74 results about "Magnetorheological elastomer" patented technology

The invention relates to the technical field of robot intelligent actuators, and discloses a magneto-rheological end effector accurate grasping system based on force feedback, which comprises a multi-curved-surface bionic fingertip formed by a magneto-rheological elastomer, and a three-dimensional distributed excitation coil array is embedded in the fingertip. The coil array is excited by a high-frequency chopping constant-current driving module to generate a space gradient magnetic field, and the magnetic field changes the shear modulus of the elastomer within millisecond-level time, so that the fingertip surface hardness jumps in real time along with a control instruction; and the force feedback closed-loop control unit comprises an ultrathin film strain sensing net attached to the inner curved surface of the fingertip. Through time-sharing switching of a negative pressure micropore adsorption layer and a magneto-rheological rigidity keeping mode, traditional adsorption and rigid clamping are changed into a pre-fixing and rigidity gradual change two-section type process, instantaneous force impact during adsorption release is eliminated, meanwhile, thin film wrinkling caused by continuous negative pressure is avoided, and it is ensured that an ultrathin and high-added-value workpiece is kept flat and traceless in the whole transfer process.

The invention discloses a hardness self-adaptive adjustment high-voltage insulation shielding cover which comprises a composite insulation cover body, the composite insulation cover body sequentially comprises an outer insulation layer, a middle magnetorheological elastomer interlayer and an inner attaching layer from outside to inside, and a miniature electric field sensor is embedded in the surface of the outer insulation layer and used for monitoring the intensity of a surrounding electric field in real time; the flexible electromagnetic coil is embedded in the middle magnetorheological elastomer interlayer; the intelligent induction energy storage module is integrated in a lightweight waterproof box at the top of the composite insulation cover body and comprises a magnetic field controller, a micro super capacitor, an electric field signal processor and a pressure signal converter, and the magnetic field controller is connected with the flexible electromagnetic coil through a wire; through the three-layer structure design of the composite insulation cover body and corresponding material selection, double guarantee of insulation protection and self-adaptive fitting is realized.

The invention belongs to the technical field of bridge steel shell hoisting construction, and particularly relates to a fine adjustment device suitable for stability of a gravity center changing curve type steel shell, the fine adjustment device comprises a steel shell, mounting angle blocks are symmetrically arranged on the side face of the upper end of the steel shell, and an adjusting mechanism is arranged at the upper end of each mounting angle block. According to the fine adjustment device, a flexible adjustment structure composed of the magnetorheological elastomer and the electromagnetic coil is arranged, and a steel cable traction adjustment mechanism driven by the hydraulic motor is combined, so that bidirectional precise regulation and control over the stability of the steel shell are achieved, and the shear modulus of the magnetorheological elastomer can be linearly regulated and controlled through the current of the electromagnetic coil; the stress change caused by gravity center shift can be quickly responded, and the dynamic unbalance force can be counteracted in real time.

The invention discloses a machining device for a complex curved surface safety filter screen of an aircraft hydraulic system, and relates to the technical field of aerospace non-traditional machining equipment.The machining device comprises a phase transformation chuck assembly, the working surface of the phase transformation chuck assembly is composed of a magneto-rheological elastomer, and the magneto-rheological elastomer can be in a flexible state when no magnetic field exists; and when a magnetic field is applied, a rigid state is presented. By utilizing the field-induced phase change characteristic of the magneto-rheological elastomer, the magneto-rheological elastomer can be used as a flexible shaping device to copy the accurate negative shape of the mounting base without stress, and can also be used as a rigid clamp to firmly maintain the shape, so that the assembly error caused by inconsistent reference in the traditional processing is eliminated. And the stress deformation in the machining process of the thin-wall workpiece is greatly inhibited by integrating a resonant stripping machining structure and utilizing a micro stripping effect generated by high-frequency micro-amplitude vibration of the ultrasonic tool bit. And through cooperative control, a whole-process closed-loop manufacturing normal form is formed. And the machining precision and the machining consistency are improved.

