31 results about "Dynamic strength" patented technology

The invention discloses a multivariable coupling control rock and composite material explosion impact characteristic testing method and system, and relates to the technical field of rock explosion characteristic testing, and the method comprises the following steps: dividing a rock material gradient based on a gradient sensitive function, and generating an initial grid; encrypting explosion holes and crack path areas of the initial grid based on multi-physics field response characteristics to obtain an encrypted grid; based on the encrypted grid, the RHT model and the heat conduction equation, constructing a multi-field coupling model, and outputting a simulation result; and carrying out an explosion experiment, and inverting the dynamic strength and fracture toughness parameters of the material by comparing a simulation result with experimental data. The device and the method are used for solving the problem of inaccurate characteristic test simulation under explosion impact of rocks and composite materials.

The invention discloses a flow-induced vibration velocity effect similarity method based on an equivalent mode, and belongs to the field of aircraft structure dynamic strength optimization. According to the method, the scaling model is established, the flow velocity difference caused by different sound velocities of the scaling model and the full-size model is considered at the same time, a new thickness scaling factor is established in combination with the velocity ratio on the basis of a length scaling factor, and the structural vibration parameters of the full-size model are predicted through the scaling model. The influence caused by flow velocity difference can be made up, the characteristic frequency and the structural response of the full-size model can be accurately predicted through the scaling model, and the flow-induced vibration velocity effect similarity prediction precision based on the equivalent mode is improved. According to the method, a complex structure characteristic frequency is changed into a similar form only containing the combination of a thickness scaling factor and a length scaling factor through an equivalent modal method, and a curved plate flow-induced vibration structure response similar expression is deduced, so that the defects of a current flow-induced vibration similarity theory are overcome; and the prediction reliability of the aircraft structure dynamic response similarity method is improved.

The application belongs to the field of aircraft structure dynamic strength design, and particularly relates to a dynamic load static equivalent coefficient determination method and a structure parameter design method, which comprises the following steps: S1: according to a water ditching dynamic load measurement test, a relationship curve between a water pressure load of a bottom of an aircraft fuselage and a time history is obtained, and a peak value Ps of the water pressure load is determined according to the relationship curve; S2: a water ditching test of an elastic model of the bottom of the fuselage is performed to determine a critical failure parameter of the elastic structure; S3: a static mechanical property test is performed with the critical failure parameter of the elastic structure to obtain a maximum static pressure Pd that can be borne by the elastic structure; and S4: a water ditching dynamic load static equivalent coefficient is calculated. The static equivalent coefficient of the water ditching water pressure dynamic load is obtained through a scale model test. The application aims to solve the problem of lacking of design load in aircraft water ditching performance design.

The present invention discloses a method and system for predicting the tensile strength of layered rock masses based on the Brazilian splitting test, which relates to the technical fields of rock mechanics and geotechnical engineering, and includes: performing Brazilian splitting tests on multiple groups of shale disc specimens with different bedding dip angles respectively to obtain initial experimental data; calculating the theoretical tensile strength based on the principle of the Brazilian splitting test; performing normalization processing on the initial experimental data and the theoretical tensile strength to obtain the experimental data after preprocessing; constructing a target relationship between the dynamic increase factor and the relative strain rate based on the experimental data after preprocessing; constructing a dynamic fracture pressure model based on the dynamic strength criterion of layered rock masses based on the target relationship and a preset static layered strength criterion to predict the tensile strength of layered rock masses. The present invention can not only perfectly fit the strength characteristic that the strength of layered rocks first decreases and then increases with the increase of the bedding dip angle, but also predict the dynamic tensile strength of layered rock masses within a certain strain rate range.

