Adjustable foreign object impact damage preparation device and preparation method thereof

Abstract

The invention provides a foreign object impact damage preparation device and a preparation method thereof. Wherein the preparation device comprises an impact part, an impact part, a driving part and a driving part, the triggering part comprises a force bearing seat, a pre-tightening piece and an elastic clamping piece; wherein the relative positions of the force bearing seat and the test piece in the z direction are fixed; the pre-tightening piece is fixedly connected with the force bearing seat and adjustably pre-tightens the elastic clamping piece in the direction perpendicular to the z direction. The first end of the elastic clamping piece makes contact with the pre-tightening piece so that the elastic clamping piece can be pre-tightened, and the second end of the elastic clamping piece is provided with a curved surface protruding part so that the elastic clamping piece can be elastically connected with the bayonet of the impact part in a clamped mode. The impact part is clamped with the elastic clamping piece and keeps the relative position of the test piece in the z direction, and the impact part is in a to-be-triggered state; the impact part is subjected to pressure, is separated from the clamping connection with the elastic clamping piece and impacts the test piece in the z direction, and is in a trigger state.

Description

Technical Field

[0001] This disclosure relates to the field of aero-engine technology, and in particular to an adjustable apparatus for preparing external impact damage and a method thereof. Background Technology

[0002] During the service life of aero-engines, powerful airflow pressure may draw in external environmental substances (such as gravel, metal, stones, and plastic from the runway), causing damage to engine blades due to impact. Damage characteristics, such as dents and notches, typically vary in size and morphology. These damage features generate significant stress concentration, and under the combined effects of temperature loads, centrifugal force, and aerodynamic loads, the blade's fatigue resistance significantly decreases, thus affecting the service safety and lifespan of the aero-engine. To ensure the reliability and economy of aero-engines, it is necessary to study the impact of foreign object impact damage on blade fatigue performance. A key aspect of this research is the effective fabrication of impact damage of specific sizes and morphologies. Summary of the Invention

[0003] Through in-depth research, the inventors discovered that the main technologies for obtaining the characteristics of external object damage through laboratory simulation include: machining, quasi-static extrusion, pendulum impact, and air cannon methods, each with its own advantages and disadvantages.

[0004] Machining methods remove material using cutting tools to create damage features. This method can effectively control the size and morphology of damage features and has good repeatability. However, its drawback is that the formation mechanism of these damage features differs significantly from the damage features generated in actual service.

[0005] The quasi-static extrusion method prepares damage features by controlling the extrusion depth of the indenter. This method can effectively control the size and morphology of the damage features through indenter preparation and extrusion depth control, exhibiting good repeatability. However, its drawback is that the formation mechanism of the damage features differs significantly from the damage features generated in actual service.

[0006] The pendulum method prepares damage features by converting potential energy into kinetic energy. Specifically, a pendulum is raised to a certain height and then triggered, and upon falling, it impacts the simulated test piece to generate damage features. This method can simulate the damage formation mechanism under external impact to a certain extent, and can control the size and morphology of the damage relatively well. However, its disadvantages are that the impact effect is limited by the mass and maximum height of the pendulum device, and the pendulum's bounce can easily cause secondary damage, interfering with the preparation effect.

[0007] The air gun method prepares damage features by using compressed gas to launch a projectile that impacts a simulated test specimen. This method can realistically simulate the formation mechanism of damage under impact from foreign objects, but its disadvantages are that the prepared damage features are not easy to control and have poor repeatability; they also have large dispersion, and the preparation location of the damage features is not easy to control; moreover, because the gas pressure in the high-pressure chamber needs to be adjusted to control the projectile velocity and angle, the preparation device is complex and costly.

[0008] In view of the above, this disclosure aims to solve at least one of the following technical problems, including but not limited to: overcoming the problem that the formation mechanism of damage features is different from the damage features generated in actual service, and there is a significant difference; overcoming the problem that the impact effect is limited by the mass and maximum height of the pendulum device; overcoming the problem of secondary damage caused by the pendulum bounce; overcoming the problem that the size and morphology of the prepared damage features are not easy to control and the repeatability is poor; overcoming the problem of large dispersion; overcoming the problem that the preparation device is complex and costly, etc.

[0009] The purpose of this disclosure is to provide an adjustable apparatus for preparing external impact damage.

[0010] Another object of this disclosure is to provide a method for preparing the preparation apparatus.

[0011] According to one aspect of this disclosure, an apparatus for preparing external impact damage includes: an impact part having a latch on its side; and a triggering part including a support seat, a pre-tightening member, and an elastic latch; wherein the support seat is fixed in a z-direction relative position with the test piece; the pre-tightening member is fixedly connected to the support seat and is adjustablely pre-tightened in the vertical z-direction; the elastic latch has a first end in contact with the pre-tightening member so that it can be pre-tightened, and a curved protrusion at the second end so that it can elastically engage with the latch of the impact part; the impact part engages with the elastic latch and maintains a z-direction relative position with the test piece, which is a state awaiting triggering; the impact part is subjected to pressure, disengages from the elastic latch, and impacts the test piece in the z-direction, which is a state of triggering.

