156results about How to "High strain rate" patented technology

Systems and methods for noninvasive assessment of cardiac tissue properties and cardiac parameters using ultrasound techniques are disclosed. Determinations of myocardial tissue stiffness, tension, strain, strain rate, and the like, may be used to assess myocardial contractility, myocardial ischemia and infarction, ventricular filling and atrial pressures, and diastolic functions. Non-invasive systems in which acoustic techniques, such as ultrasound, are employed to acquire data relating to intrinsic tissue displacements are disclosed. Non-invasive systems in which ultrasound techniques are used to acoustically stimulate or palpate target cardiac tissue, or induce a response at a cardiac tissue site that relates to cardiac tissue properties and/or cardiac parameters are also disclosed.

The invention provides a stretching and compression stress wave generator based on electromagnetic force and an experimental method. The stress wave generator is such structured that a capacitor charger is connected with a loading gun. A main coil, an insulating layer and a secondary coil all sleeve the locating shaft of a tapered amplifier. A power supply system is employed to provide the main coil of the loading gun with instant strong current, so strong eletromagnetic repulsion is generated between the main coil and the secondary coil; and the eletromagnetic repulsion is converted into stress waves which are amplified by the tapered amplifier and then output to a Hopkinson bar. The stretching and compression stress wave generator has a simple structure and strong controllability, can realize a strain rate and a strain scope which cannot be reached by a traditional disconnect-type Hopkinson bar, allows Hopkinson bar experimental techniques to be standardized, realizes integration of experimental apparatuses of a pull bar and a pressure bar and reduces complexity and occupied space of equipment.

A gamma prime precipitation-strengthened nickel-base superalloy and method of forging an article from the superalloy to promote a low cycle fatigue resistance and high temperature dwell behavior of the article. The superalloy has a composition of, by weight, 16.0-22.4% cobalt, 6.6-14.3% chromium, 2.6-4.8% aluminum, 2.4-4.6% titanium, 1.4-3.5% tantalum, 0.9-3.0% niobium, 1.9-4.0% tungsten, 1.9-3.9% molybdenum, 0.0-2.5% rhenium, greater than 0.05% carbon, at least 0.1% hafnium, 0.02-0.10% boron, 0.03-0.10% zirconium, the balance nickel and incidental impurities. A billet is formed of the superalloy and worked at a temperature below the gamma prime solvus temperature of the superalloy so as to form a worked article, which is then heat treated above the gamma prime solvus temperature of the superalloy to uniformly coarsen the grains of the article, after which the article is cooled to reprecipitate gamma prime. The article has an average grain size of not coarser than ASTM 7 and is substantially free of critical grain growth.

A method of manufacturing a rotor includes: (a) providing a core shaft; (b) cold spraying alloy powder particles onto the core shaft; (c) controlling the cold spraying to form sections at least of different shape along the core shaft to thereby form a near-net shape rotor; and (d) heat treating the near-net shape rotor to relieve stresses and to form diffusion bonding across interfaces between individual powder particles and the core shaft, and finish-shaping said near-net shape rotor.

A cut deal laser inherent stress composite peen forming features in the clipper using robot, using carbon dioxide to realize the basic formation, profile measuring feedback system controlling the deformation quantity, left stress meter measuring the surface stress of the board, optical scanning the pre formation, realizing board through model analog software, getting optimized process parameter instructing laser consecutive peen formation, using neodymium glass laser providing short pulse strong laser light, laser impact wave as the force source of precise forming, using the profile feedback device and on line measuring board surface stress left stress to control the deformation quantity to realize precision forming with complex shapes.

A high-speed tensile test device is disclosed, which measures the stress-strain behavior, up to failure, of polymeric materials, at high strains (as much as 1000%), and high strain rates (up to 10⁴/s). A weight, when dropped down a vertical track, impacts two L-levers positioned below and on each side of the weight, pushing the horizontal arms of the L-levers. The L-levers have cable connected to the vertical arms of the L-levers and are looped around pulleys, then connected to shuttles located on a horizontal track. The shuttles are attached to load cells, which are connected to grips that hold a sample to be tested. When the horizontal arms of the L-levers are pushed by the weight, they pivot, causing the cables to pull on the shuttles, load cell, and grip, which move in an outward direction, stretching the sample.

