218 results about "Underwater explosion" patented technology

The invention discloses a system for passively positioning underwater targets and a method, wherein an underwater sensor device collects the noise signal of an underwater target, obtains and transmits the energy information of the noise signals; a buoy device is communicated with the sensor device for transferring the energy information to a center processing device; the buoy device is used as the anchor point of the system; the center processing device is communicated with the buoy device for obtaining the direction of the underwater target based on maximum likelihood method according the received energy information and the information of the anchor point. The invention can be used to position underground sounding bodies such as underground vehicles, whales and underground explosive sound source, to complete target detection in underground condition.

The invention discloses a model test device for carrying out underwater explosion research on a centrifuge platform. The model test device comprises a model box, a data acquisition and analysis unit and a synchronous control unit. The model box is internally equipped with a test medium; an explosion device is arranged in the test medium; the bottom of the model box is fixedly provided with a target body; the model box is internally provided with a data receiving unit; the data receiving unit is connected with a data transmission unit; and the data transmission unit is connected with the data acquisition and analysis unit. When the explosion device is detonated, the data receiving unit receives various test data; the test data is transmitted to the data acquisition and analysis unit for processing through the data transmission unit; and the processed data is uploaded to the synchronous control unit. The model test device for carrying out underwater explosion research on a centrifuge platform can be suitable for centrifuge high-speed rotation special mechanical environment, and realizes precise and safe detonation of the explosion device in the centrifugal model test and signal synchronous acquisition and transmission.

The invention provides an experimental device and an experimental method for generation of bubbles of an electric spark in water. Two copper wires are fixed on two metal electrodes respectively; the two metal electrodes and a capacitor (C) are connected in parallel to two ends of a resistor (R) and two ends of a power supply (U); the experimental device also comprises a single-pole double-throw switch (K); the single-pole double-throw switch (K) is connected with one end of the power supply, one end of each copper wire and one end of the capacitor respectively; the two metal electrodes are placed in a transparent water tank; a high-speed camera and a light source are arranged on two sides of the water tank; the high-speed camera and the light source are in the same horizontal plane; and degassed water is filled in the water tank. The experimental device serves as a generation device of the bubbles in a mode of electric spark lighting, and the copper wires are melted by great energy which is released by electrode discharging so as to gasify surrounding fluids to form the bubbles. By the invention, real underwater explosion can be simulated simply relatively; the experimental method becomes powerful experiment means which replaces the real explosion; and an effective experimental way is provided for research of a bubble theory.

The invention discloses a test system and a test method for an underwater explosion impact equivalent loading experiment. The test system comprises a bullet emission system, a bullet speed measurement system, a water target cabin system and a pressure measurement system, wherein the dynamic energy of a bullet is converted to an impact load in a water target cabin by colliding the bullet with the water target cabin system, finally the impact load is loaded on a test piece to be tested, and a pressure time interval is measured by the pressure measurement system. The test system and the test method disclosed by the invention are capable of greatly realizing equivalent underwater explosion equivalent loading in laboratory conditions, and has the advantages of being high in controllability, simple to operate, low in experiment danger, high in repeatability, low in experiment cost, and the like.

The invention provides a subaqueous explosion pressure measurement device based on an improved Hopkinson bar, and is used for measuring shock wave pressure and bubble jet pressure of subaqueous shortest field explosion. The subaqueous explosion pressure measurement device comprises an energy absorption and recovery device which absorbs all the subaqueous explosion shock wave pressure pulse kinetic energy falling into flying sheets; a shock wave load separation device which is used for transferring all the subaqueous explosion shock wave pressure pulse in the improved Hopkinson bar to the flying sheets so as to realize shock wave load separation; and an improved Hopkinson bar measurement element which is used for amplifying subaqueous explosion shock wave pressure and bubble jet pressure signals and realizing shock wave load separation with the help of the shock wave load separation device so as to finally realize time-space separated measurement of the shock wave pressure and the bubble jet pressure of subaqueous shortest field explosion.

