A laser cutting-based knife-edge web flattening device and method thereof

Abstract

This invention relates to the field of laser cutting and thin-walled metal component processing technology, specifically to a laser-cut edge and web flattening processing device and method; it includes a processing base, a laser cutting head, an array-type magnetorheological fluid support bed, a thermally driven adaptive antagonistic tensioning mechanism, an acoustic emission receiving probe, and a control system; the device utilizes the parasitic waste heat generated during cutting to cause a bimetallic shape memory alloy spring to undergo phase change expansion, which is then driven by a micro-lever amplifier to apply reverse tensile prestress to the workpiece; its core is to achieve automatic suppression of in-plane thermal compressive stress accumulation without external drive by coordinating the thermally driven tensioning mechanism with the local variable stiffness support provided by the array-type magnetorheological fluid support bed; this invention solves the problem that traditional rigid supports cannot adaptively adjust, significantly reducing out-of-plane warping and in-plane compressive instability of thin-walled metal components during processing.

Description

Technical Field

[0001] This invention relates to the field of laser cutting and thin-walled metal component processing technology, specifically to a laser cutting-based tool edge and web flattening processing device and method. Background Technology

[0002] In the processing and manufacturing of thin-walled metal components, especially variable cross-section blade-edge webs, laser cutting technology is widely used due to its high precision and non-contact characteristics. To ensure the cutting quality of the workpiece, existing solutions typically use rigid fixtures to fix and support the two ends or bottom of the workpiece and perform laser cutting according to a preset trajectory and fixed parameters. Although this solution has a certain degree of stability in the processing of plates of conventional thickness, for components such as blade-edge webs with continuous thickness transitions and extremely thin edges, the parasitic waste heat generated during cutting can easily lead to the accumulation of in-plane thermal compressive stress due to the highly concentrated local heat input and the bending stiffness of the blade-edge area being lower than the preset stiffness threshold. Existing rigid supports cannot adaptively adjust to the micro-deformation of the workpiece under heat, and lack real-time sensing and compensation intervention for local focal length shifts and thermal instability, making the components prone to out-of-plane warping and in-plane compressive instability, resulting in exceeding processing tolerances and affecting subsequent bending and welding processes.

[0003] Therefore, how to improve the adaptive control and suppression of thermal deformation and local instability of thin-walled components with variable cross-sections during laser cutting has become an urgent technical problem to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a device and method for machining the blade edge and web plate based on laser cutting. Specifically, the technical solution of the present invention is as follows: A laser-cut edge and web flattening processing device includes: A processing base, the top of which is fixed to a gantry frame, the gantry frame including a crossbeam, and a rectangular groove is opened in the middle of the processing base; A laser cutting head is slidably connected to the crossbeam of the gantry frame; An array-type magnetorheological fluid support bed is fixed in a rectangular groove. An independent excitation coil is fixed to the top of the bottom heat-conducting substrate and wrapped by a flexible sealing film. The flexible sealing film and the bottom heat-conducting substrate form a closed cavity filled with magnetorheological fluid. A thermally driven adaptive antagonistic tensioning mechanism is provided on the side of the array-type magnetorheological fluid support bed on the machining base. Its thermally conductive support is fixed to the machining base. A bimetallic shape memory alloy spring is fixed to the top of the thermally conductive support and a micro lever amplifier is hinged to the middle. The free end of the bimetallic shape memory alloy spring abuts against the input end of the micro lever amplifier. The output end of the micro lever amplifier is fixed to a chuck to hold the non-cutting edge of the blade web. The acoustic emission receiver probe is fixed to the side of the processing base and is pointed directly below the laser cutting head. The control system is electrically connected to and controls the laser cutting head and the independent excitation coil, and acquires sensing data from the acoustic emission receiving probe.

[0005] Furthermore, both the bottom heat-conducting substrate and the heat-conducting support are made of copper, the independent excitation coils are arranged in a matrix, and the edge of the flexible sealing film is sealed and fixed to the four edges of the bottom heat-conducting substrate.

[0006] Furthermore, the ratio of the input lever arm length to the output lever arm length of the miniature lever amplifier is set to 1:5, and the clamp includes upper and lower jaws and a spring; wherein, the spring is connected to the upper and lower jaws, and the spring is used to provide an initial preload.

[0007] Furthermore, a linear guide rail is fixedly connected to the crossbeam of the gantry frame, and the laser cutting head is slidably connected to the crossbeam of the gantry frame via the linear guide rail.

[0008] A method for flattening the blade edge and web plate based on laser cutting includes: S1. Place the blade edge web to be processed above the flexible sealing membrane of the array-type magnetorheological fluid support bed, control the chuck to hold the non-cutting edge of the blade edge web, and keep the independent excitation coil in a de-energized state. S2. Control the laser cutting head to start and move towards the extremely thin blade edge area of ​​the blade edge web plate according to a predetermined trajectory to perform cutting; S3. Apply a detection pulse to the independent excitation coil and acquire the transient voltage signal within the open-circuit sampling window. Obtain the back electromotive force change of the independent excitation coil based on the transient voltage signal, and obtain the plasma plume acoustic emission main frequency drift received by the acoustic emission receiving probe. S4. Calculate the stress concentration index of the current blade edge region based on the back electromotive force mutation and the plasma plume acoustic emission frequency drift.

[0009] Further, the step in S4 of calculating the stress concentration index of the current blade edge region based on the back electromotive force mutation and the plasma plume acoustic emission dominant frequency drift includes: S401. Obtain the preset deformation weight coefficient determined by pre-calibration, and multiply the normalized value of the back electromotive force mutation by the preset deformation weight coefficient to obtain the first calculated value. S402. Obtain the preset thermal deviation weighting coefficient determined by pre-calibration, and multiply the normalized value of the plasma plume acoustic emission main frequency drift by the preset thermal deviation weighting coefficient to obtain the second calculated value. S403. Add the first calculated value to the second calculated value to obtain the stress concentration index.

[0010] Furthermore, the S4 is followed by: S501. Obtain a preset safety threshold and determine the relationship between the stress accumulation index and the preset safety threshold. S502. When the stress concentration index is greater than or equal to the preset safety threshold, reduce the duty cycle of the laser cutting head pulse and simultaneously increase the excitation current of the independent excitation coil directly below the current cutting edge area to control the solidification of the magnetorheological fluid to provide anti-buckling support force. S503. When the stress concentration index is less than the preset safety threshold, the duty cycle of the laser cutting head pulse and the excitation current of the independent excitation coil remain unchanged.

[0011] Further, the part after S2 and before S3 includes: S201. Obtain the parasitic waste heat generated during cutting, and use the parasitic waste heat to conduct along the blade edge web to the chuck, and further conduct it to the heat-conducting support and the bimetallic shape memory alloy spring. S202. The bimetallic shape memory alloy spring expands upon heating, generating an expansion displacement to push the input terminal of the micro lever amplifier. S203. The output of the micro lever amplifier is used to drive the chuck to generate radial tensile displacement, and reverse tensile prestress is applied to the blade edge web.

