A drill rod damping device based on a semi-active nonlinear energy sink

Abstract

The present application relates to the technical field of drill pipe damping, in particular to a drill pipe damping device based on semi-active nonlinear energy sink. In order to solve the problem that the traditional active nonlinear energy sink damping structure cannot be applied to deep hole machining damping, a new drill pipe damping device based on semi-active nonlinear energy sink is provided, which comprises a connecting base, an NES mechanism and a PID controller. The NES mechanism comprises two flexible hinges, two mass blocks, a left elastic secondary beam, an elastic main beam and a right elastic secondary beam. The left elastic secondary beam is composed of two left semicircles, which are distributed in the axial left end of the annular groove. The right elastic secondary beam is composed of two right semicircles, which are distributed in the axial right end of the annular groove. The elastic main beam is composed of two main semicircles, which are distributed in the axial middle of the annular groove. The device has a simple structure and obvious damping effect.

Description

Technical Field

[0001] This invention relates to the field of drill pipe vibration reduction technology, specifically a drill pipe vibration reduction device based on a semi-active nonlinear energy sink. Background Technology

[0002] During deep hole machining, drill rods are prone to chatter when the length-to-diameter ratio of the hole being machined is large, leading to a significant decrease in the machining quality of the parts, and in severe cases, even causing the parts to be scrapped. Therefore, research on methods for controlling the mechanical vibration of drill rods is particularly important. As a major factor affecting machining accuracy, tool durability, and cutting efficiency, the main causes of drill rod vibration include: when drilling deep holes with a large length-to-diameter ratio, the drill rod is relatively slender, equivalent to a cantilever beam, with weak bending stiffness; imbalance between the weight of the tool holder and the cutting forces between the cutting edges; poor stiffness of the power transmission system; and non-uniform workpiece material.

[0003] To effectively suppress the vibration of drill pipe systems, the main methods currently employed are damping vibration reduction and vibration absorption technologies. Among these, nonlinear energy traps are highly effective in suppressing nonlinear passive vibration. Traditional nonlinear energy traps are a passive control technology with significant vibration suppression effects. They mainly consist of three parts: a relatively light added mass, strong nonlinear stiffness, and damping elements. The energy transfer mechanism between the nonlinear energy trap and the main structure is targeted energy transfer. This transfer is characterized by high speed and unidirectional (irreversible) characteristics. However, traditional active nonlinear energy trap vibration suppression structures are relatively complex and have certain limitations in application. For example, in deep hole machining, the environment is confined, sealed, and complex, making traditional active nonlinear energy trap vibration suppression structures unsuitable and resulting in poor vibration suppression effects. Summary of the Invention

[0004] In order to solve the problem that traditional active nonlinear energy trap vibration suppression structures are not suitable for vibration reduction during deep hole machining and have poor vibration suppression effect, this invention provides a new drill rod vibration reduction device based on a semi-active nonlinear energy trap.

[0005] This invention is achieved using the following technical solution:

[0006] A drill pipe vibration damping device based on a semi-active nonlinear energy trap includes a columnar connecting base, a strip-shaped mounting plate, a NES mechanism, and a PID controller. An annular groove is formed in the axial center of the connecting base, and mounting grooves are formed on the top of the two side walls of the annular groove. The mounting plate is placed inside the annular groove, and its two ends are fixed to the two mounting grooves respectively. The NES mechanism includes two square flexible frames, two piezoelectric ceramic stacks, two mass blocks, a left elastic sub-beam, an elastic main beam, and a right elastic sub-beam. The two piezoelectric ceramic stacks are respectively placed in the two flexible frames to form two... Two flexible hinges are positioned one in front of the other at the axial center of the mounting plate, with their expansion and contraction directions arranged circumferentially. The left elastic sub-beam consists of two left semicircular arcs, positioned one in front of the other at the left end of the annular groove. Each left semicircular arc is equipped with a left strain gauge. The upper ends of the two left semicircular arcs are fixed to the front and rear ends of the left side of the mounting plate, respectively. The left sides of the two flexible frames are fixedly connected to the right sides of the upper ends of the two left semicircular arcs, respectively. A left gap is provided between the lower ends of the two left semicircular arcs. The right elastic sub-beam consists of two right semicircular arcs. Two right semicircular arcs are distributed front and rear at the axial right ends within the annular groove. Each right semicircular arc is equipped with a right strain gauge. The upper ends of the two right semicircular arcs are fixed to the front and rear ends of the right end of the mounting plate, respectively. The right sides of the two flexible frames are fixedly connected to the left sides of the upper ends of the two right semicircular arcs, respectively. A right gap is provided between the lower ends of the two right semicircular arcs. The elastic main beam consists of two main semicircular arcs, distributed front and rear at the axial middle within the annular groove. Each main semicircular arc is equipped with a main strain gauge. The upper ends of the two main semicircular arcs are fixedly connected to the front and rear ends of the right end of the mounting plate, respectively. The front and rear sides of the frame are fixedly connected. There is an axial gap between the left elastic sub-beam, the elastic main beam, and the right elastic sub-beam. There is a radial gap between the left elastic sub-beam, the elastic main beam, the right elastic sub-beam and the bottom of the annular groove of the connecting base. Two mass blocks are fixed between the lower end of the left elastic sub-beam and the lower end of the elastic main beam, and between the elastic main beam and the lower end of the right elastic sub-beam, respectively. The input of the PID controller receives the signals from the left strain gauge, the right strain gauge, and the main strain gauge. The output of the PID controller controls the piezoelectric ceramic stack to drive the flexible frame to expand and contract.

[0007] Working Principle: The NES mechanism described in this invention uses an elastic main beam as a nonlinear spring, with left and right elastic secondary beams as damping elements. In use, one end of the columnar connecting base is connected to the drill rod, and the other end is connected to the drill bit. When the drill rod vibrates within a certain frequency band, the left and right strain gauges detect the existing vibration signal and transmit it to the PID controller. The PID controller outputs a certain voltage to the piezoelectric ceramic stack based on the vibration magnitude, thereby driving the flexible frame to push the elastic main beam to produce bending deflection. This adjusts the elastic main beam to a suitable nonlinear stiffness for vibration suppression. The main strain gauge feeds back the detected elastic main beam stiffness value to the PID controller. When the bending deflection of the elastic main beam reaches the required level, the driving of the flexible frame through the piezoelectric ceramic stack stops. When the bending deflection of the elastic main beam does not reach the required level, the vibration energy decreases, and the nonlinear vibration escapes the existing nonlinear stiffness suppression range. The left and right strain gauges will then detect the vibration again and repeat the above process until the bending deflection of the elastic main beam reaches the required level, at which point the driving of the flexible frame through the piezoelectric ceramic stack stops.

[0008] Furthermore, both flexible frames have V-shaped front and rear sides, which facilitates expansion and contraction.

[0009] Furthermore, a vertical partition is provided in the middle of the mounting plate in the front-rear direction. A left limiting plate and a right limiting plate are fixed to the left and right ends of the mounting plate, respectively. The left and right ends of the vertical partition are fixed to the middle of the left and right limiting plates in the front-rear direction, respectively. Two flexible hinges are located on the front and rear sides of the vertical partition. Left connecting plates are fixed to the upper ends of both left semicircles. The left sides of the two left connecting plates are respectively attached to the front and rear ends of the right side of the left limiting plate. The front and rear sides of the two left connecting plates are respectively attached to the front and rear sides of the left end of the vertical partition. Similarly, right connecting plates are fixed to the upper ends of both right semicircles. The right sides of the two right connecting plates are respectively attached to the front and rear ends of the left side of the right limiting plate. The front and rear sides of the two right connecting plates are respectively attached to the front and rear sides of the right end of the vertical partition. This structure is more stable, specific, and standardized.