The invention discloses a method for analyzing the influence of ultra-high performance concrete components on dynamic compressive strength, particularly relates to the field of dynamic performance analysis of building materials, and is used for solving the technical problem of concrete dynamic strength discretization caused by industrial solid waste fluctuation. The method comprises the following steps: acquiring industrial solid waste raw material particle size distribution data and impurity content data, and combining dynamic impact strength sequence analysis; after invalid data is removed, quantitative mapping of coarse particle components and stress wave transmission efficiency is established; calibrating the pore characteristics based on the impurity content, tracking the impurity migration trajectory when the connected pores exceed the standard, and calculating the collaboration degree of the impurity migration trajectory and the strain rate change; and finally, outputting a dynamic compressive strength standard deviation through a multi-factor linear regression model. Accurate prediction of dynamic performance under solid waste fluctuation is realized, and an anti-discrete design basis is provided for a maritime work anti-seismic structure.

The invention belongs to the technical field of aviation hydraulic piping system testing, and particularly relates to an airplane hydraulic piping system fluid-structure interaction dynamic strength test platform and a test method thereof. The coupling effect of high-pressure pulsating fluid excitation and complex structure vibration excitation borne by the hydraulic piping system in the flight process of an aircraft is simulated in a high-fidelity mode, so that the dynamic strength weak link of the piping system is effectively exposed, and technical support is provided for optimization design and reliability verification of the hydraulic piping system. And efficient, safe and low-cost development of the aircraft hydraulic piping system is realized.

The invention provides a dynamic load prediction and dynamic intensity checking method and system for a water surface aircraft cabin section. The method comprises the steps of obtaining feature information of a water surface aircraft cabin section structure; simplifying the cabin section of the water surface aircraft into a two-dimensional model according to the feature information; establishing a hydrodynamic load prediction analysis model of the water surface aircraft cabin based on a potential flow theory; obtaining the dynamic load of each skin in the vertical water entry process according to the water entry dynamic load prediction analysis model; calculating a dynamic load factor at each skin position; calculating an equivalent static load according to the dynamic load of each skin in the vertical water entry process and the corresponding dynamic load factor, and applying the equivalent static load to the skin at the bottom; the underwater dynamic load prediction analysis model is adopted to carry out dynamic load rapid prediction of underwater of a water surface aircraft cabin section, large-scale numerical calculation of a traditional fluid-solid coupling algorithm is avoided, and a large amount of time and hardware resources are remarkably saved; and structure dynamic strength checking based on statics is realized.

This invention discloses a design method for refractory high-entropy alloys, belonging to the technical field of compositional design of refractory high-entropy alloys. The design method includes the following steps: for refractory high-entropy alloys in the Nb-Ta-Hf-Zr-Mo-Ti-W system, establishing a compositional design method containing 10... ‑3 s ‑1 up to the 2000s ‑1 This invention presents a composition-performance dataset covering a strain rate range. Core physical features are extracted, and the dataset is expanded using Monte Carlo sampling after data cleaning. A random forest model is employed, with alloy composition and physical features as inputs and dynamic strength and fracture strain as outputs. The optimal model is selected through cross-validation, and the MeanUds' regulatory mechanism on performance is analyzed using SHAP value analysis. Target alloy compositions are then selected based on compositional design constraints. This invention achieves a synergistic improvement in the strength and quasi-static ductility of refractory high-entropy alloys.

The application discloses a kind of energy-time density atlas model establishment and prediction method for evaluating rock energy consumption, specifically related to rock mechanics technical field, including the following steps: selecting rock sample, to obtain stress and strain signal by Hopkinson experiment;The stress-strain signal obtained is processed using a deep learning denoising model to obtain the purified stress-strain signal;Based on the purified stress-strain signal, calculate dynamic strength data and energy-time density;For a variety of rocks, use K-means clustering algorithm and kernel density estimation to construct a two-dimensional energy-time density atlas model;For a single rock, an interpolation model of machine learning is used to construct an intuitive two-dimensional energy-time density continuous atlas;The change trend of energy-time density can be predicted using the two-dimensional energy-time density atlas, and then the energy dissipation condition is analyzed.