[0012] Under pressure, the impact part detaches from the triggering part and contacts the test piece in an impact manner, effectively simulating the formation mechanism of damage features in actual service. The impact part has a defined mass and height relative to the test piece; therefore, the impact effect is not determined by its mass or height, but by the elastic force provided by the preload and the elastic clamp. This elastic force can be set by selecting elastic clamps with different elastic coefficients and adjusting the preload. In other words, under the defined conditions of the preparation device, only the preload of the preload on the elastic clamp needs to be adjusted during use, making operation simple. Furthermore, the pressure required to reach the triggering state and the impact force of the impact part, limited by the elastic force, also have defined thresholds, ultimately achieving controllable impact effects and ensuring the accuracy and repeatability of damage feature preparation. The preparation device has a simple structure and low manufacturing cost.

[0013] In one or more embodiments of the preparation apparatus, the pre-tightening member is provided with an impact force scale line, used to determine the impact force threshold F based on the deformation h of the elastic clip, with the following relationship:

[0014]

[0015] In the formula, α is the correction coefficient, K1 is the elastic coefficient of the elastic clip, R1 is the radius of the latch, and R2 is the radius of the curved protrusion. The correction coefficient α can be obtained through a loading test. Specifically, the impact force sensor is fixed directly below the impact part, i.e., at the fixed position of the test piece; the preload is adjusted to cause the elastic clip to deform by a deformation h, and the corresponding impact force scale value aligned with the preload is recorded. Pressure is gradually applied until the impact part is triggered, and the impact force value recorded by the sensor is the impact force threshold F corresponding to the impact force scale value. Based on the known elastic coefficient K1 of the elastic clip, the side latch radius R1 of the impact part, the radius R2 of the curved protrusion, the deformation h, and the impact force threshold F, the correction coefficient α can be calculated using the above formula.

[0016] The impact force scale design allows for quantitative adjustment of the impact force threshold F, which facilitates more precise control of the impact effect and the size of the damage characteristics, ensuring repeatability.

[0017] In one or more embodiments of the preparation device, the bearing seat is provided with a first through hole in the z-direction and a first threaded hole perpendicular to the z-direction, the first threaded hole extending to the side wall of the first through hole; the pre-tightening member is a pre-tightening bolt that mates with the first threaded hole; the elastic clamping member includes a first spring and a metal ball and is disposed in the first threaded hole; the impact part passes through the first through hole.

[0018] In one or more embodiments of the preparation apparatus, the impact portion includes an impact pin and an impact head; the impact head is hinged to the impact pin and includes multiple damage indenters extending radially along the axis of rotation.

[0019] By employing a variety of damage indenter designs, the morphology of the prepared damage features can be adjusted, thereby improving the versatility of the preparation device.

[0020] In one or more embodiments of the preparation apparatus, the plurality of damage indenters include at least one of a linear damage indenter, a conical damage indenter, a spherical damage indenter, and a square damage indenter.

[0021] In one or more embodiments of the preparation apparatus, the preparation apparatus includes: a base for positioning the test piece; the base includes a mounting plate; the mounting plate is used to provide a mounting position of the trigger portion in the z-direction directly opposite the test piece, and the mounting plate has a second through hole communicating with the first through hole for the trigger portion to pass through.

[0022] The preparation device can be movable, such as handheld; or it can be fixed, such as including the base. In this case, the test piece is positioned by the base, and the impact part only moves in the z-direction, making the preparation position precise and the dispersion extremely low.

[0023] In one or more embodiments of the preparation apparatus, the base includes a pressure rod; the pressure rod is z-displaceable relative to the trigger portion and is connected to the impact portion via a second spring for providing pressure.

[0024] In one or more embodiments of the preparation apparatus, the side of the impact portion is provided with a positioning groove, and the interior of the second through hole is provided with a boss that mates with the positioning groove.

[0025] In one or more embodiments of the preparation apparatus, the base includes an x-axis adjusting screw, an x-axis slide, a y-axis adjusting screw, and a y-axis slide; wherein the base has an x-axis groove that mates with the x-axis slide, the x-axis groove has x-axis graduation lines, and the end wall of the x-axis groove has an x-axis screw positioning hole, the x-axis adjusting screw passes through the x-axis screw positioning hole and is fixedly connected to the x-axis slide; the x-axis slide has a y-axis groove that mates with the y-axis slide, the y-axis groove has y-axis graduation lines, the end wall of the y-axis groove has a y-axis screw positioning hole, the y-axis adjusting screw passes through the y-axis screw positioning hole and is fixedly connected to the y-axis slide.