This invention relates to the field of vibration control technology for civil engineering structures. It discloses a triaxial magnetorheological quasi-zero stiffness intelligent vibration isolation bearing for large-span spatial structures and its control method. The bearing includes a top plate and a bottom plate. A middle plate is fixed to the bottom of the horizontally stacked magnetorheological elastomer vibration isolation / vibration unit. A vertical magnetorheological quasi-zero stiffness vibration isolation / vibration unit is fixed to the bottom plate and slidably connected to the inner side of the middle plate. The control method uses sensors to collect the structural response in real time, identifying three operating conditions: high-frequency micro-vibration, low-frequency moderate vibration, and large earthquake safety. It automatically switches control modes to achieve coordinated adaptive control of vertical damping and horizontal stiffness and damping. This invention combines high static load-bearing capacity with low dynamic stiffness, enabling triaxial decoupling and multi-mode intelligent coordinated control, and is suitable for broadband vibration control of roof supports for large-span spatial structures.

The application relates to a robot milling semi-active vibration suppression end effector and a control method based on an MRF-MRE hybrid medium, which comprises a hybrid medium system constructed in parallel with a magneto-rheological fluid and a magneto-rheological elastomer, controllable energy dissipation damping provided by the MRF filled in a shearing gap, variable dynamic stiffness provided by the MRE as a supporting element, tracking adjustment of an inherent frequency and independent suppression of a vibration amplitude realized through differential or common-mode magnetic fields generated by double excitation coils, and a heat-magnetic compensation mechanism based on impedance monitoring of the excitation coils, which effectively solves the performance drift problem in long-time machining. The end effector adopts a non-rotating design, the mover assembly is radially vibrated with the cutter but not rotated with the cutter through the antifriction bushing, and the reliability and sealing life in the high-speed milling working condition are remarkably improved.

The invention discloses a magnetorheological elastomer self-adaptive clamping mechanism for ceramic body machining, and relates to the technical field of ceramic machining. The device comprises a base, symmetrical clamping arms, a linear driver, a self-adaptive clamping plate assembly and a main control unit, a magneto-rheological elastomer column and a micro vortex vacuum pump are arranged in the self-adaptive clamping plate assembly, and the main control unit achieves clamping force closed-loop control with + / -0.02 N precision through a PID algorithm; the miniature vortex vacuum pump forms stable pressure difference adsorption in a 5Pa vacuum environment, and the friction force of the miniature vortex vacuum pump, the nanometer silica gel anti-skid layer and the clamping force of the magnetorheological elastomer form triple synergistic fixation. The technical problems of clamping damage and adsorption failure of the ceramic green body in the vacuum environment are solved, and the vacuum spraying device is suitable for machining procedures such as vacuum spraying and fettling of the unsintered / semi-sintered ceramic green body.

The present application relates to a kind of variable stiffness variable damping hydrodynamic inertance vibration isolation device, including cylinder, piston being movably arranged in the inside of cylinder, annular end cover being arranged in the top port of cylinder, the central axis of the piston is vertically through annular end cover;The inner peripheral side wall of the annular end cover is fixedly provided with annular end cover magneto-rheological elastomer, the inner peripheral side wall of the end cover magneto-rheological elastomer is fixedly provided with end cover electrically conductive sleeve, the inner side of the end cover electrically conductive sleeve is provided with end cover magnetic block fixed in the central axis of piston, end cover excitation coil is arranged on the end cover magnetic block and annular end cover, and the rigidity and damping of end cover magneto-rheological elastomer are controlled by the magnetic field generated by the energization of end cover excitation coil.The present application is reasonable in design, can realize the dynamic adjustment of rigidity and damping, effectively solve the problem that traditional structure is not good in vibration isolation effect when facing different frequency vibrations, and improve the practicality and universality of vibration isolation technology.