[0012] The present invention has the following beneficial effects: 1. This invention solves the problem of traditional rigid supports being unable to adaptively adjust by setting up an array-type magnetorheological fluid support bed and a thermally driven adaptive antagonistic tensioning mechanism; it utilizes the parasitic waste heat generated during cutting to cause the bimetallic shape memory alloy spring to undergo phase change expansion, which is then driven by a micro lever amplifier to apply reverse tensile prestress to the workpiece; this mechanism can automatically suppress the accumulation of in-plane thermal compressive stress without external drive; combined with the local variable stiffness support provided by the array-type magnetorheological fluid support bed, it reduces out-of-plane warping and in-plane compressive instability of thin-walled components; 2. This invention calculates the stress concentration index by acquiring the back electromotive force mutation of the independent excitation coil and the main frequency drift collected by the acoustic emission receiving probe. This overcomes the deficiency of traditional processing methods that lack real-time sensing of thermal instability. When the stress concentration index reaches the preset safety threshold, the control system synchronously reduces the pulse duty cycle of the laser cutting head to reduce heat input and increases the excitation current in the deformation zone to solidify the magnetorheological fluid to provide anti-buckling support force. This achieves closed-loop synergy between heat input control and stiffness enhancement, ensuring processing accuracy. Attached Figure Description

[0013] The following drawings, illustrating embodiments of this application, are incorporated herein by reference and are used to understand this application. The drawings illustrate embodiments of this application and their descriptions, serving to explain the principles of this application. In the drawings, Figure 1 This is a schematic diagram of the overall external structure of the device; Figure 2 This is a schematic diagram of the machining base and its connection structure; Figure 3 This is a schematic diagram of the thermally driven adaptive antagonistic tensioning mechanism; Figure 4 This is a schematic diagram of a flexible sealing membrane and its connection structure; Figure 5 This is a flowchart of the method of the present invention.

[0014] In the diagram: 100, machining base; 110, gantry frame; 120, rectangular groove; 130, crossbeam; 140, linear guide rail; 200, laser cutting head; 300, array-type magnetorheological fluid support bed; 310, bottom heat-conducting substrate; 320, independent excitation coil; 330, flexible sealing membrane; 340, closed cavity; 350, magnetorheological fluid; 400, thermally driven adaptive antagonistic tensioning mechanism; 410, heat-conducting support; 420, bimetallic shape memory alloy spring; 430, miniature lever amplifier; 440, chuck; 441, upper and lower grippers; 442, spring; 500, acoustic emission receiving probe; 600, control system; 700, blade edge web; 710, non-cutting edge; 720, ultra-thin blade edge area. Detailed Implementation

[0015] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0016] Example 1: A laser-cutting-based blade edge and web flattening processing device, such as Figure 1 As shown, it includes: A processing base 100 is formed, and a gantry frame 110 is fixedly connected to its top. The gantry frame 110 includes a crossbeam 130, such as... Figure 2 As shown, a rectangular groove 120 is formed in the middle of the processing base 100; The laser cutting head 200 is slidably connected to the crossbeam 130 of the gantry frame 110; An array-type magnetorheological fluid support bed 300 is fixed within a rectangular groove 120, such as... Figure 4As shown, an independent excitation coil 320 is fixed to the top of the bottom heat-conducting substrate 310 and wrapped by a flexible sealing film 330. A closed cavity 340 filled with magnetorheological fluid 350 is formed between the flexible sealing film 330 and the bottom heat-conducting substrate 310. A thermally driven adaptive antagonistic tensioning mechanism 400 is located on the side of the array-type magnetorheological fluid support bed 300 on the machining base 100, such as... Figure 3 As shown, its heat-conducting support 410 is fixed to the processing base 100. The top of the heat-conducting support 410 is fixed to the bimetallic memory alloy spring sheet 420 and the middle is hinged to the micro lever amplifier 430. The free end of the bimetallic memory alloy spring sheet 420 abuts against the input end of the micro lever amplifier 430. The output end of the micro lever amplifier 430 is fixed to the chuck 440 to clamp the non-cutting edge 710 of the blade web 700. The acoustic emission receiver probe 500 is fixed to the side of the processing base 100 and is pointed directly below the laser cutting head 200. The control system 600 is electrically connected to and controls the laser cutting head 200 and the independent excitation coil 320, and acquires the sensing data of the acoustic emission receiving probe 500. The flattening processing device is used to solve the problems of out-of-plane warping and in-plane compression instability of the variable cross-section blade edge web 700 during laser cutting due to local heat input concentration and low bending stiffness in the blade edge area; the processing base 100 serves as the load-bearing component of the whole machine, with a gantry frame 110 installed on its upper part and a rectangular groove 120 set in the middle. The rectangular groove 120 is used to accommodate the array-type magnetorheological fluid 350 and the array-type magnetorheological fluid support bed 300, so that the blade edge web 700 to be processed can obtain continuous support below the cutting area; The laser cutting head 200 slides along the crossbeam 130 of the gantry frame 110 to perform a predetermined trajectory cut on the blade edge web 700; the bottom heat-conducting substrate 310 in the array-type magnetorheological fluid 350 array-type magnetorheological fluid support bed 300 provides mechanical support and heat dissipation functions; the independent excitation coil 320 is used to establish an adjustable magnetic field at the corresponding position; and the flexible sealing film 330 is used to isolate the magnetorheological fluid 350 and provide an upwardly conformable support surface. It should be noted that when the flexible sealing film 330 wraps the independent excitation coils 320, it means that the flexible sealing film 330 covers all the independent excitation coils 320 arranged in a matrix. It does not tightly wrap a single coil, but together with the four edges of the bottom heat-conducting substrate 310, it defines a connected closed cavity 340 to ensure the free flow and pressure transmission of the magnetorheological fluid 350 in the entire array bed cavity. Magnetorheological fluid 350 exhibits a low shear yield stress state in the absence of a magnetic field. After being energized, it forms a target stiffness region greater than the initial stiffness, so as to implement zoned reinforcement support for the local instability location of the blade edge web 700. The thermally driven adaptive antagonistic tensioning mechanism 400 is located on the side of the array-type magnetorheological fluid 350 and the array-type magnetorheological fluid support bed 300. Its function is not to apply force through external servo drive, but to use the parasitic waste heat generated by cutting to conduct through the non-cutting end edge 710 of the blade web 700 to the chuck 440, and then to the heat-conducting support 410 and the bimetallic memory alloy spring 420, so that the bimetallic memory alloy spring 420 generates thermal displacement, which drives the micro lever amplifier 430 to move, and the chuck 440 applies a tensile displacement to the non-cutting end edge 710 of the blade web 700 in the opposite direction of thermal expansion, thereby reducing the accumulation of compressive stress in the cutting area. The acoustic emission receiving probe 500 is fixed to the side of the processing base 100 and points to the area directly below the laser cutting head 200. It is used to collect high-frequency acoustic information when the plasma plume is formed. This information can reflect the focal length shift and local thermal input state. The control system 600 is electrically connected to the laser cutting head 200, the independent excitation coil 320 and the acoustic emission receiving probe 500. The control system 600 can be a combination of an industrial control computer, an analog-to-digital acquisition card and a multi-channel current drive module, used to receive probe data, control the duty cycle of the laser cutting head 200 and implement zoned excitation control for each independent excitation coil 320. This device combines thermal tensioning, localized variable stiffness support, and acoustic monitoring on the same platform, enabling the blade web 700 to simultaneously obtain axial stress adjustment and bottom out-of-plane support during the cutting process, reducing the height offset of the cutting zone and lowering the cumulative tolerance of subsequent bending and welding processes.

