171results about How to "Increase the damping ratio" patented technology

A voltage converter includes a first circuit and a second circuit. The first circuit includes two or more reactors and at least one switching element. One terminal of each of the reactors is connected in parallel with respect to a power source. The at least one switching element is connected to the other terminal of each of the reactors. The second circuit includes at least one rectifier of which one terminal is connected to the electrical load. The second circuit shares with the first circuit the at least one switching element connected to the at least one rectifier. The first circuit is connected such that the power source charges the respective reactors when the at least one switching element is turned ON. The second circuit is connected such that the reactors discharge power to the electrical load when the at least one switching element is turned OFF.

The invention relates to a permanent-magnet type eddy current tuned mass damper which comprises a steel magnetic-conducting baseplate (10), wherein end plates (3) are respectively arranged at two ends of the baseplate (10). The permanent-magnet type eddy current tuned mass damper is characterized by also comprising a circular shaft (4) and a linear bearing seat (5), wherein two ends of the circular shaft (4) are respectively arranged on the corresponding end plates (3), and the linear bearing seat (5) is sleeved on the circular shaft (4) and can slide on the circular shaft (4); the lower part of the bearing seat (5) is connected with a mass block (6), and two ends of the mass block (6) are respectively connected with the corresponding end plates (3) through spiral springs (7); the lower part of the mass block (6) is connected with a permanent magnet (13), and a copper plate (12) is arranged below the permanent magnet (13) and connected with the baseplate (12) through a cushion block (11). By adopting an eddy current damping model with special design, the permanent-magnet type eddy current tuned mass damper realizes the damping adjustability of the damper in a larger range, realizes the complete separation between the system rigidity and the damper, and cancels the mechanical friction energy consumption and stress concentration elements, thereby avoiding the common TMD damage failure.

A system for positioning an object, having a fixed base, a support for the object, an actuator for applying a force to displace the support relative to the fixed base, a sensor for measuring the load force on the support, and a controller for processing the measured load force to control the position of the support and/or damp at least one resonance frequency of the system. A method of controlling the system is also provided.

The invention relates to a rigid sectional mold damp continuous regulating device for a wind-tunnel test. The device comprises a sectional mold, wherein two ends of the sectional mold are respectively and fixedly connected with two rigid connecting rods correspondingly; two ends of each rigid connecting rod are respectively connected with corresponding springs; the upper end of each spring is fixedly connected with an intrinsic boundary, and the lower end of each spring is connected with a base. The device is characterized in that the end part of the rigid connecting rod is provided with an electric magnetic damper regulator. According to the invention, through continuously regulating the input current, the continuous regulating of the ratio of the vertical damping to the torsion damping of the sectional mold system is realized, so that the debugging process of the damping ratio is simplified, and the problem of unstable damping ratio in the test process is avoided.

The invention relates to mineral fiber-modified flexible rubber concrete. The mineral fiber-modified flexible rubber concrete comprises rubber cement concrete, chopped basalt fiber and a dispersant methylcellulose, wherein the rubber cement concrete consists of rubber particles, cement, sand, stones, a water reducing agent and water; and the chopped basalt fiber is 0.1 to 0.5 percent of the volume of the rubber cement concrete, and the dispersant is 0.05 to 0.2 percent of the weight of the water. The concrete is applicable to road engineering, and has high compressive strength, bending tensile strength and deformability, and low modulus of elasticity.

The invention discloses a buffer energy-consuming anti-drop-beam device for a bridge, which can effectively resist to an earthquake disaster, prevent an adverse impact caused by over lateral displacement of the bridge and avoid the damage caused by the drop of a beam, and is convenient to mount and replace. The buffer energy-consuming anti-drop-beam device comprises an upper mounting plate which is fixedly mounted on a beam body, and a lower mounting plate which is fixedly mounted on a bridge pier. A guide groove structure is arranged at the lower end of the upper mounting plate; a transverse bridge direction guide groove of which the lower end is provided with an opening is formed in the guide groove structure. Energy consuming pieces which are made of soft steel and are provided with variable-width plate bodies are arranged between the upper mounting plate and the lower mounting plate in the transverse bridge direction at intervals; the upper parts of the energy consuming pieces are positioned in the transverse bridge direction guide groove and are restrained by the transverse bridge direction guide groove; the lower parts of the energy consuming pieces are fixedly connected with the lower mounting plate.

