CN110146394A - Material properties shock acoustic response test simulation system - Google Patents

Abstract

An acoustic response impact test system for material properties, which consists of three parts: impact system, data acquisition and data analysis. The impact system is composed of a pressure trigger, impact warhead, impact rod and sample chamber, which implements impact on materials and generates audio signals. The data acquisition system is composed of pressure sensors, speed sensors, audio sensors, etc., and collects the sound information generated by the impact; the data analysis system is composed of computers, oscilloscopes and other terminals, which process and analyze data through software. The feature of the present invention is to implement the impact response test of the material, through the audio characteristic test of the sound generated when the material is impacted, to measure the structure, damage, yield strength, failure strength, acoustic elastic modulus, hardness and density of the material and other parameters. The invention is applicable to the quantitative test of the dynamic characteristics of various hard material structures and strengths.

Description

Material properties shock acoustic response test simulation system

technical field

The invention relates to an acoustic test system for material structure and strength characteristics, a test technology for hard materials such as rocks, which can perform impact acoustic response tests on materials on a laboratory test platform, and determine the material's performance according to the acoustic response characteristics. structure and strength. It belongs to the field of rock mechanics and material testing.

Background technique

For testing the strength characteristics of materials, material testing machines are usually used to obtain the strength parameters of materials through compression, tension, shearing and other tests. For example, testing of material compressive strength, tensile strength, shear strength and hardness, testing of material density and moisture content, etc.

Material strength testing in the laboratory requires specimen processing and testing in accordance with certain standards. The processing and testing process of the test piece must strictly abide by certain standards, and it is a destructive experiment, so it is difficult to conduct direct non-destructive testing on the product. Moreover, the test results are affected by the processing accuracy of the sample, the loading rate and the characteristics of the testing machine, so the results have large errors and poor consistency.

When testing the material structure, in addition to microscopic detection and analysis such as electron microscope, scanning electron microscope, transmission electron microscope and various ray instruments, the comparative experiment of sound wave velocity is usually carried out to investigate the integrity of the material structure. However, these testing methods have the following problems: (1) independent testing is required, and it is difficult to test the structure and strength of the material at the same time; The sample and surface treatment procedures are complicated, the preparation time is long, and it is difficult to detect the internal structure of the material; (3) To judge the structural characteristics of the material through the sound wave/ultrasonic test, the input-output measurement of the signal wave is required, and the structure cannot be determined. composition and size.

Among the existing material dynamics test systems, split Hopkinson bar (SHPB), Schmidt hammer and pendulum test are typical material dynamics impact test systems. Among them, SHPB has become a standard test method for material dynamics. These impact test methods provide the technical basis for the impact simulation of the present invention.

The present invention establishes a rock material characteristic impact acoustic response testing system, which performs progressive impact testing on materials on a laboratory impact platform, and measures the impact velocity and impact energy of the warhead and the impact rod, as well as the audio characteristics of the collision between the impact rod and the sample. Through testing and analysis, the strength and structure of the loaded material are determined under the condition of no damage to the sample.

Contents of the invention

The purpose of the present invention is to establish a comprehensive test system for the impact audio response of material properties, which can perform impact tests under certain progressive cyclic loads, and realize material structure and strength characteristic tests based on audio properties. The use of progressive cyclic loading overcomes the contingency of a single impact, and the error can be statistically corrected through multiple experiments. At the same time, due to the progressive impact, the impact damage to the material in the experiment is reduced, and the material characteristic test under almost non-destructive conditions can be realized. Through the relationship between progressive impact velocity, impact energy and audio amplitude, loudness, frequency and its composition, the relationship model between material strength and structure and audio characteristics is established, and then the static strength of the sample and its composition are determined through calibration.

The invention relates to a shock audio response test system for material structure and strength characteristics, which includes a shock system, a data acquisition system and a data analysis system. Among them, the shock system is a shock launch system that applies high-speed dynamic loads to materials. The data acquisition system measures the working parameters of the shock system and the audio characteristics generated by the impact through various sensor technologies. The working parameters of the shock system include shock pressure and shock velocity; the audio characteristics include the frequency, amplitude, volume and power spectral density of sound waves , and perform signal amplification and A/D conversion, and transmit the data to the data analysis system after integration. The data analysis system performs data analysis, storage and output through oscilloscopes, computers and other terminals and data analysis software.

