Protection evaluation method for sympathetic detonation multi-physics field load collaborative loading

Abstract

The invention relates to a protection evaluation method for sympathetic detonation multi-physics field load collaborative loading, belongs to the field of explosion impact protection evaluation, and solves the problem of sympathetic detonation multi-physics field load collaborative loading protection evaluation. The method comprises the following steps: S1, building a sympathetic detonation multi-physical field load collaborative loading test system, and realizing collaborative loading of explosive shock waves and fragment groups; s2, acquiring multi-physics field cooperative load parameter information and damaged state information of the to-be-tested piece through a test system; s3, calculating a sympathetic detonation cooperative load strength evaluation index and a protection performance evaluation index of the to-be-tested piece according to various data tested in the step S2; s4, performing nondimensionalization on the protection performance evaluation index of the to-be-tested piece to obtain a protection efficiency comprehensive evaluation function of the to-be-tested piece; and various evaluation indexes are introduced to obtain a comprehensive protection evaluation index phi of the to-be-tested piece. According to the invention, sympathetic detonation multi-physical field load cooperative loading and quantitative evaluation of the protection performance of the to-be-tested piece are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of explosion shock testing and protection evaluation, and particularly to a protection evaluation method for collaborative loading of multi-physical field loads in sympathetic detonation. Background Art

[0002] Improvised explosive devices may be accidentally stimulated during transportation, disposal, and destruction, resulting in high-intensity reactions such as explosion and detonation. The sympathetic detonation near-field loads generated pose a serious threat to the safety of critical equipment and personnel. The multi-physical field coupled loads formed by improvised explosive devices mainly include detonation products, air shock waves, and dense fragment groups, etc. Among them, detonation products and air shock waves are collectively referred to as explosion shock waves. The peak overpressure of near-field detonation products is about several hundred MPa, the fireball temperature can reach thousands of K, the peak overpressure of air shock waves is about several tens of MPa, and the average velocity of the fragment group load is about 1-2 km / s. During the actual test of sympathetic detonation multi-physical field coupled loads, problems such as harsh test environment, high amplitude response of near-field explosion loads, complex coupling mechanism of collaborative loads, and short transient loading time are faced. Most of the existing methods for collaborative loading of explosion shock waves and fragment group loads use simulation test devices to approximately achieve the explosion shock wave load history by driving aluminum foam projectiles with a light gas gun or loading with a detonation shock tube, and achieve high-speed loading of fragments by driving with a cannon or ballistic gun. The above simulation test protection evaluation method can only achieve low-amplitude (less than 0.1 MPa) shock wave pressure and single-fragment impact loading, and cannot meet the test requirements of high-amplitude (not less than 100 MPa) explosion shock wave pressure and combined damage loading of dense fragment groups during the near-field explosion process. At the same time, effects such as dynamic pressure of near-field detonation products, ablation of high-temperature detonation product flow, fluid-structure coupling of explosion shock waves and protection structures, and collaborative impact of dense fragment group loads have not been considered, making it difficult to accurately reflect the typical characteristics of sympathetic detonation coupled multi-physical field loads and severely restricting the reliable evaluation of the protection effectiveness under near-field loading of equipment in sympathetic detonation.

[0003] The existing test method for the combined load action of simulated explosion shock waves and high-speed fragment groups in the field of sympathetic detonation load collaborative loading and evaluation can be used to carry out test research on the combined damage response of protection structures under near-distance conditions, but it does not directly synchronously measure the characteristic parameters of explosion collaborative loads and cannot quantitatively evaluate the combined damage response characteristics of protection structures.

[0004] Therefore, it is urgent to carry out research on sympathetic detonation multi-physical field load collaborative loading test and characterization evaluation technology to provide effective support for the optimal design and effectiveness evaluation of protection equipment. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a protection evaluation method for the collaborative loading of multi-physical-field loads in sympathetic detonation, so as to solve the problems of weak consistency in the collaborative loading and synchronous testing of multi-physical-field loads in sympathetic detonation, low amplitude and accuracy of explosion shock wave testing, unclear transient response process of the structure to be tested, and imperfect protection performance evaluation method in the existing testing process.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A protection evaluation method for the collaborative loading of multi-physical-field loads in sympathetic detonation, comprising the following steps:

[0008] Step S1: Build a test system for the collaborative loading of multi-physical-field loads in sympathetic detonation, and detonate the initiating detonator of the near-field collaborative explosion load loading device through the initiating system to achieve the collaborative loading of explosion shock waves and fragment groups;

[0009] Step S2: Measure and obtain the free-field incident overpressure history P i (t) and the wall-reflected overpressure history P r (t) of the wall of the specimen to be tested through the free-field incident overpressure test system and the wall-reflected overpressure test system; obtain the average residual velocity V r of the pre-controlled fragment group after penetrating the target through the laser velocity measurement system; obtain the damaged state information of the specimen to be tested through the transient three-dimensional DIC test system combined with three-dimensional scanning: the number of fragment perforations N p , the collaborative damage area S p of the shock wave and fragment group, the peak deflection D max (r) of the back panel deformation and the peak deflection D fmax of the final state deformation;

[0010] Step S3: Calculate the evaluation index of the sympathetic detonation collaborative load intensity and the evaluation index of the protection performance of the specimen to be tested according to the various data measured in Step S2;

[0011] The evaluation index of the sympathetic detonation collaborative load intensity includes: the evaluation index of the explosion shock wave load intensity and the evaluation index of the fragment group load intensity; the evaluation index of the explosion shock wave load intensity includes: the scaled distance R, the incident peak overpressure P imax , the incident peak impulse I imax , the reflected peak overpressure P rmax , the reflected peak impulse I rmax and the positive pressure zone pulse width τ; the evaluation index of the fragment group load intensity includes: the average initial velocity V b of the fragment group, the total mass m t of the fragment group and the total number N t of the fragments;

[0012] The evaluation indexes of the protection performance of the specimen to be tested include: the protection index of the explosion shock wave load and the protection index of the fragment group load; the protection index of the explosion shock wave load: the peak deflection D of the final state deformation fmax , the cumulative characteristic impulse I s (r) of the radial distribution of the specimen to be tested, and the peak deflection D max (r) of the backplate deformation; the protection index of the fragment group load: the overall kinetic energy loss E r of the fragment group before and after piercing the target, the number N p of fragment perforations, and the collaborative damage area S p of the shock wave and the fragment group;

[0013] Step S4: Nondimensionalize the evaluation indexes of the protection performance of the specimen to be tested to obtain the comprehensive evaluation function of the protection efficiency of the specimen to be tested: where π1 = l / D fmax , π2 = I s (r)τ / D max (r)ρl, l is the thickness of the specimen to be tested; ρ is the density of the specimen to be tested; E r is the kinetic energy loss of the fragment group before and after piercing the target; E0 = 1 / 2m t V b 2 , E0 is the initial kinetic energy of the fragment group; α1, α2, β1, β2, and β3 are weight distribution factors; substituting the parameter values of each evaluation index determined in the above step S3 into the comprehensive evaluation function of the protection efficiency of the specimen to be tested, the comprehensive protection evaluation index Φ of the specimen to be tested can be obtained.