The invention belongs to the technical field of elastomer materials, and provides a high-performance neodymium iron boron / silicone rubber composite magnetorheological elastomer and a preparation method thereof. The preparation method comprises the following steps: activating neodymium-iron-boron magnetic powder, immersing the neodymium-iron-boron magnetic powder into a dopamine hydrochloride aqueous solution for deposition reaction, and adding a silane coupling agent for condensation reaction to obtain neodymium-iron-boron magnetic powder coated with a PDA-silane composite modified layer; and mixing the neodymium iron boron magnetic powder coated with the PDA-silane composite modified layer with a silicone rubber matrix, and sequentially carrying out curing treatment and magnetization treatment to obtain the high-performance neodymium iron boron / silicone rubber composite magnetorheological elastomer. The method is simple and low in cost, the magnetorheological elastomer with high-strength interface bonding, high magnetic responsiveness, excellent mechanical property, excellent electrical property and excellent thermal stability is successfully prepared, and a material foundation is laid for development of magnetic-force-electricity multifunctional coupling devices, advanced sensors and intelligent drivers.

The invention discloses a variable-stiffness magnetorheological fluid elastic vibration isolator for a variable-speed rotorcraft, which comprises a closed cavity formed by a magnetic flux outer cylinder, a magnetic flux inner cylinder and an annular magnetorheological elastomer connected between the magnetic flux outer cylinder and the magnetic flux inner cylinder, inertia liquid is filled in the cavity, and a magnet exciting coil is arranged in an outer ring groove of the magnetic flux inner cylinder. The magnetic flux outer cylinder, the magneto-rheological elastomer and the magnetic flux inner cylinder form a closed magnetic circuit, and the magnetic field intensity is changed by adjusting the current of the magnet exciting coil, so that the shear modulus of the magneto-rheological elastomer is continuously and reversibly adjusted and controlled, and online adjustment of the rigidity of the vibration isolator is achieved. The inner cylinder connected with the magnetic flux inner cylinder is provided with an inertia channel, when external vibration is introduced, liquid flows in the channel, and inertia force opposite to exciting force is generated at an anti-resonance frequency point to achieve efficient vibration isolation. The variable vibration frequency of the rotor wing is dynamically matched through the electronic control rigidity, the problems that a traditional vibration isolator is narrow in frequency band, and a mechanical frequency conversion scheme is slow in response and complex in structure are solved, and the vibration isolator has the advantages of being fast in response and compact in structure.

The invention belongs to the field of advanced pipe plastic processing and intelligent material application, discloses a pipe bending forming method based on a multi-dimensional gradient distribution magneto-rheological elastomer, and aims to solve the problems that an existing single-dimensional MRE cannot adapt to the pipe bending multi-area rigidity requirement, and the inner side wrinkles, the outer side wall thickness is reduced and the like due to the fact that a device is not provided with a special regulation and control module. The method comprises the following steps: preparing an axial (transition section-bending section magnetic particle gradual increase) and radial (center-circumference magnetic particle gradual change) multi-dimensional gradient MRE core mold, filling a pipe, and cooperatively optimizing a magnetic field and pressure through a fuzzy-PID (Proportion Integration Differentiation) algorithm by using a device comprising a non-magnetic component and a peripheral electromagnetic coil in combination with axial pressure, magneto-rheological rigidity and centrifugal force formula control parameters; the method can efficiently restrain forming defects, is suitable for high-strength, thin-wall and small-bending-radius pipes, and improves the forming quality and efficiency.

The invention relates to the technical field of elastic bushings, in particular to a magneto-rheological elastomer bushing for an automobile suspension and a vehicle suspension system. The magneto-rheological elastomer bushing comprises an inner sleeve and an outer sleeve which are coaxially arranged; the magnetorheological elastomer layer is filled between the inner sleeve and the outer sleeve, and the magnetorheological elastomer layer serves as a main bearing and rigidity adjusting component; the magnet exciting coil is arranged on the inner sleeve or the outer sleeve, and the magnet exciting coil applies a magnetic field to the magnetorheological elastomer layer to adjust the radial rigidity of the magnetorheological elastomer layer; the magneto-rheological elastomer composite material further comprises at least one magnetic conductive reinforcing piece which is arranged in the magneto-rheological elastomer layer in the radial direction, and the magneto-rheological elastomer layer is divided into at least two sub-layers in the radial direction by the magnetic conductive reinforcing piece. The rigidity of the vehicle can be instantly improved to enhance the control stability when high supporting performance is needed, the rigidity can be instantly reduced to optimize the riding comfort when high vibration filtering performance (such as a bumpy road surface) is needed, and dynamic intelligent balance between the two is achieved.