[0017] Both the bottom heat-conducting substrate 310 and the heat-conducting support 410 are made of copper. The independent excitation coils 320 are arranged in a matrix. The edge of the flexible sealing film 330 is sealed and fixed to the four edges of the bottom heat-conducting substrate 310. The key structures are limited in terms of materials and arrangement to improve thermal conductivity, support uniformity, and sealing stability. The bottom heat-conducting substrate 310 is made of copper, which has a higher thermal conductivity than conventional steel plates and aluminum alloys. It can quickly diffuse the heat from the bottom of the blade web 700 along the plane and conduct it outward, reducing the long time that high-temperature areas stay. The heat-conducting support 410 is also made of copper. Its purpose is to shorten the heat conduction path between the chuck 440 and the bimetallic shape memory alloy spring 420, so that the parasitic waste heat from cutting can act on the bimetallic shape memory alloy spring 420 more quickly, thereby improving the thermal drive response speed. When the independent excitation coils 320 are arranged in a matrix, the array-type magnetorheological fluid support bed 300 can be divided into multiple independently controllable regions, which is suitable for differential stiffness adjustment at different positions of the blade web 700. In one embodiment, the independent excitation coils 320 are arranged in a 10x10 matrix, with the center spacing of each coil being 15mm to 30mm and the outer diameter of each coil being 8mm to 20mm. The coil windings can be made of high-temperature resistant enameled copper wire. To prevent magnetic particles in the magnetorheological fluid 350 from causing short circuits between coil turns, the outer surface of each independent excitation coil 320 is coated with a high-temperature resistant epoxy resin insulating encapsulation layer. Meanwhile, the power supply pins of each independent excitation coil 320 are led out to the outside of the enclosed cavity 340 through a micro-wire hole reserved at the bottom of the bottom heat-conducting substrate 310. The gaps in the micro-wire hole are filled with high-temperature resistant sealant, thereby ensuring power supply while preventing leakage of the magnetorheological fluid 350. The edge of the flexible sealing film 330 is sealed and fixed to the periphery of the bottom heat-conducting substrate 310, forming a stable closed cavity 340 to prevent the magnetorheological fluid 350 from leaking and to maintain the continuity of the upper surface. This sealing and fixing method can be achieved by pressing with a pressure plate and screws, or by using a combination of heat-resistant sealant and a surrounding pressure frame. The flexible sealing membrane 330 can be made of fluororubber, silicone rubber, or polyurethane film, with a thickness ranging from 1mm to 3mm. It has appropriate deformation when bearing the weight of the blade edge web 700, and can effectively transfer the local high stiffness formed by the magnetorheological fluid 350 to the bottom of the workpiece after the independent excitation coil 320 is energized. In order to resist the high-temperature plasma thermal radiation and molten slag splashing that accompany laser cutting, the upper surface of the flexible sealing membrane 330 is also coated with a micron-level high-temperature resistant boron nitride ceramic heat insulation coating, so that the surface of the array-type magnetorheological fluid support bed 300 can withstand high-temperature thermal shock and mechanical wear for a long time without damage or leakage. This combination of materials and structural arrangement enables the array-type magnetorheological fluid 350 and array-type magnetorheological fluid support bed 300 to take into account heat conduction, compliant fit, and zoned variable stiffness control.

[0018] The ratio of the input lever arm length to the output lever arm length of the miniature lever amplifier 430 is set to 1:5. The chuck 440 includes upper and lower jaws 441 and a spring 442. The spring 442 is connected to the upper and lower jaws 441 and is used to provide the initial preload. The displacement transmission relationship and clamping method in the thermally driven adaptive antagonistic tensioning mechanism 400 are defined. The purpose is to obtain an effective tensile displacement that can be used to suppress the thermal compression instability of the blade edge web 700 under the condition that the thermally induced displacement of the bimetallic memory alloy spring sheet 420 is small. When the ratio of the input lever arm length to the output lever arm length of the miniature lever amplifier 430 is set to 1:5, the 0.1mm to 0.5mm displacement generated at the free end of the bimetallic shape memory alloy spring 420 can be converted into a tensile displacement of 0.5mm to 2.5mm at the chuck 440 to meet the axial compensation requirements of the thin-walled blade edge web 700 during the laser cutting heating stage. It should be noted that the above-mentioned 0.5mm to 2.5mm displacement refers to the theoretical idle stroke displacement under no-load conditions. In actual clamping operations, part of the theoretical displacement is absorbed by the structural flexibility of the miniature lever amplifier 430 itself and converted into internal elastic potential energy. The tensile stress actually borne by the blade edge web 700 is... Always satisfied ,in This is the yield strength of thin-walled metals, thus preventing permanent plastic deformation of the workpiece; The miniature lever amplifier 430 can adopt a single-stage rigid lever structure, with the middle part hinged to the heat-conducting support 410 via a pin. Wear-resistant sleeves or miniature bearings are provided at both ends of the pin to reduce frictional resistance and decrease response hysteresis. The chuck 440 includes upper and lower jaws 441 and a spring 442. The spring 442 is used to provide a clamping preload to the upper and lower jaws 441 to ensure that the non-cutting edge 710 of the blade web 700 does not slip under laser cutting vibration and thermal shock conditions. The spring 442 can be a compression spring, a torsion spring or a leaf spring. In one embodiment, the clamping force is set to 50N to 300N. The clamping surfaces of the upper and lower jaws 441 can be equipped with a wear-resistant toothed layer or a high-friction coefficient pad to improve clamping stability and avoid large-area crushing of the workpiece. To meet the core requirement of efficiently transferring the parasitic waste heat generated by laser cutting through the chuck 440 to the rear heat conduction support 410, the high-friction coefficient pad uses a flexible graphite calendered pad doped with high thermal conductivity powder or a high thermal conductivity silicone pad. The wear-resistant toothed layer uses a metal toothed pad with flattened tooth tips and a high thermal conductivity silver or copper coating on the surface, thereby providing frictional preload while avoiding increasing contact thermal resistance. In addition, the initial distance between the clamping point of the chuck 440 and the ultra-thin cutting edge region 720 is limited to the effective heat conduction radius. Inside, among which For the thermal diffusivity of the material, The characteristic time of heat conduction during laser cutting; combined with the high thermal conductivity of the high friction coefficient pad, it ensures that parasitic waste heat is conducted to the bimetallic shape memory alloy spring sheet 420 at a millisecond rate before being dissipated into the air, thus achieving synchronous antagonism of thermal stress; The 1:5 lever ratio, when combined with the spring 442 and the preloaded chuck 440, allows thermally amplified displacement to be applied to the blade web 700 and maintains stable clamping boundary conditions, thereby providing a temperature-related reverse tensile force when the cutting heat load increases.