[0014] Further, in the above step S3, integrating the free-field incident overpressure history P i (t) and the wall-reflected overpressure history P r (t) of the specimen to be tested with respect to time to obtain the incident impulse history I i (t) and the reflected impulse history I r (t); obtaining the incident peak overpressure P i (t), the reflected peak overpressure P r (t), and the positive pressure zone pulse width τ from the free-field incident overpressure history P imax and the wall-reflected overpressure history P rmax of the specimen to be tested; obtaining the incident peak impulse I i (t) and the reflected peak impulse I r (t) from the incident impulse history I imax and the reflected impulse history I rmax .

[0015] Further, in the above step S3, the overall kinetic energy loss E of the fragment group before and after piercing the target is calculated using the formula ​r ; where m t is the total mass of the fragment group, V b is the average initial velocity of the fragment group, and V r is the average residual velocity of the pre-controlled fragment group after penetrating the target.

[0016] Furthermore, in the step S3, the cumulative characteristic impulse I s (r) of the specimen in the radial distribution is calculated by the formula I s (r) = ρlV max (r); where ρ is the density of the specimen to be tested, l is the thickness of the specimen to be tested, and V max (r) is the peak velocity along the radial direction at the center of the specimen to be tested.

[0017] Furthermore, in the step S4, π1 is the final-state deformation impedance factor, π2 is the peak deformation impedance factor, and π1 and π2 are used to characterize the explosion shock wave protection performance; ω1 is the fragment velocity impedance factor, and ω2 and ω3 are both fragment perforation impedance factors, and ω1, ω2, and ω3 are used to characterize the protection performance of the dense fragment group of the specimen to be tested.

[0018] Furthermore, in the step S4, according to the evaluation requirements of the protection performance of the specimen to be tested in the actual application process, each weight distribution factor of the explosion shock wave and fragment group load protection indexes is determined; the weight distribution factors α1, α2, β1, β2, and β3 are all greater than or equal to 0 and satisfy: {∑(α i +β j ) = 1, i = 1, 2; j = 1, 2, 3}.

[0019] A test system for collaborative loading of multi-physical field loads in sympathetic detonation is used to implement the above protection evaluation method; the test system includes: a near-field collaborative explosion load loading device, a free-field incident overpressure test system, a wall-reflected overpressure test system, a specimen to be tested, a clamping and fixing device for the specimen to be tested, a laser velocimetry system, a transient three-dimensional DIC test system, a detonating system, and a data acquisition and storage system;

[0020] The free-field incident overpressure test system and the wall-reflected overpressure test system are used to obtain the free-field incident overpressure history and the wall-reflected overpressure history of the specimen to be tested; the specimen to be tested is fixedly installed in the middle of the clamping and fixing device for the specimen to be tested; the laser velocimetry system is used to measure the average velocity of the loaded fragment group; the transient three-dimensional DIC test system can realize the visual measurement of the dynamic response process and deformation displacement field of the specimen to be tested; the detonating system is used to detonate the detonating detonator; the data acquisition and storage system is used to collect and store the various data measured by the test system.

[0021] Further, the near-field collaborative explosion load loading device includes: a detonating detonator, an expanding explosive charge, a detonator seat, a loading explosive charge, and a pre-controlled fragment group.

[0022] Further, the back of the test specimen includes a white background area and a central test area; the central test area is circular, and a plurality of random and dense speckles are hand-painted inside the central test area with a marker pen.

[0023] Further, the test specimen clamping and fixing device includes a front panel flange and a rear panel flange for clamping and fixing the test specimen. Central holes overlapping with the central test area are provided at the centers of the front panel flange and the rear panel flange; the free-field incident overpressure test system is arranged in front of the test specimen, and the wall reflection overpressure test system is arranged on the front panel flange; both the laser velocity measurement system and the transient three-dimensional DIC test system are arranged on the back side of the test specimen.

[0024] Compared with the prior art, the technical solution provided by the present invention has at least one of the following beneficial effects:

[0025] 1. The test system for the collaborative loading of sympathetic detonation multi-physical field loads proposed by the present invention can realize the joint loading of multi-physical field loads such as high-amplitude explosion products, air shock waves, and dense fragment groups at different explosion distances within the near field range, and synchronously measure and obtain the incident and reflected peak overpressure impulses of the explosion shock wave and the average velocity of the fragment group. The dynamic response process and deformation displacement field of the test protective structure can be visually and quantitatively characterized through the transient three-dimensional DIC test system.

[0026] 2. The protective evaluation method for sympathetic detonation multi-physical field loads proposed by the present invention can realize the quantitative characterization of the intensity of near-field sympathetic detonation collaborative loads, the protective performance of the explosion shock wave and dense fragment groups of the test specimen. According to the protective performance evaluation requirements of the test specimen in the actual application process, the weight distribution factors of the protective indexes of the explosion shock wave and fragment group loads are determined, and the dimensionless comprehensive protective performance index is obtained through the comprehensive evaluation function of the protective efficiency of the test specimen, so as to optimize and give the best protective structure, providing support for the evaluation of the protective efficiency of equipment under the collaborative loading of sympathetic detonation multi-physical field loads.

[0027] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification, or understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0028] The accompanying drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs denote the same components.