The impact testing system is used for applying impact load to the material to be tested. The impact rod obtains a certain impact velocity under the action of the bullet, hits the end face of the sample and produces an impact sound. After the impact, the experimental rod rebounds under the reaction force of the end face and breaks away from the end face of the sample to complete an impact. The system consists of a test platform, a pressurization mechanism, a pressure trigger, an impact rod, a sample chamber and its fixtures. The system test platform is a horizontal rigid support that is fixed and installed directly on the level ground. The pressurizing mechanism, the pressure trigger and the striking rod are fixedly installed on the system platform through the bracket, and the striking rod is a solid circular section rod with a shoulder. The pressure trigger is composed of a pressure source, a pressure regulator, and a launch switch. The striking rod system is composed of a warhead and a striking rod. The pressure source is compressed air, which is generated by an air compressor; the sample chamber is used to carry the sample, and the size and shape of the chamber can be adjusted according to the shape and specification of the sample.

The data acquisition system is composed of a pressure sensor, a speed sensor, an audio sensor, an amplifier, a data A/D conversion box, a digital dynamic strain gauge and a data integration box, and converts and digitizes the received sensing data signal integrated. The audio sensor collects information such as the frequency, amplitude, volume (loudness) and sound wave power spectrum of the audio signal.

The data analysis system transmits the converted and digitally integrated data to the data analysis system such as a computer, an oscilloscope, etc. for storage, analysis and output through a data interface and a cable, and analyzes the impact parameters and the structure and strength of the material, etc. Features are analyzed, evaluated, stored and output.

The operating voltage of the air compressor is 380V.

The working voltage of the digital dynamic strain gauge is 220V.

The working voltage of the laser and infrared photoelectric speed sensor is 220V.

The working voltage of the data integration box is DC12V.

The beneficial effect of the present invention is that, due to the adoption of the above technical solution, on the one hand, the relationship between the structural characteristics of the test material and the audio characteristics generated by the impact. By testing the audio characteristics generated by the impact sample material, analyzing the sound frequency and its composition, amplitude, sound intensity (loudness) and sound wave power spectrum, the quantitative test of the structural properties of the material can be realized, and the degree of development of joints and fissures in hard materials such as rocks can be determined. Structural integrity and compactness, to determine the defects or damage of metal materials such as holes and micro-cracks. On the other hand, test the relationship between material strength and other characteristics and audio characteristics, realize the test of material strength and other characteristics, and analyze and determine the yield strength, failure strength and acoustic elastic modulus of materials such as rocks by testing the audio characteristics generated by impact , hardness, density and moisture content parameters, to determine the strength, hardness and density parameters of metal materials.

Description of drawings

Fig. 1 is a system configuration diagram of the present invention.

Fig. 2 is a connection diagram of the pressure sensor in Fig. 1 .

Fig. 3 is a layout diagram of the speed measuring sensor in Fig. 1 .

Fig. 4 is a layout diagram of the sample chamber in Fig. 1 .

Fig. 5 is a layout diagram of the test system in Fig. 1 .

As shown in the figure, 12DC.12 volt DC power supply, I. input, O. output, 1-compressed air source; 2-voltage regulator; 3-pulse transmitter; 4-infrared light source; 5-directional sleeve; 6 -shoulder impact rod; 7-audio sensor; 8-laser source; 9-sample chamber; 10-rigid fixed end; 11-laser receiver; 12-amplifier; 13-infrared receiver; 14-pressure sensor; -amplifier; 16-digital-analog A/D converter; 17-dynamic strain gauge; 18-data integration box; 19-analysis terminal; 20-pressure switch; 21-pressure gauge; 22-connector; 23-signal cable 24-laser beam; 25-signal cable; 26-sample mold cover; 27-sample; 28-sample hatch cover hole; 29 sample hatch cover; I-I and II-II laser beam through hole.

