Multidirectional dynamic strain detection structure

Abstract

The invention discloses a multidirectional dynamic strain detection structure, and belongs to the technical field of functional structures. The multidirectional dynamic strain detection structure comprises a regular hexagonal structure frame, a crank sliding block mechanism, a mechanical push rod mechanism and a fixing structure. Through the combination of the regular hexagonal structure frame, the crank sliding block mechanism and the mechanical push rod mechanism, independent movement or micro rotation of each part can be realized under the limitation of a wedge angle, so that multi-directional dynamic strain detection is completed. And the wedge angle is used as a fulcrum, so that the adjacent beams of the regular hexagonal structure frame symmetrically deform and accumulatively deform when being stressed, and the detection structure has relatively high flexibility and adaptability. The piezo-electric crystal material is in contact with or separated from the electrode through the movement of the piston push rod, voltage reactions at different positions are generated, and the voltage signals can reflect strain changes in all directions after being processed by the multi-channel charge amplifier. And through the design of the six-claw fixing plate and the fixing plate, the strength of the structure is improved, meanwhile, the self-adaptive capacity of the structure is enhanced, the influence of tangential stress on the structure is reduced, and the service life is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of functional structures, and in particular relates to a multi-directional dynamic strain detection structure. Background Art

[0002] The traditional strain detection structure is a method of detecting strain by using force to change its resistance and thus affect the current. This strain detection method is widely used in the fields of industry, aerospace, and medical to measure physical quantities such as force, pressure, and vibration.

[0003] The Chinese invention patent with publication number CN109275203A discloses an expandable distributed honeycomb flexible sensor network. This technical solution aims to provide a micro-sensor arrangement method, and is not a structural improvement on the strain detection structure itself.

[0004] Therefore, a new technical solution is urgently needed in the prior art to solve this problem. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to provide a detection structure that can be used for multi-directional dynamic strain to solve the problem that the existing strain detection can only perform unidirectional strain measurement, cannot provide a comprehensive strain distribution diagram, and may also miss key structural stress points, increasing the risk of structural failure; the existing patent is an improved microsensor arrangement method, rather than improving the structure of the detection structure itself, etc.

[0006] A multi-directional dynamic strain detection structure, comprising a regular hexagonal structural frame, a crank slider mechanism, a mechanical push rod mechanism and a fixing structure; six inner corners of the regular hexagonal structural frame are provided with wedge angles; two wedge angle fixing pins are fixedly installed on the inner walls on both sides of the wedge angles;

[0007] The crank slider mechanism comprises a semi-open rib plate I, a semi-open rib plate II, a slotted special-shaped slide rod and a piston push rod; a limit column I is symmetrically arranged on the side wall of one end of the slotted special-shaped slide rod, and a symmetrically arranged limit groove is opened on the other end of the slotted special-shaped slide rod;

[0008] One end of the semi-open rib plate I is connected to the limiting column I to form a rotation pair, and the other end of the semi-open rib plate I is connected to the wedge angle fixing pin at the proximal end of the wedge angle to form a rotation pair;

[0009] A limiting column II is symmetrically arranged at one end of the piston push rod, and the end of the piston push rod is movably inserted into the slotted special-shaped sliding rod, and the limiting column II slides in the limiting groove after passing through the limiting groove, and a piston-like plate is arranged at the other end of the piston push rod;

[0010] One end of the semi-open rib plate II is connected to the limiting column II to form a rotation pair, and the other end of the semi-open rib plate II is connected to the wedge angle fixing pin at the far end of the wedge angle to form a rotation pair;

[0011] An electrode I is fixedly attached to the outer end surface of the piston-like plate;

[0012] The mechanical push rod mechanism comprises a cylinder and a reset spring; the inner bottom of the cylinder is fixed with an electrode II, the cylinder is filled with piezoelectric crystal material, the upper end of the cylinder is fixed with a cylinder cap, and the outer side wall of the cylinder is provided with a latch; the reset spring is provided between the cylinder cap and the piston-like plate;

[0013] The fixing structure comprises a six-claw fixing plate and a fixing plate; the six claws of the six-claw fixing plate are arranged one by one corresponding to the six inner corners of the regular hexagonal structure frame, the tops of the six claws are provided with through holes matching the latches, and the six-claw fixing plate is connected to the latches through the through holes; one side of the fixing plate is fixedly connected to the six-claw fixing plate, and the other side of the fixing plate is located in the same plane as the bottom surface of the regular hexagonal structure frame, and both are adhered and fixed to the surface of the object to be measured;

[0014] The electrode I and the electrode II are electrically connected to a multi-channel charge amplifier respectively.