[0029] Figure 1 It is a test system for the collaborative loading of multi-physical field loads of sympathetic detonation of the present invention;

[0030] Figure 2 It is a schematic structural diagram of the initiation system of the present invention;

[0031] Figure 3 It is a schematic structural diagram of the data acquisition and storage system of the present invention;

[0032] Figure 4 It is a schematic structural diagram of the near-field collaborative explosion load loading device of the present invention;

[0033] Figure 5 It is a schematic structural composition diagram of the loading explosive source of the present invention;

[0034] Figure 6 It is a schematic structural diagram of the pre-controlled fragment group of the present invention;

[0035] Figure 7 It is a schematic structural diagram of the clamping and fixing device for the test piece to be tested of the present invention;

[0036] Figure 8 It is a schematic structural diagram of the test piece to be tested of the present invention;

[0037] Figure 9 It is a schematic structural diagram of the laser velocity measurement system of the present invention;

[0038] Figure 10 It is a schematic structural diagram of the high-speed camera protection device of the present invention;

[0039] Figure 11 It is the test history of the incident and reflected overpressure of the near-field explosion shock wave of the present invention;

[0040] Figure 12 It is the final state deformation deflection cloud map of the three-dimensional scanning of the test piece to be tested of the present invention;

[0041] Figure 13 It is the displacement field cloud map at a typical moment of the sympathetic detonation collaborative loading of the test piece to be tested of the present invention.

[0042] Reference signs:

[0043] 1 - Near-field collaborative explosion load loading device; 2 - Free-field incident overpressure test system; 3 - Wall reflection overpressure test system; 4 - Test piece to be tested; 5 - Clamping and fixing device for the test piece to be tested; 6 - Laser velocity measurement system; 7 - Transient three-dimensional DIC test system; 8 - Initiation system; 9 - Data acquisition and storage system;

[0044] 11 - Initiating detonator; 12 - Booster charge column; 13 - Detonator seat; 14 - Loading charge column; 15 - Pre - controlled fragment group; 16 - Vertical support rod; 17 - Horizontal support rod; 18 - Chassis bushing; 19 - Chassis

[0045] 31 - Wall pressure sensor; 32 - Teflon bushing

[0046] 41 - White background area; 42 - Central test area

[0047] 51 - Front panel flange; 52 - Rear panel flange; 53 - Fixed panel; 54 - First light - shielding plate; 55 - Second light - shielding plate; 56 - Fixed bracket; 57 - Fixed base; 58 - Fastening bolt

[0048] 61 - Retro - reflective screen; 62 - Starting curtain target; 63 - Stopping curtain target; 64 - Laser emission and information storage host

[0049] 71 - Front panel; 72 - Bullet - proof glass; 73 - Vertical supporting square steel; 74 - Bottom support plate; 75 - High - speed camera protection device fastening bolt Specific embodiments

[0050] The following will specifically describe the preferred embodiments of the present invention in conjunction with the accompanying drawings. Among them, the accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principle of the present invention, rather than to limit the scope of the present invention.

[0051] Embodiment 1

[0052] A specific embodiment of the present invention provides a method for evaluating the protection of the synergistic loading of multi - physical - field loads in sympathetic detonation, including the following steps:

[0053] Step S1: Build a test system for the synergistic loading of multi - physical - field loads in sympathetic detonation, and detonate the initiating detonator 11 of the near - field synergistic explosion load loading device 1 through the initiating system 8 to achieve the synergistic loading of explosion shock waves and fragment groups;

[0054] Step S2: Measure and obtain the free - field incident over - pressure history P i (t) and the wall - reflected over - pressure history P r (t) of the test specimen to be tested through the free - field incident over - pressure test system 2 and the wall - reflected over - pressure test system 3; Obtain the average remaining velocity V r of the pre - controlled fragment group after penetrating the target through the laser velocity measurement system 6; Test the dynamic response process of the test specimen 4 through the transient three - dimensional DIC test system 7 to obtain the damaged state information of the test specimen 4, and combine three - dimensional scanning to obtain: the number of fragment perforations N p , the synergistic damage area S p of the shock wave and fragment group, and the peak deflection D of the back - plate deformationmax (r) and the peak deflection D of the final state deformation fmax ;

[0055] Step S3: Calculate the evaluation index of the sympathetic detonation collaborative load intensity and the evaluation index of the protection performance of the test specimen according to the various data measured in the step S2;

[0056] The evaluation index of the sympathetic detonation collaborative load intensity includes: the evaluation index of the explosion shock wave intensity and the evaluation index of the fragment group load intensity; the evaluation index of the explosion shock wave load intensity includes: the scaled distance R, the peak incident overpressure P imax , the incident peak impulse I imax , the reflected peak overpressure P rmax , the reflected peak impulse I rmax and the positive pressure zone pulse width τ; the evaluation index of the fragment group load intensity includes: the average initial velocity V of the fragment group b , the total mass m of the fragment group t and the total number N of fragments t ;

[0057] The evaluation index of the protection performance of the test specimen includes: the explosion shock wave load protection index and the fragment group load protection index; the explosion shock wave load protection index: the peak deflection D of the final state deformation fmax , the cumulative characteristic impulse I s (r) of the radial distribution of the test specimen, the peak deflection D max (r) of the back plate deformation; the fragment group load protection index: the overall kinetic energy loss E of the fragment group before and after piercing the target r , the number N of fragment perforations p and the collaborative damage area S of the shock wave and the fragment group p ;

[0058] Furthermore, in the step S3, the free-field incident overpressure history P i (t) and the test specimen wall surface reflected overpressure history P r (t) are integrated with respect to time to obtain the incident impulse history I i (t) and the reflected impulse history I r (t); according to the free-field incident overpressure history P i (t) and the test specimen wall surface reflected overpressure history P r (t), the peak incident overpressure P imax , the reflected peak overpressure P rmax and the positive pressure zone pulse width τ are obtained; according to the incident impulse history I i (t) and the reflected impulse history I r (t), the incident peak impulse I imax and the reflected peak impulse I rmax .

[0059] In a specific embodiment of the present invention, in step S3, the formula is used to calculate the overall kinetic energy loss E of the fragment group before and after penetrating the target r ; in the formula, E r is the kinetic energy loss of the fragment group before and after penetrating the target, m t is the total mass of the fragment group, V b is the average initial velocity of the fragment group, and V r is the average remaining velocity of the pre-controlled fragment group after penetrating the target.

