CN118050145A - High temperature vibration modal fixture for carbon fiber resin matrix composites - Google Patents

Abstract

The invention provides a high-temperature vibration mode clamp for a carbon fiber resin matrix composite, which comprises an infrared radiation heating array, a supporting plate, a sliding supporting frame, a sheet type armoured thermocouple, a carbon fiber resin matrix composite test piece, a sliding clamp, a supporting chute, a ceramic rod, a high-temperature baffle, a sliding supporting plate, a metal bracket, a high-temperature sliding block, a vibration exciter and a high-temperature threaded ejector rod. During high-temperature vibration mode test, one end of a carbon fiber resin matrix composite test piece is fixed on the sliding support frame, the other end of the carbon fiber resin matrix composite test piece is clamped by the ceramic rod connected sliding clamp, the infrared radiation heating array provides a high-temperature environment for the carbon fiber resin matrix composite test piece, and the vibration exciter is connected with the ceramic rod to provide random excitation for the carbon fiber resin matrix composite test piece. The clamping scheme is provided for testing the high-temperature vibration mode of the composite material in the aerospace flight environment on the premise of not damaging the carbon fiber resin-based composite material.

Description

High temperature vibration modal fixture for carbon fiber resin matrix composites

Technical Field

The invention relates to the field of high temperature environment vibration modal testing of flight components, and in particular to a high temperature vibration modal fixture of a carbon fiber resin-based composite material.

Background technique

With the development of science and technology, carbon fiber resin-based composite materials are widely used in aerospace, transportation, and automobile manufacturing due to their unique physical and chemical properties. Especially in the field of aerospace, they are processed and manufactured into key components of large aircraft due to their light weight, high strength, and good corrosion resistance, playing a vital role. However, with the rapid development of hypersonic aircraft, the ablation resistance and vibration fatigue damage resistance of carbon fiber resin-based composite materials in harsh high-temperature flight environments have attracted more and more attention from researchers. In particular, carbon fiber resin-based composite aircraft undergo changes in structural properties under the vibration of high-temperature thermal environments. The modal dynamic changes under high-temperature vibration directly affect the stability and service life of the aircraft flight. Therefore, researchers urgently need to carry out high-temperature vibration tests on carbon fiber resin-based composite materials, conduct good simulation predictions on the test components in the high-temperature environment flight process on the ground, and carry out research on the damage mechanism of high-temperature vibration on flight components.

In order to accurately obtain the vibration modal parameters of the test component, ensuring the integrity of the structure is the primary condition, especially for carbon fiber resin-based composite materials, whose special manufacturing process causes the internal structure to be very different from that of metal materials. The fiber layer thickness and layer angle will affect the vibration modal parameters, so it is not possible to punch holes on the surface of the material to fix it, which will damage the structural integrity. At the same time, under the action of high temperature environment above 1000℃, the structural performance of carbon fiber resin-based composite materials changes dramatically, the material is severely carbonized, and the overall stiffness is reduced, which brings certain challenges to the stable clamping of carbon fiber resin-based composite test pieces. Therefore, researchers urgently need to research and develop a high-temperature vibration modal test fixture for carbon fiber resin-based composite materials, which can stably provide a high-temperature environment above 1000℃, and can stably clamp carbon fiber resin-based composite materials without destroying the integrity of the material, so as to achieve accurate acquisition of high-temperature modal parameters of the test piece, and provide experiments and clamping methods for the vibration modal data collection of carbon fiber resin-based composite flight components in aerospace high-temperature flight environments.

Summary of the invention

In order to solve the above problems, the present invention discloses a high-temperature vibration modal clamp for carbon fiber resin-based composite materials, which can stably clamp the flight components in high-temperature thermal environment vibration modal tests above 1000°C in the aerospace field without damaging the carbon fiber resin-based composite materials, and obtain the precise vibration modal dynamic change law of the flight components, thereby providing experiments and clamping means for the vibration modal data collection of carbon fiber resin-based composite flight components in high-temperature flight environments in aerospace.