[0019] A linear guide rail 140 is fixedly connected to the crossbeam 130 of the gantry frame 110, and the laser cutting head 200 is slidably connected to the crossbeam 130 of the gantry frame 110 through the linear guide rail 140. The installation and guiding form of the laser cutting head 200 on the gantry 110 are defined to ensure the accuracy of the cutting trajectory and the repeatability of the motion; the linear guide rail 140 is fixedly connected to the crossbeam 130 of the gantry 110. The linear guide rail 140 can be arranged in a parallel double guide rail configuration. Each guide rail is fixed to the processing reference surface of the crossbeam 130 by bolts. The parallelism of the guide rail can be controlled from 0.02mm / m to 0.10mm / m. The laser cutting head 200 is slidably connected to the crossbeam 130 of the gantry frame 110 via a guide rail slider. The slider and the mounting plate of the laser cutting head 200 are rigidly connected to ensure the stability of the laser cutting head 200 during movement. The drive method can be a servo motor with a ball screw or a linear motor. When using a ball screw, the screw lead can be set to 5mm to 20mm, and a closed-loop position control can be achieved with an encoder, so that the laser cutting head 200 moves relative to the blade edge web 700 along a predetermined trajectory. The purpose of using the linear guide rail 140 is to reduce the sway and skew of the laser cutting head 200 in the lateral movement and to prevent additional offset of the focal position due to mechanical motion error. After the blade edge web 700 enters the extremely thin region, if the motion accuracy of the laser cutting head 200 is insufficient, it will cause changes in the kerf width and local overheating due to the superposition of thermal deformation of the workpiece. The high straightness guidance provided by the linear guide 140 can reduce such interference, so that the signals subsequently collected by the acoustic emission receiving probe 500 and the independent excitation coil 320 mainly reflect the workpiece deformation itself, rather than the error of the motion mechanism. This structure is conducive to improving the accuracy of the control system 600 in judging the instability trend.

[0020] Example 2: A method for flattening the blade edge and web plate based on laser cutting, such as Figure 5 As shown, it includes: S1. Place the blade edge web 700 to be processed on the flexible sealing membrane 330 of the array magnetorheological fluid 350 array magnetorheological fluid support bed 300, control the chuck 440 to hold the non-cutting edge 710 of the blade edge web 700, and keep the independent excitation coil 320 in the de-energized state. S2. Control the laser cutting head 200 to start and move towards the ultra-thin blade edge area 720 of the blade edge web 700 to cut according to the predetermined trajectory; S3. Apply a detection pulse to the independent excitation coil 320 and collect the transient voltage signal in the open sampling window. Obtain the back electromotive force change of the independent excitation coil 320 based on the transient voltage signal, and obtain the plasma plume acoustic emission main frequency drift received by the acoustic emission receiving probe 500. S4. Calculate the stress concentration index of the current blade edge region based on the abrupt change in back electromotive force and the drift of the dominant frequency of acoustic emission from the plasma plume. In S1, the blade edge web 700 to be processed is placed above the flexible sealing membrane 330 of the array-type magnetorheological fluid 350 array-type magnetorheological fluid support bed 300. The blade edge web 700 refers to a thin-walled metal component with a continuous transition from a thick web to an extremely thin edge. Its material can be stainless steel, high-strength steel or titanium alloy. When the independent excitation coil 320 is kept de-energized, the magnetorheological fluid 350 in the closed cavity 340 is in a low yield stress flow dynamic. The flexible sealing membrane 330 fits against the bottom contour of the blade web 700 under the action of the workpiece's own weight, which can reduce the initial additional stress caused by the mismatch of hard support in the early stage of clamping. The chuck 440 clamps the non-cutting edge 710 of the blade web 700, forming a stable end constraint. In S2, the control system 600 controls the laser cutting head 200 to emit pulsed or continuous laser beams and move to the ultra-thin blade edge area 720 for cutting according to the numerical control trajectory. During the cutting process, the heat capacity of the target thin-walled area is lower than the preset heat capacity threshold, and the local temperature rises higher than that of the thick web area, which easily forms thermal expansion compressive stress and out-of-plane warping tendency. In S3, the control system 600 collects and filters the voltage at the terminals of the independent excitation coil 320 to extract the back electromotive force mutation. This back electromotive force mutation originates from the influence of magnetic particles and medium microflow inside the magnetorheological fluid 350 on the change of coil flux after the flexible sealing membrane 330 is pressed down by the blade web 700. The control system 600 simultaneously acquires the plasma plume signal collected by the acoustic emission receiving probe 500 and obtains the acoustic emission main frequency drift through spectrum analysis. The acoustic emission main frequency drift corresponds to the laser focal length shift and the change in material removal state, which can indirectly reflect the change in surface height of the blade web 700. In S4, the control system 600 inputs the back electromotive force mutation and the plasma plume acoustic emission frequency drift into the calculation module to obtain the stress accumulation index of the current cutting edge region. This index is used to characterize the comprehensive instability risk of the current cutting position. This method combines the electromagnetic response of the support structure under the workpiece with the acoustic response of the cutting area, avoiding the need to place conventional displacement sensors in high temperature and strong light areas, and improving the feasibility of data acquisition. To ensure a clear source for the back electromotive force mutation in S3, while keeping the independent excitation coil 320 de-energized in a supporting sense, the control system 600 applies a detection pulse with an amplitude lower than the normal excitation current and a duration shorter than the main control cycle to the monitored coil between adjacent sampling cycles. The open-circuit sampling window immediately follows the end of the detection pulse. Since this detection pulse does not form a continuous magnetic field sufficient to substantially stiffen the magnetorheological fluid 350, it can still be considered that the independent excitation coil 320 is de-energized. Specifically, the detection pulse applied to the independent excitation coil 320 uses a microampere-level high-frequency AC carrier signal, whose frequency is much higher than the mechanical response characteristic frequency of the magnetic particles inside the magnetorheological fluid, and does not generate an effective magnetic field force sufficient to induce particle chaining. Simultaneously, the control system 600 integrates a lock-in amplifier circuit, which uses phase-sensitive detection technology to accurately extract the weak inductance change caused by the micron-level deformation of the flexible sealing film from the environmental electromagnetic noise. The essential physical mechanism of the sudden change in back electromotive force here is that after the local deformation of the blade edge web 700 presses down on the flexible sealing membrane 330, the thickness of the magnetorheological fluid 350 above the coil and the microscopic distribution of the internal magnetic particles change, causing a transient change in the equivalent inductance and magnetic reluctance of the independent excitation coil 320. When the detection pulse is turned off, the change in the equivalent inductance and magnetic reluctance will cause the transient induced voltage generated by the self-inductance at both ends of the coil to change its decay characteristics. The control system 600 can characterize the degree of local deformation by collecting the change in this transient voltage. Within the open-circuit sampling window of the coil, the control system 600 collects the transient induced voltage at both ends of the coil and compares it with the corresponding baseline value to obtain the back electromotive force change. The baseline value is preferably collected before the blade web 700 is heated, the surface is flat, and the laser cutting head 200 reaches the current monitoring area. The average value of multiple consecutive sampling points can be taken to reduce the influence of environmental electrical noise. The processing flow of S3 can be executed in the following order: The control system 600 determines the target coil area directly below and adjacent to the laser cutting head 200 based on the current position of the laser cutting head 200; detection pulses are applied to the target coil area in sequence and transient voltage signals within the open-circuit sampling window are acquired; The transient voltage signal is processed by bandpass filtering and abnormal spike removal to obtain the current sample value; the current sample value is subtracted from the corresponding baseline value and the absolute value is taken to obtain the change in back electromotive force of a single coil; When the target coil area contains multiple coils, the control system 600 can select the maximum value or the weighted average value as the back electromotive force change at the current moment, wherein the coils closer to the projection position of the laser cutting head 200 have higher weights. The purpose of this processing is to uniformly map the local deformation response of the partitioned array magnetorheological fluid support bed 300 into a deformation characterization quantity that can participate in subsequent judgment; the process of obtaining the main frequency drift of the plasma plume acoustic emission is as follows: the control system 600 first collects the original acoustic signal through the acoustic emission receiving probe 500, then processes the original acoustic signal into frames according to a preset time window, performs spectrum analysis on each frame and extracts the main frequency component with the largest energy, and calculates the difference between the current main frequency and the reference main frequency to obtain the main frequency drift; The reference frequency can be pre-recorded under the same material, laser power, and cutting speed conditions when the workpiece is being cut stably in a flat area. If the frequency fluctuation exceeds the preset range within multiple consecutive time windows, the control system 600 can use the median filtering result as the current frequency to reduce misjudgments caused by splashing, external impact noise, or airflow disturbance. In addition, the operating frequency band of the acoustic emission receiving probe 500 is specially configured in the ultra-high frequency range of 100kHz to 400kHz. With the help of a hardware high-pass filter, the low-to-medium frequency environmental noise below 50kHz generated by auxiliary gas injection, equipment mechanical vibration, and slag collision is directly shielded at the signal acquisition physical level. This ensures that the extracted frequency drift simply reflects the intrinsic state of the plasma plume, guaranteeing extremely high stability of the judgment result. The physical meaning of the stress concentration index in S4 is a dimensionless judgment quantity used to comprehensively characterize the out-of-plane deformation trend and thermal input deviation trend that exist simultaneously at the current cutting position. Among them, the back electromotive force mutation mainly characterizes the contact state and local deflection change of the lower surface of the workpiece, and the plasma plume acoustic emission main frequency drift mainly characterizes the focal length shift and local thermal input deviation. After the index is generated, it is output to the subsequent threshold comparison module and serves as a common input for judging whether to reduce the duty cycle of the laser cutting head 200 pulses and whether to increase the excitation current of the corresponding independent excitation coil 320. This makes the data flow relationship clear: the transient voltage signal of the coil and the original acoustic emission signal respectively form the back electromotive force change and the main frequency drift, which together form the stress accumulation index and enter the control decision. From the perspective of the evaluation model, step S4 essentially constructs a real-time evaluation model that integrates multi-source information. The purpose of this model is to quickly estimate the combined risk of thermal compression instability and out-of-plane warping in the current cutting area when the dynamic thermal stress and small deformation of the blade edge web 700 cannot be directly measured. The model logically receives two independent data streams: one is the underlying mechanical deformation data represented by the back electromotive force mutation, and the other is the surface thermophysical state data represented by the plasma plume acoustic emission frequency drift. After synchronous acquisition and feature extraction, the two are input into the evaluation model for weighted mapping, and finally output a single dimensionless stress accumulation index. The model as a whole characterizes the coupling relationship between heat input deviation and out-of-plane deformation of the structure during laser cutting, and simulates the dynamic physical process of thermal stress accumulating in an extremely thin region and evolving toward the instability critical point.