[0060] Step S4: Nondimensionalize the evaluation indexes of the protection performance of the test piece to obtain the comprehensive evaluation function of the protection effectiveness of the test piece: where π1 = l / D fmax , π2 = I s (r)τ / D max (r)ρl, l is the thickness of the test piece; ρ is the density of the test piece; E r is the kinetic energy loss of the fragment group before and after penetrating the target; E0 = 1 / 2m t V b 2 , E0 is the initial kinetic energy of the fragment group; α1, α2, β1, β2 and β3 are weight distribution factors; substituting the parameter values of each evaluation index determined in step S3 into the comprehensive evaluation function of the protection effectiveness of the test piece can obtain the comprehensive protection evaluation index Φ of the test piece.

[0061] In a specific embodiment of the present invention, the cumulative characteristic impulse I s (r) of the radial distribution of the test piece is calculated by the formula I s (r) = ρlV max (r); in the formula, ρ is the density of the test piece, l is the thickness of the test piece, and V max (r) is the peak velocity along the radial direction of the center of the test piece, which is obtained by differentiating the displacement history of the back plate with respect to time.

[0062] In a specific embodiment of the present invention, in step S4, π1 is the final state deformation impedance factor, and π2 is the peak deformation impedance factor. π1 and π2 are used to characterize the protection performance of the explosion shock wave; ω1 is the fragment velocity impedance factor, and ω2 and ω3 are both fragment perforation impedance factors. ω1, ω2 and ω3 are used to characterize the protection performance of the dense fragment group of the test piece.

[0063] In a specific embodiment of the present invention, according to the evaluation requirements of the protection performance of the test piece in the actual application process, each weight distribution factor of the protection indexes of the explosion shock wave and the fragment group load is determined; the weight distribution factors α1, α2, β1, β2 and β3 are all greater than or equal to 0 and satisfy: {∑(α i+β j ) = 1, i = 1, 2; j = 1, 2, 3}.

[0064] The following combines specific cases to detail the protective evaluation method for the coupled loading of multi-physical field loads in the sympathetic detonation of the present invention:

[0065] In this embodiment, the evaluation index parameters of the protective efficacy of the test piece under the coupled sympathetic detonation loading are related to the input load amplitude. Therefore, the evaluation indexes for the intensity of the coupled sympathetic load are given, including the evaluation index for the intensity of the blast shock wave: the scaled distance R, the peak incident overpressure P imax , the peak incident impulse I imax , the peak reflected overpressure P rmax , the peak reflected impulse I rmax and the positive pressure zone pulse width τ, as well as the evaluation indexes for the intensity of the fragment group load: the average initial velocity V of the fragment group b , the total mass m of the fragment group t and the total number N of fragments t ; Considering the deficiencies such as the single evaluation index of the performance of the protective structure under the existing coupled loading and the limited applicable range, in order to comprehensively evaluate the protective performance of the test piece, the comprehensive protective index for the blast shock wave load is given: the peak deflection D of the final deformation fmax , the cumulative characteristic impulse I s (r) of the radial distribution of the test piece and the peak deflection D max (r) of the backplate deformation, as well as the protective index for the fragment group load: the overall kinetic energy loss E of the fragment group before and after penetrating the target r , the number N of fragment perforations p and the collaborative damage area S of the shock wave and the fragment group p .

[0066] In this embodiment: During the explosion process of the explosive source, the formed detonation products rapidly compress the surrounding air to form an air shock wave with a finite thickness at the front. The pressure amplitude in the overpressure region of the air shock wave is greater than the local ambient atmospheric pressure. During the decay of the overpressure with time, the stage where the pressure is higher than the ambient pressure is defined as the positive pressure zone. The free-field incident overpressure history P i (t) and the wall reflected overpressure history P r (t) of the test piece are obtained through the near-field explosion shock wave overpressure test system. Specifically, the free-field pressure sensor of the free-field incident overpressure test system 2 is used to test the free-field incident overpressure history P i (t) during the explosion process, and the wall pressure sensor of the wall reflected overpressure test system 3 is used to monitor the impact pressure of the detonation products and the air shock wave on the surface area of the test piece to obtain the wall reflected overpressure history P r (t) of the test piece.

[0067] Furthermore, for the free-field incident overpressure history P i(t) and the reflected overpressure history P of the wall surface of the specimen to be tested r Integrate (t) with I = ∫p(t)dt to obtain the incident impulse history I i (t) and the reflected impulse history I r (t); According to the free-field incident overpressure history P i (t), the reflected overpressure history P of the wall surface of the specimen to be tested r (t), the incident impulse history I i (t) and the reflected impulse history I r (t), quantitatively give the strength evaluation indexes of the explosion shock wave load at different scaled distances R: the incident peak overpressure P of the shock wave imax , the reflected peak overpressure P rmax , the incident peak impulse I imax , the reflected peak impulse I rmax , the positive pressure zone pulse width τ, etc. Specifically, the incident peak overpressure P of the shock wave imax is the maximum value of the free-field incident overpressure history P i (t), and the reflected peak overpressure P rmax is the maximum value of the reflected overpressure history P of the wall surface of the specimen to be tested r (t); The incident peak impulse I imax , the reflected peak impulse I rmax are respectively the maximum values of the incident impulse history I i (t) and the reflected impulse history I r (t). The positive pressure zone pulse width is the time interval from the start of the peak step of the front air shock wave front to the stage of decaying to the local ambient atmospheric pressure, and the positive pressure zone pulse width τ is obtained according to the free-field incident overpressure history P i (t).

[0068] As Figure 11 shown, in a specific embodiment of the present invention, the scaled distance R = 0.32 m / kg 1 / 3 , and the test obtains that the incident peak overpressure P of the shock wave imax = 14.98 MPa, the reflected peak overpressure P rmax = 116.27 MPa, the incident peak impulse I imax = 440.26 MPa·μs, the reflected peak impulse I rmax = 2355.68 MPa·μs, and the positive pressure zone pulse width τ = 67 μs.

[0069] The test results show that: due to the dynamic pressure impact effect of the near-field detonation products, the cumulative reflected impulse on the wall surface is 5.3 times the incident impulse.

[0070] In this embodiment: The average initial velocity (velocity in front of the target) V of the fragment group load is calculated by using the one-dimensional unsteady charge detonation driving theory proposed by formula (I)b .

