29 results about "Impact velocity" patented technology

The invention relates to the technical field of numerical simulation of rock dynamics, in particular to a numerical simulation method and system for the whole process of ore rock fracture based on FDEM impact loads.The method comprises the steps that a continuous medium structure is discretized into a finite element network composed of triangular units through FDEM, and an ore rock impact test model is constructed; setting material parameters and impact speed boundary conditions according to the ore rock impact test model; a normal contact force calculation model and a tangential contact force calculation model are established according to material parameters and impact speed boundary conditions, and coordinates and speed updating results of triangular unit nodes are obtained in combination with the Newton second law and the calculation models; and performing visual analysis based on the coordinate and speed updating result, and outputting crack propagation, stress field and energy evolution results under the impact load. The method can accurately simulate the crack propagation, the fracture mode and the energy evolution law of the ore rock under the impact load, quantitatively researches the crushing characteristics and the energy evolution law of the ore rock, and provides a calculation method for the research of the crushing mechanism of the ore rock.

The invention provides a coal body strain synchronous in-situ monitoring device and method based on true triaxial impact, and relates to the field of coal body dynamic testing and structural damage monitoring. Comprising a sample bearing module, an impact loading module, an internal fiber bragg grating dynamic strain monitoring module, a surface strain gauge monitoring module, a synchronous data acquisition module, a microscopic crack detection module and a macroscopic failure analysis module, the impact loading module is used for applying a transient impact load with a set impact speed to the gas-solid coupling coal sample, and the internal fiber bragg grating dynamic strain monitoring module is embedded with at least one fiber bragg grating sensing grating point along three mutually orthogonal directions of the gas-solid coupling coal sample respectively. The damage evolution mechanism of the gas-solid coupling coal body under the high strain rate condition is disclosed, and a means is provided for risk analysis of the rock burst-coal and gas outburst hybrid power disaster.

Shock struts are provided that include a first energy absorbing stage or first load limiter and a second energy absorbing stage or second load limiter. The second energy absorbing stage or second load limiter can include one or more disc springs (205). The shock struts can be used in both fixed and retractable landing gear while providing design tunability for obtaining a load-deflection curve that accommodates a range of descent or impact velocities.

The application discloses a kind of surface nanocrystalline powder metalling device, including infiltration tank, transmission mechanism and clamping mechanism, it is characterized in that, the transmission mechanism is by fixed frame, input shaft, first bevel gear, second bevel gear and third bevel gear are formed, the infiltration tank is by left end cover, tank body and right end cover are formed, tank body inner surface is evenly provided with baffle, heating plate is arranged between tank body and heat preservation box, rotating shaft in tank body is provided with left sealing plate, right sealing plate and clamping mechanism, workpiece is installed on clamping mechanism, projectile and infiltrant are arranged between left sealing plate and right sealing plate, the linear velocity of projectile is 2.5~10m / s, the radius r of tank body and projectile linear velocity satisfy formula, beneficial to transmission mechanism so that tank body and rotating shaft produce reverse rotation, increase the relative impact velocity of projectile and workpiece, make plastic deformation on the surface of workpiece and form nanometer layer, effectively solve the problem that material after nanocrystallization pretreatment faces in heat expansion infiltration process.

The application discloses a kind of one-dimensional force electric characteristics of concrete test piece and system, it is related to the cross field of detection and intelligent sensing technology of civil engineering material dynamic mechanical property.Testing method includes the following steps: S1: using one-dimensional Hopkinson pressure rod experimental device to the concrete test piece pre-embedded piezoelectric sensor is axially impacted loading, obtains incident wave signal, reflection wave signal and transmission wave signal;The current and voltage corresponding to the resistance obtained in parallel to the two ends of piezoelectric sensor;S2: obtaining the one-dimensional stress-strain curve of concrete test piece;S3: based on current and voltage, the charge amount generated by piezoelectric sensor is obtained;S4: the impact velocity of impact rod is changed and the stress-charge amount variation curve is obtained by repeating steps S1-S3.Getting the axial stress of concrete test piece and the charge amount output by piezoelectric sensor simultaneously, constructs stress-charge amount relationship curve, realizes the quantitative calibration of dynamic sensitivity.

