Experimental device for testing dynamic shearing mechanical property of fiber monofilament interface

Abstract

The utility model provides an experimental device for testing the dynamic shearing mechanical property of a fiber monofilament interface. The experimental device comprises a loading part, a clamping part, a testing part and an adjusting part, the loading part comprises a sleeve bullet, a flange, an electromagnetic driving device and an absorbing device; the clamping part comprises an incident rod, a clamp, a single-axis displacement platform, a sample, a transmission rod, a first bracket and a second bracket; the testing part comprises a PDV speed measuring device, a support and a strain gauge; the adjusting part comprises a microscope, a connecting rod, a universal table base and a base. According to the utility model, dynamic shearing of materials is realized in a high-strain-rate state.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of dynamic mechanical property testing equipment, specifically relates to an experimental device for the dynamic shear mechanical property test of fiber monofilament interface. BACKGROUND

[0002] Fiber composite materials are widely used in aerospace and other fields, and deep space probes are faced with high-speed operation and complex environmental temperature, and the dynamic problem of the interface bonding between fiber monofilament and resin must be solved in the macroscopic process of the composite material, therefore, it is urgent to clarify the micromechanical influencing factors of the dynamic behavior of the fiber and resin interface. The research on the interface mechanical property of the fiber mainly adopts microdroplet embedding static mechanical test technology, but due to the difficulty in the dynamic mechanical property experiment technology of the fiber monofilament, the research on the interface dynamic deformation and rate-related failure mechanism of the fiber monofilament and resin is still lacking. Therefore, the development of the equipment for testing the dynamic shear strength between the interfaces of different materials is the key to promoting these researches.

[0003] The traditional mechanical property test means of fiber-resin composite material mainly depends on the research on the mechanical property of the whole composite material, and the interface strength between materials cannot be evaluated, and the mechanical behavior of the microcosmic interface of the new type of fiber and resin directly determines the dynamic characteristics of the macroscopic composite material. Based on the microscale characteristics of the fiber monofilament and the difficulty in the interface dynamic mechanical experiment design, the current research mainly concentrates on the dynamic tensile mechanical property of the fiber monofilament and the research on the transverse mechanical characteristics, and in the process of the structural protection application of the new type of fiber composite material, the dynamic problem of the interface between the fiber monofilament and the resin will inevitably exist. CONTENT OF THE UTILITY MODEL

[0004] In order to solve the above technical problems, the utility model provides an experimental device for the dynamic shear mechanical property test of fiber monofilament interface, which realizes the dynamic shear of the material under the condition of high strain rate.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] An experimental device for testing the dynamic shear mechanical properties of fiber monofilament interface, comprising a loading part, a clamping part, a testing part and an adjusting part; the loading part comprises a sleeve bullet, a flange, an electromagnetic drive device, an absorption device; the clamping part comprises an incident rod, a clamp, a single-axis displacement platform, a sample, a transmission rod, a first support, a second support; the testing part comprises a PDV speed measuring device, a support, a strain gauge; the adjusting part comprises a microscope, a connecting rod, a gimbal base, a base; the PDV speed measuring device is installed on the support; the support is installed on the base; the first support is installed on the single-axis displacement platform; the single-axis displacement platform is installed on the base; the second support is installed on the base; the laser of the PDV speed measuring device is aligned with the center of the transmission rod; the sample is composed of a sample card, a fiber and a polymer droplet, the polymer droplet is attached to the fiber, the fiber with the polymer droplet is bonded to the sample card, one end of the sample card is clamped to the chuck of the transmission rod, and the other end of the fiber with the polymer droplet is clamped to the clamp, the microdroplet is clamped in the clamping groove of the clamp by adjusting the single-axis displacement platform; the clamp is fixed on the incident rod; the incident rod is fixedly installed on the second support; the transmission rod is fixedly installed on the first support; the electromagnetic drive device is fixedly installed on the base; the sleeve bullet is fixedly installed between the electromagnetic drive device and the incident rod; the flange is fixedly installed between the incident rod and the absorption device; the absorption device is installed on the base; the microscope is connected to the gimbal base through the height-adjustable connecting rod; the gimbal base is installed on the base; the strain gauge is attached to the incident rod.

[0007] Further, the PDV speed measuring device comprises a laser, a Doppler interferometer and an oscilloscope; the laser generates incident light, the Doppler interferometer is used for measuring frequency shift, and the oscilloscope is used for displaying and analyzing signals;

[0008] Further, the sample is located in the center of the field of view of the microscope.