An underwater positioning system provides position information for a rover, moveable within a reference frame. The system may comprise: at least one beacon having a light source, located at a fixed position within the reference frame; an underwater imaging device, moveable with the rover in the reference frame to observe the light source from different viewpoints and determine direction data representing a direction or change in direction of the light source with respect to the imaging device; an orientation sensor, associated with the imaging device to determine an orientation of the imaging device with respect to the reference frame and generate orientation data; and a scaling element for providing scaling data representative of a distance between the imaging device and the light source. Various different beacons may be provided.

In alternative system implementations, the locations of light source(s) and underwater imaging device are reversed between rover and beacon(s).

The invention aims to provide an underwater positioning method based on a differential technology. The method comprises the following steps of: firstly, after receiving an interrogation signal of an interrogator of a short-baseline acoustic positioning unit through an underwater responser, sending an answer signal; determining a pseudo-range value of the underwater responser; secondly, measuring the distance between the interrogator and the responser in a manner of interrogating and responding; recording position data of high-precision a DGPS (Differential Global Positioning System); taking the obtained position of the responser as an absolute reference position; and finally, calculating the distance between the responser to each array element of the short baseline; comparing the calculated real distance with the pseudo-range value which is measured by using the short baseline in a manner of responding; solving a correction value; using the correction value to correct the pseudo-rangevalue of the responser measured by the short-baseline positioning system; obtaining a position coordinate of the responser; and then, completing underwater positioning. In the method disclosed by theinvention, the algorithm is simple; a correction value is only necessary to be added in a positioning and ranging equation; the method is applicable for most underwater positioning systems; public errors of the systems can be effectively eliminated; and the object positioning precision can be improved.

The invention discloses a method for measuring near field blast wave pressure of underwater explosion of an explosive. The measuring method is characterized in that a thin-film stress gauge is glued on cotton cloth by use of an epoxy adhesive, the thin-film stress gauge is welded with a coaxial cable, the other end of the coaxial cable is connected with a charge amplifier, the charge amplifier is connected with a signal wire, and the other end of the signal wire is connected with a data acquisition instrument. The cotton cloth glued with the thin-film stress gauge is put on a test support, a sample is fixed in a position away from the thin-film stress gauge by a certain distance by use of a cotton thread and an enameled wire, a detonator is connected to the sample, the test support is sunk in water, the technical parameters of the data acquisition instrument are set, the test sample is detonated, and the near field output pressure of underwater explosion of the sample is measured. The method can be applied to testing in a small pool; the test process is simple, and the test data can be obtained directly without secondary deduction. The test components are simple and easy to manufacture, and relatively low in cost. The method is capable of measuring the underwater near field blast wave pressure of samples at a hectogram level.

The invention discloses an equivalent loading experimental device capable of realizing the shock compression of material underwater explosion shock waves. The equivalent loading experimental device mainly comprises an emission system, a speed measuring system, a water tank system, a hydraulic system and a measurement system; the emission system and the water tank system are arranged horizontally and linearly; the port of the emission pipe of the emission system is opposite to the port of the head of a high-pressure water tank; the speed measuring system is installed at the port of the emission pipe; and the main body part of the water tank system includes two water tanks and a transmission rod. A bullet is utilized to impact the water tank system; and the kinetic energy of the bullet can be converted into the energy of shock waves in the water tank. According to the equivalent loading experimental device of the invention, explosion shock waves under underwater environments of different depths can be obtained under a condition that no explosives are used; and dynamic shock compression mechanical behavior analysis of a plurality of materials under underwater explosion shock waves can be completed. The equivalent loading experimental device has advantages of high repeatability, high safety, low experimental cost, simple operation and so on.