The invention discloses a method for determining the weakest bird strike part of a fan rotor blade of an aero-engine. The method comprises the following steps: acquiring blade parameters, setting the axial relative speed of a bird body and the radial rotation radius of a strike position, establishing a fan blade bird strike mathematical model, and outputting the relative strike speed between the bird body and the blade; setting bird body parameters, constructing a cylindrical bird body model, and calculating the maximum bird body impact mass; calculating impact kinetic energy in combination with the relative impact speed; constructing bird strike equivalent stress, obtaining standard bird strike equivalent stress, and drawing a standard equivalent stress C-R distribution curve; and in the C-R distribution curve, the position of the radial rotation radius corresponding to the maximum equivalent stress on the blade is determined as the weakest bird impact part. According to the method, quick and quantitative identification of the weak bird impact area of the fan blade under various flight conditions is realized, the design of a bird impact resistant structure and the formulation of a whole machine bird swallowing test scheme can be effectively guided, and the method is high in engineering practicability, high in analysis efficiency and wide in adaptability.

This invention discloses an electromagnetic pulse welding coil for welding tubular metals. The electromagnetic pulse welding coil is arranged circumferentially along a driving tube. The driving tube can obtain Lorentz force through electromagnetic induction of the electromagnetic pulse welding coil, providing the impact velocity for welding. The electromagnetic pulse welding coil is composed of several circumferentially connected "convex"-shaped structures. The "convex"-shaped structures are arranged with an inward rotation of 90°, and the wide end at the outer end has a notch. One side of the notch is connected to the other side of the notch of the adjacent "convex"-shaped structure through a connecting block, thereby connecting all the "convex"-shaped structures into a whole, forming a ring structure around the driving tube. This invention has the advantages of significantly improving the electromagnetic energy utilization efficiency, increasing electromagnetic energy, and being applicable to electromagnetic pulse welding of difficult-to-deform metals.

The invention relates to an impact speed mechanical sensor applied to a severe environment, and relates to the field of sensors, the impact speed mechanical sensor comprises a shell, an upper cover plate, an inner core and a force sensor, the force sensor is placed at the bottom of the shell, and a plurality of groups of square strips which are different in length and made of super-viscoelastic and super-elastic materials are arranged in the inner core at intervals; the inner core is placed on the force sensor, the upper cover plate is placed on the inner core and is in sliding connection with the shell, and the device has the advantages that impact signals can be converted into visual information or force signals only through a mechanical structure, and the device can be widely applied to impact monitoring scenes with high requirements for reliability and environmental adaptability.

The invention relates to the technical field of welding, and provides a method for eliminating welding stress of high-strength steel and a removing device and system. The method comprises the steps that S1, welded high-strength steel is fixed, so that the flatness error of a plane corresponding to a welding seam of the welded high-strength steel meets a set threshold value; the strength of the high-strength steel is greater than or equal to 1500MPa; s2, based on the strength of the high-strength steel, impact parameters of the stress removing device are configured, and the impact parameters at least comprise the amplitude of an impact head, the impact frequency of the impact head, the impact speed and the diameter of an impact needle; and S3, a stress removing device is adopted for impacting the thermal response area of the weld joint according to a preset strategy so as to eliminate residual stress generated after high-strength steel welding. The technical defect that the fatigue life of a high-strength welding part is poor due to the fact that the welding stress is too large after the high-strength steel is welded is overcome.

The invention discloses a runner wear-resistant method and system by controlling the particle impact speed, and the method can effectively reduce the impact speed of solid particles on runner blades to be below a material critical value, obviously alleviate the abrasion damage, prolong the service life of a runner, and improve the wear resistance of the runner. And the lubricating oil has good working condition adaptability and synergistic application potential with the existing anti-wear technology.

The present application provides a portable device and a method for relieving the impact force of a pump station flap, which comprises: an inertia disc for containing fluid sheared with a brake vane, the inertia disc being interference fitted with a fixed shaft of the pump station flap; a surface of the inertia disc facing the pump station flap is concave to form a containing cavity I for containing fluid; a fluid filler receiving box for providing fluid, which is provided with a containing cavity II in communication with the containing cavity I, the volume of the containing cavity II being adjustable; a transmission turntable for driving the brake vane to do centrifugal motion, the transmission turntable being arranged in the containing cavity I of the inertia disc; one end of the brake vane is hinged to a surface of the transmission turntable, and the other end is a free end; a resistance reset unit for prolonging the action time of the brake vane with the fluid and resetting the brake vane in the radial direction; and a sealing plate for sealing the surface of the inertia disc facing the pump station flap. The present application can slow down the impact speed of the pump station flap and reduce the impact force of the pump station flap on the door seat when the pump station flap is closed.