A high-temperature vibration modal fixture for carbon fiber resin-based composite materials, comprising an infrared radiation heating array, a support plate, a sliding support frame, a thin-sheet armored thermocouple, a carbon fiber resin-based composite material test piece, a ceramic rod, a sliding support plate, a metal bracket, a high-temperature slider, an exciter and a high-temperature threaded top rod; the sliding support frame is slidably connected to the metal bracket through a high-temperature slider; the support plate is arranged at one end of the sliding support frame; a hole groove is provided at the upper end, one end of the infrared radiation heating array is fixed in the hole groove of the support plate and the other end is fixed on the hole groove of the sliding support plate; the carbon fiber resin-based composite material test piece is arranged on the sliding support frame and one end is connected to the sliding fixture assembly; the upper and lower surfaces of the carbon fiber resin-based composite material test piece are both fitted with the thin-sheet armored thermocouple; the thin-sheet armored thermocouple is externally connected to a temperature collector; the exciter is connected to the sliding fixture assembly through a high-temperature ceramic rod.

The exciter transmits the excitation source to the sliding fixture through a high-temperature ceramic rod, applying random excitation to the carbon fiber resin-based composite material; the support plate and the sliding support plate fix the infrared radiation heating array to slide up and down between the metal brackets to heat the upper surface of the carbon fiber resin-based composite material, simulating the high-temperature thermal environment during actual flight.

Furthermore, the sliding fixture assembly includes a supporting slide and a sliding fixture; the supporting slide is fixed with a nested sliding fixture. The sliding fixture can be adjusted horizontally along the supporting slide, and the high-temperature threaded push rod passes through the sliding fixture. When clamping, the high-temperature threaded push rod is rotated and the sliding fixture is adjusted to clamp carbon fiber resin-based composite test pieces with different variable thicknesses and cross-sections.

Furthermore, bolt holes are provided on the sliding support frame, and adjustment slots are provided at both ends of the support plate; wherein the adjustment bolts pass through the adjustment slots and are locked in the bolt holes.

Furthermore, the high temperature baffle is located between the extended end of the high temperature ceramic rod and the vibrator, with a 12 mm round hole in the middle, and the high temperature ceramic rod passes through the round hole in the middle of the high temperature baffle to connect to the vibrator. The high temperature baffle wraps the vibrator housing as a whole to prevent the vibrator from being affected by the high temperature environment.

Furthermore, the sliding support plate is slidably arranged on the metal bracket.

Furthermore, a rectangular hole with a length of 350 mm and a height of 10 mm is opened in the middle of the crossbeam of the sliding support frame, and a bracket is provided at the lower end of the rectangular hole. A high-temperature threaded top rod is opened on the bracket every 40 mm to support the bottom of the carbon fiber resin-based composite material test piece.

Furthermore, the two ends of the high-temperature armored thermocouple are respectively fixed in the elliptical hole groove on the sliding support frame, and the thin-film armored thermocouple can withstand a high-temperature thermal environment of 1200°C, and is evenly attached to the upper and lower surfaces of the carbon fiber resin-based composite material test piece, and is externally connected to a temperature data acquisition instrument to monitor the temperature change of the carbon fiber resin-based composite material test piece in real time.

The high temperature ceramic rod has a diameter of 10 mm and a length of 250 mm, and integrally penetrates the fixed connection support slide groove; the excitation source is transmitted to the sliding fixture through the high temperature ceramic rod to apply random excitation to the carbon fiber resin-based composite material.

The principle of the present invention is as follows: a high-temperature threaded top rod is used in the middle of the sliding support frame to clamp one end of the carbon fiber resin-based composite material test piece, a support plate is connected to both ends of the sliding support frame by high-temperature bolts, the upper end of the support plate is fixedly connected to one end of the infrared radiation heating array, and the other end of the infrared radiation heating array is fixedly supported by the hole groove at the upper end of the sliding support plate, so as to heat the upper surface of the carbon fiber resin-based composite material test piece, and simulate the thermal environment during the actual flight process. The thin-sheet armored thermocouple passes through the elliptical hole groove of the sliding support frame, and the temperature of the upper and lower surfaces of the carbon fiber resin-based composite material test piece is measured respectively. The temperature data acquisition instrument is connected externally to detect the temperature change in real time. At the same time, the other end of the carbon fiber resin-based composite material test piece is clamped by the two ends of the sliding clamp on the support slide, and the two ends of the carbon fiber resin-based composite material test piece are fixedly supported. The exciter is connected to a high-temperature ceramic rod through a high-temperature baffle to connect the support slide and the sliding clamp, and provides random excitation to one end of the carbon fiber resin-based composite material. The present invention can provide heat-mechanics-vibration coupling test conditions without destroying the integrity of the carbon fiber resin-based composite material test piece, and provide a clamping scheme for high-temperature vibration modal testing of composite materials in an aerospace flight environment.