[0021] The steps in S4 for calculating the stress concentration index of the current blade edge region based on the abrupt change in back electromotive force and the drift of the dominant frequency of acoustic emission from the plasma plume include: S401. Obtain the preset deformation weight coefficient determined by pre-calibration, and multiply the normalized value of the back electromotive force mutation by the preset deformation weight coefficient to obtain the first calculated value. S402. Obtain the preset thermal deviation weighting coefficient determined by pre-calibration, and multiply the normalized value of the plasma plume acoustic emission main frequency drift by the preset thermal deviation weighting coefficient to obtain the second calculated value. S403. Add the first calculated value to the second calculated value to obtain the stress concentration index; The specific calculation method of the stress concentration index is defined, enabling the control system 600 to convert different physical quantities into a unified evaluation index in an executable linear weighting manner; in S401, the control system 600 multiplies the back electromotive force mutation by a preset deformation weighting coefficient to obtain the first calculated value; the back electromotive force mutation can be obtained by subtracting the baseline voltage from the coil terminal voltage change and processing the absolute value, and the unit can be mV or volt; The preset deformation weight coefficient is used to reflect the mapping relationship between the sudden change in back electromotive force and the out-of-plane micro deformation of the workpiece. This coefficient is obtained through pre-calibration. The calibration method can use a standard thickness sample, record the change in coil back electromotive force under different known pressure displacement conditions, and perform linear fitting or piecewise fitting to determine the deformation weight coefficient. In the scenario of multi-variety mixed production line, the preset deformation weight coefficient, preset thermal deviation weight coefficient, and preset safety threshold can not only be obtained through destructive test cutting. The control system 600 has an embedded process mapping database and finite element proxy model, which can directly generate the appropriate coefficients and thresholds based on the currently input material grade, thickness gradient, and cutting parameters through a multi-dimensional space interpolation algorithm, which greatly reduces calibration costs and improves versatility. In S402, the control system 600 multiplies the acoustic emission frequency drift of the plasma plume by a preset thermal deviation weighting coefficient to obtain a second calculated value. The acoustic emission frequency drift can be represented by the difference between the current frequency and the reference frequency. The reference frequency can be acquired when the thermal input is stable and the surface is flat. The thermal deviation weighting coefficient is used to reflect the correspondence between focal length shift, thermal input deviation and instability risk, and is also determined through trial cutting calibration. In S403, the first calculated value and the second calculated value are added together to obtain the stress concentration index. This index can be set as a dimensionless value for easy comparison with subsequent safety thresholds. In one embodiment, the back electromotive force mutation and the plasma plume acoustic emission frequency drift are both normalized before participating in the solution of the corresponding calculated values. The normalization reference range is taken as their respective calibrated upper limit value. When the measured value exceeds the calibrated upper limit value, it is processed according to the upper limit value to prevent abnormal peak interference control judgment. The reason for using a linear weighted instead of a complex nonlinear model is that this calculation method has a small computational load and is suitable for real-time execution on an industrial control computer. At the same time, it retains the sensitivity of the back electromotive force mutation to deformation and the sensitivity of the acoustic emission main frequency drift to focal length shift, so that the stress concentration index can reflect both local out-of-plane deflection and laser thermal input deviation. The preset deformation weight coefficient and preset thermal deviation weight coefficient are not arbitrarily assigned values, but are used to adjust the proportion of structural deformation information and thermal input deviation information in the comprehensive judgment. If the thickness of the web of the cutting edge to be processed is thinner and it is more prone to out-of-plane instability, the preset deformation weight coefficient can be set to a larger value. If the cutting process is more sensitive to focal length and thermal input, the preset thermal deviation weight coefficient can be set to a larger value. Both are preferably determined through preliminary experiments on the same type of workpiece: under known laser power, cutting speed and plate thickness gradient, the back electromotive force mutation, main frequency drift and corresponding measured warping results at multiple cutting positions are recorded, and then the applicable weight range is determined by comparing the correlation between each variable and the measured warping degree; after this setting, the role of the weight coefficient in the control logic is to convert the original monitoring quantities with different dimensions and different sensitivities into comparable risk contribution values; To clarify the specific calculation process and data flow of S401 to S403, the control system 600 can execute the following sequence: first, read the back electromotive force mutation at the current moment; then, read the acoustic emission main frequency drift at the same moment or within the same sampling window; call the pre-stored preset deformation weight coefficient and preset thermal deviation weight coefficient respectively; generate the first calculated value and the second calculated value; add the two together to obtain the stress concentration index, and write the index into the real-time cache for S501 to call; In other words, the input sources of S401 to S403 are the back electromotive force mutation output by the coil voltage sampling module and the main frequency drift output by the acoustic emission processing module, respectively. The output result is the stress accumulation index, and the output flow is to the threshold comparison and linkage control module. In the implementation using normalization, the back electromotive force (EMF) mutation is first compared with its calibrated upper limit to obtain the normalized back EMF value; then, the dominant frequency drift is compared with its calibrated upper limit to obtain the normalized dominant frequency drift value; when any measured value is greater than the corresponding calibrated upper limit, the normalized value is set to 1 to suppress the amplification effect of occasional spikes on the results; then, the stress concentration index is calculated using the following formula: I = K1 × D + K2 × F Where I represents the stress concentration index, K1 represents the preset deformation weighting coefficient, D represents the normalized value of the back electromotive force, K2 represents the preset thermal deviation weighting coefficient, and F represents the normalized value of the main frequency drift. This expression is only used to illustrate the business rules of linear weighting. Its focus is on illustrating that the two input quantities are summed after being weighted and mapped, rather than relying on complex algorithm models. The above linear weighted calculation steps clarify the direct causal relationship between components, steps and the resulting effects; because the sensitivity of the blade web 700 to thermal deviation and mechanical deformation varies significantly with different materials and thicknesses, it is necessary to adjust them independently by setting the deformation weight coefficient and the thermal deviation weight coefficient. When the blade edge thickness is lower than the preset thickness threshold and the bending stiffness is lower than the preset stiffness threshold, even a small out-of-plane deformation means an instability risk that exceeds the safe range. At this time, the effect of the deformation weighting coefficient is amplified, making the system more sensitive to small changes in back electromotive force. When the material has a large coefficient of thermal expansion and is more sensitive to local heat input anomalies, the effect of the thermal deviation weighting coefficient is amplified. This causal-driven weight allocation mechanism logically ensures that the stress concentration index can adapt to different processing conditions, avoiding control misjudgments that may be caused by relying on a single monitoring index, thereby achieving accurate and robust quantification of instability risk. To enable those skilled in the art to clearly implement the above linear weighted calculation, a specific quantitative derivation example is provided below to illustrate the data flow and calculation rules: Assume that the pre-calibrated upper limit of the back EMF mutation is 50mV and the upper limit of the main frequency drift is 20kHz; within a certain control cycle, the voltage sampling module of the control system 600 outputs the current back EMF mutation as 30mV and the acoustic emission processing module outputs the current main frequency drift as 15kHz; The control system 600 performs normalization processing, calculating the normalized value of back electromotive force D as 30 divided by 50 equals 0.6, and the normalized value of main frequency drift F as 15 divided by 20 equals 0.75; if any input value exceeds the upper limit, it is forcibly assigned a value of 1.0 to avoid anomalies. The control system 600 calls the preset weighting coefficients in the memory. Assuming that for the current 0.5mm thick stainless steel blade web 700, the preset deformation weighting coefficient K1 is set to 0.6 and the preset thermal deviation weighting coefficient K2 is set to 0.4; the control system 600 performs weighted summation, calculates the first calculated value as 0.6 multiplied by 0.6 equals 0.36, the second calculated value as 0.4 multiplied by 0.75 equals 0.30, and the final output stress concentration index I equals 0.36 plus 0.30 equals 0.66; The index, as a dimensionless floating-point number, is directly written to the real-time buffer via the internal data bus for use by the threshold comparison module in the next control cycle. This deduction process clearly demonstrates the data flow path and calculation logic from the raw data of the underlying sensors to the final evaluation index, thus enabling the quantification of risk.