A plastic micro-forming method by using strong laser shock and a device thereof belong to the field of micro-electro-mechanical system (MEMS) processing and laser micro-processing technology. The method is characterized in that the method comprises the following steps: polishing both sides of a target for experiment by electrolysis; pressing a transparent optical medium with a thickness of micrometer level on a press plate as a constrained layer; tightly pressing a metal flying plate on the optical medium; fastening the optical medium, the metal flying plate, the target and a template on a special target clamping machine through the press plate; turning on a nano-second pulsed laser; adjusting the optical path to focus the laser outputted from the nano-second pulse laser on the target surface; subjecting the nano-second pulsed laser to single emission to achieve single pulse laser shock on the target. The method can generate ultrahigh pressure and strain rate during production of a sample, and the application of pressure of the generated shock wave has higher planarity, completeness and repeatability, thus improving surface rigidity of micro-metal parts and improving micro-sensing sensitivity. Accordingly, a micro-driving device can provide higher drive force, torsional moment and energy.

The invention relates to a magnesium alloy plastic processing technology, and relates to a forging method for multi-direction, circulatory and high-speed hammer forging of a magnesium alloy. The method comprises the specific steps: after carrying out homogenization annealing of a casting-state or deformation-state magnesium alloy, carrying out continuous high-speed hammer forging along one direction of the bulk material at a certain temperature; after a certain deformation amount is reached, overturning the material, and continuing to carry out continuous high-speed hammer forging along another direction to reach a certain deformation amount; then overturning the material to another direction, and carrying out such circulatory hammer forging until the material reaches a predetermined deformation amount and size; and finally, carrying out heat treatment on the material. The method utilizes the textured micostructure formed during the processes of high-speed hammer forging of the magnesium alloy to be combined to change the hammer forging direction, thereby improving the ultimate deformation amount that the magnesium alloy can withstand and is not cracked during forging, and improving the plastic processing performance of the magnesium alloy. The method is suitable for magnesium and the alloy material thereof, and improves the forging processing production efficiency of magnesium and the alloy material thereof.

The invention relates to an experimental method of dynamic mechanics performance testing of materials, in particular to a single-axis two-way loading and split Hopkinson pressure bar and pull bar device and an experimental method. The device comprises a loading device and two incident bars, the loading device comprises a power source, a capacitor charger and loading guns, a power supply part of existing electromagnetic riveting equipment is adopted for the capacitor charger, and the loading guns with the same parameters are connected into the capacitor charger after being in parallel connection. By means of the single-axis two-way loading and split Hopkinson pressure bar and pull bar device and the experimental method, incident waves at the two sides simultaneously and symmetrically load aspecimen dynamically, symmetric loading of the specimen is achieved to shorten the balancing time of stress inside the specimen, the strain rate of the specimen is increased, and thus the defects ofexisting equipment of being low in strain rate and inaccurate in testing of elastic sections are overcome.

An output member for a Direct Impact Hopkinson pressure bar includes an elongate tube portion and a disc-shaped cap portion. The tube portion has a first end and an opposite second end, while the cap portion includes a first face and an opposite second face. A circular stub protrudes from a centre of the first face, and a circular cavity is formed in the second face. Each of the stub and the cavity is concentric with the cap portion, with a diameter of the cavity being greater than a diameter of the stub. The second face of the cap portion is positioned in intimate contact with the first end of the tube portion, with the cap portion being concentric with the tube portion.

The invention discloses an electrohydraulic forming method for formed sheet metal blank. The method includes pressing against the die blank by pressure generated from the liquid filled container; eliminating the pressure from the tool; generating a shockwave within the fluid for force generation so that the blank abuts against the die.

The present invention generally relates to a tensile impact apparatus that is designed to give dynamic stress-strain curves and fracture characteristics for a rubber specimen undergoing tensile impact loading. More particularly, this invention relates to a tensile impact apparatus that is capable of achieving strains of up to fracture. The apparatus is also capable of visually recording fracture phenomena.