[0010] Furthermore, the outer surfaces of the lower ends of both left semicircular arcs are provided with left semicircular arc grooves, the outer surfaces of the lower ends of both right semicircular arcs are provided with right semicircular arc grooves, and the inner surfaces of the lower ends of both main semicircular arcs are provided with middle semicircular arc grooves. Connecting circular holes are provided at the front and rear ends of both mass blocks. The left semicircular arc grooves, connecting circular holes, middle semicircular arc grooves, and right semicircular arc grooves are arranged in a compatible manner. Two connecting rods pass through the corresponding left semicircular arc grooves, connecting circular holes, middle semicircular arc grooves, and right semicircular arc grooves respectively to connect the two mass blocks to the elastic main beam, the corresponding left elastic secondary beam, and the corresponding right elastic secondary beam. This structure is specific, standardized, and facilitates installation and disassembly.

[0011] Furthermore, the NES mechanism is entirely located within an annular groove, occupying little space and adapting to deep hole environments, thus avoiding the situation where a complex and bulky overall structure is unsuitable for deep hole machining.

[0012] Furthermore, the left end of the connecting base is provided with an external thread for connecting with the drill rod, and the right end of the connecting base is provided with an internal thread for connecting with the drill bit, which facilitates installation and disassembly during use.

[0013] The beneficial effects of this invention are as follows: Based on a semi-active nonlinear energy trap, this invention can effectively dissipate the energy generated by drill pipe vibration, resulting in a significant vibration suppression effect. The nonlinear stiffness in the semi-active nonlinear energy trap ensures internal resonance with the main structure, achieving excellent vibration suppression capabilities over a wide frequency band. This invention is rationally designed, has a simple structure, occupies little space, effectively reduces drill pipe vibration, improves workpiece machining quality, and provides a new approach and method for vibration suppression during deep hole machining. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the connector structure;

[0018] Figure 3 This is a schematic diagram of the mounting plate structure;

[0019] Figure 4 A schematic diagram of the NES mechanism;

[0020] Figure 5 This is a structural diagram of the left semicircular arc, the right semicircular arc, the main semicircular arc, and the connecting rod;

[0021] Figure 6 This is a structural diagram of the left mass block and the right mass block;

[0022] Figure 7 Simulation of free vibration attenuation of drill pipe with NES component as described in this invention;

[0023] Figure 8This is a schematic diagram showing the amplitude of a drill pipe with and without the NES component described in this invention.

[0024] In the diagram: 1-Connecting base, 2-Mounting plate, 3-Annular groove, 4-Mounting groove, 5-Flexible hinge, 6-Mass block, 7-Left elastic sub-beam, 8-Right elastic sub-beam, 9-Elastic main beam, 10-Vertical partition, 11-Left limiting plate, 12-Right limiting plate, 13-Left connecting plate, 14-Right connecting plate, 15-Connecting rod. Detailed Implementation

