阅读说明：本技术 一种可定量调控压电陶瓷圆管表面预应力的纤维缠绕方法 (Fiber winding method capable of quantitatively regulating and controlling surface prestress of piezoelectric ceramic round tube ) 是由 黄世峰 张晓芳 林秀娟 杨长红 程新 于 2021-07-22 设计创作，主要内容包括：本发明提供一种可定量调控压电陶瓷圆管表面预应力的纤维缠绕方法,包括表面预应力的分解和计算,缠绕部件的组装与调整,压电陶瓷圆管性能的测量、计算和比较,缠绕完成的固定机制。本发明可以利用纤维胶带重复进行缠绕,实现压电陶瓷圆管表面预应力的定量调控,具备成本低、方法简单、调控准确、适用范围大等优势。(The invention provides a fiber winding method capable of quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube, which comprises the steps of decomposing and calculating the surface prestress, assembling and adjusting a winding part, measuring, calculating and comparing the performance of the piezoelectric ceramic round tube and a fixing mechanism for finishing winding. The method can repeatedly wind by using the fiber adhesive tape, realizes quantitative regulation and control of the prestress on the surface of the piezoelectric ceramic round tube, and has the advantages of low cost, simple method, accurate regulation and control, wide application range and the like.)

1. A method for quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube by winding a fiber adhesive tape is characterized by comprising the following steps of:

(1) fixedly clamping the piezoelectric ceramic round tube by utilizing a bolt structure;

(2) determining a stress expected value, and determining optimal initial winding parameters including the number of winding layers of the fiber adhesive tape and the mass of the suspension block by combining the size of the transducer;

(3) cutting a proper length of the fiber adhesive tape, and pre-bonding a circle on the outer surface of the piezoelectric ceramic round tube;

(4) adjusting the suspension device according to the mass of the suspension block, and fixing the other end of the fiber adhesive tape to the suspension device by using a fiber fixing clamp plate of the suspension device;

(5) assembling the bolt structure with winding equipment to complete the preset number of fiber winding layers;

(6) screwing down the clamping plate fixing device, removing the suspension device, and shaping by using a bolt structure and the clamping plate fixing device;

(7) measuring the static capacitance and impedance characteristic curve of the piezoelectric ceramic round tube, and calculating the electromechanical coupling coefficient and the piezoelectric strain constant of the piezoelectric ceramic round tube;

(8) evaluating the electromechanical coupling coefficient and the piezoelectric strain constant, and if the use requirement is met, removing the clamping plate and keeping the piezoelectric circular tube for later use; if the electromechanical coupling coefficient and the piezoelectric strain constant are smaller, the fiber adhesive tape can be disassembled, and the steps are repeated by adjusting the mass of the suspension block to adjust the prestress.

2. The method of claim 1, wherein the number of layers of fiber tape windings and the mass of the hanging block in step (2) are determined by:

firstly, measuring the inner diameter R of the piezoelectric ceramic round tube₁Outer diameter R₂And height h, calculating the stress constantα：

；

Preparing fiber adhesive tape, measuring fiber thickness T, and inquiring stretching limit T_c；

Determining the prestress requirement T of the piezoelectric ceramic round tube_θAccording to the radius R of the intended transducer after shaping₃And performing optimal value calculation on the prestress:

；

and fourthly, determining the number n of fiber winding layers of the initial fiber winding parameter, and calculating the mass m of the suspension block.

3. The method of claim 1, wherein the bolt structure is: the bolt structure comprises a left end cap (5) and a right end cap (7), the left end cap (5) and the right end cap (7) are respectively sleeved at two ends of the piezoelectric ceramic round tube (1), and positioning gaskets (4) are arranged on the inner sides of the left end cap (5) and the right end cap (7); clamping screw rods (6) for axially clamping the piezoelectric ceramic round tubes are arranged between the left end cap (5) and the right end cap (7), connecting rods (8) are arranged on the lower portions of the left end cap and the right end cap and are fixed to the two ends of a connecting layer clamping plate (11), upper clamping plates (9) are arranged on the two sides of the middle of the connecting layer clamping plate, and fixing bolts (10) are arranged at the two ends of each upper clamping plate.

4. The method according to claim 1, wherein the left end cap, the right end cap and the screw are made of stainless steel or brass, the piezoelectric circular tube is clamped in the axial direction, and the positioning gasket (4) is made of polytetrafluoroethylene, nylon or plastic.