[0015] The wedge angle is 90°.

[0016] The slotted special-shaped sliding rod is provided with a protruding limiting structure at the distal end of the limiting groove.

[0017] The outer side of the six-claw fixing plate is parallel to the outer frame of the regular hexagonal structural frame, and the six claws of the six-claw fixing plate are arranged on the six corners of the six-claw fixing plate in a one-to-one correspondence.

[0018] A slideway is arranged on the side wall of the cylinder; a rotary slide rail is interference-connected in the slideway; and the latch is arranged outside the rotary slide rail.

[0019] A half-width snap ring is provided on one end side of the semi-open rib plate I and is clamped with the limit column I to form a rotating pair. A full-width snap ring is provided on the other end side of the semi-open rib plate I and is clamped with the wedge angle fixing pin at the proximal end of the wedge angle to form a rotating pair.

[0020] A half-width snap ring II is arranged on one end side of the semi-open rib II and is clamped with the limit column II to form a rotating pair. A full-width snap ring II is arranged on the other end side of the semi-open rib II and is clamped with the wedge angle fixing pin at the far end of the wedge angle to form a rotating pair.

[0021] Through the above design scheme, the present invention can bring the following beneficial effects:

[0022] The multi-directional dynamic strain detection structure can realize independent movement or slight rotation of each part under the restriction of wedge angle through the combination of regular hexagonal frame, crank slider mechanism and mechanical push rod mechanism, so as to complete the detection of multi-directional dynamic strain. The wedge angle is used as a fulcrum, so that the adjacent beams of the regular hexagonal structure frame deform symmetrically and accumulate deformation when subjected to force, so that the detection structure has high flexibility and adaptability. The movement of the piston push rod generates voltage responses at different positions through the contact or separation of the piezoelectric crystal material and the electrode. These voltage signals can reflect the strain changes in all directions after being processed by a multi-channel charge amplifier. The design of the six-claw fixed plate and the fixed plate not only improves the strength of the structure, but also enhances the adaptive ability of the structure, effectively reduces the influence of tangential stress on the structure, and prolongs the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below with reference to the accompanying drawings and specific embodiments:

[0024] Figure 1 It is a structural schematic diagram of a multi-directional dynamic strain detection structure of the present invention;

[0025] Figure 2 A top view of a multi-directional dynamic strain detection structure of the present invention;

[0026] Figure 3 It is a rear view of a multi-directional dynamic strain detection structure of the present invention;

[0027] Figure 4 It is a side view of a multi-directional dynamic strain detection structure of the present invention;

[0028] Figure 5 It is a structural schematic diagram of a crank slider mechanism in a multi-directional dynamic strain detection structure of the present invention;

[0029] Figure 6 An exploded diagram of a crank slider mechanism in a multi-directional dynamic strain detection structure of the present invention;

[0030] Figure 7 It is a structural schematic diagram of a mechanical push rod mechanism in a multi-directional dynamic strain detection structure of the present invention;

[0031] Figure 8 An exploded diagram of a mechanical push rod mechanism in a multi-directional dynamic strain detection structure of the present invention;

[0032] Fig. 9 It is a structural schematic diagram of a fixed structure in a multi-directional dynamic strain detection structure of the present invention;

[0033] Fig.10 An exploded diagram of a fixed structure in a multi-directional dynamic strain detection structure of the present invention;

[0034] Fig.11 It is an enlarged view of the wedge angle in a multi-directional dynamic strain detection structure of the present invention;

[0035] Fig.12 A schematic diagram of various points of a multi-directional dynamic strain detection structure of the present invention;

[0036] Fig.13 This is a diagram of the connection between the electrodes and the wires in the cylinder of a multi-directional dynamic strain detection structure of the present invention;

[0037] Fig.14 It is a structural schematic diagram of a multi-directional dynamic strain detection structure of the present invention attached to a cantilever beam and connected to a charge amplifier;

[0038] Fig.15 This is a diagram of the micro-rotation of a cylinder of a multi-directional dynamic strain detection structure of the present invention caused by tangential stress when the cylinder is under stress.

