the CFRT part. This adjustment process deeply integrates the fiber layup orientation information of the material (such as 0°, ±45°, 90° layup). By analyzing the angle between the tool and the fiber, when facing unfavorable fiber directions that easily lead to delamination, the optimal tilt angle and lead / lag angle are automatically calculated, allowing the main cutting edge to act on the material efficiently in a shearing manner and effectively suppressing splitting. To further enhance process stability, a segmented variable angle strategy is adopted. In the initial area of ​​the path with the weakest rigidity (such as the end of a sharp corner), a larger inward tilt angle (such as a side tilt of 5°~10°) is used to strengthen the support for the thin-walled edge through the "pressure cutting" effect. As the machining progresses to the area with strong rigidity, the tilt angle is smoothly reduced to near zero, thereby achieving a smooth transition and transmission of cutting force and ensuring the integrity of the machining process.

[0030] In another exemplary embodiment, step S300, setting the cutting parameters of the milling tool during the cutting process, includes the following steps: S301: Set the spindle speed of the milling cutter ; In this step, the spindle speed of the milling cutter Calculated based on the following formula:

[0031] Among them, 60 is a constant, representing that there are 60 seconds in one minute; Indicates the harmonic order; Indicates the natural frequency of the cutting tool; Indicates the number of teeth on the cutting tool; S302: Set the depth of cut for the milling tool ; In this step, the cutting depth of the milling tool Calculated based on the following formula:

[0032] in, Indicates the damping ratio; Indicates the system stiffness; This represents the cutting force coefficient, ranging from 80 to 300. N / mm 2 ; Indicates the angular velocity of the main shaft; Represents pi; Indicates the number of teeth on the cutting tool.

[0033] In addition, damping ratio and system stiffness Calculated based on the following formula:

[0034] in, This indicates the initial amplitude of the system's free vibration induced by the hammer impact test. Indicates the first n The amplitude of the oscillation in each cycle, Indicates machine tool rigidity, Indicates workpiece rigidity, Indicates the rigidity of the cutting tool.

[0035] S303: Set the cutting width of the milling tool ; In this step, the cutting width of the milling tool Calculated based on the following formula:

[0036] in, Indicates the radius of the tool's bottom corner; This indicates the maximum residual height; the specific formation process is shown in the attached figure. Figure 7 As shown.

[0037] S304: Obtain the feed rate of the milling tool ; In this step, the feed rate of the milling tool Based on cutting stress Maximum load at material failure To obtain, it is represented as:

[0038] The specific acquisition process is as follows: Step 1: Obtain cutting parameters through orthogonal experiment and regression analysis fitting. With cutting stress The mapping relationship between them is specifically represented as follows:

[0039] Based on the formulas shown in steps S201 to S203, the working conditions under low cutting vibration are obtained respectively. The value is taken, and then the cutting stress is obtained. With feed rate The relationship.

[0040] Step 2: The maximum load for material failure is determined by the characteristics of the weak rigidity of the sharp corner and the material itself. For the characteristics of the weak rigidity of the sharp corner, the load manifested is the interlaminar shear failure load. ) or axial crushing load ( In particular, if the material fails in either interlaminar shear or axial crushing, the small sharp corner area will be milled. In this step, the interlaminar shear failure load ( ) or axial crushing load ( Specifically, it is expressed as follows:

[0041] in, The coefficient of friction between the cutting tool and the fiber. e and[ F 1( e )] -2 / 3 These are the elliptic eccentricity and the correction factor, respectively. R For the equivalent radius, a、b These are the major and minor axes of the ellipse representing the contact area. f z1 For single-fiber cutting force, This represents the fiber volume fraction. To express the correction factor function, y and z represent the fracture deflection of the fiber in the y and Z directions, respectively. The shear strength of the thermoplastic resin matrix. The axial compressive strength of thermoplastic resin, This represents the volume fraction of the thermoplastic resin. E ft * To account for the anisotropic properties of carbon fibers, the equivalent modulus is, where, e and E ft * It is expressed as follows:

[0042] in, E tool and v tool These represent the Young's modulus and Poisson's ratio of the cutting tool, respectively. v 3 represents the transverse Poisson's ratio of the composite material; 1.112 and 0.0004935 are fitting constants, empirical coefficients obtained through experimental fitting, used to correct the influence of the extremely strong anisotropy of carbon fiber on the contact stiffness. Indicates the transverse modulus of thermoplastic composites; This represents the Young's modulus of carbon fiber.