5. The method according to claim 1, wherein said suspension means has a layered structure with a fiber holding clamp plate (3-1) on top to facilitate holding of the fibers; the bottom consists of a plurality of layers of layered suspension blocks (3-3), so that the quality adjustment is convenient; meanwhile, the layered suspension block (3-3) is provided with a suspension mass block fixing bolt (3-2) for fixing the multilayer layered suspension block.

6. The method of claim 1, wherein the fibers are polyester, fiberglass, or carbon fiber tape.

Technical Field

The invention relates to the technical field of ultrasonic sensors, in particular to a fiber winding method capable of quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube.

Background

Piezoelectric ceramics are widely used in ultrasonic sensors, can be used for ultrasonic ranging, ultrasonic cleaning, ultrasonic flaw detection and the like, and are widely applied to medicine, military, industry and agriculture. The performance of the ultrasonic sensor directly influences the performance of the system and is a key component of the system. The ultrasonic sensor prepared by utilizing the radially polarized piezoelectric ceramic round tube has the advantages of simple structure, no horizontal directivity, high sensitivity and the like, however, in order to improve the mechanical limit of the piezoelectric ceramic, or improve the waterproof, impact-resistant and corrosion-resistant performances and the like of the piezoelectric round tube transducer, the fiber layer is often wound outside the transducer, and organic glue such as epoxy resin is utilized for curing, so that after the winding is finished, the stress of the piezoelectric ceramic tube cannot be changed.

In addition, the stress introduced on the surface of the circular piezoelectric ceramic tube by the fiber winding and curing process directly affects the electromechanical performance and the piezoelectric performance of the circular piezoelectric ceramic tube, and further affects the sensitivity and the efficiency of the piezoelectric transducer. If the stress is not applied properly, the piezoelectric ceramic round tube can only be scrapped and cannot be recycled.

Disclosure of Invention

The invention provides a fiber winding method capable of quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube, aiming at the defects that the stress of the piezoelectric ceramic round tube cannot be changed and the piezoelectric ceramic round tube cannot be recycled after epoxy resin is cured in the conventional fiber winding process of the piezoelectric ceramic round tube. The surface prestress of the piezoelectric ceramic round tube is quantitatively regulated and controlled by winding the fiber adhesive tape, and the process control is carried out on the piezoelectric property and the electromechanical property of the piezoelectric ceramic round tube after the fiber winding is completed, so that the cost is reduced, and the sensitivity and the efficiency of the transducer are improved.

The purpose of the invention is realized by the following technical scheme:

a method for quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube by winding a fiber adhesive tape comprises the following steps:

(1) fixedly clamping the piezoelectric ceramic round tube by utilizing a bolt structure;

(2) determining a stress expected value, and determining optimal initial winding parameters including the number of winding layers of the fiber adhesive tape and the mass of the suspension block by combining the size of the transducer;

(3) cutting a proper length of the fiber adhesive tape, wherein the length is more than or equal to the length, and pre-bonding a circle on the outer surface of the piezoelectric ceramic round tube;

(4) adjusting the suspension device according to the mass of the suspension block, and fixing the other end of the fiber adhesive tape to the suspension device by using a fiber fixing clamp plate of the suspension device;

(5) assembling the bolt structure with winding equipment to complete the preset number of fiber winding layers;

(6) screwing down the clamping plate fixing device, detaching the suspension device, and shaping the fiber adhesive tape by using the bolt structure and the clamping plate fixing device;

(7) respectively measuring static capacitance C of piezoelectric ceramic round tube₀And impedance curve, maximum value of G-f and R-f curve is taken to obtain series resonance frequencyf _sAnd parallel resonant frequencyf _pThe electromechanical coupling coefficient of the piezoelectric ceramic round tube can be calculated by obtaining the radius height normalized correction parameters a and b of the piezoelectric round tube according to the radius height ratio of the piezoelectric round tubek ₃₁And piezoelectric strain constantd ₃₁；

；

(8) Evaluating the electromechanical coupling coefficient and the piezoelectric strain constant, and if the use requirement is met, removing the clamping plate and keeping the piezoelectric circular tube for later use; if the electromechanical coupling coefficient and the piezoelectric strain constant are small, the fiber adhesive tape can be disassembled, the steps are repeated by adjusting the mass of the suspension block, and the prestress is adjusted until the electromechanical coupling coefficient and the piezoelectric strain constant of the circular tube meet the requirements.