The invention discloses an annular liquid damper mainly used for damping a steel chimney. The annular liquid damper comprises at least two layers of annular liquid damper bodies vertically connected in series, each annular liquid damper body is composed of one or more water tanks, and each water tank comprises a tank body, a horizontal damping net and a vertical damping net, wherein the horizontal damping net is fixed to the inner side wall of the tank body, one end of the vertical damping net is fixed to the bottom of the tank body, the other end of the vertical damping net is fixed to the horizontal damping net, and tuning liquid is contained in the water tank. As the horizontal damping net and the vertical damping net are added into each water tank, the damping ratio of the TLD (tuned liquid damper) is increased, and the TLD meets the optimal damping ratio requirement needed by the steel chimney; meanwhile, two or more layers of water tanks vertically connected in series are adopted according to structural stress calculation, and therefore the annular liquid damper can be used for damping a steel chimney with the diameter of 25 m or more.

The invention discloses a glass fiber reinforced polyester mineral composite material and a preparation method thereof, which belong to the technical filed of composite materials. The glass fiber reinforced polyester mineral composite material comprises an adhesive substrate, an aggregate and a glass fiber, and is prepared by the steps of evenly mixing the adhesive substrate, the aggregate and the glass fiber, casting and curing the mixture, and the like, wherein the mass fraction of the adhesive substrate is 9 to 20 percent; the mass fraction of the aggregate is 79 to 90 percent; and the mass fraction of the glass fiber is 0.1 to 1 percent. The composite material has excellent damping property and physical and mechanical properties, improves the compressive strength by 15 to 25 percent compared with a polyester mineral material without reinforced fiber, improves the damping ratio by 9.5 to 23 percent, and can be used as an excellent mechanical basic element material.

The invention discloses an autonomous non-overshoot state switching method of a ship inertial navigation system, comprising the following steps of: determining the damping ratio of a correction link; determining the time domain parameter during the calibration process; determining the cut-off frequency during the correction link; determining the system bandwidth; determining two handover frequencies during the correction link; determining a low-frequency band during the correction link; determining a high-frequency band during the correction link; determining the convergence frequency band of the correction link; determining the transmission function during the correction link; determining the switching time; determine the switching step length; determining the velocity variable before and after the correction; acquiring acceleration and angular velocity of the inertial device output; compensating for the inertia device output according to the error source of the inertial device; integrating the acceleration information to obtain the speed; acquiring a velocity correction value; acquiring speed after the correction; acquiring angular velocity information after the correction and feeding back by the Shura loop; and integrating the speed after the correction to obtain the position after the correction. By the adoption of the method provided by the invention, overshoot errors generated during the state switching process can be inhibited without depending on the external speed.

The invention relates to a cable-stayed prestressed steel and concrete combined type fan tower. The combined fan tower is composed of a lower reinforced concrete cylinder structure, cable-stayed prestressed cables, a transition section and an upper single-pipe steel cylinder structure. The lower reinforced concrete cylinder structure is composed of a bottom straight cylinder section and a top conversion section, wherein the bottom straight cylinder section is of an equal-outer-diameter and equal-wall-thickness annular reinforced concrete structure, and the bottom of the bottom straight cylinder section is provided with a door opening and a reinforcing ring; a plurality of circumferential prestressed cables are arranged in the top conversion section, and a plurality of arc-shaped prestressed cable casing pipes are evenly arranged in the top conversion section in the circumferential direction; and outlets in the upper ends of the arc-shaped prestressed casing pipes are in the vertical direction, and the angles of outlets in the lower ends of the arc-shaped prestressed casing pipes are consistent with and the angles of the cable-stayed prestressed cables. The cable-stayed prestressed cables apply prestressing force to the lower reinforced concrete cylinder structure, so that the crack resistance and fatigue resistance of a concrete cylinder are improved, and the overall rigidity of the lower structure is also improved; and the cable-stayed prestressed cables penetrate through the embedded arc-shaped prestressed casing pipes on the conversion section at the top of the concrete cylinder to be guided into the tower cylinder, so that tensioning, anchoring and operating maintenance of the cable-stayed prestressed cables are facilitated.