[0071]

[0072] In the formula, V b is the average initial velocity of the fragments, D e is the detonation velocity of the explosive, and μ represents the dimensionless mass ratio of the explosive to the fragment group.

[0073] Furthermore, the average residual velocity V r of the pre-controlled fragment group after penetrating the target is obtained through the laser velocity measurement system 6, and the overall kinetic energy loss E r of the fragment group before and after penetrating the target is calculated using formula (II). r E

[0074]

[0075] In the formula,

[0076] E r is the kinetic energy loss of the fragment group before and after penetrating the target;

[0077] m t is the total mass of the fragment group.

[0078] Furthermore, the initial kinetic energy of the fragment group is calculated using formula (III):

[0079] E0 = 1 / 2m t V b 2 Formula (III)

[0080] In this embodiment: The total number of fragments N t calculated is 25 pieces, the average initial velocity V b is 1150 m / s, the average residual velocity V r of the pre-controlled fragment group after penetrating the target is obtained through the laser velocity measurement system, and the overall kinetic energy loss E r of the fragment group before and after penetrating the target is calculated according to formula (II) and is 37.37 kJ.

[0081] In step S2: The number of fragment perforations N p of the test piece after the test, the collaborative damage area S p of the shock wave and the fragment group, and the peak deflection D fmax of the final state deformation are obtained through the three-dimensional scanning technology.

[0082] Among them, the number of fragment perforations N P of the test piece after the test and the collaborative damage area S pIt can be used as an index for the protection performance of the fragments of the specimen to be tested. The fewer the number of perforations in the specimen to be tested and the smaller the area of the collaborative fragment region, the better the protection performance of the fragment group; and the peak deflection D of the final state deformation f max It can be used as an index for the protection performance against the explosion shock wave. The smaller the peak value of the deflection of the final state deformation, the better the protection performance against the explosion shock wave;

[0083] Such as Figure 12 shown, in this embodiment, the specimen 4 to be tested is a polyurea fiber sandwich target (thickness l = 10 mm), and the number N of perforations of the specimen to be tested is obtained by using the three-dimensional scanning technology p = 14, the collaborative damage area S of the shock wave fragment group p = 50.26 cm 2 , and the peak deflection D of the final state deformation fmax = 27.39 mm.

[0084] In this embodiment, based on the transient three-dimensional DIC test system, the dynamic response process and the visual measurement of the deformation displacement field of the specimen to be tested are given, and the energy dissipation mode of the protection structure is analyzed through the dynamic response process of the specimen to be tested.

[0085] Furthermore, by processing the data of the deformation displacement field and based on formula (IV), the quantitative relationship between the cumulative radial impulse I s (r) at the center of the specimen to be tested and the peak deflection D max (r) of the back plate is obtained. As an index for the protection performance of the specimen to be tested against the explosion shock wave, when the cumulative characteristic impulse is close, the smaller the peak deflection, the better the protection performance against the explosion shock wave;

[0086] I s (r)=ρlV max (r) Formula (IV)

[0087] In the formula,

[0088] I s (r) is the cumulative radial impulse along the center of the specimen to be tested;

[0089] ρ is the density of the specimen to be tested;

[0090] l is the thickness of the specimen to be tested;

[0091] V max (r) is the peak velocity of the radial displacement along the center of the specimen to be tested, which is obtained by differentiating the back plate displacement history with respect to time through the transient three-dimensional DIC test system 7.

[0092] Such as Figure 13As shown, it is the displacement field nephogram at a typical moment of the sympathetic detonation co - loading of the specimen to be tested; in this embodiment, the test results of the transient three - dimensional DIC test system 7 are analyzed, and it is obtained that the energy - dissipation modes of the specimen to be tested 4 include the large - deformation visco - elastic energy - dissipation of the polyurea layer, the debonding between and within the sandwich fiber layers, the viscoplastic energy - dissipation such as the tensile fracture of the fiber bundles, the energy - dissipation due to the debonding of the material layer interfaces, the energy - dissipation due to the transverse rarefaction wave effect, etc., which is a comprehensive energy - dissipation mode.

[0093] In this embodiment, the cumulative radial impulse I s (r) at the center of the specimen to be tested is calculated by formula (IV) and approximately linearly decays, while the peak deflection D max (r) of the backplate deformation shows an approximately second - order polynomial non - linear decay.

[0094] In this embodiment, considering the actual differences in the protection requirements of the explosive shock wave and the fragment group load during the actual design process of the protection structure, the distribution weight factors α1, α2, β1, β2, and β3 of the explosive shock wave and the fragment group are introduced. α1, α2, β1, β2, and β3 are all greater than or equal to 0 and satisfy {∑(α i +β j ) = 1, i = 1, 2; j = 1, 2, 3}, which is used to more effectively carry out the comprehensive performance evaluation of the structure under different protection requirements.

[0095] At the same time, to eliminate the influence of the unit system, dimensionless parameters are introduced:

[0096] The final - state deformation impedance factor π1 = l / D fmax ;

[0097] The peak - deformation impedance factor π2 = I s (r)τ / D max (r)ρl;

[0098] The fragment - velocity impedance factor

[0099] The first - fragment perforation impedance factor and the second - fragment perforation impedance factor

[0100] Among them, π1 and π2 are the protection performance factors of the explosive shock wave, and ω1, ω2, ω3 are the protection performance factors of the dense fragment group.

[0101] The comprehensive protection evaluation index Φ of the specimens to be tested with different ratios under co - loading is calculated by formula (V), so as to evaluate and give the optimal protection structure, providing support for the protection efficiency evaluation under the sympathetic detonation multi - physical - field load co - loading.

[0102] The comprehensive evaluation function of the protection efficiency of the specimen to be tested is:

[0103]

[0104] In the formula,

[0105] Φ is the comprehensive protection performance evaluation index;

[0106] α1 and α2 are the near-field explosion shock wave protection weight factors;

[0107] β1~β3 are the fragment group protection weight factors;

[0108] Under the premise of satisfying the principle of weight factor selection, α i and β i The specific value is determined based on the emphasis of the actual protection design.