[0043] Step 3: Construct the cutting parameters and shear failure load as shown below ( ) and axial crushing load ( Relationship model between )

[0044] in, This indicates the cutting force.

[0045] The maximum allowable cutting speed can be obtained from the above relationship model. To ensure the reliability margin of the machining, the actual cutting speed is selected according to a certain proportion of the maximum cutting speed as a safety margin.

[0046] S305: Spindle speed based on milling cutter The depth of cut, width of cut, and feed rate set the cutting force of the milling tool. .

[0047] In this step, the cutting force It is expressed as follows:

[0048] in, Indicates cutting force parameters (related to CFRT fiber / matrix, PCD tool); , , These represent the power-law exponents (e.g., =0.8, =0.6, =0.3); This represents the low-speed enhancement factor, used to compensate for the increase in force caused by heat accumulation and viscoelastic effects at low speeds; Indicates the thermo-mechanical coupling attenuation coefficient; Indicates the vibration amplification modulation coefficient ( ); Represents pi; Indicates the cutting excitation frequency; This represents the first-order modal natural frequency of the workpiece; Indicates the nonlinear decay exponent of rotational speed (e.g.) ).

[0049] The cutting force formula described above is highly flexible and accurate, and can comprehensively consider the influence of various cutting parameters on the cutting force. , , The nonlinear effect on cutting force is reflected in exponential form; the reciprocal of the spindle speed reflects the changing trend of cutting force during high-speed machining; the exponential decay term... The complex relationship between cutting speed, depth of cut, and spindle speed is described to ensure accurate prediction of cutting forces under different machining conditions; the final sinusoidal modulation term... By introducing the cutting excitation frequency With natural frequency The coupling effect effectively captures dynamic changes during the machining process. In summary, the above model enables precise control of cutting forces, significantly improving machining accuracy and surface quality, reducing tool wear and workpiece damage, and optimizing process parameters to meet the needs of efficient and stable machining of different materials and complex geometries.

[0050] In another exemplary embodiment, step S400, machining the CFRT rigid, weak, sharp-angled feature based on the planned cutting path and cutting angle, and the set cutting parameters, includes the following steps: S401: Integrate the set cutting parameters into the milling tool control system; In this step, firstly, the key parameters such as the pre-planned cutting path, tool tilt angle, spindle speed, feed rate, depth of cut, and width of cut are compiled into CNC code (NC program) that the machine tool can recognize using CAM (Computer-Aided Manufacturing) software. Then, post-processing adaptation is performed in conjunction with the control system of the specific five-axis machining center (such as Siemens 840D or Heidenhain) to ensure that the linkage accuracy between the tool path and the tilt angle meets the micron-level requirements. At the same time, tool compensation, RTCP (Rotating Tool Center Point) function, and safety protection logic need to be embedded in the program to prevent collisions or overcuts caused by sudden changes in posture in small sharp corner areas. After the program is uploaded, the entire tool path needs to be verified using virtual simulation software (such as VERICUT) to confirm that there is no interference and no erroneous operation before it can be put into actual machining, thereby ensuring the accurate, safe, and reliable execution of machining instructions.

[0051] S402: Real-time monitoring of cutting vibration signals; In this step, this application installs a high-sensitivity triaxial accelerometer on the machine tool spindle or tool holder to continuously collect vibration data during the machining process at a sampling frequency of not less than 20kHz. Edge computing devices are used to process the signals in real time, and FFT (Fast Fourier Transform) analysis is used to identify whether the current excitation frequency is close to the workpiece's first few modal natural frequencies (e.g., ...). Figures 4 to 6 As shown), once a resonance trend is detected or the vibration amplitude exceeds a preset threshold (e.g., RMS > 2.5 m / s), 2 The system immediately triggers an early warning mechanism, which can automatically reduce the feed rate or suspend processing. At the same time, it combines acoustic emission sensors to capture early signals of fiber breakage or delamination inside the material, realizing dynamic closed-loop monitoring of processing stability and effectively avoiding small sharp corner breakage or surface damage caused by vibration.

[0052] S403: Inspect the CFRT after cutting.