[0026] In one or more embodiments of the preparation apparatus, the y-axis slide is provided with a rectangular placement groove for positioning the test piece and a racetrack-shaped fixing groove for fixing the test piece.

[0027] According to another aspect of this disclosure, a method for preparing the apparatus includes:

[0028] Adjust the preload to set the impact force;

[0029] To reach the aforementioned triggerable state;

[0030] Gradually increase the pressure until the trigger state is reached.

[0031] In one or more embodiments of the preparation method, the preload is provided with an impact force scale line for determining the impact force threshold F based on the deformation h of the elastic clip, and the preparation method includes:

[0032] Adjust the preload to align with the set impact force scale line.

[0033] In one or more embodiments of the preparation method, the impact portion includes an impact pin and an impact head; the impact head is hinged to the impact pin and includes multiple damage indenters extending radially along the axis of rotation; wherein, the preparation method includes:

[0034] Select the damage indenter described above.

[0035] In one or more embodiments of the preparation method, the preparation apparatus further includes: a base for positioning the test piece; the base includes a pressure rod; the pressure rod is z-displaceable relative to the trigger portion and is connected to the impact portion via a second spring to provide pressure; wherein, the preparation method includes:

[0036] Position the test piece onto the base;

[0037] Raise the lever to reach the trigger-ready state;

[0038] The pressure bar is gradually pressed down until the trigger state is reached.

[0039] In one or more embodiments of the preparation method, the base includes an x-axis adjusting screw, an x-axis slide, a y-axis adjusting screw, and a y-axis slide; wherein the base has an x-axis sliding groove that mates with the x-axis slide, and the end wall of the x-axis sliding groove has an x-axis screw positioning hole, the x-axis adjusting screw passing through the x-axis screw positioning hole and fixedly connected to the x-axis slide; the x-axis slide has a y-axis sliding groove that mates with the y-axis slide, the end wall of the y-axis sliding groove has a y-axis screw positioning hole, the y-axis adjusting screw passing through the y-axis screw positioning hole and fixedly connected to the y-axis slide; wherein the preparation method includes:

[0040] Adjust the x-axis adjusting screw to position the test piece in the x-axis direction, and / or adjust the y-axis adjusting screw to position the test piece in the y-axis direction. Attached Figure Description

[0041] The above and other features, properties, and advantages of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features. It should be noted that these drawings are merely illustrative and are not drawn to scale, and should not be construed as limiting the scope of protection actually claimed by this disclosure, wherein:

[0042] Figure 1 This is a schematic diagram of the structure of an external impact damage preparation device according to one embodiment.

[0043] Figure 2 This is a schematic diagram of the trigger section in one embodiment.

[0044] Figure 3 This is a structural schematic diagram of a load-bearing seat according to one embodiment.

[0045] Figure 4 This is a schematic diagram of the impact pin structure according to one embodiment.

[0046] Figure 5 This is a schematic diagram of the structure of an impact head according to one embodiment.

[0047] Figure 6 This is a schematic diagram of the base structure of one embodiment.

[0048] Figure 7 This is a schematic diagram of the structure of an x-axis slide table according to an embodiment.

[0049] Figure 8 This is a schematic diagram of the structure of a y-axis slide table according to an embodiment.

[0050] Figure 9 This is a flowchart of a method for preparing external impact damage according to one embodiment.

[0051] Explanation of reference numerals in the attached figures:

[0052] 1. Apparatus for preparing external impact damage;

[0053] 11. Impact part; 111. Bayonet; 112. Impact pin; 1121. Pin hole; 1122. Rectangular groove; 1123. Bolt connection hole; 113. Impact head; 1131. Damage indenter; 1132. Linear damage indenter; 1133. Conical damage indenter; 1134. Spherical damage indenter; 1135. Square damage indenter; 114. Positioning groove;

[0054] 12. Triggering part; 121. Support seat; 1211. First through hole; 1212. First threaded hole; 122. Preload; 123. Elastic retainer; 1231. First spring; 1232. Metal ball; 1233. Curved protrusion;

[0055] 13. Base; 131. X-axis slide groove; 1311. X-axis slide groove end wall; 1312. X-axis screw positioning hole; 132. X-axis adjusting screw; 133. X-axis slide table; 1331. Y-axis slide groove; 1332. Y-axis slide groove end wall; 1333. Y-axis screw positioning hole; 1334. First threaded through hole; 134. Y-axis adjusting screw; 135. Y-axis slide table; 1351. Rectangular placement slot; 1352. Racetrack-shaped fixing slot; 1353. Second threaded through hole; 136. Column;

[0056] 14. Vertical plate; 141. Mounting plate; 1411. Second through hole; 1412. Boss; 142. Pressure rod; 143. Top of vertical plate; 144. Second spring;

[0057] x. Lateral (x-direction); y. Longitudinal (y-direction); z. Vertical (z-direction); a. Preload bolt screwing direction; b. Rotating shaft. Detailed Implementation

[0058] Reference will now be made in detail to various embodiments of this disclosure, examples of which are shown in the accompanying drawings and described below. Although this disclosure will be described in conjunction with exemplary embodiments, it should be understood that this disclosure is not intended to be limited to those exemplary embodiments. Rather, this disclosure is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of this disclosure as defined by the appended claims.

