14 results about "High strain rate" patented technology

The application relates to a kind of high strain rate under fiber concrete material dynamic axial tensile performance test method, comprising: setting Hopkinson tensile rod device, using the verified Hopkinson tensile rod device to pulse wave is applied to test piece, and the deformation of resistance strain gauge is collected;The deformation is converted into voltage signal, for calculating the strain of resistance strain gauge and the average compressive stress of test piece;Based on strain and average compressive stress, determine the dynamic tensile stress-strain relationship of test piece, according to the dynamic tensile stress-strain relationship of test piece, the dynamic tensile stress time history and dynamic axial strain time history are point by point corresponding pairing on time axis, and the dynamic tensile stress-strain curve of test piece under high strain rate is obtained.The application can make the performance test of fiber concrete and other materials under high strain rate more easily realized, provide the basis for the dynamic performance characterization of material, help the application and popularization of high-performance materials under extreme working conditions such as explosion impact.

This application discloses a method, apparatus, and electronic device for predicting fracture strain in metallic materials. The method includes first determining the stress triaxiality and Lode angle of the metallic material under test based on the stress state at the test point; then constructing a stress fracture prediction model based on the correlation function between fracture strain and stress triaxiality and Lode angle; next, coupling this model with the Johnson-Cook fracture model to form a thermo-mechanical-strain rate coupled fracture prediction model; and finally, determining the target fracture strain based on this model. This approach not only overcomes the limitation of insufficient consideration of the Lode angle in existing fracture models but also achieves efficient model construction with very few parameters to be calibrated. The model is applicable to fracture prediction under complex stress, high temperature, and high strain rate multi-field coupling, significantly improving prediction accuracy while enhancing the model's engineering applicability and robustness, providing a reliable fracture assessment tool for cutting-edge engineering scenarios such as advanced manufacturing and extreme environment equipment design.

This invention discloses a force-thermal coupled intelligent protective heterogeneous structure, its preparation method, and its application, relating to the field of protective materials technology. The force-thermal coupled intelligent protective heterogeneous structure comprises a three-dimensional continuously torsional nacre-like skeleton phase and a dilatational energy-dissipating phase filling the pore channels of the three-dimensional continuously torsional nacre-like skeleton phase; wherein the volume fraction of the three-dimensional continuously torsional nacre-like skeleton phase is 30% to 90%; the three-dimensional continuously torsional nacre-like skeleton phase is formed by multiple rigid brick-like structural units continuously rotated and arranged along the thickness direction. This invention, through the synergistic design of the three-dimensional continuously torsional nacre-like skeleton phase and the dilatational energy-dissipating phase, enables the rigid brick-like structural units to undertake stress transmission and crack deflection, while the dilatational energy-dissipating phase hardens and dissipates impact energy under high strain rate loading, thereby achieving stress wave dispersion, interface energy dissipation, and penetration resistance protection, improving the material's impact energy dissipation capacity and residual impact force buffering capacity.

The application provides a material stress prediction method and a server. The prediction method comprises the following steps: a first correction model is established according to a strain hardening effect model and a thermal softening effect model. A strain rate strengthening term in a JC model is replaced by the first correction model to establish a corrected JC model. The JC model is a product of a strain hardening term, a strain rate strengthening term and a temperature softening term. The stress of the material is predicted according to the corrected JC model. According to the corrected JC model, the complex strain rate effect of the material under high strain rate can be accurately characterized, the prediction accuracy is improved, and a theoretical basis is provided for production and processing. For users, when the condition parameters are changed, the target of the metal sheet component to be prepared can also be obtained according to the corrected JC model, the trial-and-error method of the users to obtain the target of the metal sheet component to be prepared is reduced, the cost is saved, and the time is saved.

The application discloses a kind of alloy surface low-temperature gradient mechanical strengthening method, comprising the following steps: after cleaning treatment, the alloy surface is treated at low temperature, the temperature of the low-temperature treatment is-160~‑196 ℃;Alloy surface is sequentially treated by first shot blasting, low-temperature treatment, second shot blasting, low-temperature treatment and third shot blasting.The application is treated at low temperature before each shot blasting treatment, to reduce the alloy temperature to below-160 ℃, when first shot blasting, random high strain rate shear deformation is generated on the surface of alloy material, dynamic recovery in alloy deformation process is inhibited, modified layer grain refinement is realized, and the thickness of modified layer is increased, when second shot blasting, Almen strength in shot blasting process is reduced, and crack is inhibited on the surface in later shot blasting, finally, through third shot blasting treatment, the surface of alloy is repaired, protrusions and burrs on the surface of material are removed, the surface roughness of alloy is reduced, and the surface quality of aluminum alloy is improved.

This invention relates to the field of composite material preparation technology, and particularly to a method for preparing aluminum-clad magnesium composite rods. The specific steps are as follows: S1: Grinding and cleaning the surface of the magnesium alloy core rod; S2: Grinding and cleaning the inner wall and surface of the aluminum alloy tube; S3: Placing the magnesium alloy core rod obtained in step S1 into the aluminum alloy tube obtained in step S2; S4: Feeding the initial billet assembled in step S3 into a rotary forging mill for multi-pass continuous rotary forging, with a diameter reduction of 1-2 mm per pass, and the initial billet having a diameter of approximately 10-10 mm. 2 s ‑1 The high strain rate and deformation under high hydrostatic stress generated by mold impact ultimately yield aluminum-clad magnesium composite rods. Advantages of this invention: This invention utilizes cold-working rotary forging technology to achieve dissimilar metal composites, making magnesium alloys, which are difficult to form at room temperature, easier to form under the cladding of aluminum alloys. This results in aluminum-clad magnesium composite rods with a mechanically interlocked composite interface and accompanying metallurgical bonding, significantly reducing processing difficulty and cost.