[0022] S4 followed by: S501. Obtain the preset safety threshold and determine the relationship between the stress accumulation index and the preset safety threshold. S502. When the stress concentration index is greater than or equal to the preset safety threshold, reduce the duty cycle of the laser cutting head 200 pulses and simultaneously increase the excitation current of the independent excitation coil 320 directly below the current cutting edge area, and control the magnetorheological fluid 350 to solidify to provide anti-buckling support force. S503. When the stress concentration index is less than the preset safety threshold, keep the duty cycle of the laser cutting head 200 pulses and the excitation current of the independent excitation coil 320 unchanged. Subsequent control actions were limited so that the stress concentration index was not only used for evaluation, but also directly involved in laser heat input and support stiffness adjustment; in S501, the control system 600 obtained a preset safety threshold and compared the stress concentration index with the threshold. The preset safety threshold can be determined comprehensively based on the material yield strength, workpiece thickness gradient, cutting speed and test cutting results; in one embodiment, multiple test cuts are performed on the same type of blade edge web 700, and the stress concentration index before measurable warping occurs is recorded, with 80% to 95% of it used as the preset safety threshold. In S502, when the stress concentration index is greater than or equal to the preset safety threshold, the control system 600 reduces the duty cycle of the laser cutting head 200 pulses to reduce the heat input per unit time from the source; the reduction in duty cycle can be set to 5% to 30% of the original set value. The control system 600 synchronously increases the excitation current of the independent excitation coil 320 directly below the current cutting edge area. After the excitation current increases, the magnetic particles inside the magnetorheological fluid 350 align along the magnetic field direction, and the yield stress and equivalent elastic modulus in the local area increase, thereby providing anti-buckling support force to the bottom of the cutting edge web 700 through the flexible sealing membrane 330. The independent excitation coil 320 adopts zone control, increasing the current only for the coil directly below the deformation area or its adjacent coils to reduce unnecessary energy consumption and overall hardening. Even under extreme conditions where the highest industrial cutting speed is 10m / min and the magnetorheological fluid curing response time is 50ms, the sliding distance of the cutting head during the response period is about 1.67mm. Since the outer diameter of a single independent excitation coil 320 is 8mm to 20mm, this hysteresis distance is still completely within the effective magnetic field coverage radius of the current main support coil (greater than 4mm), which is sufficient to ensure that the stiffness enhancement position can accurately cover the area where actual deformation occurs. In S503, when the stress concentration index is less than the preset safety threshold, the duty cycle of the laser cutting head 200 pulse and the excitation current of the independent excitation coil 320 are kept constant, so that the system maintains the current stable cutting state. In another embodiment, when the stress concentration index is lower than a certain proportion of the preset safety threshold for multiple consecutive sampling periods, the control system 600 can gradually restore the duty cycle and excitation current according to the preset slope to reduce the heat input fluctuation caused by parameter sudden change. This control logic enables heat input adjustment and support stiffness adjustment to be executed in tandem under the same evaluation index, which can reduce the accumulation of thermal compression in the cutting zone when instability occurs and enhance local bottom support. The logical role of the preset safety threshold in the control process is to distinguish between a stable state that allows continued cutting according to the current process and an intervention state that requires immediate suppression of the risk of thermal instability. This threshold is not simply an empirical constant, but is derived from trial cutting data: multiple sets of trial cuts are first completed under the same material, the same thickness gradient, and similar cutting speed conditions. Then, record the temporal changes of the stress concentration index and the corresponding warpage, cut offset, or overheating for each group of test cuts; determine the stress concentration index range when measurable signs of instability begin to appear; reserve a safety margin below the lower limit of this range to form a preset safety threshold. With this setting, the preset safety threshold becomes the direct basis for determining whether S502 is triggered; in order to clarify the determination logic of the independent excitation coil 320 directly below the deformation area, the control system 600 can make a joint determination based on the current coordinates of the laser cutting head 200, the fixed position coordinates of each independent excitation coil 320 in the array magnetorheological fluid 350 array magnetorheological fluid support bed 300, and the local back electromotive force change distribution obtained in S3; Specifically, first, a target coil area is initially delineated below the laser cutting head 200 based on its projection position; then, the back electromotive force changes of each coil in this area are compared, and the coil with the largest change is selected as the main support coil; if necessary, its adjacent coils are also selected as auxiliary support coils; this ensures that the excitation enhancement action in S502 corresponds to the actual location where the bending trend occurs, rather than uniformly increasing the current for the entire coil bed. The linkage control in S502 can be executed in the following order: when the stress accumulation index is greater than or equal to the preset safety threshold, the control system 600 first outputs a first control command to the laser cutting head 200, causing the pulse duty cycle to decrease by a preset step; within the same control cycle, it outputs a second control command to the main support coil and the auxiliary support coil, causing the excitation current to increase by a preset step; and in the next sampling cycle, it recalculates the stress accumulation index. If the recalculated stress concentration index is still higher than the preset safety threshold, the duty cycle will continue to be reduced and the excitation current will be increased in a stepwise manner until the stress concentration index falls back below the preset safety threshold, or the preset minimum duty cycle and maximum excitation current limit values ​​are reached. The purpose of setting these limit values ​​is to avoid insufficient cutting due to low cutting energy, and also to avoid overheating of the coil or excessive hardening of the magnetorheological fluid 350. In S502, the control of magnetorheological fluid 350 curing refers to the transformation of magnetorheological fluid 350 from a low yield stress flow dynamic to an apparent cured support state with higher yield stress and higher equivalent stiffness after the excitation current increases. It is not irreversible curing in the chemical sense. The role of this apparent solidified support state in the control logic is to provide immediate enhanced bottom support when the blade edge web 700 shows a tendency to become unstable locally; when the subsequent stress concentration index decreases and the excitation current is restored, the magnetorheological fluid 350 can return to a lower stiffness state to maintain the compliant fit of the subsequent area. To ensure the programmable implementation of the above-mentioned linkage control logic and the clarity of data flow, the control system 600 can use a finite state machine model to execute S501 to S503. Specifically, the control system 600 reads the current stress accumulation index from the real-time buffer through the internal bus and compares it with the preset safety threshold. When the index reaches 0.85, the state machine switches from the stable cutting state to the intervention state. In the intervention state, the decision module of the control system 600 generates adjustment instructions according to a fixed control cycle: First, it sends a duty cycle adjustment signal to the laser controller through the pulse width modulation interface, and decreases the current duty cycle by a preset step size; Second, it sends a current setpoint to the multi-channel current drive module through the digital-to-analog conversion interface, and increases the excitation current of the main support coil by a preset step size. After the above adjustment command is issued, the system rereads the updated stress concentration index in the next control cycle. If the index is still higher than or equal to 0.80, the above step size adjustment continues until the duty cycle reaches the minimum allowable limit or the excitation current reaches the maximum allowable limit. If the index falls below 0.80, the state machine switches back to the stable cutting state, stops the decreasing and increasing actions, and can gradually return to the initial setting value according to the preset recovery step size which is smaller than the adjustment step size. This detailed description of the control logic and interface interaction clarifies the specific input judgment, processing procedure and output form of the algorithm module, enabling those skilled in the art to directly write control code based on it.