[0059] In the following description, the terms “upper,” “lower,” “inner,” “outer,” “top,” “bottom,” or other directional terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed and / or be implemented in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0060] This disclosure uses specific terms to describe embodiments of the present disclosure. For example, "an embodiment" and / or "one embodiment" refers to a particular feature, structure, or characteristic associated with at least one embodiment of the present disclosure. Therefore, it should be emphasized and noted that "an embodiment" or "one embodiment" mentioned twice or more in different locations in this disclosure does not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the present disclosure can be appropriately combined.

[0061] In this disclosure, "axial" refers to the direction along the central axis of the columnar object and / or the axis of rotation of the object; "radial" refers to the direction (diameter) through the center of the axis in a vertical section of the axis; "circumferential" refers to the direction about the axis in a vertical section of the axis; "z-direction" refers to the vertical direction based on the figures, i.e., the vertical direction; "horizontal" refers to the direction perpendicular to the "z-direction", which includes the mutually perpendicular "x-direction", i.e., the transverse direction, and "y-direction", i.e., the longitudinal direction.

[0062] refer to Figures 1 to 3 The inventors, through in-depth research, have proposed a device 1 for preparing external impact damage, comprising: an impact part 11 with a latch 111 on its side; and a trigger part 12, which includes a support seat 121, a pre-tightening member 122, and an elastic latch 123. The support seat 121 is fixed in a z-direction relative position with the test piece. The pre-tightening member 122 is fixedly connected to the support seat 121 and can adjustably pre-tighten the elastic latch 123 in the vertical z-direction. The elastic latch 123 contacts the pre-tightening member 122 at its first end, allowing it to be pre-tightened, and has a curved protrusion 1233 at its second end, allowing it to elastically engage with the latch 111 of the impact part 11. The impact part 11 engages with the elastic latch 123 and maintains a z-direction relative position with the test piece, which is a state awaiting triggering. When the impact part 11 is subjected to pressure, it disengages from the elastic latch 123 and impacts the test piece in the z-direction, which is a state of triggering. The curved protrusion 1233 has at least a partial spherical or arcuate surface, allowing the latch 111 to slide and disengage in the z-direction under pressure. The pre-tightening member 122 and the elastic clamp 123 are disposed in a horizontally confined space, allowing the pre-tightening member to adjustably limit the horizontal deformation of the elastic clamp and elastically clamp the test piece.

[0063] Under pressure, the impact part 11 disengages from the trigger part 12 and contacts the test piece in an impact manner, effectively simulating the formation mechanism of damage features in actual service. The impact part 11 has a defined mass and height relative to the test piece; therefore, the impact effect is not determined by its mass or height, but by the elastic force provided by the pre-tightening member 122 and the elastic clamp 123. This elastic force can be set by selecting elastic clamps 123 with different elastic coefficients and adjusting the pre-tightening member 122. In other words, under the defined conditions of the preparation device 1, only the pre-tightening of the pre-tightening member 122 on the elastic clamp 123 needs to be adjusted during use, making operation simple. Furthermore, the pressure reaching the trigger state and the impact force of the impact part 11, limited by the elastic force, also have defined thresholds, ultimately achieving controllable impact effects and ensuring the accuracy and repeatability of damage feature preparation. The preparation device 1 has a simple structure and low manufacturing cost.

[0064] In one or more embodiments of the preparation apparatus 1, the pre-tightening member 122 is provided with impact force scale lines to determine the impact force threshold F based on the deformation h of the elastic clip 123, with the following relationship:

[0065]

[0066] In the formula, α is the correction coefficient, K1 is the elastic coefficient of the elastic clip 123, R1 is the radius of the latch 111, and R2 is the radius of the curved protrusion 1233. The correction coefficient α can be obtained through a loading test. Specifically, the impact force sensor is fixed directly below the impact part 11, i.e., the fixed position of the test piece; the preload 122 is adjusted to cause the elastic clip 123 to produce a deformation h, and the corresponding impact force scale value aligned with the preload 122 is recorded. Pressure is gradually applied until the impact part 11 is triggered, and the impact force value recorded by the sensor is the impact force threshold F corresponding to the impact force scale value. Based on the known elastic coefficient K1 of the elastic clip 123, the radius R1 of the latch 111 on the side of the impact part 11, the radius R2 of the curved protrusion 1233, the deformation h, and the impact force threshold F, the correction coefficient α can be calculated using the above formula.