The invention discloses a roll finishing device. The roll finishing device comprises a rolling wheel, a bearing block, a guide rail, a linear bearing, a cylinder guide rod connected with the guide rail as well as a belleville spring group and a sliding bearing which are mounted on the cylinder guide rod, wherein a rotary shaft is arranged in the bearing block, the rolling wheel is fixed at the lower end of the rotary shaft, the guide rail is inserted into the linear bearing and mounted on the bearing block, the linear bearing is inserted into a casing and fixed at the front end of the casing, one end of the cylinder guide rod is inserted into the guide rail, the other end is connected with a pressure sensor, the outer side of the pressure sensor is mounted on a regulating ring which is connected onto the casing, a first pressure bearing pad and a second pressure bearing pad are fixed on the cylinder guide rod, a gap between the first pressure bearing pad and the second pressure bearing pad is sleeved with the belleville spring group, the sliding bearing is arranged on the second pressure bearing pad, and the first pressure bearing pad is propped against the guide rail. The roll finishing device is compact in structure, rolling pressure input by the regulating ring is transmitted to a rolling cutter accurately, and pressure component loss is avoided.

The invention belongs to the technical field of building structure vibration attenuation, and particularly relates to a tuned mass damping device utilizing eddy current for providing damping. The tuned mass damping device comprises a conductor plate and a permanent magnet, and is characterized by also comprising a main shaft, a spring and an eccentric mass block, wherein the eccentric mass block is fixedly arranged on the main shaft, or a rotating bearing is arranged between the eccentric mass block and the main shaft, one end of the spring is connected with the eccentric mass block, the conductor plate is fixedly arranged at one side of the eccentric mass block in a direction vertical to an axle line of the main shaft, the permanent magnet is positioned between the conductor plate and the eccentric mass block and is fixedly arranged on the eccentric mass block, a gap is formed between the conductor plate and the permanent magnet, and the conductor plate, the permanent magnet, the main shaft, the spring and the eccentric mass block jointly form a group of eddy current tuned mass damping structures. The eccentric eddy current tuned mass damping device has the advantages that the structure is simple, the practicability is high, safety and reliability are realized, the cost performance is higher, the tuned mass damping device can be widely applied to structure vibration control of various high-rise and super high-rise buildings, drawn-up structures or long-span buildings, and the market application prospects are very wide.

The invention discloses a multi-model electromagnetic vibration absorber. The multi-model electromagnetic vibration absorber is characterized by mainly comprising an elastic frame body, a vibration absorber mass, a permanent magnet, an electromagnetic coil sleeve, an electromagnetic coil and an external circuit, wherein the permanent magnet and a controlled structure are fixedly connected; the vibration absorber mass is fixedly mounted on the top of the elastic frame body; the electromagnetic coil sleeve is fixedly mounted on the top of the inner wall of the elastic frame body; and the bottom of the electromagnetic coil sleeve does not contact with the inner wall of the elastic frame body. The electromagnetic coil is wound on the electromagnetic coil sleeve, and the two ends of the electromagnetic coil are connected with the external circuit to form a closed circuit. According to the multi-model electromagnetic vibration absorber disclosed by the invention, the external circuit can eliminate inductance influences of the coil and can improve a multi-model damping coefficient of the system, so that the multi-model vibration absorption characteristic is realized.