[0025] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0026] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0028] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] like Figures 1 to 6As shown, a drill pipe vibration reduction device based on a semi-active nonlinear energy trap includes a columnar connecting base 1, a strip-shaped mounting plate 2, an NES mechanism, and a PID controller. An annular groove 3 is formed in the axial center of the connecting base 1, and mounting grooves 4 are formed on the top of the two side walls of the annular groove 3. The mounting plate 2 is placed inside the annular groove 3, and its two ends are respectively fixed in the two mounting grooves 4. The NES mechanism includes two square flexible frames, two piezoelectric ceramic stacks, two mass blocks 6, a left elastic sub-beam 7, an elastic main beam 9, and a right elastic sub-beam 8. The two piezoelectric ceramic stacks are respectively placed in the two flexible frames. Two flexible hinges 5 are formed within the frame, positioned front to back at the axial center of the mounting plate 2, with their expansion and contraction directions arranged circumferentially. The left elastic sub-beam 7 consists of two left semicircular arcs, positioned front to back at the left ends of the annular groove 3. Each left semicircular arc is equipped with a left strain gauge. The upper ends of the two left semicircular arcs are fixed to the front and rear ends of the left end of the mounting plate 2, respectively. The left sides of the two flexible frames are fixedly connected to the right sides of the upper ends of the two left semicircular arcs, respectively. A left gap is provided between the lower ends of the two left semicircular arcs. The right elastic sub-beam 8 consists of two right... The main beam 9 is composed of two main semicircular arcs, with two right semicircular arcs distributed front and rear at the axial right ends within the annular groove 3. Each of the two right semicircular arcs has a right strain gauge. The upper ends of the two right semicircular arcs are fixed to the front and rear ends of the right end of the mounting plate 2, respectively. The right sides of the two flexible frames are fixedly connected to the left sides of the upper ends of the two right semicircular arcs, respectively. A right gap is provided between the lower ends of the two right semicircular arcs. The elastic main beam 9 is composed of two main semicircular arcs, distributed front and rear at the axial middle within the annular groove 3. Each of the two main semicircular arcs has a main strain gauge. The upper ends of the two main semicircular arcs are fixed to the flexible frames, respectively. The front and rear sides are fixedly connected. An axial distance is provided between the left elastic sub-beam 7, the elastic main beam 9, and the right elastic sub-beam 8. A radial distance is provided between the left elastic sub-beam 7, the elastic main beam 9, the right elastic sub-beam 8 and the bottom of the annular groove of the connecting base. Two mass blocks 6 are respectively located between the lower end of the left elastic sub-beam 7 and the lower end of the elastic main beam 9, and between the elastic main beam 9 and the lower end of the right elastic sub-beam 8. The input end of the PID controller receives the signals from the left strain gauge, the right strain gauge, and the main strain gauge. The output end of the PID controller controls the piezoelectric ceramic stack to drive the flexible frame to expand and contract.

[0030] Working Principle: In the NES mechanism described in this invention, the elastic main beam 9 acts as a nonlinear spring, and the damping elements are the left elastic secondary beam 7 and the right elastic secondary beam 8. During use, one end of the columnar connecting base is connected to the drill rod, and the other end is connected to the drill bit. When the drill rod vibrates within a certain frequency band, the left and right strain gauges detect the existing vibration signal and transmit it to the PID controller. The PID controller outputs a certain voltage to the piezoelectric ceramic stack based on the vibration magnitude, thereby driving the flexible frame to push the elastic main beam to produce bending deflection, thus moving the elastic main beam... Once the nonlinear stiffness is adjusted to a suitable level for vibration suppression, the main strain gauge feeds back the detected stiffness value of the elastic main beam to the PID controller. When the bending deflection of the elastic main beam reaches the required level, the drive of the flexible frame through the piezoelectric ceramic stack stops. When the bending deflection of the elastic main beam does not reach the required level, the nonlinear vibration will escape the existing vibration suppression range of the nonlinear stiffness due to the reduced vibration energy. The left and right strain gauges will then detect the vibration again and repeat the above process until the bending deflection of the elastic main beam reaches the required level, at which point the drive of the flexible frame through the piezoelectric ceramic stack stops.

[0031] In practice, both the front and rear sides of the two flexible frames are V-shaped to facilitate expansion and contraction.

[0032] In specific implementation, a vertical partition 10 is provided in the middle of the front-rear direction of the mounting plate 2. A left limiting plate 11 and a right limiting plate 12 are fixed to the left and right ends of the mounting plate 2, respectively. The left and right ends of the vertical partition 10 are fixed to the middle of the front-rear direction of the left limiting plate 11 and the middle of the front-rear direction of the right limiting plate 12, respectively. Two flexible hinges 5 are located on the front and rear sides of the vertical partition 10, respectively. A left connecting plate 13 is fixed to the upper end of each of the two left semicircles. The left side of each of the two left connecting plates 13 is attached to the front and rear ends of the right side of the left limiting plate 11, respectively. The front and rear sides of each of the two left connecting plates 13 are attached to the front and rear sides of the left end of the vertical partition 10, respectively. A right connecting plate 14 is fixed to the upper end of each of the two right semicircles. The right side of each of the two right connecting plates 14 is attached to the front and rear ends of the left side of the right limiting plate 12, respectively. The front and rear sides of each of the two right connecting plates 14 are attached to the front and rear sides of the right end of the vertical partition 10, respectively. The structure is more stable, specific, and standardized.