The present invention discloses a method for predicting the dynamic response of thin-walled structures taking into account modal matching, which belongs to the field of dynamic strength of aircraft skin structures. The present invention defines the characteristic parameters of the load mode and the structural resonance mode according to the comparative relationship between the wavelength and the structural characteristic length, constructs a load integral term expression taking into account the matching conditions of the load space mode and the vibration mode, and substitutes the wavelength ratio Kn into the calculation of the structural dynamic response. The dynamic load spatial correlation and the structural coupling law are characterized by Kn, thereby realizing the prediction of the dynamic response of thin-walled structures taking into account the matching of the load space mode and the vibration mode. The present invention can not only calculate the time-frequency characteristics of the structural dynamic response, but also obtain the structural dynamic response characteristics under different matching conditions of the dynamic load space mode and the structural characteristic mode; through dynamic response modeling analysis, the vibration law and mechanism of the dynamic load space correlation can be more effectively explained, and the optimal modal matching conditions can be met by adjusting the Kn value to suppress the vibration of the thin-walled structure.

The invention relates to the technical field of oil and gas well engineering, and provides a while-drilling rock breaking efficiency optimization method based on dynamic energy consumption and dynamic rock strength, which comprises the steps of selecting a target well section and a rock, determining the type and parameters of the rock, determining the parameters of the target well section, and calculating the dynamic energy consumption corresponding to the target rock broken by a drill column through the energy flow of the drill column. Establishing a probability distribution relation model between the dynamic strength and the dynamic energy consumption of the target rock, dividing the dynamic strength of the target rock by the dynamic energy consumption to obtain dynamic rock breaking efficiency, and calculating and optimizing drilling parameters through non-dominated sorting and congestion degree by taking the drilling speed and the dynamic rock breaking efficiency as indexes. The invention provides a calculation method for optimizing drilling while drilling parameters, provides important guidance and support for parameter optimization of drilling engineering, tool optimization or optimization, speed increase, cost reduction and benefit increase, and has a wide application prospect.

The invention relates to a parachute canopy fabric numerical simulation method and a computer readable storage medium. The method comprises the steps that material parameters and historical states are initialized and read; updating an accumulated total strain tensor based on the strain increment and calculating a strain rate tensor; the principal direction modulus is evolved according to the accumulated total strain tensor, the material stiffness matrix is updated, and then the pure elastic stress increment is calculated; viscous damping stress is calculated in combination with the strain rate and the stiffness matrix, and a trial stress tensor is obtained after superposition and historical stress; performing wrinkle correction on the trial stress according to the strain state in the main direction, eliminating the stress in the compression direction and reducing the corresponding shear stress; calculating a dynamic strength threshold value by adopting a logarithmic strengthening model based on the strain rate and judging failure; and finally storing the updated state and outputting the stress tensor. A computer program is stored on the readable storage medium, the method can be implemented when the program is executed, and high-fidelity numerical simulation of the mechanical behavior of the canopy fabric is achieved.

The invention discloses an EGS surrounding rock thermal efficiency estimation method and system based on a dynamic strength criterion, and relates to the technical field of dry hot rock geothermal resource development, and the method comprises the steps: introducing a temperature correction term and a bedding direction coefficient based on a Nova-Zaninetti criterion, and building a dynamic strength equation; establishing a three-dimensional roadway model of the enhanced geothermal system based on excavation; constructing a heat transfer model of the enhanced geothermal system based on the unsteady heat conduction equation; based on the dynamic strength equation, a solid mechanical field model of the enhanced geothermal system is constructed; the heat transfer model and the solid mechanical field model are coupled into the three-dimensional roadway model, and a surrounding rock heat efficiency numerical model of the enhanced geothermal system is constructed; and estimating the thermal efficiency of the enhanced geothermal system based on the surrounding rock thermal efficiency numerical model. According to the invention, the technical problem of large deviation between the thermal efficiency estimation result and the actual thermal efficiency estimation result in the prior art is relieved.