Compared with the prior art, the present invention has the following beneficial effects:

(1) Most of the existing high-temperature vibration test fixtures are designed for alloy structural parts, and only a small number of them have been used to study the design of high-temperature vibration fixtures for composite materials. Most of them require drilling holes on the surface of the material and connecting vibration equipment to provide excitation. However, drilling holes on the surface of the composite material not only destroys the integrity of the structural parts, but also changes the braided structure of the composite material, affecting the accuracy of obtaining high-temperature modal parameters. The present invention uses a sliding fixture and a sliding support frame to stably clamp the carbon fiber resin-based composite material test piece without destroying the overall structure. The random excitation signal is stably transmitted to the sliding fixture through a high-temperature ceramic rod, providing random vibration for the carbon fiber resin-based composite material test piece, simulating the vibration change law in the flight environment.

(2) The present invention is suitable for providing different thermal environments for carbon fiber resin-based composite material test pieces. The support plate is slidably connected to the two ends of the sliding support frame by high-temperature bolts. A hole groove is provided at the upper end of the support plate to fix and support one end of the infrared radiation heating array, and the other end is fixed and supported by a hole groove provided at the upper end of the sliding support plate. By moving the height of the infrared radiation heating array, the irradiation area is changed and the heating environment of the carbon fiber resin-based composite material is adjusted.

(3) The present invention is suitable for high temperature vibration testing of carbon fiber resin-based composite test pieces of different lengths, thicknesses and cross sections. Both ends of the sliding support frame can slide along the external metal bracket to ensure the clamping of carbon fiber resin-based composite test pieces of different lengths. The sliding clamp on the sliding support slide can clamp carbon fiber resin-based composite test pieces of different cross sections, and the high temperature threaded push rod on the rotating sliding clamp can adapt to carbon fiber resin-based composite test pieces of different thicknesses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of the present invention;

FIG2 is a partial overall schematic diagram of the present invention;

FIG3 is a front view of the present invention;

FIG. 4 is a schematic diagram of a clamp of the present invention.

Detailed ways

The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

As shown in Figures 1, 2, 3 and 4, the present invention consists of an infrared radiation heating array 1, a support plate 2, a sliding support frame 3, a thin-film armored thermocouple 4, a carbon fiber resin-based composite material tester 5, a sliding fixture 6, a supporting slide 7, a ceramic rod 8, a high-temperature baffle 9, a sliding support plate 10, a metal bracket 11, a high-temperature slider 12, an exciter 13 and a high-temperature threaded top rod 14.

The clamp designed in this embodiment is suitable for clamping and fixing carbon fiber resin-based composite material test pieces of different thicknesses and lengths without destroying the integrity of the carbon fiber resin-based composite material. One end of the carbon fiber resin-based composite material test piece 5 passes through the middle truss of the sliding support frame 3, and the high-temperature threaded push rod 14 of the middle truss of the rotating sliding support frame 3 is fixed to one end of the carbon fiber resin-based composite material test piece 5. The two ends of the sliding support frame 3 can be slid and fixed on the outer metal bracket 11 by the high-temperature slider 12, and the sliding support frame 3 can move along the metal bracket 11, which is suitable for fixing test pieces of different lengths. The other end of the carbon fiber resin-based composite material 5 is placed on the support slide 7, and the sliding clamps 6 at both ends of the moving support slide 7 are adapted to test pieces of different lengths, and the threaded push rod on the rotating sliding clamp 6 is adjusted to be suitable for carbon fiber resin-based composite material test pieces of different thicknesses.

Since the fixture designed by the present invention is suitable for modal data acquisition in high-temperature thermal environments. The sliding support frame 3 is locked and connected to the support plate 2 by high-temperature bolts. The support plate 2 is perforated with an infrared radiation heating array 1. The other end of the infrared radiation heating array 1 is perforated and placed on the sliding support plate 10. The two support plates fix the infrared radiation heating array 1. The infrared radiation heating array 1 provides a high-temperature thermal environment of more than 1000°C for the upper surface of the carbon fiber resin-based composite material test piece 5. The thin-film armored thermocouple 4 passes through the middle elliptical hole grooves at both ends of the sliding support frame 3 and is attached to the upper and lower surfaces of the carbon fiber resin-based composite material test piece 5 to measure its temperature. The exciter 13 is connected to the support slide 7 through the high-temperature ceramic rod 8 through the high-temperature baffle 9, and the random excitation signal is transmitted to one end of the carbon fiber resin-based composite material test piece 5, realizing the coupled simulation of the thermal-mechanical-vibration environment during the actual flight process.