The invention relates to the field of ocean engineering and hydrodynamics, and discloses a method and device for evaluating the impact load of a deep sea density flow on a structure, and the method comprises the steps: constructing a computational fluid dynamics two-phase flow model, simulating the transient impact of the deep sea density flow on the structure under the conditions of different initial impact heights, impact speeds and Reynolds numbers based on the two-phase model, and calculating the impact load of the deep sea density flow on the structure. Obtaining a resistance time travel curve of the structure; the peak resistance coefficient of the offshore structure is determined after the limit peak resistance and the maximum acting height of the density flow are extracted from the resistance time history curve; determining a load analysis model based on the peak resistance coefficient, the limit peak resistance, the maximum acting height of the density flow, the speed and the density; and determining an impact load result of the deep sea density flow on the offshore structure based on the load analysis model. According to the scheme, actual measurement does not need to be carried out every time in actual engineering application, the load result can be obtained based on impact load model analysis, and the evaluation efficiency of the impact effect of the deep sea landslide on the fan pile foundation is improved.

The invention discloses an aero-engine fan blade foreign matter impact detection device, and relates to the technical field of aero-engine performance detection.The technical scheme includes that the aero-engine fan blade foreign matter impact detection device comprises a detection unit, a foreign matter emission unit and a linkage unit, and the detection unit comprises an electricity guiding device connecting socket, a camera connecting socket, a high-speed detection camera and a controller connecting plug; the foreign object launching unit comprises a feeding mechanism, a low-speed launching mechanism, a high-speed launching mechanism and an air cylinder, the linkage unit can switch any launching mechanism to be connected with the air cylinder, the air cylinder can store energy for the connected launching mechanism, and the low-speed launching mechanism and the high-speed launching mechanism can launch materials in the feeding mechanism after storing energy. According to the fan blade impact detection device, through the arrangement of the overall structure, the influence of different impact speeds on fan blades can be detected, and the detection result is more accurate.

The application discloses a kind of instrumented impact testing machine dynamic force sensor calibration method based on double-pulse method, standard cuboid sample is generated by using pendulum impact standard, and standard double-pulse force can be traced to sample attribute (sample size, mass and Young's modulus) and pendulum impact velocity (or pendulum effective length) above, and then the calibration method of instrumented impact testing machine dynamic force sensor is traced to source;Propose a kind of design method for the sample required for the sweep frequency calibration of instrumented impact testing machine dynamic force sensor, to achieve the purpose of sweep frequency calibration of instrumented impact testing machine dynamic force sensor.This method can stably, reliably and quickly realize the high-frequency calibration of instrumented impact testing machine dynamic force sensor under the premise of effectively ensuring calibration accuracy, and fills the blank of existing instrumented impact testing machine dynamic force sensor calibration method.

The invention belongs to the technical field of geological disaster protection engineering, and discloses a reinforced concrete slab damage evaluation method based on an M-V curve, and the method comprises the steps: determining related design parameters of a reinforced concrete slab; defining the threshold values of the four damage degrees of mild damage, moderate damage, severe damage and complete failure; calculating critical values M0 and V0 of four damage degrees in the M-V curve; drawing an M-V curve; scanning side slope characteristics, simulating a side slope rockfall movement track, and obtaining a plurality of groups of rockfall mass and impact speed combinations; determining the damage grade of the reinforced concrete slab according to the actual rockfall quality and impact speed; counting the number of falling rocks in different damage areas, and calculating the damage probability. The damage evaluation method provided by the invention can rapidly quantify and predict the impact damage degree of the composite cushion layer concrete slab, can be used for evaluating the impact resistance of the reinforced concrete slab with any section covered by any composite cushion layer with any thickness, and provides a reference for the prevention and treatment of rockfall disaster resistance of the reinforced concrete slab.

