A fixture and test method suitable for analytical research on penetration process of composite materials

Abstract

A fixture and test method suitable for analytical research on penetration process of composite materials, belonging to the technical field of composite material test equipment. The upper and lower fixed sliders are respectively slidably connected to the groove of the clamping end support, and the upper and lower fixed sliders are fixedly connected to the rear side wall of the groove to clamp and fix the test piece; the rear side wall of the groove is provided with an incident notch, the penetration rod slide is fixed in the penetration rod support, the penetration rod and the penetration rod slide are slidably matched, and the center of the penetration area of ​​the test piece is collinear with the penetration rod and the center of the incident rod; two laser velocimeters are respectively arranged on the outside between the penetration rod support and the clamping end support and on the outside between the incident rod and the penetration rod support; high-speed cameras one and two are respectively aimed at the side of the test piece and the impact section area of ​​the penetration rod, and high-speed cameras three and four are arranged in the back direction of the penetration direction of the test piece; the high-frequency laser displacement meter is aimed at the back of the penetration area of ​​the test piece; the infrared thermal imager is arranged in the side direction of the test piece. The present invention is used for analytical research on penetration process of composite materials.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material testing equipment, and in particular relates to a fixture and a testing method suitable for analytical research on penetration process of composite materials. Background Art

[0002] Multiphase materials composed of two or more components with different properties are called composite materials. Compared with traditional metal materials, carbon fiber reinforced composite materials have the characteristics of high specific strength, high specific modulus, excellent fatigue resistance and corrosion resistance, and are one of the most widely used advanced materials in aerospace and other fields at this stage. However, through dynamic mechanical properties experimental research, it is found that carbon fiber resin-based composite materials are typical strain rate sensitive materials. Under impact loads, especially high-speed penetration, the mechanical properties of the material are significantly different from those under quasi-static loading conditions. Therefore, it is necessary to carry out high-speed penetration tests on typical test pieces of such materials to support the impact resistance research of related application structures under actual service conditions.

[0003] At present, high-speed penetration tests of rigid projectiles on composite materials are usually carried out using typical flat test pieces. The clamping method usually adopts four-sided clamping constraints. During the test, the projectile velocity (residual velocity) is measured to evaluate and analyze the impact resistance of the material, and the effectiveness of the simulation model is verified based on the test results. However, there are some problems with this type of test method: (1) The clamping method of the four-sided clamping constraint makes the geometric dimensions of the typical test piece usually much larger than the geometric dimensions of the projectile. Considering the objective problem of performance discreteness in the preparation process of composite materials, a large number of tests are required to obtain effective test data. The cost of test materials is very high, and it is difficult to prepare composite material in-plane directions (11, 22 directions; 11 direction is defined as the longitudinal direction in the material plane; 22 direction is defined as the transverse direction in the material plane) test pieces that match this type of test fixture. Therefore, it is impossible to carry out research on the penetration process of composite materials in the in-plane direction; (2) Due to the complex failure mechanism of composite material penetration, the current conventional test methods are usually based on the composite material post-impact damage mechanism obtained by non-destructive testing after the test to support the simulation model. However, the rigid projectile penetration test itself has a local effect. There will be serious damage and deformation in the projectile-target contact area, and the degree of damage in the non-contact area will decrease with increasing distance. If the test piece is cut after the test for local damage observation, the original damage morphology will inevitably be destroyed. At the same time, the internal macroscopic damage of the composite projectile flat plate test piece in the projectile-target contact area, such as delamination and cracks, will not be detected in the non-contact area. (3) Unlike metal materials, carbon fiber resin-based composite materials are brittle materials. During the penetration test, a large amount of debris will splash. The use of a velocimeter to measure the residual velocity of the projectile will be seriously disturbed by the debris. At the same time, it is difficult to fully characterize the performance of composite materials under high strain rate loading based only on the projectile velocity (residual velocity). Conventional test methods and fixture designs do not consider real-time synchronous acquisition of strain, displacement (deflection), temperature and other responses of different regions of the composite test piece during the penetration test. (4) Penetration tests usually use light gas guns as dynamic loading devices. For penetrators with irregular geometric shapes (non-circular) punches, they need to be accelerated in the barrel with the help of non-standard cylindrical shell supports. Therefore, it is difficult to achieve stable control of the expected impact posture of the penetrator.

[0004] Therefore, it is of great significance to provide a fixture that is easy to install, has high test efficiency, does not require a specific dynamic loading device (light gas gun) and can effectively reduce the test cost, and a test method that can effectively measure multiple key physical quantities for the analytical research on the penetration process of composite materials. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the background technology and to provide a fixture and a test method suitable for analytical research on the penetration process of composite materials.

[0006] The present invention proposes a fixture and a test method suitable for analytical research on the penetration process of composite materials, which can realize penetration tests and multi-information in-situ synchronous observation of composite material test pieces with different geometric sizes and different loading directions at different impact velocities of penetrators with different geometric shapes.

[0007] The present invention proposes a fixture suitable for carrying out penetration tests on composite material test pieces with different geometric sizes and different loading directions at different impact velocities of penetrators with different geometric shapes, and a test method for multi-information in-situ synchronous observation. The device has a simple structure, is efficient, durable, and easy to install, and is suitable for various types of light gas guns.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A fixture suitable for analytical research on penetration process of composite materials, comprising a clamping end bottom plate, a clamping end support, an upper fixed slider, a lower fixed slider, an incident rod, a penetration rod, a penetration rod support, a penetration rod slide, a high-frequency laser displacement meter, an infrared thermal imager, two laser velocimeters, and four high-speed cameras; the four high-speed cameras are high-speed camera 1, high-speed camera 2, high-speed camera 3, and high-speed camera 4;

[0010] The clamping end support is fixed on the clamping end bottom plate, and a groove is provided at the left front corner of the clamping end support. The upper and lower ends of the groove are respectively provided with an upper slide groove and a lower slide groove along the front and rear directions. The upper fixed slider and the lower fixed slider are respectively slidably connected with the upper slide groove and the lower slide groove, and the upper fixed slider and the lower fixed slider are respectively detachably fixedly connected with the rear side wall of the groove, so that the composite material test piece is clamped and fixed between the upper fixed slider, the lower fixed slider and the rear side wall of the groove; an incident slot is provided on the rear side wall of the groove, and the incident slot is located between the upper fixed slider and the lower fixed slider. The penetration rod support is arranged at the rear side of the clamping end support, and the penetration rod support is provided with a through hole penetrating the front and rear side walls. The penetration rod slide groove is tightly fitted and fixed in the through hole. The penetration rod is slidably fitted with the penetration rod slide groove, and the front end of the penetration rod can pass through the incident slot. The incident rod is arranged behind the penetration rod, and the center of the penetration area of ​​the composite material test piece is in line with the penetration rod and the center of the incident rod.

