A device and method for determining real excitation overload of a loading base based on double-interface pressure measurement

Abstract

This invention belongs to the field of impact dynamics testing, specifically a device and method for determining the true excitation overload of a loading base based on dual-interface pressure measurement. It includes a base, a circuit body, a buffer assembly, an impact-end thin-film pressure sensor, a contact-surface thin-film pressure sensor, and an acceleration sensor. The base includes a base shell with a front cover at the front end and a rear cover at the rear end. A front chamber is located inside the front side of the base shell, and a rear chamber is located inside the rear side. The circuit body is located within the rear chamber. The buffer assembly is located within the rear chamber, between the loading base and the circuit body. The impact-end thin-film pressure sensor is attached to the front cover. The contact-surface thin-film pressure sensor is attached between the loading base and the buffer assembly. The acceleration sensor is mounted in the front chamber or on the front cover. This invention improves the accuracy, reliability, and engineering applicability of input excitation identification in high-g impact tests.

Description

Technical Field

[0001] This invention belongs to the field of impact dynamics testing, specifically a device and method for determining the true excitation overload of a loading base based on dual-interface pressure measurement. Background Technology

[0002] Small electronic instruments, due to their unique operating environments, require evaluation of their impact resistance characteristics under high-g overload conditions. Currently, a common method involves using a gas cannon to launch a mass block, impacting a loading base to generate a high-g overload with a specific amplitude and pulse width, thus subjecting the electronic instrument to impact loading. To enhance the impact resistance of the electronic instrument, a buffer component is typically added at the front end to isolate the strong impact between the electronic instrument and the loading base. In high-g impact tests, the input excitation acceleration is a crucial parameter characterizing the intensity and pulse characteristics of the impact environment. It is also the foundation for evaluating the impact resistance performance of electronic instruments, optimizing the design of interface buffer components, and analyzing the potting protection mechanism. Accurate measurement of the excitation overload is crucial for determining the instrument's impact resistance threshold. How to accurately obtain the true excitation acceleration of the simulated base under high overload has always been a significant technical challenge in the field of high-g impact testing. Currently, a common approach is to fix a high-range accelerometer on the simulated base, directly measuring the acceleration time-history signal of the simulated base during the impact process, and using this as the input excitation for the impact test. This method is relatively simple, but it has the following limitations: 1) Direct acceleration measurement on the loading base is inevitably affected by local vibrations of the base and the installation method: The acceleration signal measured at a certain measuring point on the base not only includes the acceleration component of the overall rigid body motion of the base, but also superimposed local structural vibrations, high-frequency impact fluctuations, and coupling effects of the installation interface. This leads to a deviation between the measured excitation signal and the actual rigid body excitation of the base. The introduction of high-frequency signals also makes it difficult to obtain the true excitation overload amplitude. Among these factors, the rigid body acceleration of the loading base is an important indicator for measuring the impact level of the test, which is directly related to the impact resistance threshold of electronic instruments and their buffer components. However, measuring the overload signal through an accelerometer mounted on the base is complex and affected by factors such as the structural characteristics of the base, the measurement position, and the installation method of the accelerometer. It is difficult to accurately interpret the level of input overload, reconstruct and analyze the acceleration transmission path, and is also not conducive to the quantitative evaluation of the comprehensive protection effectiveness of active protection and passive buffering.

[0003] 2) It is difficult to accurately reflect the net excitation level of the base under the condition of internal buffer and complex structure: The loading base has both the input impact load at the front end and the feedback load of the internal buffer element in the test. There are significant differences between the two in response time and load characteristics. It is difficult to accurately reflect the true rigid acceleration characteristics of the base by relying solely on the input load or the signal measured by the acceleration sensor. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a device and method for determining the true excitation overload of a loading base based on dual-interface pressure measurement.