The invention discloses a ship whole elastic-plastic movement response predication method and system under the action of underwater explosion. The method comprises the following steps: S1, simplifying a ship into a free ship body beam with an equal section; S2, dividing load pressure of the free ship body beam into five time phases under the action of the underwater explosion; S3, solving movement displacement of the free ship body beam in the five time phases under the action of the underwater explosion; S4, solving a bending moment of the ship body beam; S5, solving forward plastic movement parameters of the ship body beam; S6, solving backward elastic unloading movement parameters of the ship body beam; S7, solving backward plastic movement parameters of the ship body beam; S8, solving forward plastic movement parameters of the ship body beam. The invention further provides a system for realizing the method. According to the method and the system disclosed by the invention, the ship plastic movement process is analyzed on the basis of comprehensively considering the impact effect on the whole ship body by impact waves and air bubble loads, and engineering predication of ship whole elastic-plastic movement deformation under the action of the underwater explosion can be accurately and conveniently realized.

The invention discloses an unmanned intelligent surveying vessel which comprises a vessel body, a thrusting device installed in the vessel body, a manipulator, a control system, a surveying system and a power-supply device. The vessel body comprises a body and side bodies symmetrically arranged at the two sides of the body. Each side body comprises an over-water portion, a hollow strut penetrating through the water surface and an underwater float bowl from top to bottom. The cross section of each underwater float bowl and the cross section of each strut are respectively of a vase shape with the narrow upper portion and the wide lower portion, the longitudinal section of each strut is of a shape with the thick middle portion and the two sharp ends, the head portion of each float bowl is oval, the tail portion of each float bowl is tapered off gradually and is of a smooth streamline, and the bottom face of each float bowl is parallel to the body. According to the unmanned intelligent surveying vessel, the novel double-body vessel type design is adopted, the underwater portion of each side body and the over-water portion of the side body are connected through the corresponding hollow strut with the thin and long streamline section, so that when surveying is conducted, the navigational speed is higher, the swinging degree of the vessel body is greatly reduced, and the efficiency and the accuracy of surveying are greatly improved.

The invention discloses an underwater explosion experiment system. The underwater explosion experiment system comprises a laser generator, a camera unit and a container with a certain volume, wherein the preset amount of water is arranged in the container; a light-transmitting restraining unit is fixedly arranged in the container, an underwater structure simulating impaction is arranged in the container, and the restraining unit is close to the underwater structure; and an absorbing unit is arranged on one surface (close to the restraining unit) of the underwater structure. The underwater explosion experiment system disclosed by the invention can greatly simulate an underwater explosion process.

The invention discloses an initiation state inspection method of an exploder for simulating a high G value test of a centrifuge. The method comprises the steps of establishing an explosion test devicefor a series of explosion tests under conditions of different explosive loads Wi, explosive load submersion and air pressure equivalent water column heights, measuring a shock wave peak Pmi and a bubble pulsation period Ti of underwater explosion of the ith test, performing fitting operation with a theoretical formula to form an equivalent explosive load coefficient n, and further providing an initiation state of an explosive and a detonator. According to the method, data of the measured shock wave peak and the bubble pulsation period are compared with data of the empirical formula; a least square fitting result is processed, so that the equivalent explosive loading coefficient and an equivalent explosive quantity are obtained; judgment and inspection of the initiation state of the explosive are achieved; the underwater explosion test of the centrifuge is simulated actually; and the method has the characteristics of good convenience, stability and reliability.

The invention discloses a mixing interference distributed optical fiber-based leakage detection device for an underwater long-distance pipeline. The mixing interference distributed optical fiber-based leakage detection device comprises an optical fiber sensing system, a signal demodulating system, a signal processing and communication system and a human-machine interaction system, wherein a small-coherent-length high-power light source of the optical fiber sensing system, an optical circulator, a first coupler, a delay optical fiber, a second coupler, a sensing optical fiber, a Faraday rotating mirror and a phase modulator constitute a Sagnac/Mach-Zehnder mixing interferometer; a light signal output by the interferometer is converted into an electric signal by the signal demodulating system, is demodulated, and is transmitted to the signal processing and communication system; a DSP (Digital Signal Processor) is used for processing signals, and determining leakage point position information; a 3G (three-generation) module is communicated with the human-machine interaction system; and monitoring information is displayed on the human-machine interaction system. The device can be usedfor detecting the leakage state of the underwater long-distance pipeline in real time, and has very high sensitivity and high positioning accuracy.