The present application belongs to the technical field of Hopkinson bar test, and relates to a kind of metal material high strain rate true tensile test control method, and the relationship between launch air pressure and impact sleeve velocity is established;According to the impact sleeve velocity V and the impact sleeve length L, the distance between the pulse absorber and the input rod flange is calculated as follows: △=L×V / C;The test system is assembled according to the calculated distance;Impact test is carried out and strain signal is collected;Finally, the stress-strain curve is obtained by calculation.The present application accurately calculates the dynamic matching distance between the absorber and the flange, fully absorbs the reflected compression wave without sacrificing the incident tensile wave amplitude, solves the problem of repeated "tension-compression" loading in traditional methods, and has higher test accuracy and material applicability.The test system of the present application has simple structure, the control method is easy to operate, the test results have good repeatability, and is suitable for high strain rate true tensile test of various metal materials.

This invention relates to an efficient forming and manufacturing method for high-strength aluminum alloys using high-strain-rate hot forming, belonging to the technical field of high-efficiency preparation and development of high-strength aluminum alloys. After solution treatment, this invention first performs deep cryogenic treatment, followed by preheating and holding at high strain rate to obtain the formed component. Forming and heat treatment are integrated into a single process. Compared to conventional aging forming methods that require tens of hours of heat treatment, this invention significantly shortens the overall process time, improves efficiency, and facilitates industrial application. Simultaneously, it ensures that the strength of the aluminum alloy component is not lower than that of the T6 state, while also achieving good plasticity and ductility.

The application discloses a kind of apple bruise resistance dynamic detection and grading method based on solid-liquid decoupling, belong to agricultural product test technical field.The method includes: (1) based on the same library reference product generates dynamic judgment threshold, namely apparent density determination threshold ρ th And hysteresis loss rate determination threshold H th , construct two-dimensional evaluation matrix;(2) extract apple sample from the batch to be measured, determine apparent density ρ And hysteresis loss rate under high strain rate HLR;(3) the measured data is mapped to two-dimensional evaluation matrix to grade the fruit of the batch to be measured, and then trigger the corresponding physical shunt and intervention instruction.Compared with the existing single detection technology that relies on static hardness, the application utilizes the solid-liquid intrinsic decoupling characteristics of the flesh porous medium, converts the apparent density representing the strength of the solid skeleton and the HLR representing the viscous dissipation ability of the fluid into a two-dimensional orthogonal judgment signal, achieving precise identification and automatic damage prevention intervention of different damage failure modes.

This invention discloses a closed-loop controlled constant-amplitude impact loading device and method for electromagnetic impact fatigue testing, belonging to the field of materials testing technology. The device includes an impact loading module, a specimen clamping and carrier wave transmission module, and a closed-loop control circuit consisting of a data acquisition module and an automatic control module. The impact loading module uses a pulsed power supply to drive an electromagnetic coil to generate eddy current repulsion, pushing a punch to impact an incident rod, generating a high-strain-rate stress wave. The data acquisition module acquires the reflected or transmitted wave signal of the specimen under load through strain gauges on the incident or transmitted rod, and calculates the deviation from the preset value based on the signal. The automatic control module calculates the input parameters for the next loading in real time based on the deviation signal and adjusts the impact energy to achieve constant-amplitude loading throughout the entire life cycle. This invention solves the problem of existing impact fatigue tests failing to maintain a constant load after specimen cracking, achieving closed-loop adaptive control and providing reliable data for material performance evaluation.

This invention discloses a method for preparing a highly ductile DLC film, comprising: preparing a raw DLC film; depositing metal nanoparticles on the surface of the raw DLC film; and forming a surface-protruding nanostructure on the metal nanoparticles using an electrochemical degradation method to obtain a highly ductile DLC film. By forming a surface nanostructure on the surface of the DLC film, the technical solution of this invention can effectively improve the ductility of the DLC film surface, thereby improving its failure problem under high load and high strain rate conditions, greatly enhancing its application effect and service life, without affecting the performance and cost of the DLC film.

The application discloses a segmented superplastic deformation method of large-grain magnesium alloy and belongs to the technical field of magnesium alloy plastic forming. The application directly takes a large-grain magnesium alloy blank which is not subjected to severe plastic deformation pretreatment as an object, and realizes forming by regulating a deformation rate in stages after heating. Firstly, deformation is carried out at a high strain rate, dynamic recrystallization is induced to refine the coarse-grain structure in situ, when the microstructure evolution or mechanical response reaches a predetermined state, the strain rate is switched to a low strain rate, and the grain boundary sliding mechanism is activated to complete superplastic flow. The method effectively solves the problems of complex pretreatment process and low efficiency in the traditional process, and is suitable for low-cost preparation of complex components in the fields of aviation, aerospace and transportation.

This invention discloses a thermoplastic elastomer composite material with high strain rate sensitivity, its preparation method, and its application, belonging to the field of polymer composite material technology. This invention uses SEBS as a continuous matrix and disperses PBDMS as a strain rate-sensitive functional phase within it. Through a specific PBDMS synthesis process and a physical blending-hot pressing process with SEBS, effective encapsulation and dispersion of PBDMS in SEBS are achieved. The physical crosslinking network of SEBS provides morphological stability and basic elasticity. Simultaneously, the dynamically reversible B-O coordination bonds within the dispersed PBDMS phase enable the material to remain compliant at low strain rates. Under high strain rate impact, the B-O bonds are suppressed due to dissociation, resulting in a large number of temporary crosslinks that rapidly harden the PBDMS phase. The reinforcing effect is then transferred to the entire composite material through the two-phase interface, thereby improving macroscopic mechanical properties.