[0005] This invention adopts the following technical solution: a device for determining the true excitation overload of a loading base based on dual-interface pressure measurement, comprising: Base, the base comprising: The base housing has a front cover at its front end to withstand external impact loads and a rear cover at its rear end. The front chamber is located inside the front side of the base housing; Rear chamber, wherein the rear chamber is located inside the rear side of the base housing; The circuit body, which is the electronic test instrument under test, is located in the rear chamber; A buffer assembly is disposed in the rear chamber, located between the loading base and the circuit body, and is used to buffer and absorb impact loads. The impact-end diaphragm pressure sensor is attached to the impact-affected surface of the front cover and is used to measure the pressure time history signal of the impact input load. The contact surface thin film pressure sensor is attached to the contact interface between the loading base and the buffer assembly, and is used to measure the reverse load generated by the internal structure on the loading base during the impact process. An acceleration sensor, which is installed in the front chamber or on the front end cover, is used to acquire the acceleration response signal of the base.

[0006] In some embodiments, the impact end thin-film pressure sensor and the contact surface thin-film pressure sensor are array-type piezoelectric thin-film pressure sensors.

[0007] In some embodiments, the array-type piezoelectric thin film pressure sensor includes a PVDF piezoelectric thin film, multiple sensing elements, and electrode leads; the PVDF piezoelectric thin film is covered with Pt electrodes on both sides; the multiple sensing elements are formed on the PVDF piezoelectric thin film through local polarization, and only the sensing elements have a piezoelectric effect; the sensing elements generate positive and negative charge signals under pressure, which are led out for measurement through the electrode leads.

[0008] In some embodiments, the plurality of sensing units adopt an independent output mode, and the interface average pressure time history signal is obtained by averaging the measurement signals of the plurality of sensing units; or the plurality of sensing units adopt an in-plane parallel output mode, and directly output the interface average pressure time history signal.

[0009] In some embodiments, the thickness of both the impact end thin film pressure sensor and the contact surface thin film pressure sensor is no greater than 0.1 mm. They are attached to the corresponding measurement interface with adhesive. Before attachment, the mounting interface is polished, cleaned, and degreased to ensure that the sensor sensitive surface is coplanar with the mounting interface.

[0010] In some embodiments, the buffer assembly employs a crushable energy-absorbing material, which is one of foamed metal, metal fiber network material, or multicellular thin-walled structure.

[0011] In some embodiments, the circuit body is encapsulated and fixed in the rear cavity with epoxy resin to simulate the encapsulation state of an actual electronic module.

[0012] In some embodiments, the accelerometer is a piezoelectric high-range accelerometer with a range of not less than 100,000g and a frequency response of not less than 50kHz, and is fixed by a threaded mounting method.

[0013] A method for determining the true excitation overload of a loading base based on dual-interface pressure measurement includes: S1: During the test, an impact mass block was launched by an air gun, causing it to strike the pulse shaper at the front end of the base, thereby generating a high g-value impact load in the base; S2: The pressure time history signals of the two interfaces are simultaneously acquired by the impact end thin film pressure sensor and the contact surface thin film pressure sensor, and the acquired pressure signals are averaged to obtain the impact input average pressure signal p1(t) and the reverse action average pressure signal p2(t). S3: Combining the effective force-bearing areas of the two interfaces, the average pressure signal is converted into impact input force F1(t) and reverse force F2(t), where F1(t) = p1(t) × A1, F2(t) = p2(t) × A2, A1 is the effective force-bearing area of ​​the impact end interface, and A2 is the effective force-bearing area of ​​the contact surface. S4: Calculate the net force history F(t) of the base during the impact process, F(t) = F1(t) - F2(t); S5: Based on Newton's second law, calculate the time history of the actual excitation acceleration of the base: a (t)= F (t) / M ,in M The mass of the loading base.

[0014] In some embodiments, the method further includes S6: acquiring an acceleration response signal by means of an acceleration sensor mounted on the loading base, and comparing and verifying it with the calculated real excitation acceleration signal.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a dual-interface pressure synchronous measurement method, which can obtain the net force on the loading base and thus obtain its rigid body acceleration based on the dynamic principle. This provides an initial system input excitation load for further evaluation of the acceleration transmission path, such as the base vibration response and the overload characteristics of the circuit body. Compared with the traditional direct measurement of single or multi-point acceleration of the base, this invention eliminates measurement deviations caused by factors such as the base's own vibration response, stress wave propagation, and sensor installation. The interfacial thin-film pressure sensor used in this invention adopts an array layout and can be processed by manual averaging after multi-point measurement or by averaging the output after mutual compensation of multi-point measurement. This can fully ensure the stable and accurate measurement of stress on the high-speed impact surface and provide a good measurement method for determining the system input impact load.