The invention relates to the technical field of mechanical engineering, and discloses an anti-vibration linear guide rail device which comprises a guide rail, a vertical vibration reduction sliding block structure, an objective table, a damping vibration reduction plate and a solid lubricating plate. The number of the vertical vibration reduction sliding block structures is at least two, the two vertical vibration reduction sliding block structures are arranged on the guide rail, the two vertical vibration reduction sliding block structures are connected through a damping vibration reduction plate, a solid lubricating plate is fixedly arranged below the damping vibration reduction plate, and an objective table is arranged above the damping vibration reduction plate; the damping vibration attenuation plate is made of a variable rigidity material; an electromagnetic coil in the vertical vibration attenuation sliding block structure is used for generating a changing magnetic field to change the rigidity of the damping vibration attenuation plate. The damping vibration attenuation plate is made of the magneto-rheological elastomer material, the variable magnetic field generated by the electromagnetic coil arranged in the guide rail is used for regulating and controlling the damping vibration attenuation plate in real time, the rigidity of the damping vibration attenuation plate is changed, and therefore the inherent frequency of a system is actively shifted, and the resonance condition is damaged.

A system may include a magnetic sensing elastomer. A system may include a rigid frame connected to the magnetic sensing elastomer. A system may include the magnetic sensing elastomer having a first end, a magneto-rheological elastomer (MRE) link and a second end; and wherein the magnetic sensing elastomer is configured to deflect in a direction by an amount based on an applied magnetic field and properties of a sample.

The present application relates to a kind of composite powder for laser selective sintering and its preparation method, belong to magnetic material technical field.The present application is used for the composite powder of laser selective sintering, comprising: thermoplastic resin powder, magnetic powder and binder;The average particle size of the thermoplastic resin powder is greater than the average particle size of the magnetic powder;The magnetic powder is coated in at least part of the surface of the thermoplastic resin powder.The three-dimensional magneto-rheological elastomer product made of laser selective sintering using the composite powder has high density, and under the action of external magnetic field, it shows significant magneto-rheological effect.

The invention relates to the technical field of cable protection, in particular to a cable protection sleeve. The protective sleeve comprises an inner layer, a middle layer and an outer layer, the middle layer comprises a first layer and a second layer, the first layer is fixedly connected with the inner layer, and the second layer is fixedly connected with the outer layer; the first layer is made of a glass fiber reinforced composite material, the second layer is of a grid framework structure made of a shape memory alloy material, the grid framework structure is embedded in the first layer, and inner grid spaces of the grid framework structure are filled with magnetorheological elastomers; the inner layer is a waterproof insulating layer sprayed on the first layer; the outer layer is made of a modified polyurethane material and is of a corrugated structure; the cable protection sleeve is provided with an opening structure, sealing parts are arranged on the two sides of the opening structure, the sealing parts on the two sides can abut against each other in a matched mode so that the installation cavity channel of the inner layer can be sealed and isolated from the outside, and the sealing parts are made of rubber materials. A plurality of rubber supporting rings are arranged on the inner wall face of the inner layer and protrude out of the inner wall face of the inner layer, and heat conduction grooves are formed in the rubber supporting rings.

The invention relates to a mouse spinal cord injury bionic compression modeling system and a method thereof.The system comprises a mechanical arm, a magneto-rheological-pneumatic loading compression module, a multi-mode optical fiber sensing probe and a control module, the magneto-rheological-pneumatic loading compression module comprises a shell, an air bag, a magneto-rheological elastomer and an air supply part, the shell is installed at the driving end of the mechanical arm, and the air bag is installed at the driving end of the mechanical arm; the air bag is installed in an inner cavity of the shell, the electromagnetic part is fixedly installed at the bottom of the inner cavity of the shell, the air supply part supplies air to the air bag, and the magnetorheological elastomer is fixedly installed at the end, away from the bottom of the shell, of the air bag. The multi-mode optical fiber sensing probe is installed at the end, away from the air bag, of the magnetorheological elastomer and used for detecting the microenvironment of the deep spinal cord tissue of the mouse. The injured spinal cord chronic compression animal model constructed by the scheme is high in fidelity, the clinical correlation of the model can be remarkably improved, and the experimental variability is reduced, so that a more reliable and more comprehensive research platform is provided for mechanism research and treatment strategy evaluation of degenerative spinal cord diseases.