[0033] In practical implementation, the outer surfaces of the lower ends of the two left semicircular arcs are each provided with a left semicircular arc groove, the outer surfaces of the lower ends of the two right semicircular arcs are each provided with a right semicircular arc groove, and the inner surfaces of the lower ends of the two main semicircular arcs are each provided with a middle semicircular arc groove. The front and rear ends of the two mass blocks 6 are each provided with connecting circular holes. The left semicircular arc grooves, connecting circular holes 16, middle semicircular arc grooves, and right semicircular arc grooves are arranged in a compatible manner. The two connecting rods 15 pass through the corresponding left semicircular arc grooves, connecting circular holes, middle semicircular arc grooves, and right semicircular arc grooves respectively to connect the two mass blocks 6 with the elastic main beam 9, the corresponding left elastic secondary beam 7, and the corresponding right elastic secondary beam 8. The structure is specific, standardized, and convenient for installation and disassembly.

[0034] In practice, the NES mechanism is located entirely within the annular groove 3, occupying little space and adapting to deep hole environments, thus avoiding the situation where the overall structure is complex and bulky and unsuitable for deep hole machining environments.

[0035] In practice, the left end of the connecting base 1 is provided with an external thread for connecting with the drill rod, and the right end of the connecting base 1 is provided with an internal thread for connecting with the drill bit, which facilitates installation and disassembly during use.

[0036] To verify the vibration suppression performance of the device, a simulation of the free vibration attenuation of the drill pipe is performed, such as... Figure 7 As shown, the amplitude of the NES fluctuates. When the NES first experiences a high amplitude, target energy transfer occurs, consuming the drill pipe's vibration energy, and the drill pipe amplitude with the NES decreases. Subsequently, the NES amplitude decreases, and the drill pipe amplitude with the NES increases. This is because after the previous target energy transfer, the drill pipe system's energy escapes from the NES's damping frequency band, making the NES unable to capture the existing vibration mode for damping. At this point, after the PID controller controls the piezoelectric ceramic stack and thus controls the stiffness of the elastic main beam 9, the NES experiences a high amplitude again, and target energy transfer occurs again, and so on until the variable stiffness capability is exceeded.

[0037] In addition, from Figure 8 It can be seen that the drill rod with NES has a significantly lower amplitude than the drill rod without NES, demonstrating a significant vibration suppression effect. This proves that the device described in this invention has a good vibration reduction effect, and its simple structure and small footprint make it suitable for deep hole machining.

[0038] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A semi-active non-linear energy sink based drill string vibration damping device, characterized by, The application relates to a connecting base (1) in a column shape, a mounting plate (2) in a strip shape, an NES mechanism and a PID controller, an annular groove (3) is formed in the axial middle part of the connecting base (1), mounting grooves (4) are respectively formed in the top parts of the two side walls of the annular groove (3), the mounting plate (2) is arranged in the annular groove (3) and the two ends of the mounting plate (2) are respectively fixed in the two mounting grooves (4), the NES mechanism comprises two square flexible frames, two piezoelectric ceramic stacks, two mass blocks (6), a left elastic sub-beam (7), an elastic main beam (9) and a right elastic sub-beam (8), the two piezoelectric ceramic stacks are respectively arranged in the two flexible frames to form two flexible hinges (5), the two flexible hinges (5) are distributed in the axial middle part of the mounting plate (2) in front and back directions and the stretching and contracting deformation directions of the two flexible hinges (5) are arranged in the circumferential direction, the left elastic sub-beam (7) is composed of two left semicircular arcs, the two left semicircular arcs are distributed in the axial left end part of the annular groove (3) in front and back directions, left strain gauges are arranged on the two left semicircular arcs, the upper end parts of the two left semicircular arcs are respectively fixed with the front and back end parts of the left end part of the mounting plate (2), the left side faces of the two flexible frames are respectively fixedly connected with the right side faces of the upper end parts of the two left semicircular arcs, a left spacing is arranged between the lower end parts of the two left semicircular arcs, the right elastic sub-beam (8) is composed of two right semicircular arcs, the two right semicircular arcs are distributed in the axial right end part of the annular groove (3) in front and back directions, right strain gauges are arranged on the two right semicircular arcs, the upper end parts of the two right semicircular arcs are respectively fixed with the front and back end parts of the right end part of the mounting plate (2), the right side faces of the two flexible frames are respectively fixedly connected with the left side faces of the upper end parts of the two right semicircular arcs, a right spacing is arranged between the lower end parts of the two right semicircular arcs, the elastic main beam (9) is composed of two main semicircular arcs, the two main semicircular arcs are distributed in the axial middle part of the annular groove (3) in front and back directions, main strain gauges are arranged on the two main semicircular arcs, the upper end parts of the two main semicircular arcs are respectively fixedly connected with the front and back side faces of the flexible frames, an axial spacing is arranged between the left elastic sub-beam (7), the elastic main beam (9) and the right elastic sub-beam (8), a radial spacing is arranged between the left elastic sub-beam (7), the elastic main beam (9), the right elastic sub-beam (8) and the groove bottom of the annular groove of the connecting base, the two mass blocks (6) are respectively arranged between the lower end part of the left elastic sub-beam (7) and the lower end part of the elastic main beam (9) and between the lower end part of the elastic main beam (9) and the lower end part of the right elastic sub-beam (8), the input end of the PID controller receives left strain gauge, right strain gauge and main strain gauge signals, and the output end of the PID controller controls the piezoelectric ceramic stacks to drive the flexible frames to stretch and contract.

