Soft substance dynamic impact response test system based on flexible sensing

Abstract

The invention discloses a soft material dynamic impact response test system based on flexible sensing, and relates to the technical field of sensing detection and dynamic mechanical testing, and the system comprises a flexible sensor array which is used for being tightly attached to the surface of a soft material or being embedded into the soft material, and achieves the in-situ high-precision collection of stress and strain signals in the impact process; the data acquisition and processing module is used for synchronously extracting impact response characteristic parameters including peak stress, a strain rate and an energy absorption curve; the impact loading device is used for realizing accurate application and control of a wide-area dynamic load; and the fixing clamp is used for fixing the soft substance sample and the sensor array. The method is suitable for mechanical property characterization of soft substances such as gel, polymers, biological tissues, foam materials and the like under dynamic loads such as explosion, impact and the like; according to the invention, the nonlinear response characteristics of the soft substance under the impact load can be accurately obtained, and a key test means is provided for research and development of flexible electronics, biomedical engineering and novel protective materials.

Description

Technical Field

[0001] This invention relates to the field of sensing and dynamic mechanical testing technology, and more specifically, to a soft material dynamic impact response testing system based on flexible sensing. Background Technology

[0002] Soft materials (such as polymer gels, biological soft tissues, and flexible electronic materials) have broad application prospects in aerospace, biomedicine, and intelligent equipment due to their unique viscoelasticity, nonlinearity, and large deformation characteristics. However, existing dynamic impact testing technologies (such as traditional strain gauges and laser Doppler vibration meters) face the following challenges: (1) Poor interface compatibility: The elastic modulus of traditional rigid sensors is mismatched with that of soft materials, resulting in stress transmission distortion, especially under large deformation conditions, which can easily lead to detachment or breakage; (2) Insufficient spatial resolution: Single-point sensors cannot capture the local stress concentration phenomenon of soft materials, making it difficult to reveal the microscopic damage evolution law under impact load; (3) Dynamic response lag: The sampling frequency of conventional data acquisition systems is generally low (<10kHz), which cannot accurately record the transient signal of the microsecond-level impact process.

[0003] Flexible sensors, with their high flexibility, stretchability, and biocompatibility, offer new approaches to the mechanical testing of soft materials. However, existing flexible sensing technologies still have the following shortcomings in dynamic impact testing: low sensor array integration, making it difficult to achieve high-density distributed measurement; the signal acquisition and processing system cannot process multi-channel high-frequency signals synchronously, leading to data distortion; and the lack of dedicated algorithms for the nonlinear characteristics of soft materials makes it difficult to accurately extract mechanical parameters from the raw signals. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a soft matter dynamic impact response testing system that combines high compatibility, high resolution, and high real-time performance, thereby promoting the development of soft matter science and engineering.

[0005] To achieve the above technical objectives, this application provides a soft matter dynamic impact response testing system based on flexible sensing, comprising:

[0006] Flexible sensor arrays are used to closely attach to the surface of soft materials or embed them inside, enabling in-situ high-precision acquisition of stress and strain signals during impact.

[0007] The data acquisition and processing module is used to simultaneously extract impact response characteristic parameters, including peak stress, strain rate, and energy absorption curve;

[0008] Impact loading devices are used to achieve precise application and control of dynamic loads over a wide range;

[0009] Fixtures are used to hold soft material samples and sensor arrays in place.

[0010] Preferably, the flexible sensor array adopts a composite structure of an elastic substrate and a nano-sensitive layer, wherein the substrate material is PDMS or PI; and the sensitive layer material is a carbon nanotube / PDMS composite material, graphene / dielectric elastomer, or fiber Bragg grating.

[0011] Preferably, the flexible sensor array is a two-dimensional / three-dimensional array, with a sensor spacing ≤5mm, a response frequency ≥10kHz, and a tensile strain range ≥300%.

[0012] Preferably, the data acquisition and processing module is equipped with an anti-aliasing filter circuit and integrates wavelet transform, Hilbert-Huang transform and parameter inversion algorithms based on the LabVIEW / Matlab platform.

[0013] Preferably, the impact loading device includes a drop hammer impactor, a pneumatic gun loading system, or a split Hopkinson bar, wherein the drop hammer impactor has an impact energy range of 0.1-100J and a hammer velocity resolution ≤0.1m / s; the pneumatic gun loading system can generate high-speed impact loads of 10-1000m / s, suitable for high strain rate testing ≥10 3 s-1.

[0014] Preferably, the fixing fixture adopts a three-dimensional adjustable sample fixing device to stabilize the spatial relative position of the sensor array and the soft material under test during the impact process, and suppress the influence of boundary effects on the test results.

[0015] Preferably, the data acquisition and processing module uses machine learning algorithms to denoise and extract features from the original signal, and establishes a mapping relationship between impact load, sensor response, and material mechanical parameters.