[0023] S2 after and S3 before, including: S201. Obtain the parasitic waste heat generated during cutting, and use the parasitic waste heat to conduct along the blade edge web 700 to the chuck 440, and further conduct it to the heat-conducting support 410 and the bimetallic shape memory alloy spring 420. S202, the bimetallic shape memory alloy spring 420 undergoes a phase change expansion when heated, generating an expansion displacement to push the input terminal of the miniature lever amplifier 430; S203. The output of the miniature lever amplifier 430 drives the chuck 440 to generate radial tensile displacement, and applies reverse tensile prestress to the blade edge web 700. The specific details of the participation method of the thermally driven adaptive antagonistic tensioning mechanism 400 are given, which is used to convert the parasitic waste heat from cutting into reverse tensile prestress on the blade edge web 700; in S201, the parasitic waste heat generated during the cutting process is concentrated near the kerf and also diffuses along the metal body of the blade edge web 700 to the non-cutting edge 710. The collet 440 is in direct contact with the non-cutting edge 710 of the blade web 700, thus receiving heat from the workpiece; this heat is further conducted through the collet 440 to the heat-conducting support 410 and the bimetallic shape memory alloy spring 420; to improve the heat transfer efficiency, the connection between the collet 440 and the heat-conducting support 410 can be made of a high thermal conductivity metal transition piece, and a heat-conducting medium is provided on the contact surface; In S202, the bimetallic shape memory alloy spring 420 undergoes phase change expansion upon heating, outputting a measurable displacement. The bimetallic shape memory alloy spring 420 refers to an elastic element formed by composite material layers with different thermal responses or phase change responses. After heating, the free end generates a bending displacement with a defined direction. The bimetallic shape memory alloy spring 420 has a two-way shape memory effect, and can automatically return to its initial flat shape after the cutting heat source is removed and the temperature drops, driving the clamp 440 to reset and release the tension. At the same time, a mechanical rigid limit block is fixed on the swing trajectory at the output end of the micro lever amplifier 430, forcibly constraining the maximum radial tensile displacement within a preset safe elastic boundary. In one embodiment, the spring is formed by a composite of a nickel-titanium alloy layer and a stainless steel layer, with a thickness of 0.2 mm to 1.5 mm and a free length of 20 mm to 80 mm. The working temperature range is adapted to the temperature rise range conducted to the chuck 440 when the blade edge web 700 is cutting. In S203, the expansion displacement generated by the bimetallic shape memory alloy spring 420 pushes the input end of the micro lever amplifier 430. After hinge reversal and lever arm ratio conversion, the output end of the micro lever amplifier 430 drives the chuck 440 to generate radial tensile displacement. It needs to be clarified that the radial direction here refers to the radial normal direction of the rotation axis of the output end of the miniature lever amplifier 430, which is designed to be parallel to the main axis of the blade web 700 in spatial geometry. Therefore, after the radial tensile displacement is transmitted to the non-cutting edge 710 of the blade web 700, a reverse tensile prestress is formed in the main axis of the workpiece. Since the temperature rise of the bimetallic shape memory alloy spring 420 comes from the parasitic waste heat of cutting, when the workpiece temperature rises, the tensile displacement of the chuck 440 increases synchronously. Therefore, the reverse tensile prestress and the in-plane compressive stress caused by thermal expansion are related. In this way, the heat generated by the machining process itself can be used to establish compensating tension without the need for an external independent power actuator, so that the cutting edge web 700 maintains a relatively stable axial force state when entering the ultra-thin area for cutting, and works together with the local variable stiffness support to reduce out-of-plane instability. The working principle of the thermally driven adaptive antagonistic tensioning mechanism 400 is based on a strict causal antagonistic relationship. Since the parasitic waste heat generated by laser cutting is the root cause of the local heating and expansion of the blade edge web 700, the generation of in-plane compressive stress, and the eventual induction of thermal compression instability, this embodiment cleverly utilizes the same heat source as the driving force to counteract the compressive stress. As the parasitic waste heat is conducted, the blade edge web 700 inevitably tends to thermally expand. At the same time, this waste heat is conducted to the bimetallic shape memory alloy spring 420, causing it to undergo phase change expansion. Then, through the reversal and amplification effect of the micro lever amplifier 430, the chuck 440 will inevitably produce a tensile displacement opposite to the direction of the workpiece's thermal expansion. This physical relationship of co-driven and mechanically antagonistic not only ensures that the compensating tensile force is highly synchronized with the generation of compressive stress in time, but also that its magnitude can adaptively increase with the accumulation of heat. Therefore, by adopting a waste heat-driven thermal phase change and mechanical amplification linkage structure, it is possible to achieve adaptive dynamic suppression of in-plane compressive stress in the cutting area without increasing the complexity of the external servo control system by 600, which effectively improves the autonomous feedback capability and system reliability of the processing system.