This invention belongs to the field of aero-engine technology, specifically a method for assessing erosion damage to aero-engine compressor blades that integrates multiple operating parameters. The method includes: determining the fluctuation range of operating influencing parameters through on-site sampling and flight parameters; constructing a multi-parameter sample set using Latin hypercube sampling; deriving an erosion wear theoretical model; identifying key parameters related to target material characteristics and impact velocity by combining sand particle velocity measurement and titanium alloy erosion experiments; establishing a gas-solid two-phase flow finite element model; substituting the sample set into the model to solve for the wear rate concentration value; using a polynomial chaotic expansion method to obtain the relationship between operating influencing parameters and the wear rate concentration value; and deriving the statistical characteristics of the wear rate concentration value; finally, calculating the statistical characteristics of damage depth by combining erosion time and blade surface area. This invention achieves high-precision assessment under dynamic coupling of multiple parameters, solving the problems of single parameters and poor model adaptability in traditional methods, and significantly improving its engineering practical value.

A method of controlling a moving component (22, 24) approaching a buffer (42, 46) in a hoistway (34) of an elevator system (20) is provided. The method includes: a) calculating, based on a current velocity of the moving component (22, 24), a required braking distance to decelerate the moving component (22, 24) to a maximum buffer impact velocity; b) comparing the required braking distance to a current buffer distance between the moving component (22, 24) and the buffer (42, 46) to give a comparison result; c) repeating steps a) and b) one or more times; and d) triggering an emergency stop of the moving component (22, 24) based on the comparison result.

A collision-resistant steel plate for butane pressure vessels, comprising the following components (wt%): C: 0.10–0.20%, Si: 0.20–0.45%, Mn: 1.60–1.80%, Al: 0.025–0.045%, P≤0.015%, S≤0.005%, V: 0.065–0.085%, Nb: 0.027–0.045%. The process involves: smelting, casting into a billet, heating the billet, rough rolling, finish rolling, cooling, normalizing, and stress relief. The static yield strength Rel of this invention is 460–500 MPa, and the dynamic yield strength Re is 510–760 MPa; the tensile strength is 610–700 MPa; the yield ratio is ≤0.85; and the static elongation after fracture A is 29–41% and the dynamic elongation after fracture A... d The strength-ductility product is 18995–27798 MPa·% at 28–41%; the drop hammer tear (DWTT) energy is 15–19 kJ; when the impact velocity is 5–50 m / s and the impact displacement is 1.5 m, the energy absorbed by the steel plate is 3.57–3.89 kJ, and the grain size of ferrite does not exceed 0.008 μm.

A collision-resistant pressure vessel steel for storing and transporting carbonyl chloride, comprising the following components (wt%): C: 0.10–0.20%, Si: 0.25–0.50%, Mn: 1.65–1.90%, Al: 0.025–0.045%, P≤0.015%, S≤0.005%, V: 0.070–0.10%, Nb: 0.028–0.052%. The process involves: smelting, casting into a billet, heating the billet, rough rolling, finish rolling, cooling, normalizing, and stress relief. The static yield strength Rel of this invention is 500–570 MPa, and the dynamic yield strength Re is 520–787 MPa; the tensile strength is 650–730 MPa; the yield ratio is ≤0.85; and the static elongation after fracture A is 29–42% and the dynamic elongation after fracture A... d The strength-ductility product is 21054-28434 MPa·%; the drop hammer tear (DWTT) energy is 15.7-20 kJ; when the impact velocity is 5-50 m / s and the impact displacement is 1.5 m, the steel plate absorbs 3.85-4.15 kJ of energy, and the ferrite grain size does not exceed 0.008 μm.

This invention discloses an underwater floating ice-breaking test device, comprising an ice-water pool and an ice-breaking device. The ice-water pool is used to prepare an ice layer. The ice-breaking device includes a platform and multiple floating bodies. The platform is located at the bottom of the ice-water pool, and the multiple floating bodies are arranged in an array. The floating bodies are connected to the platform by a locking mechanism, which can lock or release the floating bodies. This application can realize the release of floating bodies at a specified position, number, and sequence, thereby enabling the study of the mechanism of single or multiple floating bodies freely rising and breaking ice in one go. It can also explore the ice-breaking load characteristics, structural deformation laws, ice layer damage modes, and ice-breaking mechanisms of floating bodies under the influence of variables such as impact velocity, shape, and impact angle.