[0011] Two laser velocimeters are respectively arranged on the outside between the penetration rod support and the clamping end support and on the outside between the incident rod and the penetration rod support; high-speed camera one and high-speed camera two are arranged on the side direction of the composite material test piece, wherein high-speed camera one is aimed at the side of the composite material test piece, high-speed camera two is aimed at the impact section area of ​​the penetration rod, and high-speed camera three and high-speed camera four are arranged on the back side of the composite material test piece in the penetration direction; the high-frequency laser displacement meter is aimed at the central area on the back side of the penetration area of ​​the composite material test piece, and the infrared thermal imager is arranged on the side direction of the composite material test piece.

[0012] Furthermore, a slide groove rubber ring is fixed in the penetration rod slide groove, and the penetration rod and the slide groove rubber ring are slidably matched.

[0013] Furthermore, the penetration rod is composed of an impact section, a support section and a power section from front to back, which are integrally formed. The impact section and the support section are both cylindrical, square or rhombus-shaped, and the cross-section of the support section is larger than that of the impact section. The power section is in the shape of a disc, and the cross-section of the power section is larger than that of the support section.

[0014] Furthermore, compensation light sources are arranged near the four high-speed cameras.

[0015] A test method for analyzing the penetration process of composite materials, the method comprising the following steps:

[0016] Step 1: Experimental preparation stage;

[0017] After fixing the clamping end bottom plate of the fixture and the penetration rod support on the light gas gun test device platform, assemble the fixture and install the composite material test piece, and install the penetration rod into the launching end of the light gas gun loading device;

[0018] Step 2: Experimental implementation stage;

[0019] (1) Turn on the laser velocimeter, high-speed camera, high-frequency laser displacement meter, infrared thermal imager, and compensation light source at the same time;

[0020] (2) adjusting the air pressure of the light gas gun chamber to meet the expected impact velocity of the incident rod, and launching the incident rod by controlling the air valve of the light gas gun chamber;

[0021] (3) After the incident rod hits the penetration rod, the penetration rod moves forward along the penetration rod slide slot, and the impact section of the penetration rod hits the composite material test piece;

[0022] (4) The laser velocimeter, high-speed camera, high-frequency laser displacement meter, and infrared thermal imager start collecting multiple physical quantities when the incident rod is launched synchronously;

[0023] Step 3: Test result analysis and post-processing stage;

[0024] (1) Obtain data collected by two laser velocimeters to obtain the incident velocities V1 and V2 of the penetration rod and the incident rod respectively;

[0025] (2) The composite material specimen may have three possible states, namely, state A is a completely broken state; state B is a critical state; state C is an unbroken state, and the composite material specimen has been damaged;

[0026] (3) Obtain the acquisition results of high-speed camera 2 and calculate the penetration rod incident velocity V based on the pixel calibration method 11 , the remaining speed V of the penetration rod in state A 22 and the penetration rod reflection velocity V in states B and C 33 , the calculation formula is as follows:

[0027]

[0028]

[0029] Calculate V 22 and V 33 All apply to the above formula;

[0030] Where: V1 is used to calibrate V 11 The calculation accuracy is obtained by obtaining the pixel coordinates of the target point in different photos, and then combined with the pixel coordinates at the initial moment, the incident velocity V of the penetrating rod can be calculated by the calibration coefficient c. 11 , the pixel coordinate distance moved by the penetration rod in the time period Δt is d1, then the actual distance is d=d1·c, the start photo and the end photo serial numbers of Δt are N1 and N2 respectively, and the acquisition frame rate of the high-speed camera 2 is set to F;

[0031] (4) Obtain the acquisition results of high-speed camera 1, observe and analyze the in-situ damage mode of the composite test piece under the impact of penetrating rods of different shapes at different speeds during the test, that is, the staged damage characteristics and failure modes of the composite test piece corresponding to the three different states A, B and C, and calculate the deflection of the composite test piece based on the pixel calibration method;

[0032] Before the test, after the position of high-speed camera 2 is determined, a static calibration object will be photographed. The length of the object is known to be D, and the pixel coordinate distance corresponding to the length in the photo is d. The calibration parameter c is calculated;

[0033] c=d / D (Formula 3)

[0034] This formula is also applicable to the calculation of c in step (3);

[0035] During the test, the deformation process of the side of the composite test piece is recorded by a high-speed camera. The pixel coordinate distance of the deformation of the center point of the side of the composite test piece along the penetration direction within the time Δt during the deformation process is W, and the deflection w of the composite test piece is calculated;

[0036] w=W / c (Formula 4)

[0037] (5) Obtain the acquisition results of high-speed camera 3 and high-speed camera 4, analyze the strain and displacement changes on the back of the penetration area of ​​the composite test piece when the penetration rods of different shapes hit at different speeds during the test, identify and calculate the speckle images acquired by high-speed camera 3 and high-speed camera 4 based on the three-dimensional digital image correlation method, realize the one-to-one correspondence of the analysis points in the two sets of acquired images, and calculate the three-dimensional displacement field on the back of the penetration area of ​​the composite test piece. M ,y M ,z M ) The displacement components in three directions (u, v, w) are calculated by the first-order finite difference method. The in-plane strain components and equivalent strain are calculated according to Equation 5;

[0038]

[0039] In formula 5, the first three calculation formulas from top to bottom calculate the in-plane strain components in directions 11, 22 and 12 respectively, and the equivalent strain is calculated by the formula at the bottom of formula 5; direction 11 is defined as the longitudinal direction in the material plane, direction 22 is defined as the transverse direction in the material plane, and direction 12 is defined as the shear direction in the material plane;

[0040] The surface strain rate tensor and equivalent strain rate of the speckle area are calculated by partial differential algorithm, and the calculation formula 6 is as follows;

[0041]

[0042] In formula 6, the first three calculation formulas from top to bottom calculate the in-plane strain rates in the 11, 22 and 12 directions respectively, and the equivalent strain rate is calculated by the bottom formula of formula 6;

[0043] P: represents any point in the back speckle area in the penetration direction of the composite test piece;

[0044] (6) Obtain the acquisition results of the high-frequency laser displacement meter and analyze the deformation process of the center of the penetration area of ​​the composite material test piece along the penetration direction;

[0045] (7) Obtain the acquisition results of the infrared thermal imager, analyze the temperature changes of the penetration area of ​​the composite test piece corresponding to the test states A, B and C when the penetration rods of different shapes impact at different speeds during the test, compare the in-situ damage mode of the composite test piece obtained by synchronous acquisition with a high-speed camera, and establish a correlation characterization model between the composite damage state and the structural temperature;

[0046] (8) Analyze the energy absorption of composite test pieces when penetrating rods of different shapes impact at different speeds during penetration tests.