[0016] Preferably, the machine learning algorithm is trained based on historical test data and can identify elastic deformation, plastic flow and failure threshold during the impact process.

[0017] Preferably, the data acquisition and processing module is used to remove environmental noise from the raw signal by bandpass filtering at 50-50kHz.

[0018] Preferably, the data acquisition and processing module is used to output the dynamic stress-strain curve and impact absorption energy index of the soft material.

[0019] The present invention discloses the following technical effects:

[0020] The advantages of this invention are: high compatibility: the flexible sensor matches the elastic modulus of soft materials, can withstand tensile deformation of ≥300%, and can effectively avoid interface peeling and signal distortion; high resolution: the distributed sensor array can achieve millimeter-level spatial resolution and accurately capture local stress concentration phenomena; high real-time performance: the combination of high-speed data acquisition and intelligent algorithms enables dynamic analysis of the impact process at the microsecond level; multifunctionality: it is suitable for impact response testing of various soft materials (such as biological tissues and gels), providing key technical support for the research and development of new flexible materials. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the system structure described in this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] like Figure 1 As shown, this invention provides a dynamic impact response testing system for soft materials based on flexible sensing. By integrating a multimodal flexible sensing network (piezoresistive stress sensing, fiber Bragg grating strain monitoring, and digital image displacement tracking) with intelligent algorithms, it achieves high-precision characterization of the impact dynamics of soft materials. This invention is applicable to the characterization of the mechanical properties of soft materials such as gels, polymers, biological tissues, and foam materials under dynamic loads such as explosions and impacts. Specifically, it includes the following:

[0025] The flexible sensor array adopts a composite structure of "elastic substrate + nano-sensitive layer". The substrate material is PDMS (elastic modulus 1-10MPa) or PI (polyimide, stretchability ≥200%); the sensitive layer material is carbon nanotube / PDMS composite material (piezoresistive coefficient 10-20kPa). -1 ), graphene / dielectric elastomer (capacitance change rate ≥50%) or fiber Bragg grating (strain sensitivity 1.2pm / με); the sensor array is 2D planar or 3D stereo, and high-density integration of sensor units (minimum spacing 1mm) is achieved through micro-nano fabrication technology (such as photolithography, inkjet printing).

[0026] Data acquisition and processing module: high-speed data acquisition card with a sampling frequency ≥100kHz, number of channels ≥32, and equipped with anti-aliasing filter circuit; analysis software: based on LabVIEW / Matlab platform, integrating signal denoising (wavelet transform), feature extraction (Hilbert-Huang transform), and parameter inversion algorithm (finite element inverse analysis).

[0027] Impact loading device, drop hammer impact table: impact energy range 0.1-100J, hammer velocity resolution ≤0.1m / s; air gun loading system: capable of generating high-speed impact loads of 10-1000m / s, suitable for high strain rate testing (≥10). 3 s -1 ).

[0028] The fixed clamp adopts a flexible clamping structure (such as silicone clamp) to avoid stress concentration interference on soft materials caused by traditional rigid clamps.

[0029] This invention can accurately obtain the nonlinear response characteristics of soft matter under impact loads, providing a key testing method for the research and development of flexible electronics, biomedical engineering, and new protective materials.

[0030] Example 1: The technical solution of the present invention will be described below with reference to specific implementation examples, so as to better understand and apply the present invention. The present invention provides a soft matter dynamic impact response testing technology based on flexible sensing, specifically including the following design:

[0031] Sensor placement: For surface testing, the flexible sensor array is attached to the surface of the soft material sample using medical-grade silicone adhesive; for internal testing, the sensor array is embedded in pre-made holes or integrated into the soft material through 3D printing.

[0032] System calibration: Impact device calibration: The impact energy-hammer velocity relationship is calibrated through a standard weight drop test; Sensor calibration: Strain-signal calibration is performed on individual sensors on a tensile testing machine to establish the transfer function.

[0033] Impact Test: Set the impact energy and loading direction, and trigger a high-speed camera to synchronously record the impact process (frame rate ≥ 10). 4 (fps); The data acquisition module and the impact device are started synchronously by a trigger signal, and the acquisition time covers the entire impact process (≥10ms).

[0034] Data Processing and Analysis: Raw Signal Preprocessing: Removing ambient noise through bandpass filtering (50-50kHz); Feature Parameter Extraction: Calculating peak stress (σ_max) and strain rate. Energy absorption (E_abs=∫σdε) and damage evolution curves; result visualization: generating stress cloud diagrams, displacement field distribution and dynamic response animations, combined with finite element simulation to verify test results.

[0035] Example 2: Gel impact test based on piezoresistive flexible sensor:

[0036] System structure: Flexible sensor array: Carbon nanotube / PDMS composite sensitive layer (50μm thick) is sprayed onto PDMS substrate (0.5mm thick) to form an 8×8 array (2mm spacing); Data acquisition: NIPXIe-6368 high-speed acquisition card (200kHz sampling rate); Impact device: Drop hammer impact table (hammer mass 500g, impact height 100mm, energy ≈0.5J).