Preferably, the method for determining the number of winding layers of the fiber tape and the mass of the hanging block in the step (2) comprises the following steps:

firstly, measuring the inner diameter R of the piezoelectric ceramic round tube₁Outer diameter R₂And height h, calculating the stress constantα：

；

Preparing fiber adhesive tape, measuring fiber thickness T, and inquiring stretching limit T_c；

Determining the prestress requirement T of the piezoelectric ceramic round tube_θAccording to the radius R of the intended transducer after shaping₃And performing optimal value calculation on the prestress:

；

and fourthly, determining the number n of fiber winding layers of the initial fiber winding parameter, and calculating the mass m of the suspension block.

Preferably, the bolt structure is: the bolt structure comprises a left end cap and a right end cap, the left end cap and the right end cap are respectively sleeved at two ends of the piezoelectric ceramic round tube, and positioning gaskets are arranged on the inner sides of the left end cap and the right end cap; the clamping screw rod of axial centre gripping piezoceramics pipe is equipped with between left end cap and the right-hand member cap, and the lower part all is provided with the connecting rod to fixed to the hookup layer splint both ends, be equipped with the punch holder in the middle part both sides of hookup layer splint, the both ends of punch holder are equipped with fixing bolt.

Preferably, the left end cap, the right end cap and the screw are made of stainless steel or brass, the piezoelectric circular tube is axially clamped, the positioning gasket is made of polytetrafluoroethylene, nylon or plastic, the piezoelectric ceramic circular tube can be fixed in the radial direction, the piezoelectric ceramic circular tube is axially protected, and the ceramic tube is prevented from cracking under the action of axial stress. The positioning gasket has a simple structure, is convenient to process, and can effectively realize the fixed clamping of piezoelectric circular tubes with different sizes.

Preferably, the suspension device has a layered structure, and a fiber fixing splint is arranged on the top of the layered structure, so that fibers can be clamped conveniently; the bottom is composed of a plurality of layers of layered suspension blocks, so that the quality adjustment is convenient; meanwhile, the layered suspension block is provided with a suspension mass block fixing bolt for fixing the multilayer layered suspension block.

More preferably, the fiber is polyester fiber, glass fiber or carbon fiber tape. Pre-winding a circle on the surface of the piezoelectric ceramic by utilizing the viscosity of the adhesive tape to realize fiber fixation; the fiber is vertical to the axial direction of the ceramic round tube and is wound along the circumferential direction, and the magnitude of the surface prestress depends on the winding layer number of the fiber and the mass of the suspension block.

Has the advantages that:

(1) the fiber adhesive tape is adopted for winding, so that the fixation and the removal are convenient, the winding can be repeatedly implemented, and the cost is low;

(2) the requirement on winding equipment is low, and the regulation and control method is simple;

(3) by utilizing the number of fiber winding layers and the suspension quality, the accurate application of prestress can be realized in a larger range;

(4) the application range is wide, and the piezoelectric ceramic round tube is suitable for piezoelectric ceramic round tubes with different sizes and materials.

Drawings

FIG. 1 is a front view of a circular piezoelectric ceramic tube according to the present invention;

FIG. 2 is a side view of a circular tube of piezoelectric ceramic according to the present invention;

FIG. 3 is a schematic view of the bolt structure according to the present invention;

FIG. 4 is a front view of a suspension according to the present invention;

FIG. 5 is a side view of a suspension according to the present invention

FIG. 6 is an admittance curve after the piezoelectric circular tube is quantitatively wound after the prestressing force is quantitatively applied according to the present invention;

FIG. 7 is an admittance curve after the quantitative winding of the piezoelectric circular tube after the pre-stress regulation and control of the present invention;

FIG. 8 is a flow chart of a winding method of the present invention;

wherein, the piezoelectric ceramic vibration damper comprises 1-a piezoelectric ceramic round tube, 2-fibers, 3-a suspended block, 3-1 fiber fixing splints, 3-2 suspended mass block fixing bolts, 3-3 layered suspended blocks, 4-a positioning gasket, 5-a left end cap, 6-a clamping screw, 7-a right end cap, 8-a connecting rod, 9-an upper splint, 10-a fixing bolt and 11-a connecting layer splint.

Detailed Description

Example 1:

referring to the drawings, the device bolt structure used in the present application is: the bolt structure comprises a left end cap 5 and a right end cap 7, the left end cap 5 and the right end cap 7 are respectively sleeved at two ends of the piezoelectric ceramic round tube 1, and a positioning gasket 4 is arranged on the inner side of the right end cap 7; be equipped with the tight screw rod 6 of clamp of axial centre gripping piezoceramics pipe between left end cap 5 and the right-hand member cap 7, the lower part all is provided with connecting rod 8 to fix to connecting layer splint 11 both ends, be equipped with punch holder 9 in the both sides at connecting layer splint middle part, the both ends of punch holder are equipped with fixing bolt 10.