[0009] Further, the microscope is used for observing the deformation morphology of the sample after shearing

[0010] The specific working principle is:

[0011] The new concept proposed in the design of this utility model is mainly to calculate the displacement of the droplet by measuring the overall displacement of the fiber-polymer interface and the individual displacement of the fiber, making the data results more accurate. In addition, the device is a dynamic device and can be used under high strain rate conditions. The device uses a laser Doppler PDV speed measurement device for measurement, which is mainly composed of a laser, a Doppler interferometer, an oscilloscope, etc. The laser generates incident light, the Doppler interferometer is used to measure the frequency shift, and the oscilloscope is used to display and analyze the signal. The laser emitted by the laser irradiates the moving object, and after the light is reflected by the object, its frequency changes due to the Doppler effect. These changing frequency signals are detected by the Doppler interferometer and analyzed by the oscilloscope. When the object moves at high speed, it will produce a Doppler frequency shift to the incident laser. This frequency shift is proportional to the speed of the object. By measuring this frequency shift, the speed of the object can be calculated.

[0012] The calculation formula of the Doppler effect can be expressed as:

[0013] ;

[0014] in, , is the observer's velocity, c is the wave speed, is the calculated frequency, is the frequency.

[0015] Beneficial effects:

[0016] (1) The design principle of the utility model is simple and easy to implement;

[0017] (2) The utility model adopts a single-axis displacement platform, which can realize displacement control and meet the requirements of the micro-droplet being stuck in the card slot;

[0018] (3) The present invention adds a microdroplet test, and by measuring the overall displacement of the fiber-polymer interface and the individual displacement of the fiber, the displacement of the microdroplet is calculated, making the data results more accurate;

[0019] (4) The utility model adopts an electromagnetic drive device to fire the bullet, which has fast firing, low noise, high efficiency and reasonable mechanical structure;

[0020] (5) The utility model adopts PDV velocity measurement technology, and uses a high-precision piezoelectric sensor combined with PDV velocity measurement technology to measure the transmission wave signal, making the measurement result more accurate.

[0021] (6) The utility model is equipped with a microscope, which can observe the morphology of the sample after shearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1The utility model discloses a schematic view of experimental device for dynamic shear mechanical property test of fiber monofilament interface.

[0023] Figure 2 It is the fiber and microdrop contact part diagram;

[0024] Figure 3 It is the device whole connection drawing;

[0025] Figure 4 It is the contact part section view.

[0026] In the drawing: 1 - incident rod;2 - PDV speed device;3 - clamp;4 - single - axis displacement platform;5 - sleeve bullet;6 - flange;7 - sample;8 - transmission rod;9 - electromagnetic drive device;10 - absorption device;11 - microscope;12 - connecting rod;13 - gimbali base;14 - base;15 - strain gauge;16 - first support;17 - second support;18 - support. DETAILED DESCRIPTION

[0027] In order to make the utility model purposes, technical scheme and advantages more clearly, following combining with the drawing and example, the utility model is further detailedly explained.The specific example described here is only used to explain the utility model, and is not used to limit the utility model.In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict.

[0028] As Figures 1-3 The utility model discloses a experimental device for dynamic shear mechanical property test of fiber monofilament interface includes loading part, clamping part, test part and adjustment part.The loading part includes sleeve bullet 5, flange 6, electromagnetic drive device 9, absorption device 10;The clamping part includes incident rod 1, clamp 3, single - axis displacement platform 4, sample 7, transmission rod 8, first support 16, second support 17;The test part includes PDV speed device 2, support 18, strain gauge 15;The adjustment part includes microscope 11, connecting rod 12, gimbali base 13, base 14.

[0029] The PDV speed device 2 is mainly composed of laser, doppler interferometer, oscilloscope etc.Laser generates incident light, and doppler interferometer is used to measure frequency shift, and oscilloscope is used to display and analyze signal.The laser emitted by laser is irradiated to moving object, and the frequency of light is changed due to doppler effect after being reflected by object.These changed frequency signals are detected by doppler interferometer and are analyzed through oscilloscope.Through these signals, the speed of object can be calculated.

[0030] During the experiment, the probe is aimed at the test surface to collect the laser signal reflected from the specimen surface. The reflected light signal can be used to analyze the particle velocity on the specimen surface. The PDV speed measuring device 2 is mounted on the support 18; the support 18 is mounted on the base 14; the first bracket 16 is mounted on the uniaxial displacement platform 4; the uniaxial displacement platform is mounted on the base 14; the second bracket 17 is mounted on the base 14; the laser of the PDV speed measuring device 2 is aligned with the center of the transmission rod 8; the sample 7 is composed of a sample card, fibers and polymer droplets, and the polymer droplets are attached to the fibers. The fibers with polymer droplets are bonded to the sample card, and one end of the sample card is clamped to the clamp of the transmission rod 8, and the fibers and polymer droplets at the other end are clamped to the fixture 3. The droplets are clamped in the card slot of the fixture 3 by adjusting the uniaxial displacement platform 4; the clamp The tool 3 is fixed on the incident rod 1; the incident rod 1 is fixedly mounted on the second bracket 17; the transmission rod 8 is fixedly mounted on the first bracket 16; the electromagnetic drive device 9 is fixedly mounted on the base 14; the sleeve bullet 5 is fixedly mounted between the electromagnetic drive device 9 and the incident rod 1; the flange 6 is fixedly mounted between the incident rod 1 and the absorption device 10; the absorption device 10 is mounted on the base 14 to absorb the energy of the bullet and avoid multiple loading of the incident rod by the wave reflected from the right end; the microscope 11 is connected to the universal stage base 13 through a height-adjustable connecting rod 12; the universal stage base 13 is mounted on the base 14; the strain gauge 15 is pasted on the incident rod 1.