This invention provides an impact testing method for optimizing the energy-absorbing foam structure of the front bumper for active engine hoods. The method includes: based on a whole-vehicle impact simulation model, performing pedestrian leg-shaped and whole-vehicle impact simulations on various areas of the energy-absorbing foam in the front bumper to obtain the target compression amount of the foam in each area. The target compression amount is the maximum compression amount of the foam in the whole-vehicle impact simulation. Based on the foam impact simulation model, performing foam impact simulations at multiple impact velocities sequentially until the foam compression amount reaches the target compression amount, and using this impact velocity as the target velocity. Simulating the actual installation configuration, the pressure sensor and the foam under test are installed in place, and an impact test is performed on the foam under test at the target velocity, recording the foam deformation and pressure sensor signals. Based on the foam deformation and pressure sensor signals, an optimized foam shape is identified. This invention effectively improves the structural design efficiency of the foam for mounting pressure tube sensors, thereby effectively saving vehicle R&D and manufacturing costs.

The invention discloses a method and a system for testing mechanical and electrical characteristics of a concrete test piece, and relates to the technical field of civil engineering material testing. The testing method comprises the following steps: S1, carrying out impact loading on a concrete test piece pre-embedded with a piezoelectric sensor by utilizing a Hopkinson pressure bar experimental device, and obtaining an incident wave signal, a reflected wave signal and a transmitted wave signal in response to the impact of an impact bar on an incident bar; acquiring current and voltage corresponding to resistors connected in parallel to the two ends of the piezoelectric sensor; s2, acquiring a stress-strain curve of the concrete test piece based on the incident wave signal, the reflected wave signal and the transmitted wave signal; s3, acquiring the quantity of electric charges generated by the piezoelectric sensor based on the current and the voltage; and S4, changing the impact speed of the impact rod, and repeating the steps S1 to S3 to obtain a stress-charge quantity change curve. By synchronously acquiring the axial stress of the concrete test piece and the electric charge quantity output by the piezoelectric sensor, a stress-electric charge quantity relation curve is constructed, and quantitative calibration of the dynamic sensitivity is realized.

This invention discloses a method and apparatus for predicting the results of a thermo-pressure coupled impact rock breaking test. The prediction method includes: parameter selection; establishing a rock damage morphology test dataset using impact tests; selecting key factors that cause differences in rock damage state as parameters to be changed and used as input parameters for a neural network; these parameters include: impact velocity, drill bit shape, drill bit spacing, drill bit diameter, temperature, and confining pressure; saving the rock damage test results and corresponding input parameters as a sample data set based on the thermo-pressure coupled impact rock breaking test apparatus; changing the parameters to conduct the next set of tests until all experiments under different parameters are completed; and establishing a dataset for neural network training; etc. This application can predict the rock breaking effect under different confining pressures, temperatures, cutting teeth, and tooth spacings under rotating impact loads, thereby analyzing the influence of the above factors on the rock breaking effect under rotating impact loads.

The application discloses a kind of droplet different impact speed icing adhesion test device, it includes drip system, telescopic guide pipe, guide rail bottom plate assembly and bottom plate angle adjusting mechanism.Drip system is located at the top of device, with drip device, can produce single or continuous droplet.Telescopic guide pipe can adjust the falling height of droplet, realize the control of droplet impact speed, and then satisfy the icing experiment demand under a variety of working conditions.The guide rail bottom plate assembly is internally provided with slidable guide rail, and can install and take out the sample of copper, aluminum, steel and other materials, and the detachable ice mold device is provided on the sample plate, the bottom plate angle adjusting mechanism is composed of two precision elevators at the bottom and lateral shaft, by controlling the different height of elevator, the inclination angle of bottom plate can be adjusted, to simulate the icing process of droplet impacting the surface of material at different angles.