[0039] In the figure, 1. regular hexagonal structural frame 1; 2. half-open rib plate Ⅰ; 3. half-open rib plate Ⅱ; 4. slotted special-shaped slide rod; 5. piston push rod; 6. cylinder; 7. rotary slide rail; 8. return spring; 9. six-claw fixed plate; 10. fixed plate; 11. wedge angle fixed pin; 12. cylinder cap; 13. electrode Ⅰ; 14. electrode Ⅱ; 15. multi-channel charge amplifier; 101. wedge angle; 201. half-width snap ring; 202. full-width snap ring; 301. half-width snap ring Ⅱ; 302. full-width snap ring Ⅱ; 401. limit column Ⅰ; 402. limit groove; 501. limit column Ⅱ; 502. piston-like plate; 701. latch. DETAILED DESCRIPTION

[0040] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figures 1 to 15 As shown, a multi-directional dynamic strain detection structure includes a regular hexagonal structural frame 1, a crank slider mechanism, a mechanical push rod mechanism and a fixed structure; wedge angles 101 are provided at the six inner corners of the regular hexagonal structural frame 1, and the wedge angle 101 is preferably 90°; two wedge angle fixing pins 11 are fixedly installed on the inner walls on both sides of the wedge angle 101; the crank slider mechanism and the mechanical push rod mechanism are six each, distributed at six wedge angle positions.

[0042] The crank slider mechanism comprises a semi-open rib plate Ⅰ2, a semi-open rib plate Ⅱ3, a slotted special-shaped slide rod 4 and a piston push rod 5; a limiting column Ⅰ401 is symmetrically arranged on the side wall of one end of the slotted special-shaped slide rod 4, and a symmetrically arranged limiting groove 402 is opened on the other end of the slotted special-shaped slide rod 4;

[0043] One end side portion of the semi-open rib plate Ⅰ2 is provided with a half-width snap ring 201, and is clamped with the limit column Ⅰ401 through the half-width snap ring 201 to form a rotating pair. The other end side portion of the semi-open rib plate Ⅰ2 is provided with a full-width snap ring 202, and is clamped with the wedge angle fixing pin 11 at the proximal end of the wedge angle 101 through the full-width snap ring 202 to form a rotating pair.

[0044] A limiting column II 501 is symmetrically arranged at one end of the piston push rod 5, and the end of the piston push rod 5 is movably inserted into the slotted special-shaped slide rod 4, and the limiting column II 501 passes through the limiting groove 402 and slides in the limiting groove 402, and a piston-like plate 502 is arranged at the other end of the piston push rod 5; an electrode I 13 is fixedly attached to the outer end surface of the piston-like plate 502;

[0045] One end side of the semi-open rib plate II3 is provided with a half-width clamping ring II301, and the half-width clamping ring II301 is clamped with the limit column II501 to form a rotating pair. The other end side of the semi-open rib plate II3 is provided with a full-width clamping ring II302, and the full-width clamping ring II302 is clamped with the wedge angle fixing pin 11 at the far end of the wedge angle 101 to form a rotating pair.

[0046] The mechanical push rod mechanism includes a cylinder 6, a rotary slide rail 7 and a reset spring 8; the cylinder 6 is arranged coaxially with the piston push rod 5, an electrode II 14 is fixed to the inner bottom of the cylinder 6, the cylinder 6 is filled with piezoelectric crystal material, a slideway is arranged on the side wall of the cylinder 6, a cylinder cap 12 is fixedly installed on the upper port of the cylinder 6, an opening is arranged at the bottom end of the cylinder 6, and a convenient through hole is provided for the wire for additional detection. Whether the cylinder 6 is provided with shielding material can be determined according to the detection plan; the rotary slide rail 7 is interference connected with the slideway, and a pin 701 is arranged on the outside of the rotary slide rail 7; the reset spring 8 is arranged between the cylinder cap 12 and the piston-like plate 502, so that when the deformation is restored, the mechanical push rod mechanism can make corresponding adjustments in time to prepare for the next detection.

[0047] The fixing structure includes a six-claw fixing plate 9 and a fixing plate 10; the structural idea of ​​the six-claw fixing plate 9 is derived from a spider, and is composed of a plate and claws with a certain angle. The six claws of the six-claw fixing plate 9 are arranged one by one corresponding to the six inner angles of the regular hexagonal structural frame 1, and the tops of the six claws are provided with through holes matching the latch 701. The six-claw fixing plate 9 is connected to the latch 701 through the through holes and forms a rotating pair to offset the tangential stress caused by the overall rotation of the crank slider mechanism when the structure is deformed, so that the stress along the axial direction is transmitted to the inside of the cylinder 6. The specific stress conditions and the slight rotation of the cylinder 6 caused by the tangential stress can be referred to Fig.15One side of the fixing plate 10 is fixedly connected to the six-claw fixing plate 9, and the other side of the fixing plate 10 is located in the same plane as the bottom surface of the regular hexagonal structure frame 1, and both are adhered and fixed to the surface of the object to be measured; the six-claw fixing plate 9 and the fixing plate 10 form a double-layer structure, which is fixed in the middle by columns and bolts, and the setting of the six angled claws utilizes the triangular fixing principle, which greatly improves the strength of the overall structure and extends the service life of the detection structure.