The left end cap, the right end cap and the screw rod are made of stainless steel materials, the piezoelectric circular tube is axially clamped, the positioning gasket 4 is made of polytetrafluoroethylene materials, the piezoelectric ceramic circular tube can be fixed in the radial direction, axial protection is conducted on the piezoelectric ceramic circular tube, and the ceramic tube is prevented from cracking under the action of axial stress. The positioning gasket has a simple structure, is convenient to process, and can effectively realize the fixed clamping of piezoelectric circular tubes with different sizes.

The suspension device has a layered structure, and the top of the suspension device is provided with a fiber fixing splint 3-1, so that the fiber can be clamped conveniently; the bottom consists of a plurality of layers of layered hanging blocks 3-3, which is convenient for quality adjustment; meanwhile, the layered suspension block 3-3 is provided with a suspension mass block fixing bolt 3-2 for fixing the multilayer layered suspension block.

The fiber is glass fiber adhesive tape. Pre-winding a circle on the surface of the piezoelectric ceramic by utilizing the viscosity of the adhesive tape to realize fiber fixation; the fiber is vertical to the axial direction of the ceramic round tube and is wound along the circumferential direction, and the magnitude of the surface prestress depends on the winding layer number of the fiber and the mass of the suspension block.

A fiber winding method capable of quantitatively regulating and controlling the surface prestress of a piezoelectric ceramic round tube comprises the following steps:

(1) preparing a dimension R₁9*R₂10.75 × h26mm round piezoelectric ceramic tube, clean surface, no defect of electrode, and calculated stress constantαIs-2293.8;

(2) A3M 8915 glass fiber tape was prepared, having a thickness of 0.15mm and a tensile strength T_C596 MPa;

(3) fixedly clamping the piezoelectric ceramic round tube by utilizing a bolt structure;

(4) if the expected stress requirement T of the piezoelectric ceramic round tube_θ1MPa, radius R expected after transducer formation₃And 12.5mm, the optimal value of the prestress meets the following requirements:

；

(5) if the initial number of filament winding layers n is determined to be 3, the mass m of the pendant block is calculated to be 1.6 kg:

(6) assembling the piezoelectric ceramic bolt structure with manual winding equipment;

(7) cutting the glass fiber adhesive tape, wherein the length of the glass fiber adhesive tape is 500mm, and the glass fiber adhesive tape is fully paved on the piezoelectric ceramic circular tube in parallel and is pre-wound for a circle;

(8) adjusting the suspension device according to the mass m of the suspension block, and fixing the other end of the fiber adhesive tape to the suspension device by using a fiber fixing clamp plate of the suspension device;

(9) winding 3 layers of glass fiber by using manual winding equipment;

(10) fixing the fibers by using a clamping plate and a bolt, and dismantling the suspension device;

(11) measuring static capacitance C of the piezoelectric ceramic circular tube by using a keysight4900A impedance analyzer₀The G-f curve and the R-f curve are 15.405nF, as shown in FIG. 4, from which the series resonance frequency fs and the parallel resonance frequency fp corresponding to the maximum values are extracted, 43993.99Hz and 44234.23Hz, respectively. Obtaining radius height normalization correction parameters a and b of the piezoelectric circular tube according to CB/T4314-2013, and calculating an electromechanical coupling coefficient k of the piezoelectric ceramic circular tube₃₁And piezoelectric strain constant d₃₁：

；

K is obtained by calculation₃₁And d₃₁0.31 and 161.2 x 10 respectively^-12m/V。

(12) If k is calculated₃₁And d₃₁When the requirements are met, the clamping plate is removed, and the piezoelectric circular tube is reserved; if k is₃₁And d₃₁And (5) on the small scale, removing the fiber adhesive tape, then trying to keep the number n of winding layers unchanged, reducing the prestress by gradually reducing the mass of the suspension block, and repeating the steps (4) to (11).

(13) When the prestress is reduced to 0.1MPa, the number n of fiber winding layers is 3, the mass m of the suspension block is calculated to be 0.16kg, and the static capacitance C is measured₀For 15.306nF, the G-f curve and the R-f curve are shown in FIG. 5, from which the resonance frequency f is extracted_sAnd f_p43873.87Hz and 44144.14Hz, respectively. Extracting the normalized value of the height-diameter ratio according to CB/T4314-2013, and calculating the electromechanical coupling coefficient k of the piezoelectric ceramic round tube₃₁And piezoelectric strain constant d₃₁Increases of 0.33 and 171.1 x 10, respectively^-12m/V。

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.