[0067] The impact force scale design allows for quantitative adjustment of the impact force threshold F, which facilitates more precise control of the impact effect and the size of the damage characteristics, ensuring repeatability.

[0068] In one or more embodiments of the preparation apparatus 1, the support seat 121 is provided with a first through hole 1211 in the z-direction and a first threaded hole 1212 perpendicular to the z-direction, the first threaded hole 1212 extending to the sidewall of the first through hole 1211; the preload member 122 is a preload bolt, which cooperates with the first threaded hole 1212; the elastic retainer 123 includes a first spring 1231 and a metal ball 1232, and is disposed in the first threaded hole 1212; the impact part 11 passes through the first through hole 1211. At this time, the preload bolt provides deformation of the elastic retainer 123 by screwing in, and its screwing length corresponds to the deformation h. Therefore, the impact force scale line can be located directly below the preload bolt, and the metal ball 1232 provides the curved protrusion 1233 with the radius R2. The impact part 11 can have a z-direction limiting and / or a certain length, so that it still passes through the first through hole 1211 in the triggered state to fix the elastic retainer 123. The end of the pretensioner 122 may be provided with a groove for rotation.

[0069] like Figure 4 , Figure 5As shown, in one or more embodiments of the preparation device 1, the impact part 11 includes an impact pin 112 and an impact head 113; the impact head 113 is hinged to the impact pin 112 and includes a variety of damage indenters 1131 extending radially along the rotation axis b. A pin hole 1121 for hinging with the impact head 113 is provided at the lower end of the impact pin 112, and a rectangular groove 1122 is further provided on its side for installing and operating a fastener (not shown). The impact head 113 is connected to the impact pin 112 through the fastener. The end faces of the impact pin 112 and the impact head 113 are in a small clearance fit. The impact head 113 can rotate under the loose state of the fastener to realize the conversion of the types of the damage indenters 1131, and when the fastener is tightened, the impact head 113 cannot rotate, ensuring that the direction of the impact head 113 is fixed during impact.

[0070] The design of using a variety of the damage indenters 1131 is beneficial for selecting types according to needs to prepare damage characteristics of different forms. Through the customization and switching of different damage indenters 1131, the versatility of the preparation device is increased, and the convenience of the preparation process is also improved.

[0071] As Figure 5 shown, in one or more embodiments of the preparation device 1, the multiple damage indenters 1131 include at least one of a linear damage indenter 1132 (such as in the shape of the Chinese character 'one'), a conical damage indenter 1133, a spherical damage indenter 1134, and a square damage indenter 1135.

[0072] Refer to Figure 1 、 Figure 6 As shown, in one or more embodiments of the preparation device 1, it includes: a base 13 for positioning the test piece; the base 13 includes a mounting plate 141; the mounting plate 141 is used to provide the mounting position of the triggering part 12 facing the test piece in the z direction. The mounting plate 141 is provided with a second through hole 1411 penetrating through the first through hole 1211 for the triggering part 12 to pass through.

[0073] The preparation device 1 can be movable, such as handheld; or it can be fixed, such as including the base 13. At this time, the test piece is positioned through the base 13, and the impact part 11 only moves in the z direction, making the preparation position accurate and the dispersion extremely low.

[0074] In one or more embodiments of the preparation device 1, the base 13 includes a pressure rod 142; the pressure rod 142 can be displaced in the z direction relative to the triggering part 12 and is connected to the impact part 11 through a second spring 144 to provide pressure.

[0075] The operation of providing pressure through the pressure rod 142 is simple; in the triggered state, the impact part 11 is continuously driven by the elastic force of the second spring 144, generating a large impact speed, taking into account both the stability of the quasi-static method and the authenticity of the damage introduction mechanism of the air cannon method; in addition, the second spring 144 can press the impact part 11 to avoid secondary damage caused by the pendulum bob in the pendulum method and eliminate its interference with the preparation effect.

[0076] like Figure 1 As shown, in one or more embodiments of the preparation apparatus 1, the base includes a vertical plate 14, which facilitates raising the mounting plate 141 in the Z-direction and also provides a fixed position for the pressure rod 142; the pressure rod 142 may be hinged to the top end 143 of the vertical plate 14; the mounting plate 141 may have a column 136 at one end opposite to the vertical plate 14 for reinforcement and stability. The top end of the impact part 11 is provided with a bolt connection hole 1123 for connecting the second spring 144.

[0077] like Figure 4 , Figure 6 As shown, in one or more embodiments of the preparation apparatus 1, the side of the impact portion 11 is provided with a positioning groove 114, and the interior of the second through hole 1411 is provided with a protrusion 1412 that cooperates with the positioning groove 114. This design serves to limit the rotation of the impact portion 11 and guide the impact to be stable.