The invention discloses an energy-consumption shear wall made of a composite material, which comprises an upper steel plate, a lower steel plate, a middle steel plate, a constraining steel plate, a viscoelastic material, lead cores and bolt holes, wherein prepared holes are formed in the middle steel plate and the constraining steel plate; the viscoelastic material is arranged between the middle steel plate and the constraining steel plate; after the steel plates and the viscoelastic material are vulcanized together, lead is poured into the prepared holes to form the lead cores through curing; the bolt holes are formed in the upper steel plate and the lower steel plate; the upper steel plate and the lower steel plate can be connected with an upper frame beam and a lower frame beam through bolts to form the energy-consumption shear wall. Under vertical load, wind load and small earthquakes, the energy-consumption shear wall only provides rigidity to resist vertical load, lower horizontal load and bending moment; under middle and large earthquakes, the energy-consumption shear wall can consume earthquake energy due to the viscoelastic material and the lead cores; when the viscoelastic material and the lead cores deform greatly, the energy-consumption shear wall can provide not only rigidity but also damping to reduce various earthquake response of the energy-consumption shear wall; the numbers of the viscoelastic material layers and the lead cores can be changed as required. The energy-consumption shear wall is clear in seismic concept design, simple in structure, low in material cost, and convenient to construct and replace.

The invention relates to a seismic-resistant electrical cable comprising a conductor, a semiconductive layer, a conductor shielding layer, an insulating layer, an insulating shielding layer, a copper strip shielding layer, an elastic body packing, a wrapping layer, an isolating sleeve, a thin round steel wire armoring layer, a thick round steel wire armoring layer, a copper conductor, an isolated layer and an outer sheath. The seismic-resistant electrical cable is characterized in that a semiconductive band layer is wrapped outside the conductor; insulating materials, packing materials, isolating sleeve materials and outer sheath materials are all elastic body polymers; and double-layer steel wire armoring is adopted for the armoring layers. The invention has higher shearing rigidity, bending rigidity and damping ratio, obvious effects of shear resistance, bending moment, axial force, torsion, and the like, and excellent seismic-resistant and seismic-proof capacity.

The invention relates to a damping rubber material with low hardness, high-temperature static torque and good durability and a preparation method thereof. The damping rubber material comprises the following components in mass parts: 100 parts of nitrile rubber and butadiene styrene rubber composite, 40-70 parts of reinforcement bulking agent, 5-10 parts of nano white carbon black, 1-3 parts of coupling agent and processing agent, 10-15 parts of softened plasticizer, 2-3 parts of anti-aging agent, and 8-10 parts of curing agent and auxiliary agent; and moreover, the technological parameters of rubber material vulcanization are as follows: a press vulcanizer is adopted for vulcanization, the vulcanization time is 10-20 minutes, the vulcanization temperature is 150-160 degree C, and the vulcanization pressure is 10-14 MPa. The damping rubber material disclosed by the invention has the advantages of low hardness, high static torque at 80 degree C, good durability at high temperature of 130 degree C, as well as good processability. The material can be used as damping rubber materials used in rubber torque vibration dampers of engines, and solves the problems of high hardness, difficulty in press fitting, low static torque at high temperature, poor durability and the like in the existing rubber composite material.

Provided is a hydraulic radial steel gate constrained damping layer vibration reduction design method. The method comprises the following steps that 1, finite element simulation unit selection is conducted on components of all parts of a radial steel gate, a curved panel adopts a shell unit to simulate the stress state, support arms, beams and longitudinal beams adopt a beam unit to simulate the stress state, hanger rods adopt a rod unit to simulate the stress state, and dynamical property analysis is conducted on the radial steel gate; 2, the equivalent mass of water is calculated by adopting a Westergaard method, and the dynamic property influence of water pressure on the radial steel gate is simulated; 3, structural mode strain energy analysis is conducted on the radial steel gate, it is obtained through analysis that the value of radial steel gate support arm mode strain energy is the maximum value, and by means of a constrained damping layer arranged on the support arm structure of the radial steel gate, a flow-induced load effect of the radial steel gate can be reduced. According to the hydraulic steel radial gate constrained damping layer vibration reduction design method, structural damping of the radial steel gate is increased, and a flow-induced load vibration effect is reduced.