[0047] Furthermore, in step 1, assembling the fixture and installing the composite material test piece are specifically as follows:

[0048] Slide the penetration rod through the rubber ring of the slide groove of the penetration rod support and align it with the incident notch of the clamping end support, install the incident rod into the launching end of the light gas gun loading device, place the composite test piece in the groove of the clamping end support, and horizontally move the upper fixed slider and the lower fixed slider to make the upper fixed slider and the lower fixed slider meet the fixed support constraint conditions of the upper and lower ends of the composite test piece along the penetration direction, and then connect the clamping end support and the upper fixed slider and the lower fixed slider through the clamping connection bolts to achieve effective clamping of the composite test piece; at the same time, ensure that the center of the incident rod, the center of the penetration rod, and the center of the penetration area of ​​the composite test piece meet the three-point one-line alignment state; then, Two laser velocimeters are respectively arranged on the outside between the penetration rod support and the clamping end support and on the outside between the incident rod and the penetration rod support; high-speed camera 1 and high-speed camera 2 are arranged on the side direction of the composite test piece, wherein high-speed camera 1 is aimed at the side of the composite test piece, and high-speed camera 2 is aimed at the impact section area of ​​the penetration rod; high-speed cameras 3 and 4 are arranged on the back side of the composite test piece in the penetration direction; a high-frequency laser displacement meter is aimed at the central area on the back side of the penetration area of ​​the composite test piece to collect the displacement time history curve of the center of the penetration area of ​​the composite test piece along the penetration direction; an infrared thermal imager is arranged on the side direction of the composite test piece.

[0049] Furthermore, step three (8) is specifically as follows:

[0050] (a) For state A, calculate the energy absorption when the composite test piece penetrates:

[0051] Where: E refers to the energy absorption value, m I Refers to the mass of the penetrator rod, V 11 is the incident velocity of the penetrator rod, V 22 It refers to the residual velocity after the penetrator penetrates;

[0052] (b) For state B, the critical energy absorption threshold of the composite material specimen can be obtained:

[0053] Where: V 33 It refers to the rebound speed when the penetration rod does not penetrate. V33 with a horizontal bar refers to the speed when the penetration rod just does not penetrate and does not rebound, usually 0;

[0054] (c) For Condition C, calculate the energy absorption when the composite test piece is not penetrated:

[0055] In this way, the deflection of the composite specimen under different conditions, the strain / displacement of the back side of the penetration area, the deformation of the center of the composite specimen along the penetration direction, and the energy absorption of the composite specimen were obtained.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) Smaller composite test pieces can be used to obtain damage information that effectively supports the simulation model, which can effectively save the cost of test materials;

[0058] (2) By using small-sized composite test pieces (in traditional ballistic impact tests, in order to minimize the influence of the clamping boundary effect on the material failure mode, test pieces with a cross-sectional size of 150×150 mm or even larger are often used for testing), penetration tests in the in-plane direction of composite materials can be carried out, reducing the difficulty of preparing composite test pieces;

[0059] (3) The front and rear positions of the upper and lower fixed sliders can be freely adjusted through the upper and lower slide grooves, so that the clamp has lower restrictions on the length, width and thickness of the composite test piece;

[0060] (4) By using this fixture, the in-situ damage and destruction process of fibers, resins and macro interfaces in the impact area (penetration area) of the composite test piece can be simultaneously observed and analyzed during the penetration test, supporting the establishment and verification of the simulation model;

[0061] (5) In addition to accurately measuring the impact velocity of the penetration rod and the residual velocity (rebound velocity) to calculate the energy absorption of the composite test piece, it can also effectively measure the multi-directional strain, displacement (deflection), temperature and other physical quantities of the composite test piece to achieve a more comprehensive characterization of its dynamic response;

[0062] (6) By using this fixture, the impact posture of the irregular geometric shape of the penetration rod can be stably controlled during the penetration test, so that the influence of the change of the penetration rod geometry and impact velocity on the penetration process of the composite material can be explored during the test.

[0063] In addition, the present invention also has the following advantages:

[0064] (1) The fixture and test method can not only use small strip test pieces instead of typical flat test pieces to conduct penetration test research on composite materials, but also reduce costs based on the optimization scheme, and can also realize the analytical research of the penetration process in the in-plane direction of composite materials;

[0065] (2) By adopting the fixture and test method, by using a penetration rod with a width close to that of the composite test piece to carry out penetration tests at different speeds, it is possible to achieve synchronous collection, observation, and analysis of the in-situ damage, deformation, and destruction process of the impacted area (penetration area) of the composite test piece during the penetration test, thereby solving the problem that synchronous observation cannot be made in order to obtain in-situ damage information of key areas in flat-plate ballistic impact tests;

[0066] (3) The fixture and test method can effectively obtain the changes in physical quantities such as multi-directional strain, displacement (deflection), and temperature of the composite material test piece during the penetration test, establish a multi-information characterization method for the penetration performance of the composite material, and solve the problem of debris interfering with velocity measurement;

[0067] (4) The fixture and test method can be used to achieve stable control of the impact posture of the irregular geometric shape of the penetration rod during the penetration test. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a structural schematic diagram of a fixture suitable for analytical research on penetration process of composite materials according to the present invention;

[0069] Figure 2 It is an axonometric view of the assembly of the penetration rod and the penetration rod slide;

[0070] Figure 3 It is a schematic diagram of the structure of the penetration rod.

[0071] The names and reference numerals of the components involved in the above drawings are as follows:

[0072] Clamping end base plate 1, clamping end support 2, upper fixed slide block 3, lower fixed slide block 4, incident slot 5, incident rod 6, penetration rod 7, impact section 7-1, support section 7-2, power section 7-3, penetration rod support 8, penetration rod slide groove 9, laser speed meter 10, high-speed camera one 11-1, high-speed camera two 11-2, high-speed camera three 11-3, high-speed camera four 11-4, high-frequency laser displacement meter 16, infrared thermal imager 13, groove 14, composite material test piece 15. DETAILED DESCRIPTION

[0073] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0074] Specific implementation method 1: Figure 1-Figure 3 As shown, this embodiment discloses a fixture suitable for analytical research on penetration process of composite materials, including a clamping end bottom plate 1, a clamping end support 2, an upper fixed slider 3, a lower fixed slider 4, an incident rod 6, a penetration rod 7, a penetration rod support 8, a penetration rod slide 9, a high-frequency laser displacement meter 16, an infrared thermal imager 13, two laser velocimeters 10, and four high-speed cameras; the four high-speed cameras are respectively a high-speed camera 1 11-1, a high-speed camera 2 11-2, a high-speed camera 3 11-3 and a high-speed camera 4 11-4;

[0075] The clamping end support 2 is fixed on the clamping end bottom plate 1, and a groove 14 is opened at the left front corner of the clamping end support 2. The upper end and the lower end of the groove 14 are respectively provided with an upper slide groove and a lower slide groove along the front-back direction. The upper fixed slider 3 and the lower fixed slider 4 are respectively slidably connected with the upper slide groove and the lower slide groove. The upper fixed slider 3 and the lower fixed slider 4 are respectively (through clamping connection bolts) detachably fixedly connected with the rear side wall of the groove 14, and the composite material test piece 15 is clamped and fixed between the upper fixed slider 3, the lower fixed slider 4 and the rear side wall of the groove 14; An incident slot 5 is formed on the rear side wall of the groove 14, and the incident slot 5 is located between the upper fixed slider 3 and the lower fixed slider 4. The penetration rod support 8 is arranged on the rear side of the clamping end support 2, and the penetration rod support 8 is provided with a through hole penetrating the front and rear side walls. The penetration rod slide 9 is tightly fitted and fixed in the through hole. The penetration rod 7 is slidably fitted with the penetration rod slide 9, and the front end of the penetration rod 7 can pass through the incident slot 5. The incident rod 6 is arranged behind the penetration rod 7, and the center of the penetration area of ​​the composite material test piece 15 is collinear with the center of the penetration rod 7 and the incident rod 6.