This application provides a method for forced response analysis of an integral bladed disk (IBD), comprising: constructing a finite element model of an IBD sector; conducting disk-coupled resonance analysis of the finite element model to obtain the frequency, mode shape, and relative vibration stress of the IBD blades under one to multiple node diameters, and plotting disk-coupled resonance diagrams; determining the critical node diameter related to the number of rotor and stator blades; determining the frequency order and corresponding critical resonance speed by combining the plotted disk-coupled resonance diagrams and the critical node diameter; performing damping tests on the IBD blades to obtain the frequency order and corresponding modal damping ratios; establishing a full-ring model of the IBD rotor blades and the stator blades before and after them; conducting steady flow field analysis of the full-ring model to obtain steady results as the initial field conditions for unsteady flow field analysis; conducting unsteady flow field analysis to obtain the actual vibration stress of the IBD; and conducting dynamic strength reserve analysis to evaluate the dynamic strength reserve of the high-load IBD under the analysis conditions.

The application discloses a design method of a wing arm tilting mechanism of a tilt-rotor aircraft, and steps are as follows: combining a connecting rod mechanism principle, a tilting transition working condition rotor six force element and a tilting rudder torque threshold, transmission ratio design is completed; a distributed method and a topological optimization technology are adopted to obtain the best force transmission route and the optimal configuration of a motor support and an end frame support; a tilting transition and a peak torque working condition are taken as loads, and digital simulation and theoretical mechanics are combined to design static strength; a dynamics model is constructed based on vibration characteristics, a multi-rotor and a fixed-wing configuration wing arm vibration spectrum is taken as a load, and dynamic stress is superposed on static stress to design dynamic strength as a checking threshold. The application combines theoretical mechanics, vibration mechanics and digital simulation technology, provides a systematic design route, can realize high-G value resistance, lightweight, high stability and high reliability of the tilting mechanism design, guarantees reliable work of tilting, saves cost and shortens a development period.

The present invention discloses a method for designing the robustness of the connection stiffness of a rigid sleeve gear coupling of an engine tie rod rotor and its application, which is used for the dynamic optimization design of a three-point supported slender center tie rod rotor structure in an aircraft engine or a gas turbine. The present invention optimizes the position and structure of the coupling by establishing a finite element model for rotor dynamics analysis, calculating and analyzing the critical speed and strain energy density distribution of the rotor, and combining static and dynamic strength requirements. The method includes the steps of optimizing the fulcrum stiffness and rotor structural parameters, analyzing the positioning reliability of the coupling locating stop, moving the coupling to a low strain energy density and low stress area, and iterative verification and optimization. The present invention improves the robustness of the coupling connection stiffness, optimizes the rotor dynamics performance, and reduces the risk of rotor vibration by optimizing the coupling position and structure. It can be directly applied to the engineering design of aircraft engines and gas turbines and has important engineering application value.

The invention discloses an aircraft seat vibration reduction system and a design method thereof, and belongs to the technical field of aircraft structure dynamic strength. The system comprises two shock absorbers which are distributed left and right, and each shock absorber is composed of a shell, a spring piston rod system, a wear-resisting system, a movement connecting piece and a fastening screw. The spring piston rod system is contained in the shell and keeps a radial gap of 1-2 mm with the inner wall of the shell, a piston rod of the spring piston rod system is coaxial with the shell, and an upper spring and a lower spring are connected in parallel and pre-compressed. The design method comprises the following steps: determining a vibration isolation target frequency based on a seat joint PSD curve; calculating system design frequency and total rigidity; calculating single-spring rigidity according to the parallel structure and determining geometric parameters of the single-spring rigidity; the sizes of all parts are designed in a coordinated mode, and interference inspection is conducted; and finally manufacturing and installing. The system is compact in structure, adjustable in rigidity, high in vibration isolation rate and scientific in design method, vibration transmitted from an aircraft body to the seat can be effectively attenuated, and the problems that the vibration environment of the aircraft seat is difficult to predict, and later optimization is difficult are solved.