The system is installed on the horizontal rigid test platform in the laboratory, which is used to impact the material and test the audio and material characteristic parameters of the impact process.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

In the embodiment of Fig. 1, the system mainly consists of three parts: (i) impact system; (ii) data acquisition system and (iii) data analysis system. The impact system consists of a pressure trigger, an impact warhead, an impact rod and a sample chamber. The pressure trigger is composed of a pressure generator, a pressure regulator, a trigger switch and a launch tube. The pressure generator is a pressure source for generating compressed air, driven by 380V alternating current. A warhead is installed in the launch tube. The warhead is a cylindrical short rod, which forms an impact system together with the impact rod and the directional sleeve. shock. The data acquisition system is composed of pressure sensor, speed sensor, audio sensor, amplifier, data A/D conversion box, dynamic strain gauge and data integration box, which amplifies and converts the induction signal, transmits it to each terminal and stores it; the data analysis system consists of Composed of various terminals such as computers, oscilloscopes and iPads, data analysis, display, storage and printing are performed through special software or commonly used office software such as EXCEL.

In the embodiment of Fig. 1, the data acquisition system is installed on the experimental workbench, and the data collected by the impact system and the test system are amplified, converted, integrated and informationally transmitted.

In the embodiment of Fig. 1, a pressure sensor is arranged to measure the compressed air pressure output by the pressure source through the pressure regulator, which is the firing pressure of the pressure trigger.

The velocity sensor is used to measure the impact velocity of the warhead and the impact rod.

The two speed sensors are connected to the data integration box through cables. After the data is integrated, it is sent to data analysis terminals such as computers, oscilloscopes and iPads by the integration box.

The data acquisition system is composed of the above-mentioned various sensors, amplifiers, conversion boxes, digital dynamic strain gauges and data integration boxes. Among them, the amplifier is a typical Wheatstone Bridge (Wheatstone Bridge) preamplifier, which is used to amplify audio signals and voltage signals. The converter A/D converts the analog data collected by the pressure and audio sensors into digital signals. The present invention adopts the Japanese CSW-5A converter, which is connected with the digital strain gauge through the CR-655 interface cable. The digital dynamic strain gauge converts the pressure analog signal input by the CSW-5A conversion box into a digital signal. The present invention uses a NicoletSigma 90 (Digital Oscilloscope workstation) digital dynamic strain gauge to input data into the data integration box ( Date Integrated Box). The data integration box will integrate the input information of the impact system test and input it to the terminal equipment through the CR-553B interface cable.

In the embodiment of Fig. 2, a schematic diagram of the installation of the pressure sensor is given.

The pressure sensor 14 is installed at an appropriate position in the pressure regulator pipeline, generally in front of the pressure gauge 21 in the input I-output O circuit. When the pressure fluid is input into the transmitter pipeline, it passes through the pressure valve 20, the pressure gauge 21 and The sensor 14 is input to the pressure pipeline where it is located, and the sensor 14 is connected to the pipeline through the joint 22. When the pressure fluid passes through the pressure sensor 14, the pressure acts on the piezoresistive sheet on the sensor, deforming it so that the resistance, current or voltage, etc. The electrical signal changes. The electrical signal is transmitted to the data acquisition system through the data cable 23 through the interface. The present invention adopts British Gems 2200/2600 sensor series, and the measuring range of each pressure sensor is 0.01-25.0MPa.

In the embodiment of FIG. 3 , the present invention uses an infrared velocity sensor to measure the impact velocity of the warhead 3 . The light 24 emitted by the infrared emitting head 4 passes through the space between the projectile 3 of the launch tube and the impact rod 6, and is received by the receiver 13 of the infrared sensor. When the pressure trigger is triggered, the projectile 3 in the launch tube is launched at a certain speed along the The tube emits and cuts the infrared beam 24, the receiver 13 generates a photoelectric pulse, the signal is transmitted to the data acquisition system through the cable 25, and then transmitted to the analysis system by the acquisition system, and the warhead cutting rate is calculated according to the width and pulse time set by the infrared. The infrared speed sensor is installed horizontally, and the light is perpendicular to the axis of the emission tube.