[0076] Two laser velocimeters 10 are respectively arranged on the outside between the penetration rod support 8 and the clamping end support 2 and on the outside between the incident rod 6 and the penetration rod support 8; a high-speed camera 1 11-1 and a high-speed camera 2 11-2 are arranged on the side direction of the composite material test piece 15, wherein the high-speed camera 1 11-1 is facing the side of the composite material test piece 15, and the high-speed camera 2 11-2 is aimed at the impact section area of ​​the penetration rod 7, and a high-speed camera 3 11-3 and a high-speed camera 4 11-4 are arranged on the back side of the composite material test piece 15 in the penetration direction; a high-frequency laser displacement meter 16 is aimed at the central area on the back side of the penetration area of ​​the composite material test piece 15, and an infrared thermal imager 13 is arranged on the side direction of the composite material test piece 15.

[0077] The clamping end support 2 is used to fix and clamp the composite material test piece 15. A groove 14 is opened at the left front corner of the clamping end support 2. The upper and lower ends of the groove 14 are respectively provided with an upper slide groove and a lower slide groove along the front-to-back direction, which are used to realize the free movement of the upper fixed slider 3 and the lower fixed slider 4 in the groove 14 along the front-to-back direction. The rear side wall of the groove 14 is provided with an incident slot 5, which passes through the incident slot 5 when impacting the penetration rod 7.

[0078] The upper fixed slider 3 is fixedly connected to the clamping end support 2 by clamping connecting bolts, and is used to fix the composite material test piece 15. The position of the upper fixed slider 3 can be adjusted in the upper slide groove according to the thickness of the composite material test piece 15.

[0079] The lower fixed slider 4 is fixedly connected to the clamping end support 2 through clamping connecting bolts and is used to fix the composite material test piece 15. The position of the lower fixed slider 4 can be adjusted in the lower sliding groove according to the thickness of the composite material test piece 15.

[0080] The clamping connecting bolts are used to connect the upper fixed slider 3 , the lower fixed slider 4 and the clamping end support 2 , so as to achieve effective fixed clamping of the composite material test piece 15 .

[0081] The incident rod 6 is fired by a light gas gun, and the impact speed can be changed by adjusting the air pressure of the light gas gun air chamber to provide kinetic energy for penetrating the rod 7.

[0082] The penetration rod support 8 is used to fix the penetration rod slide groove 9 and can be freely moved and fixed to a desired position.

[0083] The penetration rod slide groove 9 is used to support the stable movement of the penetration rod 7. The size of the slide groove matches the penetration rod 7. At the same time, the design needs to be adjusted according to the geometric shape and impact posture of the penetration rod 7 to ensure stable control of the impact posture of the penetration rod 7 with irregular geometric shape.

[0084] The two laser speed meters 10, when the preset speed to be measured is higher, the collection frequency of the laser speed meter 10 is adjusted to be higher accordingly. The two laser speed meters 10 are respectively arranged on the outside between the penetration rod support 8 and the clamping end support 2 and on the outside between the incident rod 6 and the penetration rod support 8, and are used to measure the impact and rebound speed of the penetration rod 7 and the impact and rebound speed of the incident rod 6.

[0085] Four high-speed cameras are provided, a high-speed camera 1 11-1 and a high-speed camera 2 11-2 are provided on the side direction of the composite material test piece 15, wherein the high-speed camera 1 11-1 is aimed at the side of the composite material test piece 15, and the high-speed camera 2 11-2 is aimed at the impact section area of ​​the penetration rod 7 (the impact velocity and reflection velocity of the penetration rod 7 are measured based on the pixel calibration method), and a high-speed camera 3 11-3 and a high-speed camera 4 11-4 are provided on the back side direction of the penetration direction of the composite material test piece 15 (for observing the omnidirectional strain and displacement (deflection) of the composite material test piece 15).

[0086] The high-frequency laser displacement meter 16 is aimed at the central area on the back side of the penetration area of ​​the composite material test piece 15 to obtain the deformation time history curve and the maximum displacement of the composite material test piece 15 in the impact direction.

[0087] The infrared thermal imager 13 is placed on the side of the composite material test piece 15 to analyze the local temperature change of the composite material test piece 15 during the penetration test.

[0088] When the fixture is in use, the clamping end bottom plate 1 and the penetration rod support 8 are fixed on the light gas gun test bench to keep the fixture in a stable state.

[0089] Specific implementation method 2: Figure 1 , Figure 2 As shown, this embodiment is a further explanation of the specific embodiment one, a slide groove rubber ring is fixed in the penetration rod slide groove 9, and the penetration rod 7 slides with the slide groove rubber ring (for reducing the friction resistance of the penetration rod 7 during movement, and protecting the penetration rod 7 during movement).

[0090] Specific implementation method three: Figure 3 As shown, this embodiment is a further explanation of the specific embodiment one or two. The penetration rod 7 is composed of an impact section 7-1, a support section 7-2 and a power section 7-3 which are integrally formed from front to back. The impact section 7-1 and the support section 7-2 are both cylindrical, square or rhombic, and the cross section of the support section 7-2 is larger than that of the impact section 7-1. The power section 7-3 is in the shape of a disc, and the cross section of the power section 7-3 is larger than that of the support section 7-2.

[0091] The penetration rod 7 is used to impact the composite material test piece 15 to achieve a high strain rate loading state of the composite material test piece 15. The front end geometric shape of the penetration rod 7 can be adjusted according to the test needs, such as a cylindrical, square column, diamond column, etc. The penetration rod 7 is divided into three sections, namely an impact section 7-1, a support section 7-2 and a power section 7-3. The cross section of the impact section 7-1 needs to be smaller than the size of the incident slot 5 of the clamping end support 2 to meet its free impact needs. The support section 7-2 matches the size of the penetration rod slide 9. The cross section of the support section 7-2 needs to be larger than the incident slot 5 of the clamping end support 2 to achieve stopping of its movement when it reaches the limit distance after penetrating the test piece 15 to avoid damaging the fixture. The power section 7-3 is used for effective collision between the incident rod 6 and the penetration rod 7. The movement speed of the penetration rod 7 can be determined based on the law of conservation of energy, wherein the cross section of the power section 7-3 needs to be larger than the slot size of the penetration rod slide 9.