2. The semi-active nonlinear energy sink based drill string vibration mitigation device of claim 1, wherein, The front and back side faces of the two flexible frames are both in a v shape.

3. A semi-active nonlinear energy sink based drill string vibration mitigation device according to claim 2, wherein, The middle part of the mounting plate (2) in the front-rear direction is provided with a vertical partition plate (10), the left end and the right end of the mounting plate (2) are respectively fixed with a left limiting plate (11) and a right limiting plate (12), the left and right ends of the vertical partition plate (10) are respectively fixed with the middle part of the front-rear direction of the left limiting plate (11) and the middle part of the front-rear direction of the right limiting plate (12), two flexible hinges (5) are respectively located on the front and rear sides of the vertical partition plate (10), the upper end of each of the two left semicircles is fixed with a left connecting plate (13), the left side of each of the two left connecting plates (13) is respectively tightly attached to the front and rear ends of the right side of the left limiting plate (11), the front and rear sides of each of the two left connecting plates (13) are respectively tightly attached to the front and rear sides of the left end of the vertical partition plate (10), the upper end of each of the two right semicircles is fixed with a right connecting plate (14), the right side of each of the two right connecting plates (14) is respectively tightly attached to the front and rear ends of the left side of the right limiting plate (12), and the front and rear sides of each of the two right connecting plates (14) are respectively tightly attached to the front and rear sides of the right end of the vertical partition plate (10).

4. The semi-active nonlinear energy sink based drill string vibration mitigation device of claim 3, wherein, The outer side of the lower end of each of the two left semicircles is provided with a left semicircle groove, the outer side of the lower end of each of the two right semicircles is provided with a right semicircle groove, the inner side of the lower end of each of the two main semicircles is provided with a middle semicircle groove, the front and rear ends of each of the two mass blocks (6) are provided with a connecting circular hole (16), and the left semicircle groove, the connecting circular hole, the middle semicircle groove and the right semicircle groove are adaptively arranged.

5. A semi-active nonlinear energy sink based vibration mitigation device for drill pipes as claimed in claim 4, wherein, The NES mechanism is located in the annular groove (3).

6. A semi-active nonlinear energy sink based drill string vibration mitigation device according to claim 5, wherein, The left end of the connecting base (1) is provided with an external thread for connecting with a drill rod, and the right end of the connecting base (1) is provided with an internal thread for connecting with a drill bit. The left end of the connecting base (1) is provided with an external thread for connecting with a drill rod, and the right end of the connecting base (1) is provided with an internal thread for connecting with a drill bit.

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