The invention discloses a design method of a refractory high-entropy alloy, and belongs to the technical field of component design of refractory high-entropy alloys. The design method of the refractory high-entropy alloy comprises the following steps: aiming at the Nb-Ta-Hf-Zr-Mo-Ti-W system refractory high-entropy alloy, establishing a component-performance data set containing a strain rate range of 10 <-3 > s <-1 > to 2000 s <-1 >; extracting core physical characteristics, and expanding a data set based on Monte Carlo sampling after data cleaning; a random forest model is adopted, alloy components and physical characteristics serve as input, dynamic strength and fracture strain serve as output, an optimal model is screened through cross validation, a regulation and control mechanism of MeanUds on performance is analyzed through SHAP value analysis, and target alloy components are screened in combination with component design constraints. According to the method, the strength and the quasi-static ductility of the refractory high-entropy alloy are synergistically improved.

The present application provides a method for establishing a rock dynamic strength criterion based on the confining pressure-strain rate coupling effect, which relates to the field of rock engineering technology. The method includes: obtaining a power function relationship between the confining pressure, strain rate, and coupling coefficient based on experimental data, wherein the coupling coefficient is used to characterize the coupling effect between confining pressure and strain rate; constructing a coupling effect model based on the coupling effect between confining pressure and strain rate and the power function relationship; and constructing a rock dynamic strength model based on the confining pressure effect, strain rate effect, and coupling effect model. Based on the relationship between confining pressure and strain rate and the coupling coefficient, a rock dynamic strength criterion is established by comprehensively considering the confining pressure effect, strain rate effect, and coupling effect. This solves the problem that existing dynamic rock strength criteria cannot estimate dynamic strength within a wide range of confining pressure and strain rate, and eliminates the error caused by the existing dynamic rock strength criteria ignoring the coupling effect.

This invention discloses a dynamic strength testing device and method for rock samples, relating to the field of materials testing technology. The dynamic strength testing device includes a base frame, an experimental rod structure, and an excitation structure. The experimental rod structure includes an incident rod and a transmission rod, both mounted on the base frame along an axis in a first direction. The incident rod is movable along the first direction, and a test area is formed between corresponding ends of the incident rod and the transmission rod. The excitation structure includes an impact element and a reset element. The impact element is mounted on the base frame at the end of the incident rod furthest from the test area, and the impact structure is movable in the first direction. In this solution, the reset element replaces the traditional manual "bullet" filling action, greatly improving operational convenience and testing efficiency. Furthermore, it solves the problem of unstable output torque of the incident rod affecting the accuracy of test results when the filling is incomplete.

The invention provides a multi-working-condition strength verification method for an overhead guard assembly, and relates to the technical field of dynamic characteristic testing, and the method comprises the steps: collecting transient strain response signals of an overhead guard in a switching process from a static load to an impact load in real time through arranging piezoelectric dynamic strain sensor arrays at key parts of a stand column, a top beam and a base of the overhead guard assembly; and high-frequency and low-frequency components in the strain signals are extracted by using wavelet packet decomposition, dynamic stress wave propagation characteristics are analyzed based on an energy entropy principle, and a dynamic response transfer chain is further established. An accumulated damage value is calculated through a strain energy density criterion, and a dynamic strength evaluation system is constructed, so that dynamic stress distribution and a dynamic deformation field of the overhead guard under different impact load working conditions are accurately evaluated. Thus, the accuracy of dynamic strength verification of the overhead guard can be improved, the structural dynamic characteristics under the static load-impact load switching working condition can be comprehensively reflected, and the safety and reliability of the overhead guard under the complex working condition are ensured.

The application belongs to the field of aero-engines, and relates to a blisk design technology, and provides a blisk airfoil design method and system.The method comprises the following steps: acquiring a plurality of initial design variables of each section on each initial airfoil in a blisk; obtaining a characteristic parameter of each initial design variable by fitting a change curve of each initial design variable with respect to blade height; constructing a weighted target constraint function according to an excitation order, a working speed range and a dynamic strength reserve of the initial airfoil; constructing a plurality of training samples through all the characteristic parameters, acquiring a function value of the weighted target constraint function corresponding to each training sample, taking the training sample with the minimum function value as a final characteristic parameter, and acquiring each design variable according to the final characteristic parameter.The method effectively improves blade stress reserve and resonance margin, improves the strength and high-cycle fatigue characteristics of the blade, shortens the design cycle, and greatly improves the optimization design efficiency of the blade.