The invention discloses a ship whipping motion response prediction method and system under a combined effect of underwater explosive shock waves and bubbles. The ship whipping motion response prediction method comprises the steps that step 1, a ship is equivalent to a uniform cross section free ship body girder, and therefore the prediction of ship motion responses are equivalent to the predication of free ship body girder motion responses; step 2, the load pressure process of the free ship body girder under the underwater explosion effect is divided into five time phases, and a shock wave pressure peak value, a bubble pulsation phase negative pressure peak value and a bubble first time pulsation pressure peak value are collected; step 3, motion displacements in the five time phases of underwater explosion of the free ship body girder are solved. The invention further provides a ship whipping motion response prediction system. The ship whipping motion response prediction method and system comprehensively consider the shock effect of the shock wave and the bubble load on the whole ship, the underwater explosion load pressure is simplified to be five phases, the motion displacements of a ship in different phases are calculated, and therefore project prediction of ship elastic motion or whipping motion responses under medium and distal field explosion effect is achieved accurately, simply and conveniently.

The present invention provides a high-precision numerical simulation method for near-field underwater explosion shock wave load, belonging to the technical field of underwater explosion numerical simulation. The invention adopts discontinuous Galerkin method (RKDG) and third-order TVD Runge-Kutta method to discretize the nonlinear Euler equations with high compressibility. The virtual flow method(GFM) is used to pretreat the physical quantities on both sides of the gas-liquid interface, which can effectively reduce the non-physical oscillation caused by the physical quantity discontinuity. The level set method (LSM) is used to deal with the complex topological structure changes on the material interface, so as to realize the accurate capture of the moving interface. The method proposed bythe invention can effectively simulate the generation and propagation process of the near-field underwater explosion shock wave load; the numerical simulation results are in good agreement with the classical empirical formulas and the experimental results, which proves that this method has some advantages in dealing with the problems of strong compressibility, strong discontinuity, transient andstrong nonlinearity.

The invention provides a measurement and control system used for an underwater explosion model test of a centrifuge. The measurement and control system comprises an acquisition subsystem, a control detonation subsystem, a conditioning device subsystem and a test element subsystem. The acquisition subsystem comprises a host computer, a lower computer, a shooting system display and a photoelectric sliding ring. The control detonation subsystem comprises a control box and a detonation element. The control box comprises a second fiber transceiver and a control circuit. The denotation element comprises a detonator and explosives. A solid-state relay is arranged on the control circuit. The conditioning device subsystem comprises a strain amplifier, a strain bridge box, a sensor signal conditioner and a high speed shooting host. The test element subsystem comprises a strain sheet, a sensor and a high speed camera. The strain sheet and the sensor are arranged on a test model. According to the invention, simultaneous multi-parameter dynamic test is achieved on the centrifuge; a problem of failure to meet underground explosion similarity rate of a traditional model test is solved; the measurement and control system can be used for a replacement method for a prototype test; and test cost and test time are greatly reduced.

The invention discloses a flexible composite air-curtain shock absorption protective device which comprises a flexible composite air curtain, a counterweight and a hanging pull rope, wherein the upper and lower sides of the flexible composite air curtain are respectively provided with a plurality of hanging rings, the upper side of the flexible composite air curtain is connected with the hanging pull rope through the hanging rings, and the lower side of the flexible composite air curtain is connected with the counterweight through the hanging rings; and the flexible composite air curtain comprises an air cavity, a flexible air curtain surface layer, longitudinal reinforcing fiber cord threads, transverse reinforcing fiber cord threads and air cavity side walls. The invention embodies the idea of conquering the unyielding with the yielding for the impact of the underwater explosion; and due to the characteristics of high toughness, high compression capacity, convenience in mounting and the like, the flexible composite air-curtain shock absorption protective device for underwater explosion can obviously relieve the impact waves of the underwater explosion and perform favorable protective function for the protected object.