The impact rod 6 obtains a certain speed under the impact of the warhead 3, moves forward along the central sleeve hole 28 on the directional sleeve 5 and the sample hatch cover 29, and hits the left end surface of the sample 27. The sample 27 is installed in the sample mold cover 26, and the sample cabin 9 is installed horizontally on the rigid fixed end 10. The rigid fixed end 10 is a mass block, which can be connected with the test platform or installed independently, and its function is to absorb the energy from the sample. Horizontal axial momentum of cabin 9. To reduce friction between the socket and striker rod, apply a thin coat of petroleum jelly or butter to the socket and rod.

The invention adopts a point laser speed measuring sensor to measure the speed of the striking rod. Two laser velocity sensors are arranged at a certain interval (I-II) along the busbar of the sample compartment to measure the impact velocity of the impact rod 6 . The laser beam emitted by the laser source 8 passes through the central sight holes I-I and II-II on the sample chamber 9, and is received by the laser receiver 11. When the striking rod 6 is hit by the warhead 3, the striking rod 6 moves along the test path at a certain speed. The center hole 28 of the sample hatch cover 29 impacts the sample 27, the impact rod 6 cuts the laser beams in I-I and II-II, the receiver 11 generates a photoelectric pulse, and the signal is transmitted to the data integration box 18 of the data acquisition system through a cable. Then it is transmitted to the analysis system, and the impact rate of the impact rod is calculated according to the spatially set spacing and pulse time. In order to reduce the impact of the laser on the human body, the laser speed sensor is installed vertically, and the light is perpendicular to the axis of the sample chamber.

The invention adopts an audio sensor to measure the audio characteristics produced by the striking rod impacting the sample. The audio sensor 7 is installed at an appropriate position inside the sample compartment cover plate 19 to measure parameters such as the frequency, amplitude, intensity (volume/loudness) and power spectral density of the sound when the sample 27 in the sample compartment is impacted by the impact rod 6 , the output of the audio signal adopts a socket connection, and the cable is connected to the A/D converter 16 through a plug. The sample hatch cover 29 and the sample cabin 9 are airtight embedded connections, and the airtight ring is a car door type rubber ring, and the cover plate and the rubber ring can be easily disassembled. The hatch cover 29 is a double-layer structure, and its inner layer is a sound-absorbing material, which has a sound-absorbing effect; the outer layer is a metal plate, which has a sound-insulating effect. The present invention adopts three audio sensors, which are arranged at equal intervals along a certain circumferential radius on the inner cover plate.

The invention adopts a video sensor to monitor the impact process of the impact rod. The video sensor is integrated with the audio sensor 7 to provide visual information of the impact process as an auxiliary means, which is transmitted to the data analysis system synchronously with the audio information, and finally transmitted to the analysis terminal 19 .

In the embodiment of Fig. 4, the sample cabin 9 is a rigid cylindrical cylinder with a certain thickness, and its base is connected with the rigid fixed end 10, and the sample mold cover 26 can be installed in the sample cabin 9 according to the sample specification, and the mold cover The outer cylinder of 26 is meshed with the inner cylinder of the sample chamber 9, and the sample 27 is installed in the mold cover. The axiality shall meet the requirements of relevant material testing. Depending on the test requirements, different die sleeve inner diameters and sample sizes are available. The axial length of the sample chamber 9 is greater than the length of the sample mold case 26, and the excess length should meet the impact distance requirement of the impact rod when the sample impacts. When conducting destructive impact tests, the safety protection requirements for specimen rupture should also be met. After the test platform and system are determined, the impact limit distance is limited by the position and length of the shoulder of the impact rod 6 .

In the embodiment of Fig. 5, the arrangement of the present invention is shown.

The compressed air source 1 is an air compressor, which is generally arranged in a sound-proof space far away from the test site. The compressed air is introduced into the room through the pressure pipe network and communicated with the pressure regulator 2. The compressed air pressure is measured by the pressure sensor 14 and passed through The standard pressure gauge of the pressure regulator 2 is calibrated. The pressure sensor 14 is connected to the A/D converter 16 through the amplifier 15 and connected to the strain gauge 17 . The pulse emitter 3, the directional conduit 5, the impact rod 6, the sample hatch cover 29, the sample cabin 9, the sample 27 and the mold cover 26 are located on the same horizontal axis. The infrared speed measuring sensor 4 is installed between the front end of the warhead 3 and the rear end of the impact rod 6, and is communicated with the data integration box 18 by the output end of the infrared receiver 13. The audio (video) sensor 7 is arranged on the inner side of the cover plate 29 of the sample cabin 9, and two laser sensors 8 are vertically arranged between the front end of the striking rod 6 and the rear end face of the sample 27, the axis of the laser hole and the sample cabin The axis of 9 intersects and forms a vertical plane orthogonal to the axis of striking rod 6. Laser sensor, laser receiver and sample chamber are non-contact installation. The signals collected by the above pressure, impact velocity and audio sensors are integrated in the data integration box 18 and then output to the analysis terminal 19 of the data analysis system.