[0109] In this embodiment: the loading mode is the coordinated loading of explosion shock wave and fragment group, focusing on the protection of dense fragment group load, especially focusing on the protection characteristics of fragment velocity. First, through steps 1 to 4, the input load of sympathetic joint loading and the protection performance evaluation index parameters are obtained, and the relevant dimensionless protection factor is calculated. Further, according to the above actual protection requirements, the weight distribution factor is given as follows: α1=α2=0.1, β1=0.4, β2=β3=0.2, which is substituted into formula (IV) to calculate the comprehensive protection evaluation index Φ of the test piece. Finally, by comparing the protection performance indicators of the test pieces with different structures, the optimal fragment velocity protection structure is optimized to be 2mm polyurea + 6mm fiber sandwich layer + 2mm polyurea layer structure, which provides support for the subsequent protection structure system design and quantitative evaluation.

[0110] Example 2

[0111] A specific embodiment of the present invention discloses a test system for coordinated loading of multi-physical field loads for sympathetic explosion, which is used to implement the protection evaluation method for coordinated loading of multi-physical field loads for sympathetic explosion of the test piece in embodiment 1, such as Figure 1 As shown, it includes: a near-field collaborative explosion load loading device 1, a free-field incident overpressure test system 2 and a wall reflection overpressure test system 3, a test piece 4, a clamping device for the test piece 5, a laser speed measurement system 6, a transient three-dimensional DIC test system 7, a detonation system 8 and a data acquisition and storage system 9.

[0112] In view of the shortcomings of the prior art, the present invention proposes an experimental testing system for the coordinated loading of near-field detonation products, air shock waves and fragment group loads, which can realize the coordinated loading and synchronous test characterization of multi-physical field loads of near-field explosions, and conduct a comprehensive quantitative evaluation of the protection performance of the test pieces under the combined loading, thereby providing a reference for the evaluation of the protection effectiveness of equipment under coordinated loading of sympathetic detonation.

[0113] like Figure 2 and Figure 3As shown in the figure, the initiation system 8 and the data acquisition and storage system 9 in this example include equipment such as a detonator initiator, a generator, a charge amplifier, a digital acquisition instrument, and a data storage computer, and are protected by a concrete protective bunker to reduce the interference of explosion shock waves and fragment groups on the test equipment.

[0114] As Figure 4 , Figure 5 , Figure 6 shown, the near-field collaborative explosion load loading device 1 includes: an initiation sequence, an explosive source, and an adjustable clamping and fixing device; the initiation sequence composed of an initiation detonator 11, an expanding charge column 12, and a detonator seat 13, the explosive source composed of a loading charge column 14 and a pre-controlled fragment group 15, and the adjustable clamping and fixing device composed of a chassis 19, a chassis bushing 18, a vertical support rod 16, and a horizontal support rod 17.

[0115] Specifically, as Figure 4 shown, the vertical support rod 16 is fixedly connected to the chassis 19 through the chassis bushing 18; the horizontal support rod 17 is arranged perpendicular to the vertical support rod 16 and the two are fixedly connected; the initiation sequence and the explosive source are fixedly installed at the end of the horizontal support rod 17.

[0116] Specifically, as Figure 5 shown, the initiation detonator 11, the expanding charge column 12, the detonator seat 13, the loading charge column 14, and the pre-controlled fragment group 15 are arranged in sequence from top to bottom.

[0117] Specifically, as Figure 6 shown, the pre-controlled fragment group 15 is a metal plate with multiple metal bumps formed after grooving on the surface, and multiple pieces of the metal bumps are arranged in a matrix on the surface of the metal plate.

[0118] In a specific embodiment of the present invention, the expanding charge column 12 is a cylinder with a diameter of 25 mm and a height of 12.6 mm, and the mass is 10 g; the loading charge column 14 is a cylindrical TNT with a diameter of 50 mm and a height of 50 mm, and the mass is 150 g; the number of the pre-controlled fragment groups 15 is 25, and each single fragment is a square 35CrMnSiA high-strength steel with a size of 10 mm×10 mm×4 mm. The grooving thickness of the pre-controlled fragment group is 0.5 mm. Under detonation drive, compared with the prefabricated fragment group, it can fracture to form a denser fragment group load with better uniformity; the horizontal support rod 17 can adjust the length and vertical height according to different explosion positions or scaled distances.

[0119] In a specific embodiment of the present invention, a near-field explosion shock wave and fragment group collaborative loading mode is adopted. The vertical distance between the lower end surface of the loading charge column 14 and the test piece 4 to be tested is 150 mm, and the theoretical calculation gives a scaled distance R = 0.32 m / kg 1 / 3 , and the wall reflection overpressure is about 100 MPa, and the average velocity of the fragment group is 1150 m / s.

[0120] Specifically, the free-field incident overpressure test system 2 includes a high-range free-field pressure sensor, a fixing tooling, a low-noise cable, a charge amplifier, and a data acquisition and storage device; the wall-reflection overpressure test system 3 includes a wall pressure sensor, a fixed bushing, a low-noise cable, a charge amplifier, and a data acquisition and storage device.

[0121] In a specific embodiment of the present invention, the free-field pressure sensor uses a KD2002-50 piezoelectric pressure sensor with a range ≤ 50 MPa and a rise time < 1 μs. The wall pressure sensor uses an LK141PQ-500M piezoelectric pressure sensor with a range ≤ 500 MPa and a rise time < 4 μs. The triggering method is synchronous external triggering, which can accurately measure the incident and reflected overpressures of near-field high-amplitude detonation products and air shock waves. During the measurement process, a thin layer of about 0.1 mm vacuum silicone grease coating is applied at the position of the sensor sensitive element to reduce the temperature drift and noise generated by the thermal radiation effect of the explosion fireball.

[0122] The free-field incident overpressure test system 2 and the wall-reflection overpressure test system 3 share a set of data acquisition and storage system, including an LK1432B eight-channel charge amplifier, an STYV-50-2 low-noise cable, a DH5690 ultra-dynamic model test analyzer, and supporting analysis software, etc.

[0123] The clamping and fixing device for the test piece used in this example is as Figure 7 shown, and includes a front panel flange 51, a rear panel flange 52, a fixing panel 53, a first light-shielding plate 54, a second light-shielding plate 55, a fixing bracket 56, a fixing base 57, and fastening bolts 58.