[0037] Test procedure: The sensor array was attached to the surface of polyacrylamide gel (elastic modulus 10 kPa); a drop hammer was dropped to impact the center of the gel, and sensor signals and high-speed images were acquired simultaneously; data processing showed that the peak impact stress was 15 kPa and the strain rate was 200 s⁻¹. -1 Energy absorption is 0.35J, and the error between the finite element simulation and the actual energy absorption is ≤8%.

[0038] Example 3: Biotissue Shock Testing Based on Fiber Optic Sensors

[0039] System structure: Flexible fiber optic sensor: 200μm diameter polyimide-coated fiber Bragg grating embedded in pig muscle tissue (20mm thickness); Data acquisition: Fiber Bragg grating demodulator (wavelength resolution 0.01nm, sampling rate 1kHz); Impact device: Air gun loading system (projectile velocity 50m / s, impact energy 2J).

[0040] Test procedure: The fiber optic sensor was implanted 5 mm into the tissue along the direction of the muscle fibers; the projectile impacted the tissue surface and the grating wavelength drift signal was collected; the analysis showed that the peak strain caused by the impact was 800 με, corresponding to a stress of 30 kPa, and the stress propagation process inside the tissue was successfully monitored.

[0041] The performance indicators are compared as shown in Table 1.

[0042] Table 1

[0043] project Traditional strain gauge testing This invention system Sensor compatibility Rigid, easy to fall off Flexible, stretchable Spatial resolution single point millimeter-scale array Response frequency ≤1kHz ≥10kHz Applicable strain range ≤50％ ≥300％ Typical error ≤15％ ≤8％

[0044] The above embodiments demonstrate that the system of the present invention can effectively improve the accuracy and resolution of dynamic impact testing of soft matter, and meet the testing needs of research and development of new flexible materials.

[0045] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0046] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A soft matter dynamic impact response test system based on flexible sensing, characterized in that, It comprises: a flexible sensor array for closely attaching to the surface or embedding in the interior of soft matter to achieve high-precision in-situ acquisition of stress and strain signals during impact; a data acquisition and processing module for synchronous extraction of impact response characteristic parameters, including peak stress, strain rate, and energy absorption curve; an impact loading device for precise application and control of wide-range dynamic load; a fixed clamp for fixing the soft matter sample and the sensor array.

2. The soft matter dynamic impact response test system based on flexible sensing according to claim 1, characterized in that: the flexible sensor array adopts a composite structure of elastic substrate + nanosensitive layer, wherein the substrate material is PDMS or PI, and the sensitive layer material is carbon nanotube / PDMS composite material, graphene / dielectric elastomer, or optical fiber Bragg grating.

3. The soft matter dynamic impact response test system based on flexible sensing according to claim 2, characterized in that: the flexible sensor array is a two-dimensional / three-dimensional array, the sensor spacing is ≤5 mm, the response frequency is ≥10 kHz, and the tensile strain range is ≥300%.

4. The soft matter dynamic impact response test system based on flexible sensing according to claim 3, characterized in that: the data acquisition and processing module is equipped with an anti-aliasing filter circuit and is based on the LabVIEW / Matlab platform, integrating wavelet transform, Hilbert-Huang transform, and parameter inversion algorithm.

5. The soft matter dynamic impact response test system based on flexible sensing according to claim 4, characterized in that: The impact loading device includes a drop hammer impact machine, a gas gun loading system or a split Hopkinson pressure bar, wherein the drop hammer impact platform has an impact energy range of 0.1-100J and a hammer head speed resolution of ≤0.1m / s; the gas gun loading system can generate high-speed impact load of 10-1000m / s and is suitable for high strain rate test ≥10 3 s -1 .

6. The soft matter dynamic impact response test system based on flexible sensing according to claim 5, characterized in that: the fixed clamp adopts a three-dimensional adjustable sample fixing device to fix the spatial relative position of the sensor array and the measured soft matter during impact, thereby suppressing the influence of boundary effect on the test results.

7. The soft matter dynamic impact response test system based on flexible sensing according to claim 4, characterized in that: the data acquisition and processing module uses machine learning algorithm to denoise and extract features from the original signal, establishing the mapping relationship between impact load, sensor response, and material mechanical parameters.

8. The soft matter dynamic impact response test system based on flexible sensing according to claim 7, characterized in that: the machine learning algorithm is trained based on historical test data and can identify elastic deformation, plastic flow, and failure threshold during impact.

9. The soft matter dynamic impact response test system based on flexible sensing according to claim 1, characterized in that: the data acquisition and processing module is used to remove environmental noise by band-pass filtering 50-50 kHz on the original signal.

10. The soft matter dynamic impact response test system based on flexible sensing according to claim 9, characterized in that: the data acquisition and processing module is used to output the dynamic stress-strain curve and impact absorption energy index of the soft matter.

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