[0016] The thin-film pressure sensor used in this invention has a small and uniform thickness (≤0.1mm), high frequency response (~GHz), and large measurement range (~10GPa). It adopts local polarization technology, which can arbitrarily process the number, arrangement, and sensor specifications and shapes of sensitive unit arrays according to the measurement interface. It adopts interface bonding installation, which is not affected by inertial effects, installation effects, etc., and directly measures the time history curve of transmitted stress wave on the interface. It has virtually no additional impact on the original loading base, buffer components, and circuit body system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the testing and evaluation device proposed in this embodiment; Figure 2 This is a schematic diagram of the base structure proposed in this embodiment; Figure 3 This is a schematic diagram of the array of thin-film pressure sensors proposed in this embodiment. Figure 4 The impact input pressure-time curve and the interface reverse pressure-time curve generated in this embodiment; Figure 5 This is a comparison chart of acceleration curves generated in this embodiment; Figure label: 1-Base; 2-Buffer assembly; 3-Body circuit; 4-Impact end thin-film pressure sensor; 5-Contact surface thin-film pressure sensor; 6-Acceleration sensor; 1-1-Base shell; 1-2-Front end cover; 1-3-Rear end cover; 1-4-Front chamber; 1-5-Rear chamber; 4-1-Piezoelectric thin film; 4-2-Sensitive unit; 4-3-Electrode lead. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, a device for determining the true excitation overload of a loading base based on dual-interface pressure measurement includes: a base 1, which includes: a base shell 1-1, with a front cover 1-2 at the front end of the base shell 1-1 for bearing external impact loads; a rear cover 1-3 at the rear end of the base shell 1-1; a front chamber 1-4 located inside the front side of the base shell 1-1; a rear chamber 1-5 located inside the rear side of the base shell 1-1; a circuit body 3, which is an electronic testing instrument under test, located in the rear chamber 1-5; and a buffer assembly 2 located in the rear chamber 1-5. Inside, located between the loading base 1 and the circuit body 3, it is used to buffer and absorb the impact load; the impact end thin film pressure sensor 4 is attached to the impacted surface of the front cover 1-3 and is used to measure the pressure time history signal of the impact input load; the contact surface thin film pressure sensor 5 is attached to the contact interface between the loading base 1 and the buffer assembly 2 and is used to measure the reverse load generated by the internal structure on the loading base during the impact; the acceleration sensor 6 is installed in the front chamber 1-4 or on the front cover 1-2 and is used to obtain the acceleration response signal of the base.

[0020] In a specific embodiment, both the impact-end thin-film pressure sensor 4 and the contact-surface thin-film pressure sensor 5 are preferably array-type piezoelectric thin-film pressure sensors, and more preferably PVDF thin-film pressure sensors. This type of sensor features small thickness, high frequency response, and strong flexible bonding ability, enabling accurate measurement of high-g short-term impact loads without significantly altering the interface contact state. Preferably, the PVDF thin film forms an array of sensitive units through local polarization technology, thereby achieving multi-point distributed pressure measurement while ensuring the flatness of the measurement interface, and improving measurement accuracy through averaging signals from multiple measurement points. Figure 3 As shown.

[0021] The piezoelectric thin-film pressure sensor has a thickness of 0.07 mm and includes a PVDF piezoelectric thin film 4-1, four circular sensing units 4-2, each with a diameter of 5 mm. Each sensing unit is covered on both sides with 100 nm Pt electrodes. The sensing units generate positive and negative charge signals on both sides of the pressure line of action, which are then measured through the electrode leads 4-3. Based on the piezoelectric properties of the material, the output charge is proportional to the pressure exerted by the unit. Therefore, the amount of charge output by the unit is measured by an external circuit to further obtain the pressure time-history signal. The electrode leads 4-3 are located on both sides of the piezoelectric thin film, with solid and dashed lines representing the electrode leads on the front and back sides of the film, respectively.