[0048] The electrodes I13 and II14 are electrically connected to the multi-channel charge amplifier 15, respectively, and the correspondingly arranged electrodes I13 and II14 are used in cooperation with each other. In the initial position, the electrode I13 on the piston push rod 5 contacts the piezoelectric crystal material and the electrode II14 in sequence, and the contact condition can be observed through the observation slot provided on the cylinder 6.

[0049] The slotted special-shaped slide rod 4 is provided with a protruding limiting structure at the distal end of the limiting groove 402, which is used to further limit the position of the semi-open ribs Ⅰ2 to prevent the two semi-open ribs Ⅰ2 from being over-closed and unable to be opened again.

[0050] The outer side of the six-claw fixing plate 9 is parallel to the outer frame of the regular hexagonal structural frame 1 .

[0051] The half-width snap ring 201, the full-width snap ring 202, the half-width snap ring II 301 and the full-width snap ring II 302 are all provided with an open groove with a central angle of 45° along the length direction for installation to form a rotating pair.

[0052] The use process of the present invention is:

[0053] After the surface of the structure of the object to be measured is polished and smooth, Fig.12As shown, the detection structure is placed vertically at points a1 and a4 using a special adhesive, and the side with the fixing plate is adhered to the structure to be tested. When the structure to be tested receives axial tension, the piston push rods 5 at points a1 and a4 squeeze the piezoelectric material, and the piston push rods 5 at points a2, a3, a5, and a6 are all away from the piezoelectric crystal material, and the corresponding a1 and a4 meters on the multi-channel charge amplifier 15 have voltage responses. When subjected to axial pressure, the piston push rods 5 corresponding to points a1 and a4 are away from the piezoelectric material, and the piston push rods 5 at points a2, a3, a5, and a6 squeeze the piezoelectric material, and the corresponding a2, a3, a5, and a6 meters on the multi-channel charge amplifier 15 have voltage responses. When the structure is subjected to a clockwise torque along the end face of the structure, the piston push rods 5 at points a4, a5, and a6 squeeze the piezoelectric crystal material, and the piston push rods 5 at points a1, a2, and a3 stay away from the piezoelectric crystal material, and the a4, a5, and a6 meters on the multi-channel charge amplifier 15 have a voltage response. When the structure is subjected to a counterclockwise torque along the end face of the structure, the piston push rods 5 at points a1, a2, and a3 squeeze the piezoelectric crystal material, and the piston push rods 5 at points a4, a5, and a6 stay away from the piezoelectric crystal material, and the a1, a2, and a3 meters on the multi-channel charge amplifier 15 have a voltage response.

[0054] The conversion relationship between voltage signal and stress magnitude is as follows:

[0055] For example, if stress is applied along three directions, the piezoelectric coefficient of the piezoelectric crystal material can be expressed as d 33 , then the charge Q generated by the piezoelectric crystal material under stress σ3 can be expressed as:

[0056] Q=d 33 ·A·σ3;

[0057] Where A is the force-bearing area of ​​the piezoelectric crystal material; σ3 is the applied stress.

[0058] The measured voltage change V is related to the charge amount Q accumulated at both ends of the crystal through the multi-channel charge amplifier 15. f ,but:

[0059]

[0060] Combining the above charge formula, we get:

[0061]

[0062] The voltage signal measured by the multi-channel charge amplifier 15 can be used to infer the applied stress magnitude σ 3， Then the multi-directional dynamic strain detection of the object to be tested is completed, and the solution formula of the stress magnitude σ3 is:

[0063]

[0064] The above is only the structural scheme of the present invention, and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification of the above form examples according to the structural scheme of the present invention without departing from the content of the structural scheme of the present invention shall fall within the scope of the technical scheme of the present invention. The present invention is not limited to piezoelectric or resistive detection structures.