[0078] like Figure 1 , Figures 6 to 8 As shown, in one or more embodiments of the preparation apparatus 1, the base 13 includes an x-axis adjusting screw 132, an x-axis slide 133, a y-axis adjusting screw 134, and a y-axis slide 135; wherein, the base 13 is provided with an x-axis sliding groove 131 that mates with the x-axis slide 133, the x-axis sliding groove 131 may have x-axis scale lines, and the end wall 1311 of the x-axis sliding groove is provided with an x-axis screw positioning hole 1312, and the x-axis adjusting screw 134... 2. The screw passes through the x-axis positioning hole 1312 and is fixedly connected to the x-axis slide 133. The x-axis slide 133 is provided with a y-axis groove 1331 that mates with the y-axis slide 135. The y-axis groove 1331 may have y-axis scale lines. The end wall 1341 of the y-axis groove is provided with a y-axis screw positioning hole 1333. The y-axis adjusting screw 134 passes through the y-axis screw positioning hole 1333 and is fixedly connected to the y-axis slide 135. The x-axis slide 133 may be provided with a first threaded through hole 1334 for connecting with the x-axis adjusting screw 132, and the y-axis slide 135 may be provided with a second threaded hole 1353 for connecting with the y-axis adjusting screw 134.

[0079] Rotating the x-axis adjusting screw 132 can move the x-axis slide 133 in the x-axis direction and accurately position it in the x-axis direction according to the x-axis scale line; rotating the y-axis adjusting screw 134 can move the y-axis slide 135 in the y-axis direction and accurately position it in the y-axis direction according to the y-axis scale line; ultimately, the test piece is accurately positioned.

[0080] The xy-axis dual-degree-of-freedom positioning stage is designed to precisely position and adjust the relative position of the impact unit 11 and the test piece according to different experimental needs and based on the size of the test piece and the geometric parameters of the damage distribution. Under the constraint of the base 13 and the trigger unit 12, the impact unit 11 has only a z-axis degree of freedom, which can maintain the accuracy and stability of the impact position and the repeatability of the damage preparation results.

[0081] like Figure 8 As shown, in one or more embodiments of the preparation apparatus 1, the y-axis slide 135 is provided with a rectangular placement groove 1351 for positioning the test piece and a racetrack-shaped fixing groove 1352 for fixing the test piece.

[0082] Continuing from the foregoing, this disclosure also provides a method for preparing foreign object impact damage for the preparation apparatus 1, comprising:

[0083] Adjust the preload 122 to set the impact force;

[0084] To reach the aforementioned triggerable state;

[0085] Gradually increase the pressure until the trigger state is reached, avoiding excessive pressure that exceeds the threshold and affects the preparation effect.

[0086] In one or more embodiments of the preparation method, the preload 122 is provided with impact force scale lines for determining the impact force threshold F based on the deformation h of the elastic clip 123. The preparation method includes:

[0087] Adjust the preload 122 to align with the set impact force scale line, that is, control the deformation h through the preload 122 to determine the impact force threshold F according to the requirements, and finally accurately control the size of the damage feature.

[0088] In one or more embodiments of the preparation method, the preparation method includes:

[0089] The impact force threshold F is determined according to the following relationship:

[0090]

[0091] In the formula, α is the correction coefficient, K1 is the elastic coefficient of the elastic clip 123 (the first spring 123), R1 is the radius of the slot 111 on the side of the impact part 11, and R2 is the radius of the curved protrusion 1233 (the metal ball 124).

[0092] In one or more embodiments of the preparation method, the impact portion 11 includes an impact pin 112 and an impact head 113; the impact head 113 is hinged to the impact pin 112 and includes multiple damage indenters 1131 extending radially along the rotation axis b; wherein, the preparation method includes:

[0093] The damage indenter 1131 is selected according to the requirements, so that it is vertically downward or at a certain angle, and its rotation is prevented.

[0094] In one or more embodiments of the preparation method, the preparation apparatus 1 includes a base 13 for positioning the test piece; the base 13 includes a pressure rod 142; the pressure rod 142 is displaceable in the z-direction relative to the triggering part 12 and is connected to the impact part 11 via a second spring 144 to provide pressure; wherein, the preparation method includes:

[0095] Position the test piece onto the base 13;

[0096] Raise the pressure rod 142 to reach the ready-to-trigger state;

[0097] The pressure bar 142 is pressed down gradually until the trigger state is reached.

[0098] In one or more embodiments of the preparation method, the base 13 includes an x-axis adjusting screw 132, an x-axis slide 133, a y-axis adjusting screw 134, and a y-axis slide 135; wherein, the base 13 is provided with an x-axis sliding groove 131 that mates with the x-axis slide 133, and the end wall 1311 of the x-axis sliding groove 131 is provided with an x-axis screw positioning hole 1312, the x-axis adjusting screw 132 passes through the x-axis screw positioning hole 1312 and is fixedly connected to the x-axis slide 133; the x-axis slide 133 is provided with a y-axis sliding groove 1331 that mates with the y-axis slide 135, the end wall 1332 of the y-axis sliding groove 1331 is provided with a y-axis screw positioning hole 1333, the y-axis adjusting screw 134 passes through the y-axis screw positioning hole 1333 and is fixedly connected to the y-axis slide 135; wherein, the preparation method includes:

[0099] Adjust the x-axis adjusting screw 132 to position the test piece in the x-axis, and / or adjust the y-axis adjusting screw 134 to position the test piece in the y-axis.