[0092] Specific implementation method four: This implementation method is a further explanation of specific implementation method three. Compensation light sources are arranged near four high-speed cameras (all of which are ultra-high-speed digital cameras) (the function is to provide suitable lighting for the high-speed cameras, and the number and placement can be adjusted according to actual test conditions).

[0093] Specific implementation method five: Figure 1-Figure 3 As shown, this embodiment discloses an experimental method for analyzing the penetration process of composite materials using the fixture described in the fourth embodiment, and the method includes the following steps:

[0094] Step 1: Experimental preparation stage;

[0095] After fixing the clamping end bottom plate 1 and the penetration rod support 8 of the fixture on the platform of the light gas gun test device, assemble the fixture and install the composite material test piece 15, and install the incident rod 6 into the launching end of the light gas gun loading device;

[0096] Step 2: Experimental implementation stage;

[0097] (1) Turn on the laser velocimeter 10, the high-speed camera, the high-frequency laser displacement meter 16, the infrared thermal imager 13 (which is a multi-physical quantity synchronous acquisition and measurement device), and turn on the compensation light source at the same time;

[0098] (2) adjusting the air pressure of the light gas gun air chamber (the air pressure needs to be pre-tested, and the air chamber capacity, projectile mass and ballistic smoothness of different light gas guns jointly determine the pressurization level corresponding to the expected speed) to meet the expected impact speed of the incident rod 6, and launching the incident rod 6 by controlling the air valve of the light gas gun air chamber;

[0099] (3) After the incident rod 6 hits the penetration rod 7, the penetration rod 7 moves forward along the penetration rod slide groove 9, and the impact section 7-1 of the penetration rod 7 hits the composite material test piece 15;

[0100] (4) The laser velocimeter 10, the high-speed camera, the high-frequency laser displacement meter 16, and the infrared thermal imager 13 start collecting multiple physical quantities when the incident rod 6 is launched synchronously;

[0101] Step 3: Test result analysis and post-processing stage;

[0102] (1) Obtaining data collected by two laser velocimeters 10 to obtain the incident velocities V1 and V2 of the penetration rod 7 and the incident rod 6 respectively;

[0103] (2) (Considering that the commonly used resin-based composite materials are brittle materials, after carrying out this test) the composite test piece 15 may have three possible states, namely, state A is a completely broken state (i.e., the penetration rod 7 penetrates the composite test piece 15); state B is a critical state (i.e., the composite test piece 15 is broken but the penetration rod 7 does not penetrate); state C is a non-broken state, in which the composite test piece 15 has been damaged (but the penetration rod 7 directly rebounds after impact);

[0104] (3) Obtain the acquisition results of the high-speed camera 11-2 and calculate the incident velocity (impact velocity) V of the penetrating rod 7 based on the pixel calibration method 11 , In state A, the remaining speed V of the penetration rod 7 22 The reflection speed V of the penetrating rod 7 in states B and C 33 , the calculation formula is as follows:

[0105]

[0106]

[0107] Calculate V 22 and V 33 All apply to the above formula;

[0108] Where: V1 is used to calibrate V 11 The calculation accuracy (considering that the trajectory is a horizontal straight line, only one-dimensional coordinates are needed for calculation), the pixel coordinates of the target point in different photos are obtained, and then combined with the pixel coordinates at the initial moment, the incident velocity V of the penetrating rod 7 can be calculated by the calibration coefficient c. 11 , the pixel coordinate distance moved by the penetration rod 7 in the time period Δt is d1, then the actual distance is d=d1·c, the start photo and the end photo serial numbers of Δt are N1 and N2 respectively, and the acquisition frame rate of the high-speed camera 11-2 is set to F;

[0109] (6) Obtain the acquisition results of the high-speed camera 11-1, observe and analyze the in-situ damage mode of the composite material test piece 15 when the penetration rod 7 of different shapes hits at different speeds during the test, that is, the staged damage characteristics and failure modes of the composite material test piece 15 corresponding to the three different states A, B and C, such as warp and weft fiber bundle tensile and shear damage, out-of-plane compression damage, in-plane shear damage, interlayer delamination damage, etc., to provide support for the damage model for the subsequent research on the dynamic constitutive model of such composite materials, and use the same calibration coefficient c as step three (3) to calculate the deflection of the composite material test piece 15 based on the pixel calibration method;

[0110] Before the test, after the position of the high-speed camera 11-2 is determined, a static calibration object will be photographed. It is known that the length of the object is D, and the pixel coordinate distance corresponding to the length in the photo is d, and the calibration parameter c is calculated;

[0111] c=d / D (Formula 3) This formula is also applicable to the calculation of c in step (3);

[0112] During the test, the deformation process of the side of the composite test piece 15 is recorded based on a high-speed camera 11-1. During the deformation process, the pixel coordinate distance of the deformation of the center point of the side of the composite test piece 15 (the center of the thickness surface of the composite test piece 15) along the penetration direction within the time Δt is W, and the deflection w of the composite test piece 15 is calculated;

[0113] w=W / c (Formula 4)

[0114] (7) Obtain the acquisition results of the high-speed camera 3 11-3 and the high-speed camera 4 11-4, analyze the strain and displacement changes on the back of the penetration area of ​​the composite test piece 15 when the penetration rod 7 of different shapes hits at different speeds during the test, identify and calculate the speckle images acquired by the high-speed camera 3 11-3 and the high-speed camera 4 11-4 based on the three-dimensional digital image correlation method (implemented by the modular function of the software supporting the high-speed camera), realize the one-to-one correspondence of the analysis points in the two sets of acquired images, calculate the three-dimensional displacement field on the back of the penetration area of ​​the composite test piece 15, and calculate the three-dimensional displacement field on the back of the penetration area of ​​the composite test piece 15 according to the spatial coordinate point (x M ,y M ,z M ) The displacement components in three directions (u, v, w) are calculated by the first-order finite difference method. The in-plane strain components and equivalent strain are calculated according to Equation 5;

[0115]

[0116] In formula 5, the first three calculation formulas from top to bottom calculate the in-plane strain components in directions 11, 22 and 12 respectively, and the equivalent strain is calculated by the formula at the bottom of formula 5; direction 11 is defined as the longitudinal direction in the material plane, direction 22 is defined as the transverse direction in the material plane, and direction 12 is defined as the shear direction in the material plane;

[0117] The surface strain rate tensor and equivalent strain rate of the speckle area are calculated by partial differential algorithm, and the calculation formula 6 is as follows;

[0118]

[0119] In formula 6, the first three calculation formulas from top to bottom calculate the in-plane strain rates in the 11, 22 and 12 directions respectively, and the equivalent strain rate is calculated by the bottom formula of formula 6;

[0120] P: represents any point in the back speckle area in the penetration direction of the composite material test piece 15;

[0121] (6) obtaining the acquisition results of the high-frequency laser displacement meter 16 and analyzing the deformation process of the center of the penetration area of ​​the composite material test piece 15 along the penetration direction;

[0122] (7) Obtain the acquisition results of the infrared thermal imager 13, analyze the temperature changes of the penetration area of ​​the composite material test piece 15 corresponding to the test states A, B and C when the penetration rod 7 of different shapes hits at different speeds during the test, compare the in-situ damage mode of the composite material test piece 15 obtained by synchronous acquisition of the high-speed camera 11-1, and establish a correlation characterization model between the composite material damage state and the structural temperature (establish a phenomenological empirical model to analyze the correlation between the in-situ damage mode of the composite material test piece 15 during the test and its temperature change, such as the appearance of a certain damage mode will correspond to a sudden temperature rise or drop in the area);

[0123] (8) Analyze the energy absorption of the composite material test piece 15 when the penetration rods 7 of different shapes impact at different speeds during the penetration test.