The present application relates to the technical field of intelligent welding and precise assembly, in particular to a screw intelligent welding device, which comprises a laser emission head, a clamping main shaft with a coaxial light hole, a servo drive mechanism, a control system and a core electromagnetic chuck module, and is internally provided with a nickel-titanium memory alloy reed and a magnetorheological elastomer; the system realizes dynamic adjustment of clamping stiffness in combination with the control system and the excitation coil; the core is to monitor the contact thermal stress based on the inductance change rate during welding, to soften the magnetorheological elastomer to absorb the expansion thermal stress when the stress exceeds the standard, and to increase the current in a step to restore high stiffness to resist the shrinkage deflection torque during the solidification period; the present application discards the traditional static rigid clamping, solves the problem that it is difficult to balance the rigid constraint and flexible buffering in the unstructured constraint environment by using the dynamic adjustment mechanism of clamping stiffness, and realizes the dynamic cooperation of resisting the molten pool disturbance and releasing the thermal stress.

The invention provides a magneto-rheological layered damping device for a ship pipeline. The magneto-rheological layered damping device comprises a hoop unit, a supporting system, a magneto-rheological execution system, a sensing system and a central control unit. The supporting system sequentially comprises a first-layer supporting frame, a second-layer supporting frame and a third-layer supporting frame from inside to outside, the hoop unit is connected with the first-layer supporting frame through a top-layer magnetorheological damper, and the first-layer supporting frame is connected with the second-layer supporting frame through a magnetorheological elastomer liner. The second-layer support frame is connected with the third-layer support frame through the bottom-layer magnetorheological damper; the sensing system comprises a high-frequency dynamic pressure sensor, a three-axis acceleration sensor, a tilt angle sensor and a dynamic strain gauge; the central control unit identifies water hammer, cavitation, hull deformation, turbulence and other working conditions according to sensing data, and executes top layer and middle layer reinforced suppression, middle layer high-frequency dissipation, bottom layer stress release and global collaborative optimization control strategies respectively, decoupling isolation of fluid excitation and structural deformation is achieved, and the requirements of composite working conditions are met.

The invention relates to the technical field of electromagnetic protection materials, in particular to a dynamic stress balance composite cable, which comprises five layers of heterogeneous structures, namely a silver-plated copper conductor, a magneto-rheological elastomer buffer layer, a carbon nanotube enhancement layer, a shape memory alloy grid and an ultraviolet curing silica gel outer sheath from inside to outside in sequence, the asymmetric magnetic field generation system is embedded into a cable key node; stress concentration caused by eccentricity is avoided through a regular hexagon twisting mode of 1 center and 6 periphery, stress can be uniformly transmitted along the radial direction of the cable under dynamic load, and local strand overload is reduced; the nano silicon dioxide can improve the mechanical strength of the magnetorheological elastomer buffer layer, reduce the risk of deformation and cracking, enhance the interface bonding force between the buffer layer and the adjacent layer, and guarantee efficient stress transfer to assist in dynamic stress balance.

The application discloses a laminated magneto-rheological elastomer damper for axial vibration isolation, which comprises a connecting rod, an end cover, a magnetic shielding sleeve, an electromagnetic coil, a shell, a base, a heat-conducting silica gel gasket and the like which are coaxially arranged; the lower end of the connecting rod is threadedly connected with a sliding block after penetrating through alternately laminated annular magnetic conductive gaskets and annular magneto-rheological elastomers; the sliding block is alternately laminated with magnetic conductive gaskets and magneto-rheological elastomers below; the electromagnetic coil and the heat-conducting silica gel gasket are alternately laminated between the magnetic shielding sleeve and the shell. The application alternately laminates the magnetic conductive gaskets and the magneto-rheological elastomers, improves the magnetic field utilization efficiency and the stiffness adjustment sensitivity while ensuring high axial bearing capacity; laminates a plurality of low-turn number coil layers in parallel, reduces the resistance and inductance, and realizes rapid stiffness response; constructs an efficient heat dissipation path through the heat-conducting silica gel gasket, effectively suppresses the coil temperature rise, and improves the stability and reliability under high-frequency working conditions.