[0124] Specifically, central holes overlapping with the central test area 42 are provided at the centers of the front panel flange 51 and the rear panel flange 52; the front panel flange 51, the rear panel flange 52 and the edge of the test piece 4 are fixedly connected by bolts; the central test area 42 of the test piece 4 deforms under the explosion shock, as Figure 13 shown.

[0125] Specifically, as Figure 7 shown, the fixing base 57 is fixedly connected to the fixing bracket 56 by fastening bolts 58; the fixing bracket 56 is a triangular bracket; the fixing panel 53 is fixedly installed above the fixing bracket 56; the front panel flange 51 and the rear panel flange 52 are fixedly connected to the fixing panel 53 by bolts.

[0126] Specifically, the first light-shielding plate 54 is disposed above the fixed panel, and the second light-shielding plates 55 are disposed on both sides of the fixed panel 53. Both the first light-shielding plate 54 and the second light-shielding plates 55 are used to block the light generated by the explosion, thereby ensuring the accuracy of the test results of the laser velocity measurement system 6 and the transient three-dimensional DIC test system 7.

[0127] Specifically, the wall-reflected overpressure test system 3 is disposed on the front panel flange 51 for testing the wall-reflected overpressure.

[0128] Specifically, the free-field incident overpressure test system 2 is disposed in front of the test piece 4 to be tested, and the laser velocity measurement system 6 and the transient three-dimensional DIC test system 7 are both disposed on the back side of the test piece 4 to be tested.

[0129] Further, as Figure 1 shown, the transient three-dimensional DIC test system 7 is disposed on the rear side of the laser velocity measurement system 6 and two sets are symmetrically arranged left and right. In this embodiment, by providing two sets of the transient three-dimensional DIC test systems 7, the transient deformation of the test piece 4 to be tested can be accurately captured.

[0130] In a specific embodiment of the present invention, both the front panel flange 51 and the rear panel flange 52 are Q235 steel of 500 mm × 500 mm × 15 mm.

[0131] Specifically, four wall pressure sensors 31 are arranged on the upper surface of the front panel flange 51; a polytetrafluoroethylene bushing 32 is used outside the wall pressure sensor 31 to suppress mechanical vibration during the explosion test, improve the test accuracy, and a wire groove is preset on the front panel flange 51 for fixing the sensor cable.

[0132] Specifically, the fixed panel 53 is Q235 steel of 1000 mm × 1000 mm × 10 mm. The first light-shielding plate 54 and the second light-shielding plates 55 are respectively connected to the fixed bracket 56 to suppress the overexposure phenomenon of the explosion firelight to the high-speed camera during the test; four wall pressure sensors are arranged along the circumferential direction on the surface of the front panel flange 51, and a wire groove is preset for fixing the sensor cable to prevent the explosion shock wave from cutting off the cable.

[0133] Specifically, each component in the test piece clamping and fixing device 5 is connected by an M16 fastening bolt 58, and the front panel flange 51, the rear panel flange 52 and the test piece 4 are clamped by bolts and fixed by a pre-tightening force.

[0134] As Figure 8As shown, in this embodiment, the test piece 4 used is a fiber polyurea composite protective structure of 400mm×400mm×10mm, the back of the test piece 4 is sprayed with matte white primer as the white background area 41, the central test area 42 has a diameter of 300mm, and the speckle is manually randomly and densely dotted with a marker pen to improve the accuracy of digital image recognition.

[0135] like Figure 9 As shown, the laser speed measurement system 6 described in this example includes a laser emission and information storage host 64, an original reflection screen 61, a start screen target 62 and a stop screen target 63.

[0136] Specifically, the model of the laser velocity measurement system is JGM-CP400W, and the specific performance parameters are: velocity measurement range ≤2500m / s, velocity measurement accuracy ±0.5%, measurable fragment size ≥Φ3mm, capture rate ≥96%, which can realize accurate measurement of the instantaneous velocity of any fragment in a near-field dense fragment group. During the test, the laser velocity measurement system is placed behind the test piece to reduce the interference of the explosion fireball on the test.

[0137] The transient three-dimensional DIC test system 7 described in this example includes: a high-speed photography protection device, two high-frame rate synchronous high-speed cameras, synchronization and trigger cables, a fixed tripod, data acquisition and storage equipment, etc.

[0138] In this embodiment, the high-speed camera protection device includes: a front panel 71, a bulletproof glass 72, a vertical supporting square steel 73, a bottom supporting plate 74, and a high-speed camera protection device fastening bolt 75.

[0139] Specifically, Figure 10 The bulletproof glass 72 is fixedly mounted on the front panel 71 , and the front panel 71 and the vertical supporting square steel 73 , as well as the vertical supporting square steel 73 and the bottom supporting plate 74 are fixedly connected by high-angle protective device fastening bolts 75 .

[0140] In this embodiment, the components of the high-speed camera protection device are connected by M12 fastening bolts, wherein the size of the bulletproof glass is 520mm×422mm×12mm, and the vertical support square steel 73 can be adjusted in height according to the change of the field of view of the high-speed camera, thereby achieving effective protection for the high-speed camera; wherein, one end of the trigger cable is connected to the detonator initiator to achieve synchronous triggering of the initiator and the high-speed camera.

[0141] The high-frame-rate synchronous high-speed camera model is Photron FASTCAM. During the test, the camera frame rate is 50,000 fps, the resolution is 512×512, and two cameras are synchronously triggered by using a synchronous trigger cable. One end of the trigger cable is connected to the detonator initiator to achieve synchronous triggering of the detonator and the high-speed camera. Before the test, a calibration plate is used to calibrate the speckle size on the back of the specimen 4 to be tested, which is used for subsequent DIC test data processing and analysis, and can realize the visual measurement of the dynamic response process and deformation displacement field of the specimen to be tested under the loading of sympathetic detonation coupling load.

[0142] In this embodiment, the specific structural compositions of the free-field incident overpressure test system 2, the wall-reflected overpressure test system 3, the laser velocity measurement system 6, the transient three-dimensional DIC test system 7, the initiation system 8 and the data acquisition and storage system 9, as well as the connection methods between electrical components, belong to the scope that can be achieved by those skilled in the art, and will not be elaborated in this embodiment.