[0053] In this step, this application first uses a coordinate measuring machine (CMM) or optical scanner to perform high-precision measurements of the geometric dimensions, contours, and thickness of the small sharp corner area to verify whether it meets the design tolerance requirements. Then, the surface morphology is observed using a digital microscope to check for defects such as fiber pull-out, resin peeling, or edge burrs. For critical load-bearing parts, non-destructive testing, such as ultrasonic C-scanning or X-ray CT, is also required to identify potential internal delamination, porosity, or microcracks. All the above test results will be recorded and fed back to the process database for analysis of machining error sources, thereby optimizing cutting parameters and path strategies, forming a closed-loop quality control system of "machining-inspection-improvement" to ensure the high reliability and consistency of the CFRT weak rigidity small sharp corner feature.

[0054] Below, this application will clearly and completely describe the technical solution of this application with reference to specific embodiments. Specifically, this application takes a typical thermoplastic CF / PEEK part as an example. In this material, the volume fraction of carbon fiber is 78%, and the volume fraction of resin matrix is ​​22%. Figure 2 As shown, this part is formed by subtractive machining of sheet metal, using a φ20R3 eight-tooth PCD face milling cutter. The part exhibits typical weak-rigidity small sharp corners at both ends. As defined above, the apex angle of these areas is less than 15°, and the minimum thickness is less than 5mm, classifying them as high-risk machining areas. Therefore, based on the description in this application, the machining method adopted for this part is as follows: 1) Tool path determination: The tool path direction is from the sharp corner to the inside, and the tool tilt angle is biased towards the workpiece side, such as... Figure 3 As shown, ensure that the cutting force is directed inwards towards the part; 2) Cutting parameter control: S1: The cutting speed S should consider the resonant modes of the part, ensuring that the external excitation frequency avoids the structural resonant frequency. The structural resonant frequency can be obtained through finite element simulation, and the calculation results are as follows: Figures 4 to 6 As shown in Table 1, since the machine tool spindle speed in this embodiment is <22000 RPM, the resonant speeds corresponding to the first twenty stages of the eight-tooth end mill are as follows, based on the simulation calculation results: Table 1

[0055] S2: Depth of cut The machining of the chatter tool should be considered. Based on the theory of regenerative chatter, the depth of cut should be calculated using the following empirical formula:

[0056] Number of teeth of the cutting tool in this embodiment The damping ratio is 8. The system stiffness is 0.2. 714,000 N / mmCutting force coefficient For 300 N / mm 2 (The cutting force coefficient of carbon fiber composites is 80-300) N / mm 2 To ensure a safety margin, this embodiment uses the cutting force coefficient with the minimum depth of cut, i.e., the cutting force coefficient is taken as... For 300 N / mm 2 ), spindle angular velocity 942 rad / s The cutting depth is calculated. Here, a certain margin for infringement is reserved, and the actual cutting depth is taken. ; S3: Manufacturing requirements for this part Tool base corner radius R 3 mm The cutting width is calculated. Take the actual cutting width ; S4: Conduct orthogonal cutting parameter experiments on thermoplastic composite materials to obtain cutting stress, and then fit a model to obtain the mapping relationship between cutting stress and cutting parameters. In this example, the cutting stress fitting formula obtained through experimental results is as follows:

[0057] By calculating the interlayer failure load and axial crushing load Here, we take the minimum value, meaning the sharp-angle characteristic failure mode should be axial crushing failure, indicating a risk of breakage. The feed rate can be calculated. Here, a certain safety margin is taken. .

[0058] In summary, the stable cutting parameters for the weakly rigid small sharp corner feature in this implementation case are: .

[0059] After planning the cutting path, tool swing angle, and cutting parameters, these are integrated to generate a numerical control (NC) program. This program is then adapted to the specific machine tool control system through post-processing. Simultaneously, virtual simulation software (such as VERICUT) is used to verify the entire toolpath process, ensuring no interference or collisions and guaranteeing machining safety. During machining, high-sensitivity triaxial accelerometers (sampling rate ≥20kHz) mounted on the machine tool spindle or tool holder collect vibration signals in real time. This data is then combined with Fast Fourier Transform (FFT) for spectral analysis. If the excitation frequency is detected to be close to the workpiece modal frequency or the vibration amplitude exceeds a preset threshold (e.g., RMS > 2.5 m / s²), the system will detect the vibration. 2The system immediately triggers a response mechanism, automatically reducing the feed rate or pausing processing to achieve dynamic closed-loop control. Simultaneously, acoustic emission sensors capture early damage signals such as fiber breakage or delamination within the material. After processing, a coordinate measuring machine (CMM) or optical scanner is used to perform high-precision geometric measurements on small, sharp-angled areas. A digital microscope is used to inspect the surface for defects such as fiber pull-out, resin peeling, or burrs. Non-destructive testing, such as ultrasonic C-scanning or X-ray CT, is performed on critical load-bearing areas to identify potential internal delamination and porosity. Finally, all test results are systematically recorded and fed back to the process database, forming a closed-loop quality control system of "processing-inspection-optimization" to continuously improve the stability and reliability of the process.