The present application relates to a kind of explosive welding process parameter design method, belong to explosive welding technical field, solve the technical problem of reasonable determination base cladding spacing and charge thickness in explosive welding process.A kind of explosive welding process parameter design method, including the following steps: step 1, according to the mass of unit area of welding material determines the base layer and cladding in explosive welding, and the base layer and cladding are arranged in parallel;Step 2, determine the optional range of collision point speed V c When explosive welding;Step 3, determine the minimum value V p Of cladding impact velocity V pmin , and determine the value range of collision angle θ, further determine the specific value of collision angle θ, collision point speed V c And cladding impact velocity V p ;Step 4, determine the spacing A between base layer and cladding based on the principle of conservation of function;Step 5, determine the charge thickness ζ based on the principle of conservation of momentum.The present application opens up a kind of new path to determine base cladding spacing and charge thickness, more scientific than existing empirical formula.

The present application relates to a kind of tungsten alloy based on light gas gun impact strengthening and application.The tungsten phase of the tungsten alloy obtained by the present application has dislocation and dislocation entanglement, and grain refinement occurs in γ-(Ni, Fe) binder phase, the size of the refined grain is less than or equal to 150nm, and twin crystal is generated, and the total area of twin crystal accounts for more than 1 / 3 of the binder phase area;Wherein the dislocation density is greater than or equal to 10 8 / mm 2 , the dislocation entanglement density is greater than or equal to 10 5 / mm 2 . The tungsten alloy includes, by mass percentage: nickel 3-11%; iron 1-5%; the balance is tungsten and unavoidable impurities.The present application can control the microstructure in tungsten alloy by controlling the type of collision pair, target plate thickness, projectile diameter and impact velocity and other parameters during light gas gun loading, so that the tungsten alloy can be strengthened under a certain impact pressure without layer cracking damage.The present application has reasonable structure design, simple and controllable process, and the obtained product has wide application.

This invention relates to a method for assessing target structural damage under continuous blast loads, belonging to the field of ammunition damage assessment technology. It solves the problem that existing damage assessment methods cannot perform multi-dimensional and quantifiable assessments under continuous blast loads. The damage assessment method during continuous blasts includes the following steps: In the current blast process, based on the current impact velocity and angle of the warhead, the current penetration depth is obtained. If the current penetration depth is greater than or equal to the protective layer thickness, it is determined to be a severe damage level; otherwise, based on the current penetration depth, the current critical collapse thickness is obtained. If the current critical collapse thickness is greater than the current remaining thickness of the protective layer, it is determined to be a severe damage level; otherwise, the damage level of the current blast process is assessed based on damage criteria, and the crater angle of the current crater is obtained based on the warhead's impact velocity.

The present application relates to the technical field of rock dynamics numerical simulation, in particular to a numerical simulation method and system for the whole process of rock and ore fracture under impact load based on FDEM, which comprises the following steps: discretizing the continuous medium structure into a finite element network composed of triangular elements through FDEM, and constructing a rock and ore impact test model; setting material parameters and impact velocity boundary conditions according to the rock and ore impact test model; establishing a normal contact force calculation model and a tangential contact force calculation model according to the material parameters and impact velocity boundary conditions, and obtaining the coordinate and velocity update results of the triangular element nodes in combination with Newton's second law and the calculation model; and performing visual analysis based on the coordinate and velocity update results to output the crack propagation, stress field and energy evolution results under impact load. The present application can accurately simulate the crack propagation, fracture mode and energy evolution law of rock and ore under impact load, quantitatively study the rock and ore crushing characteristics and energy evolution law, and provide a calculation method for the rock and ore crushing mechanism research.

The invention discloses a reusable explosion load simulator, and relates to the technical field of explosion testing. The simulator comprises a simulator body and a simulated explosion impact test platform. The simulator body is a variable-impedance gradient elastic rod, and the impedance distribution of the simulator body is solved through a wave propagation reverse design theory. The device can be repeatedly used, the test cost is greatly reduced, and the test efficiency is improved; impedance distribution is determined through a wave propagation reverse design theory, so that a pressure-time evolution relationship between an impact load generated by a simulator body and a target explosion load is highly matched, and the problem of large waveform simulation deviation of an existing simulator is solved; the variable-impedance elastic rod can generate a high impact load, and wide-range load adjustment can be realized by adjusting the initial impact speed and material parameters; the simulator body is simple in shape, mature in processing technology, low in cost and convenient for batch production and application.