[0124] 6. The test method according to claim 5, characterized in that: in step 1, assembling the fixture and installing the composite material test piece 15 specifically comprises:

[0125] Slide the penetration rod 6 through the rubber ring of the slide groove of the penetration rod support 8 and align it with the incident slot 5 of the clamping end support 2, install the incident rod 6 into the launching end of the light gas gun loading device, place the composite material test piece 15 in the groove of the clamping end support 2, and horizontally move the upper fixed slider 3 and the lower fixed slider 4 to make the upper fixed slider 3 and the lower fixed slider 4 meet the fixed support constraint conditions of the upper and lower ends of the composite material test piece 15 along the penetration direction, and then connect and fix the clamping end support 2 with the upper fixed slider 3 and the lower fixed slider 4 through the clamping connection bolts to achieve effective clamping of the composite material test piece 15; at the same time, it is necessary to ensure that the center of the incident rod 6, the center of the penetration rod 7, and the center of the penetration area of ​​the composite material test piece 15 meet the three-point one-line alignment state; then, two laser velocimeters 10 are respectively arranged on the outside between the penetration rod support 8 and the clamping end support 2 and the incident rod 6 and the penetration The outside between the rod supports 8 (the two laser velocimeters 10 are debugged to ensure that the incident speeds of the penetration rod 7 and the incident rod 6 can be effectively measured); a high-speed camera 1 11-1 and a high-speed camera 2 11-2 are set on the side direction of the composite material test piece 15, wherein the high-speed camera 1 11-1 is aimed at the side of the composite material test piece 15, and the high-speed camera 2 11-2 is aimed at the impact section area of ​​the penetration rod 7, and a high-speed camera 3 11-3 and a high-speed camera 4 11-4 are set on the back side of the composite material test piece 15 in the penetration direction; the high-frequency laser displacement meter 16 is aimed at the central area on the back side of the penetration area of ​​the composite material test piece 15 (if other areas are concerned, it can also be adjusted according to the test needs) to collect the displacement time history curve of the center of the penetration area of ​​the composite material test piece 15 along the penetration direction; the infrared thermal imager 13 is set on the side direction of the composite material test piece 15.

[0126] (1) Design, prepare, and cut composite test pieces according to the expected loading direction of the test15, such as Figure 1 It corresponds to the out-of-plane penetration test of composite material test piece 15;

[0127] (2) The penetration rod 7 is designed according to the test requirements. According to the different requirements of the test impact posture, impact angle, etc., the impact section 7-1 of the penetration rod 7 can be designed into different geometric shapes, such as Figure 1 , Figure 2 As shown, it corresponds to the test state where the square punch penetration rod positively impacts the composite material test piece 15;

[0128] (3) Fix the clamping end bottom plate 1 of the fixture on the light gas gun test device platform, move the clamping end support 2 to a suitable position and then fix it to the clamping end bottom plate 2;

[0129] (4) Fix the penetration rod support 8 of the fixture on the light gas gun test device platform, and install the penetration rod slide 9 and the slide rubber ring in sequence;

[0130] (5) Install the incident rod 6 into the launching end of the light gas gun loading device, insert the penetration rod 7 into the rubber ring of the slide groove, adjust the impact posture of the penetration rod 7, install the high-frequency laser displacement meter 16, and ensure that the center of the incident rod 6, i.e., the center of the muzzle of the light gas gun, and the center of the penetration rod 7 are located on the same straight line;

[0131] (6) The composite material test piece 15 is placed in the groove 14 of the clamping end support 2, and the upper and lower fixed sliders are horizontally moved in the upper and lower sliding grooves of the clamping end support 2 respectively, so that the upper and lower fixed sliders meet the fixed support constraint conditions of the upper and lower ends of the composite material test piece 15 along the penetration direction, and then the clamping end support 2 and the upper and lower fixed sliders are connected and fixed by clamping connection bolts, so that the upper and lower fixed sliders will not move during the penetration test, thereby achieving effective clamping of the composite material test piece 15;

[0132] (7) In the process of fixing the composite material test piece 15, the laser must be visually observed with the help of a high-frequency laser displacement meter 16 to ensure that the center of the incident rod 6, i.e., the center of the muzzle of the light gas gun, the center of the penetration rod 7, and the center of the penetration area of ​​the composite material test piece 15 meet the alignment state of three points in a straight line;

[0133] (8) Debugging two laser velocimeters 10 to ensure that the incident velocities of the penetration rod 7 and the incident rod 6 can be effectively measured;

[0134] (9) A high-speed camera 11-1 and a high-speed camera 11-2 are set on the side of the composite material test piece 15, wherein the high-speed camera 11-1 is aimed at the side of the composite material test piece 15, and the high-speed camera 11-2 is aimed at the impact section area of ​​the penetration rod 7. Considering that this test method needs to calculate the impact speed and reflection speed of the penetration rod 7 based on the pixel calibration method, it is necessary to highlight the impact section area of ​​the penetration rod 7 for calibration, adjust the position of the compensation light source to ensure clear shooting, adjust the hardware settings of the high-speed camera, and set the acquisition frequency and other parameters to meet the acquisition and shooting requirements of this test;

[0135] (10) A high-speed camera 3 11-3 and a high-speed camera 4 11-4 are set on the back side of the penetration direction of the composite material test piece 15. With the help of the high-speed camera 3 11-3 and the high-speed camera 4 11-4, the full-field strain, displacement and other physical quantities of the penetration area of ​​the composite material test piece 15 are calculated based on the three-dimensional digital image correlation method. Considering that the three-dimensional digital image correlation method is based on the principle of binocular stereo imaging, the two high-speed cameras need to be placed at a certain angle compared to the human eye to form a binocular stereo observation system. At the same time, considering that the calculation area (i.e., the speckle area, that is, the back side of the penetration area of ​​the composite material test piece 15) needs to contain sufficient pixel information to ensure effective identification, it is necessary to draw a randomly distributed speckle pattern that meets the conditions on the observation surface of the composite material test piece 15 before the test, adjust the position of the compensation light source, complete the calibration pre-test, adjust the high-speed camera hardware settings, and set the acquisition frequency and other parameters to meet the acquisition and shooting requirements of this test;

[0136] (11) Debugging the high-frequency laser displacement meter 16 to ensure that the displacement time history curve of the center of the penetration area of ​​the composite material test piece 15 along the penetration direction can be effectively collected;

[0137] (12) An infrared thermal imager 13 is arranged on the side of the composite material test piece 15, and is aimed at the side of the composite material test piece 15, and the acquisition frequency is adjusted to meet the test acquisition requirements.