The middle part of the crossbeam of the sliding support frame can clamp a carbon fiber resin-based composite material test piece with a length of 350mm and a thickness of less than 10mm. The other end can be fixed by the two ends of the sliding clamp and the high-temperature threaded top rod can be adjusted with variable thickness. The exciter provides random excitation to one end of the carbon fiber resin-based composite material test piece through a high-temperature ceramic rod, ensuring stable clamping and vibration without destroying the integrity of the carbon fiber resin-based composite material, thereby improving the accuracy of high-temperature vibration modal parameter testing.

Since the present invention can provide accurate modal testing without destroying the structure of the carbon fiber resin-based composite material test piece, the two ends of the carbon fiber resin-based composite material test piece 5 are stably clamped by the sliding support frame 3 and the sliding clamp 6 on the supporting slide 7. By adjusting the exciter 13, random signals such as sine and impact blasting are applied, and the supporting slide 7 is connected to the carbon fiber resin-based composite material test piece 5 through the ceramic rod 8 to provide a fixed frequency or swept frequency test to ensure that the first five modal frequencies of the carbon fiber resin-based composite material test piece 5 occur normally, and the high-temperature vibration modal parameters of the carbon fiber resin-based composite material test piece 5 are obtained with the help of software processing.

The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above technical features.

Claims (8)

1. A high-temperature vibration modal fixture for carbon fiber resin-based composite materials, characterized in that it comprises an infrared radiation heating array (1), a support plate (2), a sliding support frame (3), a thin-film armored thermocouple (4), a carbon fiber resin-based composite material test piece (5), a ceramic rod (8), a sliding support plate (10), a metal bracket (11), a high-temperature slider (12), an exciter (13) and a high-temperature threaded push rod (14); the sliding support frame (3) is slidably connected to the metal bracket (11) through the high-temperature slider (12); the support plate (2) is arranged on the sliding support frame (10 ... One end of the support frame (3); a hole groove is provided at the upper end, one end of the infrared radiation heating array is fixed in the hole groove of the support plate (2) and the other end is fixed on the hole groove of the sliding support plate (10); a carbon fiber resin-based composite material test piece (5) is arranged on the sliding support frame (3) and one end is connected to the sliding fixture assembly; the upper and lower surfaces of the carbon fiber resin-based composite material test piece (5) are both in contact with the thin-sheet armored thermocouple (4); the thin-sheet armored thermocouple (4) is externally connected to a temperature collector; and the exciter (13) is connected to the sliding fixture assembly via a high-temperature ceramic rod (8). 2. The high-temperature vibration modal fixture of carbon fiber resin-based composite materials according to claim 1 is characterized in that: the sliding fixture assembly comprises a supporting slide groove (7) and a sliding fixture (6); sliding fixtures (6) are slidably provided at both ends of the supporting slide groove (7); and a threaded push rod is rotatably provided at the top of each sliding fixture (6). 3. The high-temperature vibration modal fixture of carbon fiber resin-based composite materials according to claim 1 is characterized in that: a bolt hole is opened on the sliding support frame (3), and adjustment grooves are provided at both ends of the support plate (2); wherein the adjustment bolt passes through the adjustment groove and is locked in the bolt hole. 4. The carbon fiber resin-based composite material high temperature vibration modal fixture according to claim 1, characterized in that the exciter (13) is located inside the high temperature baffle (9). 5. The carbon fiber resin-based composite material high temperature vibration modal fixture according to claim 1, characterized in that the sliding support plate (10) is slidably arranged on the metal bracket (11). 6. The high temperature vibration modal fixture of carbon fiber resin-based composite materials according to claim 1 is characterized in that: a rectangular hole with a length of 350 mm and a height of 10 mm is opened in the middle of the crossbeam of the sliding support frame (3), and a bracket is provided at the lower end of the rectangular hole. A high temperature threaded push rod is opened on the bracket every 40 mm to support the bottom of the carbon fiber resin-based composite material test piece (5). 7. The carbon fiber resin-based composite material high temperature vibration modal fixture according to claim 1, characterized in that: the two ends of the high temperature armored thermocouple (4) are respectively fixed in the elliptical hole grooves on the sliding support frame (3). 8. The carbon fiber resin-based composite material high temperature vibration modal fixture according to claim 1, characterized in that: the high temperature ceramic rod (8) has a diameter of 10 mm and a length of 250 mm, and is integrally penetrated and fixedly connected to the support slide groove (7).