The application discloses a kind of magnetic control negative stiffness adjusting methods, comprising the following steps: two magneto-rheological elastomer units are respectively arranged, and rigid member is connected between two magneto-rheological elastomer units;Pre-compression force perpendicular to two magneto-rheological elastomer units is applied to rigid member, so that deformation is generated in the direction of two magneto-rheological elastomer unit connecting line respectively and pre-shear force is generated, while negative stiffness force is generated in the direction perpendicular to two magneto-rheological elastomer unit connecting line;The same adjustable magnetic field of size is arranged on two magneto-rheological elastomer units respectively, and the size of magnetic field is controlled, so that the negative stiffness force value generated by two magneto-rheological elastomers can be controlled;The application can solve the current magneto-rheological elastomer vibration isolation mechanism stiffness value is higher and can only be positively regulated, it is difficult to carry out stiffness negative regulation, and then it is difficult to simultaneously exist for the equipment of direct disturbance and external disturbance, realize the technical problem of efficient vibration isolation and stability.

A kind of neurointervention head fixing device, neurointervention head fixing device includes base plate, temperature and humidity control module is arranged above the base plate, first detection module and second detection module are symmetrically arranged below temperature and humidity control module, first sliding rail is arranged below first detection module, second sliding rail is arranged below second detection module, pillow support module is arranged between first sliding rail and second sliding rail, first fixed support module, infrared detection module and second fixed support module are sequentially arranged from top to bottom in first sliding rail, first adjustable support module and second adjustable support module are sequentially arranged from top to bottom in second sliding rail.In the present application, the rigidity of the magnetorheological elastomer is adjusted to achieve a more suitable fit with the head, and the head micro-motion during the operation is suppressed, from point fixation to surface fixation, from the adjustment flexibility, fixed stability and other aspects to improve the fixing effect.

The invention discloses a CIP-coated Fe3O4-coated TiO2 composite magnetic particle catalyst, a polishing pad and a preparation method and application of the CIP-coated Fe3O4-coated TiO2 composite magnetic particle catalyst and the polishing pad, and belongs to the technical field of photocatalytic chemistry, high polymer materials and ultra-precision polishing, the CIP-coated Fe3O4-coated TiO2 composite magnetic particle catalyst is of a core-shell structure, the core is carbonyl iron powder CIP, the shell is nanoscale Fe3O4 and TiO2, and the core-shell structure is of a hollow structure. The magnetorheological elastic polishing pad is prepared from the following raw materials: double-end hydroxypropyl silicone oil, a polyurethane prepolymer, a chain extension cross-linking agent, a catalyst, a composite magnetic particle catalyst and hollow microspheres. According to the composite magnetic particle catalyst, photocatalytic Fenton composite reaction is driven through ultraviolet irradiation to form an efficient synergistic mechanism, the composite magnetic particle catalyst is evenly distributed in the magnetorheological elastomer polishing pad, agglomeration is avoided, ultraviolet light is effectively utilized to improve the catalytic efficiency, and the operation complexity and the production cost are reduced while the machining efficiency and surface quality optimization are guaranteed.

The application belongs to the technical field of bearings, and discloses a stiffness and damping active regulation and control foil bearing with introduced magneto-rheological elastomer, which is used for connecting a rotor and comprises a bearing shell, a magneto-rheological elastomer, a top foil, a coil, a circuit assembly, a displacement sensor and a controller, wherein the top foil is located inside the bearing shell, the rotor is located inside the top foil, the magneto-rheological elastomer is located between the top foil and the bearing shell, the coil is arranged at a position corresponding to the magneto-rheological elastomer, the circuit assembly is connected to the coil, the displacement sensor is used for monitoring the position of the rotor, and the controller is connected to the circuit assembly and the displacement sensor. The application has the beneficial effect that the introduction of the reasonably designed magneto-rheological material can help to improve the stiffness and damping characteristics of the foil bearing, so that the stiffness active regulation and control target effect of the hydrodynamic foil bearing is achieved, and the stability of the operation of the foil bearing can be ensured.