[0138] 7. The test method according to claim 5, characterized in that: step 3 (8) specifically comprises:

[0139] (a) For state A, calculate the energy absorption when the composite material test piece 15 penetrates:

[0140] Where: E refers to the energy absorption value, m I is the mass of the penetrating rod 7, V 11 is the incident velocity of the penetrating rod 7, V 22 It refers to the residual speed after the penetration rod 7 penetrates;

[0141] (b) For state B, the critical energy absorption threshold of the composite material test piece 15 can be obtained:

[0142]

[0143] Where: V 33 It refers to the rebound speed when the penetration rod 7 does not penetrate. V33 with a horizontal bar refers to the speed when the penetration rod 7 just does not penetrate and does not rebound. It is usually taken as 0 (but it is difficult to achieve this test state, and usually several groups of test data near the critical state are taken as the average value for calculation);

[0144] (c) For state C, calculate the energy absorption when the composite material test piece 15 is not penetrated:

[0145] The deflection of the composite specimen 15 under different conditions, the strain / displacement on the back side of the penetration area, the deformation of the center of the composite specimen 15 along the penetration direction, and the energy absorption of the composite specimen 15 are obtained, which will provide support for the subsequent finite element simulation model validity verification work.

[0146] According to the clamping state and material characteristics of the composite test piece 15, the penetration direction, i.e., the thickness direction of the composite test piece 15 is defined as the 33 direction of the material, and the length direction and the width direction are the 11 and 12 directions of the composite test piece 15 material; the 33 direction is defined as the normal direction of the material thickness.

[0147] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0148] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A test method for analytical research on penetration process of composite materials, characterized by: The method is implemented based on a fixture suitable for analytical research on penetration process of composite materials, wherein the fixture comprises a clamping end bottom plate (1), a clamping end support (2), an upper fixed slider (3), a lower fixed slider (4), an incident rod (6), a penetration rod (7), a penetration rod support (8), a penetration rod slide groove (9), a high-frequency laser displacement meter (16), an infrared thermal imager (13), two laser velocimeters (10), and four high-speed cameras; the four high-speed cameras are respectively a high-speed camera 1 (11-1), a high-speed camera 2 (11-2), a high-speed camera 3 (11-3), and a high-speed camera 4 (11-4); The clamping end support (2) is fixed on the clamping end bottom plate (1), and a groove (14) is provided at the left front corner of the clamping end support (2). The upper end and the lower end of the groove (14) are respectively provided with an upper slide groove and a lower slide groove in the front-back direction. The upper fixed slider (3) and the lower fixed slider (4) are respectively slidably connected to the upper slide groove and the lower slide groove. The upper fixed slider (3) and the lower fixed slider (4) are respectively detachably fixedly connected to the rear side wall of the groove (14), and the composite material test piece (15) is clamped and fixed between the upper fixed slider (3), the lower fixed slider (4) and the rear side wall of the groove (14); the rear side wall of the groove (14) An incident slot (5) is provided, the incident slot (5) is located between the upper fixed slider (3) and the lower fixed slider (4), a penetration rod support (8) is arranged at the rear side of the clamping end support (2), the penetration rod support (8) is provided with a through hole penetrating the front and rear side walls, a penetration rod slide groove (9) is tightly fitted and fixed in the through hole, the penetration rod (7) and the penetration rod slide groove (9) are slidably fitted, and the front end of the penetration rod (7) can pass through the incident slot (5), the incident rod (6) is arranged behind the penetration rod (7), and the center of the penetration area of ​​the composite material test piece (15) is collinear with the center of the penetration rod (7) and the incident rod (6); Two laser velocimeters (10) are respectively arranged on the outside between the penetration rod support (8) and the clamping end support (2) and the outside between the incident rod (6) and the penetration rod support (8); a high-speed camera 1 (11-1) and a high-speed camera 2 (11-2) are arranged on the side direction of the composite material test piece (15), wherein the high-speed camera 1 (11-1) faces the side of the composite material test piece (15), the high-speed camera 2 (11-2) is aimed at the impact section area of ​​the penetration rod (7), and a high-speed camera 3 (11-3) and a high-speed camera 4 (11-4) are arranged on the back side of the composite material test piece (15) in the penetration direction; a high-frequency laser displacement meter (16) is aimed at the central area on the back side of the penetration area of ​​the composite material test piece (15), and an infrared thermal imager (13) is arranged on the side direction of the composite material test piece (15); The penetration rod (7) is composed of an impact section (7-1), a support section (7-2) and a power section (7-3) which are made into one piece from front to back. The impact section (7-1) and the support section (7-2) are both cylindrical, square or rhombic, and the cross section of the support section (7-2) is larger than the cross section of the impact section (7-1). The power section (7-3) is in the shape of a disk, and the cross section of the power section (7-3) is larger than the cross section of the support section (7-2). Compensation light sources are arranged near the four high-speed cameras. The method comprises the following steps: Step 1: Experimental preparation stage; After fixing the clamping end bottom plate (1) and the penetration rod support (8) of the clamp on the platform of the light gas gun test device, assembling the clamp and installing the composite material test piece (15), and installing the incident rod (6) into the launching end of the light gas gun loading device; Step 2: Experimental implementation stage; (1) Turn on the laser velocimeter (10), the high-speed camera, the high-frequency laser displacement meter (16), the infrared thermal imager (13), and the compensation light source at the same time; (2) adjusting the air pressure of the light gas gun air chamber to meet the expected impact velocity of the incident rod (6), and launching the incident rod (6) by controlling the air valve of the light gas gun air chamber; (3) After the incident rod (6) hits the penetration rod (7), the penetration rod (7) moves forward along the penetration rod slide groove (9), and the impact section (7-1) of the penetration rod (7) hits the composite material test piece (15); (4) The laser velocimeter (10), the high-speed camera, the high-frequency laser displacement meter (16), and the infrared thermal imager (13) start to collect multiple physical quantities when the incident rod (6) is launched synchronously; Step 3: Test result analysis and post-processing stage; (1) acquiring data collected by two laser velocimeters (10) to obtain incident velocities V1 and V2 of the penetration rod (7) and the incident rod (6), respectively; (2) The composite material test piece (15) may have three possible states, namely, state A is a completely broken state; state B is a critical state; state C is an unbroken state, and the composite material test piece (15) has been damaged; (3) Obtain the acquisition results of high-speed camera 2 (11-2) and calculate the incident velocity V of the penetrating rod (7) based on the pixel calibration method 11 , the remaining velocity V of the penetration rod (7) in state A 22 and the reflection velocity V of the penetration rod (7) in states B and C 33 , the calculation formula is as follows: Calculate V 22 and V 33 All apply to the above formula; Where: V1 is used to calibrate V 11 The calculation accuracy is improved by obtaining the pixel coordinates of the target point in different photos, and then combining the pixel coordinates at the initial moment, the incident velocity V of the penetrating rod (7) can be calculated by the calibration coefficient c. 11 , the pixel coordinate distance moved by the penetration rod (7) in the time period Δt is d1, then the actual distance is d=d1·c, the start photo and the end photo serial numbers of Δt are N1 and N2 respectively, and the acquisition frame rate of the high-speed camera 2 (11-2) is set to F; (4) obtaining the acquisition results of the high-speed camera 1 (11-1), observing and analyzing the in-situ damage mode of the composite material test piece (15) when the penetration rod (7) of different shapes hits at different speeds during the test, that is, the staged damage characteristics and failure modes of the composite material test piece (15) corresponding to three different states A, B and C, and calculating the deflection of the composite material test piece (15) based on the pixel calibration method; Before the test, after the position of high-speed camera 2 (11-2) is determined, a static calibration object will be photographed. The length of the object is known to be D, and the pixel coordinate distance corresponding to the length in the photo is d. The calibration parameter c is calculated; c=d / D (Formula 3) This formula is also applicable to the calculation of c in step (3); During the test, the deformation process of the side surface of the composite material test piece (15) is recorded based on a high-speed camera (11-1). During the deformation process, the pixel coordinate distance of the deformation of the center point of the side surface of the composite material test piece (15) along the penetration direction within a time Δt is W, and the deflection w of the composite material test piece (15) is calculated; w=W / c (Formula 4) (5) Obtain the acquisition results of high-speed camera three (11-3) and high-speed camera four (11-4), analyze the strain and displacement changes on the back of the penetration area of ​​the composite test piece (15) when the penetration rod (7) of different shapes hits at different speeds during the test, identify and calculate the speckle images acquired by high-speed camera three (11-3) and high-speed camera four (11-4) based on the three-dimensional digital image correlation method, realize the one-to-one correspondence of the analysis points in the two sets of acquired images, calculate the three-dimensional displacement field of the back of the penetration area of ​​the composite test piece (15), and calculate the three-dimensional displacement field of the back of the penetration area of ​​the composite test piece (15) according to the spatial coordinate point (x M ,y M ,z M ) The displacement components in three directions (u, v, w) are calculated by the first-order finite difference method. The in-plane strain components and equivalent strain are calculated according to Equation 5; In formula 5, the first three calculation formulas from top to bottom calculate the in-plane strain components in directions 11, 22 and 12 respectively, and the equivalent strain is calculated by the formula at the bottom of formula 5; direction 11 is defined as the longitudinal direction in the material plane, direction 22 is defined as the transverse direction in the material plane, and direction 12 is defined as the shear direction in the material plane; The surface strain rate tensor and equivalent strain rate of the speckle area are calculated by partial differential algorithm, and the calculation formula 6 is as follows; In formula 6, the first three calculation formulas from top to bottom calculate the in-plane strain rates in the 11, 22 and 12 directions respectively, and the equivalent strain rate is calculated by the bottom formula of formula 6; P: represents any point in the back speckle area in the penetration direction of the composite material test piece (15); (6) obtaining the acquisition results of the high-frequency laser displacement meter (16) and analyzing the deformation process of the center of the penetration area of ​​the composite material test piece (15) along the penetration direction; (7) obtaining the acquisition results of the infrared thermal imager (13), analyzing the temperature changes of the penetration area of ​​the composite material test piece (15) corresponding to the test states A, B and C when the penetration rod (7) of different shapes impacts at different speeds during the test, comparing the in-situ damage mode of the composite material test piece (15) obtained by synchronous acquisition of the high-speed camera (11-1), and establishing a correlation characterization model between the composite material damage state and the structural temperature; (8) Analyze the energy absorption of the composite material test piece (15) when it is impacted by penetration rods (7) of different shapes at different speeds during the penetration test.