[0143] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A protection evaluation method for the collaborative loading of multi-physical field loads in sympathetic detonation, characterized in that, It includes the following steps: Step S1: Build a test system for the collaborative loading of multi-physical field loads for sympathetic detonation, and detonate the initiating detonator of the near-field collaborative explosion load loading device through the initiating system to achieve the collaborative loading of explosion shock waves and fragment groups; Step S2: Measure and obtain the free-field incident overpressure history P i (t) and the wall-reflected overpressure history P r (t) of the test specimen to be tested; obtain the average residual velocity V of the pre-controlled fragment group after penetrating the target through the laser velocity measurement system r ; perform three-dimensional scanning through the transient three-dimensional DIC test system to obtain the damaged state information of the test specimen to be tested: the number of fragment perforations N p , the collaborative damage area S of the shock wave and fragment group p , the peak deflection D max (r) of the back plate deformation and the peak deflection D fmax ; Step S3: Calculate the evaluation index of the intensity of the sympathetic detonation collaborative load and the evaluation index of the protection performance of the test piece to be tested according to the various data measured in Step S2; Step S4: Nondimensionalize the evaluation indexes of the protection performance of the test piece to obtain the comprehensive evaluation function of the protection effectiveness of the test piece: Among them, α1, α2, β1, β2, and β3 are weight distribution factors; π1 is the final state deformation impedance factor, and π2 is the peak deformation impedance factor. π1 and π2 are used to characterize the protection performance against explosion shock waves; ω1 is the fragment velocity impedance factor, and ω2 and ω3 are both fragment perforation impedance factors. ω1, ω2, and ω3 are used to characterize the protection performance of the test piece against a dense fragment cluster; Substituting the parameter values of each evaluation index determined in the step S3 into the comprehensive evaluation function of the protection effectiveness of the test piece, the comprehensive protection evaluation index Φ of the test piece can be obtained.

2. The protection evaluation method for the coupled loading of multi-physical field loads with sympathetic detonation according to claim 1, wherein, The evaluation indexes of the sympathetic detonation collaborative load intensity include: the evaluation index of the explosion shock wave load intensity and the evaluation index of the fragment group load intensity; the evaluation index of the explosion shock wave load intensity includes: the scaled distance R, the peak incident overpressure P imax , the peak incident impulse I imax , the peak reflected overpressure P rmax , the peak reflected impulse I rmax and the positive pressure zone pulse width τ; the evaluation index of the fragment group load intensity includes: the average initial velocity V of the fragment group b , the total mass m of the fragment group t and the total number Nt of fragments.

3. The protective evaluation method for the coupled loading of multi-physical field loads with sympathetic detonation according to claim 2, wherein The evaluation indexes for the protection performance of the specimen to be tested include: the protection index for the blast shock wave load and the protection index for the fragment swarm load; the protection index for the blast shock wave load: the peak deflection D of the final state deformation fmax , the cumulative characteristic impulse I s (r) of the specimen to be tested in the radial distribution, and the peak deflection D max (r) of the back panel deformation; the protection index for the fragment swarm load: the overall kinetic energy loss E r of the fragment swarm before and after penetrating the target, the number N p of fragment perforations, and the collaborative damage area S p of the shock wave and the fragment swarm.

4. The protection evaluation method for coupled loading of multi-physical field loads with sympathetic detonation according to claim 3, wherein In the step S3, integrating the free-field incident overpressure history P i (t) and the wall-reflected overpressure history P r (t) of the test specimen with respect to time to obtain the incident impulse history I i (t) and the reflected impulse history I r (t).

5. The protection evaluation method for coupled loading of multi-physical field loads with sympathetic detonation according to claim 4, characterized in that In the step S3, according to the free-field incident overpressure history P i (t) and the wall-reflected overpressure history P r (t) of the specimen to be tested, the incident peak overpressure P imax , the reflected peak overpressure P rmax and the positive pressure duration τ are obtained; according to the incident impulse history I i (t) and the reflected impulse history I r (t), the incident peak impulse I imax and the reflected peak impulse I rmax are obtained.

6. The method for evaluating the protection of the coupled loading of multi-physical field loads by sympathetic detonation according to claim 5, characterized in that In the step S4, π1 = l / D fmax , π2 = I s (r)τ / D max (r)ρl, l is the thickness of the specimen to be tested; ρ is the density of the specimen to be tested; E0 is the initial kinetic energy of the fragment group; E r is the overall kinetic energy loss of the fragment group before and after penetrating the target.

7. A test system for co - loading multi - physical - field loads of sympathetic detonation, which is used to implement the protection evaluation method described in any one of claims 1 - 6; characterized in that, The test system includes: a near-field collaborative explosion load loading device, a free-field incident overpressure test system, a wall-reflected overpressure test system, a test piece clamping and fixing device, a laser velocity measurement system, a transient three-dimensional DIC test system, an initiating system, and a data acquisition and storage system; The free-field incident overpressure test system and the wall-reflected overpressure test system are used to obtain the history of the free-field incident overpressure and the history of the wall-reflected overpressure of the test piece to be tested; the test piece to be tested is fixedly installed in the middle of the test piece clamping and fixing device; the laser velocity measurement system is used to measure the average velocity of the loaded fragment group; the transient three-dimensional DIC test system can realize the visual measurement of the dynamic response process and the deformation displacement field of the test piece to be tested; the initiating system is used to detonate the initiating detonator; the data acquisition and storage system is used to collect and store the various data measured by the test system.

8. The test system for the synergistic loading of multi-physical field loads with sympathetic detonation according to claim 7, wherein The near-field collaborative explosion load loading device includes: an initiating detonator, an expanding explosive charge, a detonator seat, a loading explosive charge, and a pre-controlled fragment group.

9. The test system for co-loading of sympathetic detonation multi-physical field loads according to claim 7, wherein, The back of the test piece to be tested includes a white background area and a central test area; the central test area is circular, and multiple random speckles are hand-painted densely inside the central test area with a marker pen.

10. The test system for the collaborative loading of multi-physical field loads with sympathetic detonation according to claim 9, characterized in that, The test piece clamping and fixing device includes a front panel flange and a rear panel flange for clamping and fixing the test piece to be tested, and central holes overlapping with the central test area are provided at the centers of the front panel flange and the rear panel flange; the free-field incident overpressure test system is arranged in front of the test piece to be tested, and the wall-reflected overpressure test system is arranged on the front panel flange; the laser velocity measurement system and the transient three-dimensional DIC test system are both arranged on the back side of the test piece to be tested.

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