[0022] The piezoelectric thin-film pressure sensor employs four individual sensing units for measurement. The sensor outputs pressure signals from four measurement points, which are then manually averaged to obtain the pressure time-history signal at the impact interface. In another embodiment, a parallel sensing unit layout is used, where the positive and negative electrodes of the four sensing units are connected in parallel, resulting in a single output signal from the entire sensor. This output method directly averages the output signal upon sensor response, effectively avoiding inconsistencies in stress onset time and amplitude at different points on the impact surface caused by impact parallelism issues. Furthermore, the symmetrical arrangement of the sensing units compensates for lateral or vertical pressure deviations caused by non-parallel impacts, leading to more accurate average pressure measurement at the interface.

[0023] Furthermore, the contact surface thin-film pressure sensor 5 and the impact end thin-film pressure sensor 4 are identical in principle and structure, differing only in their customized design due to the difference in their force-bearing areas. Both sets of thin-film pressure sensors are bonded to the impact interface using epoxy adhesive. Before bonding, the mounting interface is sanded, cleaned, and degreased to improve adhesion strength and interface consistency. This ensures that the sensor's sensitive surface remains coplanar or nearly coplanar with the mounting interface, thereby improving the accuracy and stability of the measurement results.

[0024] In a specific embodiment, the interface buffer component 2 uses a crushable energy-absorbing material, which includes foamed metal, metal fiber network material, or multicellular thin-walled structure, etc. Both the impact end thin-film pressure sensor 4 and the contact surface thin-film pressure sensor 5 employ a separate signal output mode with two sensitive units.

[0025] Accelerometer 6 is mounted on the front cover of the loading base. It is preferably a piezoelectric high-range accelerometer with a range of not less than 100,000 g and a frequency response of not less than 50 kHz.

[0026] In a specific embodiment, the loading base 1 is made of high-strength alloy steel, with an outer diameter of 100 mm, a total length of 180 mm, and a mass of 1.85 kg. The loading base 1 has a front chamber 1-4 with a diameter of 40 mm and a height of 40 mm, and a rear chamber 1-5 with a diameter of 60 mm and a height of 80 mm, used to install the interface buffer assembly 2 and the circuit body 3. The buffer assembly is made of foam metal material with a height of 24 mm and a diameter of 40 mm. The circuit body has an outer diameter of 60 mm, a length of 60 mm, and a mass of 0.26 kg. It houses the electronic instruments under test and sensors, and is encapsulated with epoxy resin to simulate the encapsulation state of an actual electronic module.

[0027] Example 2: A method for determining the true excitation overload of a loading base based on dual-interface pressure measurement, comprising: S1: During the test, an impact mass block was launched by an air gun, causing it to strike the pulse shaper at the front end of the base 1 at a speed of about 60 m / s, thereby generating a high g-value impact load in the base 1.

[0028] S2: The pressure time history signals of the two interfaces are synchronously acquired by the impact end thin film pressure sensor 4 and the contact surface thin film pressure sensor 5, and the acquired pressure signals are averaged to obtain the impact input average pressure signal p1(t) and the reverse action average pressure signal p2(t).

[0029] S3: Combining the effective force-bearing areas of the two interfaces, the average pressure signal is converted into impact input force F1(t) and reverse force F2(t), where F1(t) = p1(t) × A1, F2(t) = p2(t) × A2, A1 is the effective force-bearing area of ​​the impact end interface, and A2 is the effective force-bearing area of ​​the contact surface. In this embodiment, the mass of the loading base assembly is approximately 2 kg, and the effective force-bearing area of ​​the impact input pressure sensor is... The effective force-bearing area of ​​the interface reverse pressure sensor is .