The invention belongs to the technical field of airplane dynamic strength design, and particularly relates to a dynamic boundary equivalent design method considering heat influence. The method comprises the following steps: constructing a finite element model of an overall structure containing a target structure, and calculating thermal stress distribution of the overall structure under a specified temperature load; calculating the low-order modal frequency and vibration mode of the overall structure caused by thermal stress; constructing an equivalent design initial model comprising a target structure and a peripheral structure; calculating a low-order modal frequency and a vibration mode of the target structure caused by thermal stress; optimizing the peripheral structure into a plurality of boundary support thin plates by taking the maximum constraint after the low-order modal frequency of the target structure as a target function, and forming an optimal topology model; calculating a low-order modal frequency and a vibration mode of the target structure caused by thermal stress; and by taking the low-order modal frequency and vibration mode closest of the target structure and the overall structure as an optimization target, optimizing the size parameters of each boundary support thin plate, and obtaining the dynamic boundary equivalent design parameters for the target structure.

The present invention discloses a method for establishing a dynamic triaxial statistical damage constitutive model of rock, belonging to the basic research technology field of the dynamic constitutive model of rock in deep underground engineering. The method includes introducing the nonlinear Mohr-Coulomb and Hoek-Brown strength criteria, a strength criterion of rock dynamic strength and strain rate dependence based on thermal activation and viscous mechanism, and deriving a nonlinear rock dynamic strength criterion considering the strain rate effect; constructing a method for measuring the strength of rock micro-elements that can reflect the dynamic deformation characteristics of rock, establishing a dynamic triaxial statistical damage constitutive model of rock; and carrying out a sensitivity analysis of the dynamic triaxial statistical damage constitutive model of rock. The method effectively establishes a dynamic triaxial statistical damage constitutive model of rock applicable to high confining pressure and high strain rate, so as to accurately simulate the nonlinear deformation process of deep high-confining pressure rock under dynamic loads, and can be applied to the basic research technology field of the dynamic constitutive model of rock in deep underground engineering.

The invention belongs to the field of airplane structure strength test, and particularly relates to a movable airfoil structure vibration superposition static load test device which comprises an integral frame, a static load system, a movable excitation platform, an excitation device and a movable airfoil test piece. The integral frame is used for supporting the static load system, the movable excitation platform, the excitation device and the movable airfoil test piece; the movable airfoil test piece is horizontally arranged, the static load system is connected with the movable airfoil test piece, and the static load system can perform distributed static load low-rigidity loading on the movable airfoil test piece through an air bag; the two groups of excitation devices are arranged on the movable excitation platform side by side; through collaborative innovation of the movable excitation platform, the distributed static load system and the high-rigidity frame, remarkable advantages are formed in the aspects of test efficiency, working condition simulation authenticity, data precision, universality and the like, and efficient and reliable test equipment is provided for ground dynamic strength verification of the movable airfoil of the civil aircraft.

The application provides a drop test balancing adjustment device and method, the device comprises: an extension arm 1, a longitudinal balancing rod 2, a main frame 3, a vertical balancing rod 4, a transverse balancing rod 5, a gravity center tracking adjustment beam 6, a balancing block 7, a mounting interface 8, a transverse adjustment support 9, a guide limiting plate 10, a movable hanging lug 11, an adjustment screw rod 12, a rotating handle 13; the application can be used to realize the dynamic strength and performance examination of the landing gear structure, is mainly related to the tracking adjustment of the drop release hanging point gravity center position, the decoupling of the counterweight mass, the adjustment of the counterweight position, the gravity center and the moment of inertia parameter balancing and the installation of the test piece, and the accurate examination requirement of the dynamic strength and performance verification of the landing gear structure can be met.