[0100] In one or more embodiments of the preparation method, the y-axis slide 135 is provided with a rectangular placement groove 1351 for positioning the test piece, and a racetrack-shaped fixing groove 1352 for fixing the test piece; wherein, the preparation method includes:

[0101] The test piece is placed in the rectangular placement slot 1351 and fixed in the racetrack-shaped fixing slot 1352.

[0102] Figure 9 One or more embodiments of the preparation method are shown, which may be arranged or omitted as needed. The specific steps are as follows:

[0103] S1. Select the aforementioned damage indenter 1131;

[0104] S2. Adjust the pretensioner 122 to set the impact force (adjust the pretensioner 122 to align with the set impact force scale line);

[0105] S3. To bring the state to the triggering state (raise the pressure rod 142 to bring the state to the triggering state);

[0106] S4. Position the test piece to the base 13 (adjust the x-axis adjusting screw 132 to position the test piece in the x-axis, and / or adjust the y-axis adjusting screw 134 to position the test piece in the y-axis);

[0107] S5. Gradually apply pressure until the trigger state is reached (gradually press down the pressure bar 142 until the trigger state is reached);

[0108] S6. Determine whether the damage preparation is complete. If yes, end the process; otherwise, repeat steps S1 to S6.

[0109] The preparation method is simple to operate and greatly improves the preparation efficiency while ensuring the accuracy, repeatability and stability of the prepared damage.

[0110] In summary, the technological advancements of this disclosure include, but are not limited to:

[0111] 1. Under pressure, the impact part detaches from the triggering part and contacts the test piece in an impact manner, effectively simulating the formation mechanism of damage features in actual service. The impact part has a defined mass and height relative to the test piece; therefore, the impact effect is not determined by its mass or height, but by the elastic force provided by the preload and the elastic clamp. This elastic force can be set by selecting elastic clamps with different elastic coefficients and adjusting the preload. In other words, under the defined conditions of the preparation device, only the preload of the preload on the elastic clamp needs to be adjusted during use, making operation simple. Furthermore, the pressure required to reach the triggering state and the impact force of the impact part, limited by the elastic force, also have defined thresholds, ultimately achieving controllable impact effect and ensuring the accuracy and repeatability of damage feature preparation. The preparation device has a simple structure and low manufacturing cost.

[0112] While this disclosure has described above with reference to preferred embodiments, it is not intended to limit the scope of this disclosure. Any changes and modifications can be made by those skilled in the art without departing from the spirit and scope of this disclosure. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this disclosure, without departing from the content of the technical solution of this disclosure, shall fall within the protection scope defined by the claims of this disclosure.

Claims

1. A device for preparing external impact damage (1), characterized in that, include: The impact part (11) has a bayonet (111) on its side; The triggering part (12) includes a bearing seat (121), a preload member (122), and an elastic retainer (123); The bearing seat (121) is fixed in a z-direction relative position with the test piece; the pre-tightening member (122) is fixedly connected to the bearing seat (121) and can adjustably pre-tighten the elastic clip (123) in the vertical z-direction; the elastic clip (123) is in contact with the pre-tightening member (122) at its first end so that it can be pre-tightened, and has a curved protrusion (1233) at its second end so that it can elastically engage with the slot (111) of the impact part (11); The impact part (11) engages with the elastic clip (123) and maintains a relative position in the z-direction with the test piece, which is a state to be triggered; the impact part (11) is subjected to pressure, disengages from the elastic clip (123), and impacts the test piece in the z-direction, which is a state to be triggered.

2. The preparation apparatus (1) as described in claim 1, characterized in that, The preload (122) is provided with an impact force scale line, which is used to determine the impact force threshold F based on the deformation h of the elastic clip (123), with the following relationship: In the formula, α is the correction coefficient, K1 is the elastic coefficient of the elastic clip (123), R1 is the radius of the jaw (111), and R2 is the radius of the curved protrusion (1233).

3. The preparation apparatus (1) as described in claim 1, characterized in that, The bearing seat (121) is provided with a first through hole (1211) in the z direction and a first threaded hole (1212) perpendicular to the z direction. The first threaded hole (1212) extends to the side wall of the first through hole (1211). The preload (122) is a preload bolt that cooperates with the first threaded hole (1212). The elastic clip (123) includes a first spring (1231) and a metal ball (1232) and is disposed in the first threaded hole (1212). The impact part (11) passes through the first through hole (1211).