[0030] S4: Calculate the net force history F(t) of the base during the impact process, F(t) = F1(t) - F2(t); S5: Based on Newton's second law, calculate the time history of the actual excitation acceleration of the base: a (t)= F (t) / M Where M is the mass of the loading base; S6: Acceleration response signals are collected by an accelerometer installed on the loading base and compared with the calculated real excitation acceleration signals for verification.

[0031] Figure 4In Figure (a), the pressure time history signals output by the two sensitive units on the impact end thin film pressure sensor 4 in this embodiment are shown. It can be seen from the figure that the two are relatively consistent in terms of start time, peak value and curve shape, indicating that the parallelism of the impact surface is high and the measurement performance of each sensitive unit of the piezoelectric thin film pressure sensor is highly consistent. By averaging the two, it can be obtained that the average peak value of the impact input is about 90 MPa. Figure 4 Figure (b) shows the output pressure curves of the two sensitive units of the thin-film pressure sensor at the contact surface of the base 1 and the buffer component 2. As can be seen from the figure, the two curves are basically the same. There are some deviations in the pressure during the crushing response process. This is mainly related to the non-uniformity of the metal foam material itself and the crushing process. However, a better reverse pressure signal of the base can still be obtained by averaging. Its peak average intensity is about 39 MPa.

[0032] Further, by applying Newton's second law, the rigid body acceleration curve of the base can be obtained, with a peak value of approximately 33,000 g. Figure 5 As shown. To compare the effectiveness of this measurement method with the traditional direct acceleration measurement method, Figure 5 The measurement signal from the accelerometer on the front end cap 1-2 was also incorporated. As shown in the figure, the low-frequency characteristics of the two are basically the same, but the accelerometer signal is coupled with a large number of high-frequency signals. This is mainly due to the high-frequency resonance of the end cap under impact and the resonance of the accelerometer's threaded mounting. Its peak overload reaches 80,000g, but it is clearly a high-frequency spike signal. This local point measurement method cannot obtain the overall acceleration level of the base. Different measurement points on the base will obtain different acceleration signals, making it impossible to accurately determine the intensity and curve characteristics of the system input excitation under different loading conditions. This rigid body acceleration measurement method can provide richer information on the overload transmission path.

[0033] The comparison shows that this measurement method has the following advantages: Accurate acquisition of the true excitation acceleration of the base: This invention achieves accurate acquisition of the true excitation acceleration of the base by simultaneously arranging thin-film pressure sensors at the front end and internal interface of the loading base, measuring the impact input load and the reverse load of the internal structure respectively, and obtaining the net force on the base through algebraic difference calculation, thereby inverting to obtain the true excitation acceleration of the base, overcoming the error problem of the traditional measurement method based on a single acceleration sensor.

[0034] To avoid interference from local vibrations in acceleration measurement: signals measured by traditional input-end acceleration sensors are easily superimposed with local structural vibrations and installation coupling effects. However, this invention is based on pressure signal inversion acceleration and calculates from the force perspective, which can effectively reduce the impact of local vibrations on the measurement results. It also avoids the problem in traditional methods where the characteristics of the base excitation overload signal obtained from different measurement points on the base are different.

[0035] Achieving direct characterization of the impact load transmission path: By simultaneously measuring the impact input interface pressure and the internal interface reverse pressure, this invention can directly reflect the transmission relationship of the impact load between the "input end - base - interface buffer component", which is beneficial for in-depth analysis of the impact load transmission mechanism and the structural protection effect.