The invention discloses a nickel-based single crystal turbine blade typical vibration area dynamic intensity evaluation method, which comprises the following steps: analyzing typical vibration area characteristics and a principal stress direction according to a vibration characteristic simulation result, and designing typical characteristics and crystal orientation of a simulation piece; performing a high-cycle fatigue test and a tensile test on the simulation part to obtain high-cycle fatigue strength and tensile strength, and drawing a fatigue limit model considering stress concentration; testing again to obtain high-cycle fatigue strength, and drawing a three-point equal-life model considering stress concentration; the turbine blade is subjected to a core dynamic test to obtain dynamic stress, static stress is obtained according to a vibration characteristic analog simulation result, a straight line perpendicular to the abscissa is made through a static stress numerical point, and the high-cycle fatigue strength corresponding to the intersection point of the straight line and the three-point equal-life model is the vibration fatigue limit; the ratio of the dynamic stress to the vibration fatigue limit is the dynamic strength. The method considers the main stress direction and the stress concentration problem, and the evaluation result is accurate.

The invention belongs to the field of physical training devices, and relates to a kayak athlete physical training device which comprises a frame body, a physical training mechanism is arranged on the frame body, and the physical training mechanism comprises a rotating assembly, a rotating rod and a concentric annular step sleeving structure disc installed on the frame body are connected through a transmission connecting mechanism; the foundation strength adjusting assembly is close to the outer peripheral side of the fixed baffle disc in the structural disc and abuts against the fixed baffle disc; the dynamic strength adjusting assembly comprises a movable limiting structure of which one end is in sliding connection with a round seat in the center of the structural disc and the other end is rotationally connected with the transmission connecting mechanism through a thread; the friction extrusion structures are fixedly mounted on the round seat and correspondingly arranged on the two sides of the movable limiting structure; after the rotating rod rotates, the transmission connecting mechanism drives the movable limiting structure to transversely slide on the round seat, so that the movable limiting structure gets close to or away from the friction extrusion structure, and the rotating resistance is dynamically adjusted. The problem that the strength of the device is single or adjustment is tedious is solved.

The invention provides a rock dynamic strength criterion establishment method based on a confining pressure-strain rate coupling effect, and relates to the technical field of rock mass engineering, the method comprises the following steps: obtaining a power function relationship between confining pressure and a coupling coefficient as well as between a strain rate and the coupling coefficient based on test data, the coupling coefficient being used for representing the coupling effect of the confining pressure and the strain rate; constructing a coupling effect model according to the coupling effect of the confining pressure and the strain rate and the power function relationship; and constructing a rock dynamic strength model based on the confining pressure effect, the strain rate effect and the coupling effect model. Based on the relation between the confining pressure and the coupling coefficient and between the strain rate and the coupling coefficient, the rock dynamic strength criterion is established by comprehensively considering the confining pressure effect, the strain rate effect and the coupling effect, so that the problem that the dynamic strength in the wide confining pressure and wide strain rate range cannot be estimated according to the existing dynamic rock strength criterion is solved; and errors caused by neglecting the coupling effect in the existing dynamic rock strength criterion are eliminated.

The invention discloses a composite material with high density, high strength and excellent dynamic mechanical properties, the chemical formula of the composite material is Wx (FeaNibCrcVdAle) y, x and y correspond to the mass percentage of W and the mass percentage of FeaNibCrcVdAle; the method comprises the following steps: 1, selecting iron, nickel, chromium, vanadium and aluminum metal raw materials, and preparing high-entropy alloy spherical powder by adopting a vacuum suspension smelting process and a vacuum gas atomization process; secondly, the high-entropy alloy spherical powder and tungsten powder are subjected to ball milling and mixed to be uniform, and mixed powder is obtained; and 3, carrying out hot pressed sintering on the mixed powder. According to the composite material, high-density tungsten is selected as a matrix component, a high-entropy alloy component with ultrahigh dynamic strength and excellent strain localization capability is selected as a composite phase, and the composite material with high density, high strength and excellent dynamic mechanical property is obtained; the preparation method is simple and convenient in process, controllable in material component, high in material density and suitable for being used as the armor-piercing bullet core material.