[0060] In another exemplary embodiment, this application also provides a machining apparatus for rigid, weak, sharp-corner features of a CFRT (Criminal Fractured Rectangular Terrain). The apparatus includes: an identification module for identifying small sharp-corner regions in the CFRT; a planning module for planning the cutting path and cutting angle of a milling tool based on the identified small sharp-corner regions; a parameter setting module for setting the cutting parameters of the milling tool during the cutting process; and a machining module for machining the rigid, weak, sharp-corner features of the CFRT based on the planned cutting path and cutting angle and the set cutting parameters.

[0061] In another exemplary embodiment, this application also provides a storage medium including instructions that, when executed on a computer, cause the computer to perform the method as described in the preceding embodiment.

[0062] In another exemplary embodiment, this application also provides an electronic device, the electronic device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method as described in any of the preceding embodiments.

[0063] Finally, it should be noted that the above descriptions are merely optional examples of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for machining rigid, weak, sharp-angle features in CFRT, characterized in that, The method includes: Identify small, sharp-angled regions in CFRT; The cutting path and cutting angle of the milling tool are planned based on the identified small sharp corner areas; Set the cutting parameters of the milling tool during the cutting process; The rigid, weak, sharp-angled features of CFRT are machined based on the planned cutting path, cutting angle, and set cutting parameters.

2. The method according to claim 1, characterized in that, The identification of small sharp-angled regions in CFRT includes: Import the CFRT CAD model and automatically calculate the Gaussian curvature K and average curvature H of the CFRT surface based on the curvature analysis tool built into the CAD model to obtain candidate sharp corner regions of the CFRT. Candidate sharp corner regions are filtered based on geometric features to obtain small sharp corner regions.

3. The method according to claim 1, characterized in that, The planning of the cutting path and cutting angle of the milling tool based on the identified small sharp-angle regions includes: Identify the weak and strong rigid regions within the small, sharp-angled area; The cutting trajectory of the milling tool is planned based on the identified weak and strong rigid regions. During the planning of the cutting trajectory, the cutting angle of the milling tool is adjusted simultaneously so that the cutting direction of the milling tool points inward to the CFRT.

4. The method according to claim 3, characterized in that, The method of planning the cutting trajectory of the milling tool based on the identified weak and strong rigid regions includes: The machining path is formed by using the weakest region as the starting point and the strongest region as the ending point, thus creating a machining path from weakest to strongest rigidity.

5. The method according to claim 1, characterized in that, Setting the cutting parameters of the milling tool during the cutting process includes: Set the spindle speed of the milling tool; Set the cutting depth of the milling tool; Set the cutting width of the milling tool; Obtain the feed rate of the milling tool; The cutting force of the milling tool is set based on the spindle speed, depth of cut, width of cut, and feed rate of the milling tool.

6. The method according to claim 1, characterized in that, The machining of CFRT rigid, weak, sharp-angled features based on the planned cutting path and cutting angle, as well as the set cutting parameters, includes: Integrate the set cutting parameters into the milling tool control system; Real-time monitoring of cutting vibration signals; The CFRT after cutting is inspected.

7. A device for machining rigid, weak, sharp-angle features in CFRT, characterized in that, The device includes: The recognition module is used to identify small sharp-angled regions in CFRT; The planning module is used to plan the cutting path and cutting angle of the milling tool based on the identified small sharp corner areas; The parameter setting module is used to set the cutting parameters of the milling tool during the cutting process; The machining module is used to machine rigid, weak, sharp-angled features of CFRT based on the planned cutting path and cutting angle, as well as the set cutting parameters.

8. A storage medium, characterized in that, It includes instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 6.

9. An electronic device, characterized in that, The electronic device includes: Memory, processor, and computer programs stored in memory and executable on the processor, wherein, When the processor executes the program, it implements the method as described in any one of claims 1 to 6.

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