The invention relates to an underwater explosion shock resistant coating material, a preparation method and an application of the material, and belongs to the technical field of ship protection materials. The material comprises a component A and a component B, wherein the component A comprises 30-65 parts of isocyanate, 30-40 parts of polyether polyol and 0-20 parts of diluents, and the componentB comprises 20-70 parts of amine-terminated polyether, 30-40 parts of amine chain extenders, 0-8 parts of coupling agents, 0-10 parts of fillers and 2-8 parts of auxiliaries. The volume ratio of the component A to the component B is 1:(0.97-1.03). The component A and the component B are prepared, and mixed and then sprayed onto ship shell surface primer by a bi-component high-temperature high-pressure impact mixed airless spraying device to form an underwater explosion shock resistant coating. The dynamic mechanical property of a protection structure under explosive load can be improved by thestrain rate sensitivity of the coating.

The invention discloses an underwater explosive cutter component which comprises a plurality of explosive cutters and a waterproof inflatable rubber air bag, wherein each explosive cutter is composedof a cutter shell, a metal shaped-charge cover and a high explosive, and the inner part of the cutter shell is separated into an explosive chamber filled with the high explosive and an inflatable chamber by the metal shaped-charge cover. Meanwhile, the invention also discloses an application method of the underwater explosive cutter component. The practicality and flexibility of the explosive cutters are improved, and the explosive cutters can be flexibly assembled for blasted objects. Water in a shaped-charge hole is discharged by the waterproof inflatable rubber air bag, so that the underwater explosive cutter component solves the problem that the shaped cutting effect is bad due to the presence of water in underwater cutting blasting. The underwater explosive cutter component has the good characteristics of being low in cost, high in efficiency, stable, reliable, convenient and flexible, can effectively play the advantages of a shaped charge cutter, improves the working efficiency,and reduces the construction cost.

The invention relates to an underwater explosion and shock resistant device for a bridge pier. The underwater explosion and shock resistant device comprises elastic binding rings (2), a rigidity pouring jacket and a hollow rubber covering layer (6), wherein the elastic binding rings (2), the rigidity pouring jacket and the hollow rubber covering layer (6) are arranged on the outer side of the bridge pier (1) from interior to exterior in sequence. The elastic binding rings (2) are tied on the outer side of the bridge pier (1) and are fixedly connected with the rigidity pouring jacket. A truss structure (4) is arranged between the rigidity pouring jacket and the elastic binding rings (2). The hollow rubber covering layer (6) is adhered to the outer side of the rigidity pouring jacket. On the basis of the damping mismatch principle and the stress wave transformation principle, the underwater explosion and shock resistant device can effectively reduce impact responses of accelerated speed of the bridge pier and the like under the action of underwater explosion through the arrangement of the elastic binding rings, the rigidity pouring jacket, the hollow rubber covering layer and the like on the periphery of the bridge pier underwater, weakens explosive shock waves caused by underwater explosion, absorbs energy of underwater explosion, reduces damage of the bridge pier under the load of underwater explosion and achieves the purpose of protecting the bridge pier.

The invention relates to a method for testing strength of explosive for a simulated underwater explosion test. According to the technical scheme, in an explosive strength testing device for an underwater explosion test as shown in the figure, by virtue of a method combining a non-contact laser measurement method and theoretical calculation, two important parameters, a distance between a sensor anda grain and an actual radius of bubbles, in the explosive explosion strength test are accurately obtained. The method disclosed by the invention has the characteristics of being simple in operation,high-efficiency, safe, high in similarity of obtained parameters and actual parameters, accurate and reliable in result and the like.