4. The preparation apparatus (1) as described in claim 1, characterized in that, The impact part (11) includes an impact pin (112) and an impact head (113); the impact head (113) is hinged to the impact pin (112) and includes a plurality of damage indenters (1131) extending radially along the axis of rotation (b).

5. The preparation apparatus (1) as described in claim 4, characterized in that, The plurality of said damage indenters (1131) include at least one of a linear damage indenter (1132), a conical damage indenter (1133), a spherical damage indenter (1134), and a square damage indenter (1135).

6. The preparation apparatus (1) as described in claim 1, characterized in that, include: A base (13) is used to position the test piece; the base (13) includes a mounting plate (141); the mounting plate (141) is used to provide a mounting position of the trigger part (12) in the z direction directly opposite the test piece, and the mounting plate (141) is provided with a second through hole (1411) that communicates with the first through hole (1211) for the trigger part (12) to pass through.

7. The preparation apparatus (1) as described in claim 6, characterized in that, The base (13) includes a pressure rod (142); the pressure rod (142) is z-displaceable relative to the trigger part (12) and is connected to the impact part (11) via a second spring (144) to provide pressure.

8. The preparation apparatus (1) as described in claim 6, characterized in that, The side of the impact part (11) is provided with a positioning groove (114), and the second through hole (1411) is provided with a boss (1412) that cooperates with the positioning groove (114).

9. The preparation apparatus (1) as described in claim 6, characterized in that, The base (13) includes an x-axis adjusting screw (132), an x-axis slide (133), a y-axis adjusting screw (134), and a y-axis slide (135); The base (13) is provided with an x-axis slide groove (131) that mates with the x-axis slide table (133). The end wall (1311) of the x-axis slide groove (131) is provided with an x-axis screw positioning hole (1312). The x-axis adjusting screw (132) passes through the x-axis screw positioning hole (1312) and is fixedly connected to the x-axis slide table (133). The x-axis slide table (133) is provided with a y-axis slide groove (1331) that mates with the y-axis slide table (135). The end wall (1332) of the y-axis slide groove (1331) is provided with a y-axis screw positioning hole (1333). The y-axis adjusting screw (134) passes through the y-axis screw positioning hole (1333) and is fixedly connected to the y-axis slide table (135).

10. The preparation apparatus (1) as described in claim 9, characterized in that, The y-axis slide (135) is provided with a rectangular placement groove (1351) for positioning the test piece, and a racetrack-shaped fixing groove (1352) for fixing the test piece.

11. A method for preparing the preparation apparatus (1) as described in any one of claims 1-10, characterized in that, include: Adjust the preload (122) to set the impact force; To reach the aforementioned triggerable state; Gradually increase the pressure until the trigger state is reached.

12. The preparation method according to claim 11, characterized in that, The preload (122) is provided with an impact force scale line, which is used to determine the impact force threshold F according to the deformation h of the elastic clip (123). The preparation method includes: Adjust the preload (122) to align with the set impact force scale line.

13. The preparation method according to claim 11, characterized in that, The impact part (11) includes an impact pin (112) and an impact head (113); the impact head (113) is hinged to the impact pin (112) and includes multiple damage indenters (1131) extending radially along the axis of rotation (b); wherein, the preparation method includes: Select the damage indenter (1131).

14. The preparation method according to claim 11, characterized in that, The preparation device (1) includes: a base (13) for positioning the test piece; the base (13) includes a pressure rod (142); the pressure rod (142) is movable in the z-direction relative to the trigger part (12) and is connected to the impact part (11) via a second spring (144) to provide pressure; wherein, the preparation method includes: Position the test piece onto the base (13); Raise the pressure rod (142) to reach the triggering state; The pressure bar (142) is pressed down gradually until the trigger state is reached.

15. The preparation method according to claim 14, characterized in that, The base (13) includes an x-axis adjusting screw (132), an x-axis slide (133), a y-axis adjusting screw (134), and a y-axis slide (135); wherein, the base (13) is provided with an x-axis sliding groove (131) that mates with the x-axis slide (133), and the end wall (1311) of the x-axis sliding groove (131) is provided with an x-axis screw positioning hole (1312), and the x-axis adjusting screw (132) passes through the x-axis screw positioning hole (131). 2) and fixedly connected to the x-axis slide (133); the x-axis slide (133) is provided with a y-axis groove (1331) that mates with the y-axis slide (135), the end wall (1332) of the y-axis groove (1331) is provided with a y-axis screw positioning hole (1333), the y-axis adjusting screw (134) passes through the y-axis screw positioning hole (1333) and is fixedly connected to the y-axis slide (135); wherein, the preparation method includes: Adjust the x-axis adjusting screw (132) to position the test piece in the x-axis direction, and / or adjust the y-axis adjusting screw (134) to position the test piece in the y-axis direction.

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