The invention relates to a method and a device for preparing and forming a micro composite material. The device consists of an Nd:YAG laser, a reflector, a lens, a restraint layer, a single-dimension mobile platform, a micro die, a three-dimension mobile worktable, a three-dimension mobile platform controller, an L-shaped base and a computer. The method for the synchronous realization of material composite and micro forming comprises: pulsed laser is used for driving a metal foil plate to move at high speed; the metal foil plate impacts a base foil plate in the micro die at high speed after moving a certain distance; the high temperature and high pressure generated in the impact surface can realize the composite connection between the metal foil plate and the base foil plate; the connected metal foil plate and base foil plate have certain impulse and compress to the direction of the die; owing to the limitation of the die, the shape of the micro die can be duplicated, thus realizing the synchronization of composite material production and micro forming. The method and the device have the advantages of reasonable design, simple process, good consistency, and being applicable to mass production.

The invention discloses a transient unloading loose simulating system for excavating a jointed rock mass. The transient unloading loose simulating system for excavating the jointed rock mass comprises counterforce piers, a jointed rock mass model, an experimental table provided with displacement scale marks, a transitional block cushioning box, a transitional block arranged on the transitional block cushioning box, a hydraulic station, a loading device, a loading device supporting table and a monitoring system, wherein the counterforce piers are fixed on the outer sides of the loading device supporting table and the experimental table; the transitional block cushioning box is arranged on the other side of the experimental table; a slot for accommodating the jointed rock mass model is formed on the upper surface of the experimental table; the transitional block (15) is a square column with a variable cross section, and the section areas of the two ends of the transitional block are larger than the section area of the middle section; the width and height of the jointed rock mass model are matched with those of the transitional block (15); the loading device is horizontally arranged on the loading device supporting table; and the monitoring system is used for monitoring the simulating process. By the system, the load on the jointed rock mass model is quickly unloaded, and the actual unloading condition in an engineering is met well.

The invention relates to a complex processing method for prolonging the service lift of chain grate key parts, belonging to mechanical manufacturing and material processing and application technical field, which comprises: firstly, surface nondestructive testing is carried out on the key parts of the chain grate of process; molten salt complex processing are carried out in parts of the surface according to the surface drawbacks tested by surface nondestructive testing; before the laser shocks, the workpiece surface is coated with black coating layer and use water as protective layer, and the laser shock processes the area which is easy to fatigue and fracture and has concentrated stress. The molten iron pretreatment spray-feeding device before iron-making blast furnace has the advantages of simple shortcut, high efficiency, low maintenance cost, short processing time (30 minutes to 5 hours), and the continuous operation can be realized, thus, high efficiency of production is ensured.

The invention discloses a method and a device for forming magnesium alloy formed parts with excellent high-temperature mechanical property. The device mainly comprises a die, a laser, a thermal sensor, a miniature heater and the like. The method includes: heating magnesium alloy to 120-150 DEG C to realize high-speed contact molding according to the laser peening quick-forming technology which utilizes dynamic strain ageing reinforcement, heat forming and high-pressure strain rate of thermal laser peening, placing magnesium alloy plates on a die in a work cavity, attaching energy converters on the magnesium alloy plates, vacuumizing the work cavity, and realizing high-speed contact molding of the magnesium alloy plates by the thermal laser peening process through the miniature heater and the laser. Dislocation anchoring effect and nano precipitates are formed in formed parts by the thermal laser peening technology, so that the magnesium alloy formed parts have excellent high-temperature mechanical property such as high-temperature creep resistance, high-temperature strength and the like, thermal high-strain-rate forming of the magnesium alloy plates is realized, and forming performance and efficiency of the magnesium alloy are improved.

The invention relates to a magnesium alloy processing method, in particular to a method for rolling high-ductility and high-scalability Mg-Al series magnesium alloy plates. The method comprises the steps of milling, heating and heat preservation of a plate, heating and heat preservation of a roller, rolling and cooling, wherein the rolling speed is 10-100 m/min; the rolling reduction of each time of rolling is 45%-80%. As the high-speed single-pass big-dependent-variable rolling is adopted for inducing obvious dynamic recrystallization, fully fine equiaxed grains are generated, and accordingly, the magnesium alloy plates of which the ductility and the scalability are greatly improved are acquired. Besides, as the annealing process is omitted, the manufacturing cost is greatly lowered, and the method is more suitable for large-scale industrial production.