[0036] It facilitates the quantitative evaluation of the protective performance of electronic instruments: This invention can provide more realistic input excitation conditions, providing a reliable basis for evaluating the protective effect of the internal structural layout, potting materials and buffer components of electronic instruments, and is conducive to carrying out high g-value impact protection design optimization.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for determining the true excitation overload of a loading base based on dual-interface pressure measurement, characterized in that, include: Base (1), said base (1) comprising: The base shell (1-1) has a front cover (1-2) at its front end to withstand external impact loads; and a rear cover (1-3) at its rear end. A front chamber (1-4) is located inside the front side of the base shell (1-1); The rear chamber (1-5) is located inside the rear side of the base shell (1-1); The circuit body (3) is an electronic test instrument under test, which is set in the rear chamber (1-5); The buffer assembly (2) is disposed in the rear chamber (1-5) and located between the loading base (1) and the circuit body (3) for buffering and absorbing the impact load. Impact end thin film pressure sensor (4) is attached to the impact surface of the front cover (1-3) and is used to measure the pressure time history signal of the impact input load. The contact surface thin film pressure sensor (5) is attached to the contact interface between the loading base (1) and the buffer assembly (2) and is used to measure the reverse load generated by the internal structure on the loading base during the impact process. An acceleration sensor (6) is installed in the front chamber (1-4) or on the front cover (1-2) to acquire the acceleration response signal of the base.

2. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 1, characterized in that, The impact end thin film pressure sensor (4) and the contact surface thin film pressure sensor (5) are array-type piezoelectric thin film pressure sensors.

3. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 2, characterized in that, The array-type piezoelectric thin film pressure sensor includes a PVDF piezoelectric thin film (4-1), multiple sensing elements (4-2), and electrode leads (4-3). The PVDF piezoelectric thin film (4-1) is covered with Pt electrodes on both sides. The multiple sensing elements (4-2) are formed on the PVDF piezoelectric thin film (4-1) through local polarization, and only the sensing elements (4-2) have the piezoelectric effect. The sensing elements (4-2) generate positive and negative charge signals under pressure, which are derived for measurement through the electrode leads (4-3).

4. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 3, characterized in that, Multiple sensing units (4-2) adopt an independent output mode, and the interface average pressure time history signal is obtained by averaging the measurement signals of multiple sensing units (4-2); or multiple sensing units (4-2) adopt an in-plane parallel output mode, and directly output the interface average pressure time history signal.

5. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 1, characterized in that, The thickness of the impact end thin film pressure sensor (4) and the contact surface thin film pressure sensor (5) is no more than 0.1 mm. They are attached to the corresponding measurement interface with adhesive. Before attachment, the installation interface is polished, cleaned and degreased to ensure that the sensor sensitive surface is coplanar with the installation interface.

6. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 1, characterized in that, The buffer component (2) adopts a crushable energy-absorbing material, which is one of foam metal, metal fiber network material or multi-cell thin-walled structure.

7. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 1, characterized in that, The circuit body (3) is fixed in the rear chamber (1-5) by epoxy resin potting to simulate the potting state of the actual electronic module.

8. The device for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 1, characterized in that, The acceleration sensor (6) is a piezoelectric high-range acceleration sensor with a range of not less than 100,000g and a frequency response of not less than 50kHz, and is fixed by threaded installation.

9. A method for determining the true excitation overload of a loading base based on dual-interface pressure measurement, characterized in that, include: S1: Launch the impact mass block to strike the pulse shaper at the front end of the base (1), thereby generating a high g-value impact load in the base (1); S2: The pressure time history signals of the two interfaces are synchronously collected by the impact end thin film pressure sensor (4) and the contact surface thin film pressure sensor (5), and the collected pressure signals are averaged to obtain the impact input average pressure signal p1(t) and the reverse action average pressure signal p2(t). S3: Combining the effective force-bearing areas of the two interfaces, the average pressure signal is converted into impact input force F1(t) and reverse force F2(t), where F1(t) = p1(t) × A1, F2(t) = p2(t) × A2, A1 is the effective force-bearing area of ​​the impact end interface, and A2 is the effective force-bearing area of ​​the contact surface. S4: Calculate the net force history F(t) of the base during the impact process, F(t) = F1(t) - F2(t); S5: Based on Newton's second law, calculate the time history of the actual excitation acceleration of the base: a (t)= F (t) / M , where M is the mass of the base.

10. The method for determining the true excitation overload of a loading base based on dual-interface pressure measurement according to claim 9, characterized in that, It also includes S6: collecting acceleration response signals through an acceleration sensor installed on the loading base and comparing and verifying them with the calculated real excitation acceleration signals.

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