The invention discloses a flexible beam multi-point driving photovoltaic tracking support and a photovoltaic device, the photovoltaic tracking support comprises a support main body and a driving assembly; the support main body comprises a plurality of stand columns which are arranged side by side at intervals, rotatable oblique beams are arranged on the stand columns, and a plurality of support cables which are arranged side by side at intervals are arranged between two adjacent oblique beams; the driving assembly comprises a driver, a transmission device and rotating devices; the rotating device is arranged between each stand column and the oblique beam on the stand column, and the driver is in transmission connection with each rotating device through the transmission device; the photovoltaic tracking support adopts support cables to form a flexible beam structure, the terrain adaptability is improved, the steel consumption is low, the installation is convenient, the overall damping ratio of the support is increased, and wind pressure resonance can be avoided; the rotating devices can form multi-point drive, free rotation of the oblique beams can be limited, the stability and torsion resistance of the support are enhanced, and it is guaranteed that all the oblique beams act consistently, the tracking precision is high, meanwhile, the multiple rotating devices can provide larger driving force, and the single-machine installation capacity is improved.

A mechanical quantity sensor includes a current-to-voltage converter/signal adder circuit that converts electric current signals flowing through two piezoelectric vibrators into voltage signals. The piezoelectric vibrators receive stresses generated by a mechanical quantity, such as acceleration, in opposite directions. A voltage amplifier/amplitude limiter circuit amplifies an added signal obtained from the two voltage signals and limits its amplitude. A phase-difference-to-voltage converter circuit detects a difference in the phases of the added signal and a feedback voltage signal applied to an acceleration detection element. A phase shifter circuit controls the phase of the feedback voltage signal so that the phase is a predetermined phase. A filter circuit minimizes frequency components higher than an oscillation frequency in an unwanted frequency band. By increasing the resistance of resistors so as to increase the damping ratio, temperature stability is increased. Accordingly, abnormal oscillation is prevented by the filter circuit, and fluctuation in the characteristics is minimized by the phase control circuit.

The invention discloses a multifunctional solid wood processing device achieving milling and planning, and relates to the field of wood working machine tools. The multifunctional solid wood processingdevice comprises a base, wherein a working table and a beam frame are fixedly arranged on the base, a sliding plate which freely slides in the beam frame direction is arranged on the beam frame, andan engraving milling module, a vertical-axis milling module and a rotary horizontal milling module are fixedly arranged on the sliding plate. The multifunctional solid wood processing device has the technical effects that the device is not only suitable for solid wood processing, an integrated device of integrating a numerical control engraving milling machine, a numerical control vertical millingmachine, a numerical control planing side milling machine and a numerical control circular saw is provided, and automatic tool changing can be achieved.

The invention relates to the technical field of measurement calibrating equipment, in particular to a rotary vibrating table and system; the rotary vibrating table comprises a base, a support shaft and a rotary table; the base is connected with the rotary table through the support shaft, and the rotary table may rotate around the support shaft relative to the base; a driving coil and a feedback coil are disposed between the base and the rotary table; the driving coil and the feedback coil are disposed on two sides of the support shaft and are fixedly connected respectively to the rotary table; a drive magnetic circuit and a feedback magnetic circuit are fixedly connected to the base; the driving coil may rotate in reciprocating manner around the axis of the support shaft in the drive magnetic circuit, and the feedback coil may rotate in reciprocating manner around the axis of the support shaft in the feedback magnetic circuit. The rotary vibrating system comprises the rotary vibrating table. The invention is intended to provide the rotary vibrating table and system in order to solve the technical problem of the prior art that the vibrating table has high price, relatively high lowest measurement frequency and low bearing capacity.