Claims

1. A multi-directional dynamic strain detection structure, characterized by: It comprises a regular hexagonal structural frame (1), a crank slider mechanism, a mechanical push rod mechanism and a fixing structure; six inner corners of the regular hexagonal structural frame (1) are all provided with wedge angles (101); two wedge angle fixing pins (11) are fixedly installed on the inner walls on both sides of the wedge angle (101); The crank slider mechanism comprises a semi-open rib plate I (2), a semi-open rib plate II (3), a slotted special-shaped slide rod (4) and a piston push rod (5); a limiting column I (401) is symmetrically arranged on the side wall of one end of the slotted special-shaped slide rod (4), and a symmetrically arranged limiting groove (402) is opened on the other end of the slotted special-shaped slide rod (4); One end of the semi-open rib plate I (2) is connected to the limiting column I (401) to form a rotation pair, and the other end of the semi-open rib plate I (2) is connected to the wedge angle fixing pin (11) at the proximal end of the wedge angle (101) to form a rotation pair; A limiting column II (501) is symmetrically arranged at one end of the piston push rod (5), and this end of the piston push rod (5) is movably inserted into the slotted special-shaped sliding rod (4), and the limiting column II (501) slides in the limiting groove (402) after passing through the limiting groove (402), and a piston-like plate (502) is arranged at the other end of the piston push rod (5); One end of the semi-open rib plate II (3) is connected to the limiting column II (501) to form a rotation pair, and the other end of the semi-open rib plate II (3) is connected to the wedge angle fixing pin (11) at the far end of the wedge angle (101) to form a rotation pair; An electrode I (13) is fixedly attached to the outer end surface of the piston-like plate (502); The mechanical push rod mechanism comprises a cylinder (6) and a return spring (8); an electrode II (14) is fixed to the inner bottom of the cylinder (6), a piezoelectric crystal material is filled in the cylinder (6), a cylinder cap (12) is fixedly installed at the upper end of the cylinder (6), and a latch (701) is arranged on the outer side wall of the cylinder (6); the return spring (8) is arranged between the cylinder cap (12) and the piston-like plate (502); The fixing structure comprises a six-claw fixing plate (9) and a fixing plate (10); the six claws of the six-claw fixing plate (9) are arranged in one-to-one correspondence with the six inner corners of the regular hexagonal structural frame (1), the top ends of the six claws are provided with through holes matching the latch (701), and the six-claw fixing plate (9) is connected to the latch (701) via the through holes; one side of the fixing plate (10) is fixedly connected to the six-claw fixing plate (9), and the other side of the fixing plate (10) is located in the same plane as the bottom surface of the regular hexagonal structural frame (1), and both are adhered and fixed to the surface of the object to be measured; The electrode I (13) and the electrode II (14) are electrically connected to a multi-channel charge amplifier (15) respectively.

2. The multi-directional dynamic strain detection structure according to claim 1, characterized in that: The wedge angle (101) is 90°.

3. The multi-directional dynamic strain detection structure according to claim 1 is characterized in that: The slotted special-shaped sliding rod (4) is provided with a protruding limiting structure at the distal end of the limiting groove (402).

4. The multi-directional dynamic strain detection structure according to claim 1, characterized in that: The outer side of the six-claw fixing plate (9) is parallel to the outer frame of the regular hexagonal structural frame (1), and the six claws of the six-claw fixing plate (9) are arranged one by one at the six corners of the six-claw fixing plate (9).

5. The multi-directional dynamic strain detection structure according to claim 1 is characterized in that: A slideway is provided on the side wall of the cylinder (6); a rotary slide rail (7) is interference-connected in the slideway; and the latch (701) is provided outside the rotary slide rail (7).

6. The multi-directional dynamic strain detection structure according to claim 1 is characterized in that: A half-width snap ring (201) is provided on one end side of the semi-open rib plate I (2) and is snap-connected with the limit column I (401) through the half-width snap ring (201) to form a rotation pair. A full-width snap ring (202) is provided on the other end side of the semi-open rib plate I (2) and is snap-connected with the wedge angle fixing pin (11) at the proximal end of the wedge angle (101) through the full-width snap ring (202) to form a rotation pair.

7. The multi-directional dynamic strain detection structure according to claim 1, characterized in that: A half-width snap ring II (301) is provided on one end side of the semi-open rib II (3) and is snap-connected with a limit column II (501) to form a rotation pair. A full-width snap ring II (302) is provided on the other end side of the semi-open rib II (3) and is snap-connected with a wedge angle fixing pin (11) at the far end of the wedge angle (101) to form a rotation pair.

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