In the present invention, the amplifier 12, the amplifier 15, the A/D conversion, the strain gauge 17 and the data integration box 18 can be integrated, and they are listed separately in the present invention for the convenience of expression.

The basic principle of the present invention is to establish a material impact response audio characteristic testing system by adopting impact rod system, sensor technology, audio (video) technology and digital integration technology, impact the material sample surface through the impact system, and use infrared and laser The speed measuring sensor measures the speed of the warhead and the impact rod, and analyzes and determines the speed and energy transfer efficiency of the impact system; the audio sensor is used to measure the frequency, amplitude, sound pressure, volume and power spectral density of the sound that occurs when the material is struck. Audio characteristics. Since the audio characteristics that occur during impact are related to the properties, material composition, structure, hardness, and compressive strength of the impacted material, the impact volume, frequency, amplitude, and sound pressure, etc. Change relationship, determine the acoustic elastic modulus, yield strength and failure strength of the material; obtain the frequency and its composition, the power spectral density change relationship with the impact energy, analyze and determine the initial structure of the material and the evolution process of the structure, and analyze the internal structure of the material estimate the extent of damage. The present invention is characterized in that the requirements for sample processing are not strict, only the impact surface is flat and smooth, and easy to process; in addition, the test is non-destructive and repeatable.

Claims (3)

1. a kind of material property impacts acoustics response test simulation system, which is characterized in that the system includes impact system, data Acquisition system and data analysis system；

The impact system includes pressure trigger, impact bullet, trip rod and sample cabin composition.Pressure trigger is sent out by pressure Raw device, pressure regulator, trigger switch and transmitting tube composition.Pressure generator is the pressure source for generating compressed air.Peace in transmitting tube Equipped with bullet, bullet is a cylindrical quarter butt, collectively forms impact system with trip rod, orientation casing, pressure trigger Triggering is calmed the anger, and high speed pushes the bullet shock bar in transmitting tube, completes the impact to sample material in sample cabin.It is main Sound when feature is trip rod and sample shock occurs in closed sample cabin, is disturbed and is designed using anti-ambient noise, had Sound absorption, insulation against noise and vibration effect, are dissipated after being acquired by sound transducer by noise elimination structure.

The data collection system by pressure sensor, velocity sensor, audio sensor, amplifier, data A/D boxcar, Dynamic strain indicator and data integration box composition, inductive signal is amplified and is converted, be transferred to each terminal and store.It is special Point is to carry out separating test to the impact velocity of bullet and trip rod, it may be determined that the transmission efficiency of impact energy；Meanwhile passing through design Acoustic characteristic parameter when can hit to material carries out independent test, not by environmental perturbation.

The data analysis system is made of various terminals such as computer, oscillograph and iPad, by special-purpose software or common is done Public software such as EXCEL etc. carry out data processing and to the structure and physico mechanical characteristic of material carry out acoustic response analysis, display, Storage and printing can carry out the transmission of data by infrared, bluetooth, wired and Wifi etc..

2. material property according to claim 1 impacts acoustics response test system, it is characterized in that: implementing to material progressive Formula circulation impact, the structure of the acoustic characteristic quantitative measurment material generated when passing through impact material, yield strength, acoustic elasticity mould The parameters such as amount, hardness, density and damage.

3. material property according to claim 1 impacts acoustics response test system, the audio-frequency information generated is impacted, is removed Outside using impact test platform of the present invention, also can be used other shock methods generate audio-frequency information, such as using hand hammer, Schmidt's hammer, pendulum and drop impact.