[0031] The electromagnetic drive device 9 is an existing device that can use electromagnetic effect to drive the movement of the sleeve bullet 5, so it is not described in detail.

[0032] The absorption device 10 is an existing device that can absorb energy, so it is not described in detail.

[0033] The experimental process is as follows:

[0034] Before the experiment begins, the PDV velocity measuring device 2 is mounted on the support 18, the first bracket 16 is mounted on the uniaxial displacement platform 4, and the uniaxial displacement platform 4 is mounted on the base 14. The sample 7 is placed on the chuck, and the position of the uniaxial displacement platform 4 is adjusted so that the droplet is stuck in the groove. The height-adjustable connecting rod 12 is adjusted to center the sample 7 in the field of view of the microscope 11. The focus of the microscope 11 is adjusted by adjusting the universal stage base 13.

[0035] After the experiment begins, the PDV velocimeter 2 and strain gauge 15 measure the signals during the shearing process of specimen 7. A charge amplifier transmits the output signals of the PDV velocimeter 2 and strain gauge 15 to an oscilloscope, where two waveforms appear. The waveform corresponding to the strain gauge serves as a reference, allowing the accuracy of the PDV velocimeter 2 to be determined. The oscilloscope image provides a voltage-time curve for the shearing of the specimen.

[0036] The total displacement of the fiber-polymer interface is measured after shearing, and the displacement of the droplet is calculated. By testing the mechanical properties of the fiber, the dynamic mechanical properties of the fiber can be obtained, and thus the individual displacement of the fiber can be known. The displacement of the droplet can be obtained by subtracting the individual displacement of the fiber from the total displacement of the fiber-polymer interface, as shown in Figure 4 Figure 2.

Claims

1. An experimental device for testing the dynamic shear mechanical properties of fiber monofilament interfaces, characterized in that: It includes a loading part, a clamping part, a testing part and an adjusting part; the loading part includes a sleeve bullet, a flange, an electromagnetic drive device, and an absorption device; the clamping part includes an incident rod, a fixture, a uniaxial displacement platform, a sample, a transmission rod, a first bracket, and a second bracket; the testing part includes a PDV speed measuring device, a support, and a strain gauge; the adjusting part includes a microscope, a connecting rod, a universal table base, and a base; the PDV speed measuring device is installed on the support; The support is installed on the base; the first bracket is installed on the uniaxial displacement platform; the uniaxial displacement platform is installed on the base; the second bracket is installed on the base; the laser of the PDV speed measuring device is aligned with the center of the transmission rod; the sample consists of a sample card, fiber and polymer droplets, the polymer droplets are attached to the fiber, the fiber with polymer droplets is bonded to the sample card, one end of the sample card is clamped to the clamp of the transmission rod, and the fiber and polymer droplets at the other end are clamped to the fixture, and the droplets are clamped in the card slot of the fixture by adjusting the uniaxial displacement platform; the fixture is fixed on the incident rod; the incident rod is fixed on the second bracket; the transmission rod is fixed on the first bracket; the electromagnetic drive device is fixed on the base; the sleeve bullet is fixed between the electromagnetic drive device and the incident rod; the flange is fixed between the incident rod and the absorption device; the absorption device is installed on the base; the microscope is connected to the universal stage base through a height-adjustable connecting rod; the universal stage base is installed on the base; the strain gauge is pasted on the incident rod.

2. The experimental device for testing the dynamic shear mechanical properties of fiber monofilament interfaces according to claim 1, characterized in that: The PDV speed measuring device includes a laser, a Doppler interferometer, and an oscilloscope; the laser generates incident light, the Doppler interferometer is used to measure frequency shift, and the oscilloscope is used to display and analyze signals.

3. The experimental device for testing the dynamic shear mechanical properties of fiber monofilament interfaces according to claim 1, characterized in that: The specimen is located in the center of the microscope's field of view.

4. The experimental device for testing the dynamic shear mechanical properties of fiber monofilament interfaces according to claim 1, characterized in that: The microscope is used to observe the deformation morphology of the sample after shearing.

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