2. The test method according to claim 1, characterized in that: In step 1, assembling the fixture and installing the composite material test piece (15) is specifically as follows: The penetration rod 6 is slid through the rubber ring of the slide groove of the penetration rod support (8) and aligned with the incident notch (5) of the clamping end support (2), the incident rod (6) is installed into the launching end of the light gas gun loading device, the composite material test piece (15) is placed in the groove of the clamping end support (2), and the upper fixed slider (3) and the lower fixed slider (4) are horizontally moved to make the upper fixed slider (3) and the lower fixed slider (4) meet the fixed support constraint conditions of the upper and lower ends of the composite material test piece (15) along the penetration direction, and then the clamping end support (2) is fixed to the upper fixed slider (3) and the lower fixed slider (4) by clamping connecting bolts to achieve effective clamping of the composite material test piece (15); at the same time, it is necessary to ensure that the center of the incident rod (6), the center of the penetration rod (7) and the center of the penetration area of ​​the composite material test piece (15) meet the three-point straight line alignment state; then, the two laser velocimeters (10) are respectively set The invention relates to a composite material test piece (15) and a composite material test piece (15). The composite material test piece (15) is provided on the outer side between the penetration rod support (8) and the clamping end support (2) and on the outer side between the incident rod (6) and the penetration rod support (8); a high-speed camera 1 (11-1) and a high-speed camera 2 (11-2) are provided on the side direction of the composite material test piece (15), wherein the high-speed camera 1 (11-1) is aimed at the side of the composite material test piece (15), and the high-speed camera 2 (11-2) is aimed at the impact section area of ​​the penetration rod (7); a high-speed camera 3 (11-3) and a high-speed camera 4 (11-4) are provided on the back side of the composite material test piece (15) in the penetration direction; a high-frequency laser displacement meter (16) is aimed at the central area on the back side of the penetration area of ​​the composite material test piece (15) to collect the displacement time history curve of the center of the penetration area of ​​the composite material test piece (15) along the penetration direction; and an infrared thermal imager (13) is provided on the side direction of the composite material test piece (15).

3. The test method according to claim 1, characterized in that: Step 3 (8) is specifically: (a) For state A, calculate the energy absorbed when the composite material test piece (15) is penetrated: Where: E A Refers to the energy absorption value, m I is the mass of the penetrating rod (7), V 11 is the incident velocity of the penetrating rod (7), V 22 It refers to the residual velocity of the penetrator rod (7) after penetration; (b) For state B, the critical energy absorption threshold of the composite material test piece (15) can be obtained: Where: V 33 It refers to the rebound speed when the penetration rod (7) does not penetrate. V33 with a horizontal bar refers to the speed when the penetration rod (7) just does not penetrate and does not rebound, usually 0; (c) For state C, calculate the energy absorption when the composite material test piece (15) is not penetrated: Thus, the deflection of the composite material test piece (15) under different conditions, the strain / displacement of the back side of the penetration area, the deformation of the center of the composite material test piece (15) along the penetration direction, and the energy absorption of the composite material test piece (15) are obtained.

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