[0024] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. A laser-cut based knife-edge web planing device, characterized by, include: A processing base (100) is fixed to a gantry frame (110) at its top. The gantry frame (110) includes a crossbeam (130), and a rectangular groove (120) is opened in the middle of the processing base (100). A laser cutting head (200) is slidably connected to the crossbeam (130) of the gantry frame (110); An array-type magnetorheological fluid support bed (300) is fixed in a rectangular groove (120). An independent excitation coil (320) is fixed to the top of the bottom heat-conducting substrate (310) and wrapped by a flexible sealing film (330). A closed cavity (340) filled with magnetorheological fluid (350) is formed between the flexible sealing film (330) and the bottom heat-conducting substrate (310). A thermally driven adaptive antagonistic tensioning mechanism (400) is provided on the side of the array-type magnetorheological fluid support bed (300) on the machining base (100). Its thermally conductive support (410) is fixed to the machining base (100). A bimetallic shape memory alloy spring (420) is fixed to the top of the thermally conductive support (410) and a micro lever amplifier (430) is hinged to the middle. The free end of the bimetallic shape memory alloy spring (420) abuts against the input end of the micro lever amplifier (430). The output end of the micro lever amplifier (430) is fixed to a chuck (440) to hold the non-cutting edge (710) of the blade web (700). An acoustic emission receiving probe (500) is fixed to the side of the processing base (100) and pointed directly below the laser cutting head (200); The control system (600) is electrically connected to and controls the laser cutting head (200) and the independent excitation coil (320), and acquires sensing data from the acoustic emission receiving probe (500).

2. A laser cutting based knife-edge web flattening device according to claim 1, characterized in that, Both the bottom heat-conducting substrate (310) and the heat-conducting support (410) are made of copper. The independent excitation coils (320) are arranged in a matrix. The edge of the flexible sealing film (330) is sealed and fixed to the four edges of the bottom heat-conducting substrate (310).

3. The laser-cutting-based blade edge and web flattening processing device according to claim 1, characterized in that, The ratio of the input lever arm length to the output lever arm length of the miniature lever amplifier (430) is set to 1:

5. The chuck (440) includes upper and lower jaws (441) and a spring (442). The spring (442) is connected to the upper and lower jaws (441) and is used to provide an initial preload.

4. The laser-cutting-based blade edge and web flattening processing device according to claim 1, characterized in that, A linear guide rail (140) is fixedly connected to the crossbeam (130) of the gantry frame (110), and the laser cutting head (200) is slidably connected to the crossbeam (130) of the gantry frame (110) through the linear guide rail (140).

5. A method for flattening the blade edge and web plate based on laser cutting, applied to the laser cutting-based blade edge and web plate flattening apparatus described in claim 1, characterized in that, include: S1. Place the blade edge web (700) to be processed above the flexible sealing membrane (330) of the array-type magnetorheological fluid support bed (300), control the chuck (440) to hold the non-cutting edge (710) of the blade edge web (700), and keep the independent excitation coil (320) in a de-energized state. S2. Control the laser cutting head (200) to start and move towards the extremely thin blade edge area (720) of the blade edge web (700) according to a predetermined trajectory to perform cutting; S3. Apply a detection pulse to the independent excitation coil (320) and collect the transient voltage signal in the open sampling window. Obtain the back electromotive force change of the independent excitation coil (320) based on the transient voltage signal, and obtain the plasma plume acoustic emission main frequency drift received by the acoustic emission receiving probe (500). S4. Calculate the stress concentration index of the current blade edge region based on the back electromotive force mutation and the plasma plume acoustic emission frequency drift.

6. The method for flattening the blade edge and web plate based on laser cutting according to claim 5, characterized in that, The step in S4 of calculating the stress concentration index of the current blade edge region based on the back electromotive force mutation and the plasma plume acoustic emission dominant frequency drift includes: S401. Obtain the preset deformation weight coefficient determined by pre-calibration, and multiply the normalized value of the back electromotive force mutation by the preset deformation weight coefficient to obtain the first calculated value. S402. Obtain the preset thermal deviation weighting coefficient determined by pre-calibration, and multiply the normalized value of the plasma plume acoustic emission main frequency drift by the preset thermal deviation weighting coefficient to obtain the second calculated value. S403. Add the first calculated value to the second calculated value to obtain the stress concentration index.

7. The method for flattening the blade edge and web plate based on laser cutting according to claim 5, characterized in that, S4 is followed by: S501. Obtain a preset safety threshold and determine the relationship between the stress accumulation index and the preset safety threshold. S502. When the stress concentration index is greater than or equal to the preset safety threshold, reduce the duty cycle of the laser cutting head (200) pulse and simultaneously increase the excitation current of the independent excitation coil (320) directly below the current cutting edge area to control the magnetorheological fluid (350) to solidify and provide anti-buckling support force. S503. When the stress concentration index is less than the preset safety threshold, the duty cycle of the laser cutting head (200) pulse and the excitation current of the independent excitation coil (320) remain unchanged.

8. The method for flattening the blade edge and web plate based on laser cutting according to claim 5, characterized in that, The period after S2 and before S3 includes: S201. Obtain the parasitic waste heat generated during cutting, and use the parasitic waste heat to conduct along the blade edge web (700) to the chuck (440), and further conduct it to the heat-conducting support (410) and the bimetallic memory alloy spring (420). S202, the bimetallic memory alloy spring (420) undergoes phase change expansion when heated, generating expansion displacement to push the input end of the micro lever amplifier (430); S203. Using the output end of the micro lever amplifier (430), the chuck (440) is driven to generate radial tensile displacement, and reverse tensile prestress is applied to the blade edge web (700).

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