The invention provides a fiber-reinforced magnetorheological elastomer as well as a preparation method and application thereof. The fiber-reinforced magnetorheological elastomer comprises a rubber matrix, carbonyl iron powder, carbon fibers and a hydrolytic agent, wherein the hydrolytic agent is obtained by mixing water, absolute ethyl alcohol and a titanate coupling agent. By adding the hydrolytic agent into the liquid silicone rubber, the bonding capacity of magnetic particles and a rubber matrix is improved, the mechanical property of the material is ensured, meanwhile, the rigidity of the magnetorheological elastomer is enhanced by adding the carbon fibers into the liquid silicone rubber, so that the magnetorheological elastomer can be better applied to complex working conditions of large bearing and large impact, and the service life of the magnetorheological elastomer is prolonged. And the low-frequency vibration reduction effect is good in actual engineering application, and the method is suitable for being vigorously popularized in the field of vibration reduction and noise reduction.

The invention discloses a sleeper embedded damping device using magnetorheological elastomers, and belongs to the technical field of rail transit damping. The device comprises a base table of an inverted-T-shaped structure and a rail pressing assembly, magneto-rheological elastic damping mechanisms are symmetrically arranged at the sunken positions of the two sides of the base table, and the upper sides of the magneto-rheological elastic damping mechanisms are connected with the rail pressing assembly. The magneto-rheological elastic damping mechanism comprises a barrel, a piston assembly, a connecting table, a shaft rod and electromagnetic liquid, the piston assembly can move up and down in the barrel, a magnetic field is generated through a magnet exciting coil to change the rheological property of the electromagnetic liquid, and dynamic damping adjustment is achieved. The rail pressing assembly is integrated with a vibration sensor, rail vibration can be monitored in real time, and then the damping characteristic is adjusted. The sleeper damping device solves the problems that an existing sleeper damping device is fixed in damping characteristic and cannot be dynamically adjusted, has the advantages of being modular in design, convenient to install and maintain, adaptive in damping effect and the like, and can effectively improve the running comfort of rail traffic and prolong the service life of a rail structure.

The application discloses a variable stiffness wheel for lunar surface transportation, which comprises a hub, an outer wheel part and a plurality of spokes; the outer wheel part is arranged on the outer periphery of the hub; the plurality of spokes are arranged on the outer periphery of the hub in a circumferential direction, and each spoke comprises an elastic member and an excitation coil; one end of the elastic member is connected to the hub, the other end of the elastic member is connected to the outer wheel part, and the outer wheel part is adapted to produce local deformation when the elastic member is deformed; wherein at least part of the elastic member is made of a magnetorheological elastomer, the excitation coil is sleeved on the outer periphery of the elastic member, and the excitation coil generates a variable magnetic field when electrified to adjust the elastic modulus of the elastic member. The variable stiffness wheel has large carrying capacity, high-speed driving capability and stable running performance, can dynamically adjust the wheel stiffness according to different running scenes such as light load high speed, full load low speed, climbing and obstacle crossing, and effectively improves the multi-working-condition adaptability and complex terrain passability of the lunar surface transportation equipment.

The application relates to the technical field of cable protection, in particular to a cable protection sleeve. The protection sleeve comprises an inner layer, an intermediate layer and an outer layer, the intermediate layer comprises a first layer and a second layer, the first layer is fixedly connected with the inner layer, and the second layer is fixedly connected with the outer layer; the first layer is made of glass fiber reinforced composite material, the second layer is a grid skeleton structure made of shape memory alloy material, the grid skeleton structure is embedded in the first layer, and a magneto-rheological elastomer is filled in the internal grid space of the grid skeleton structure; the inner layer is a waterproof insulation layer sprayed on the first layer; the outer layer is made of modified polyurethane material, and the outer layer is a corrugated structure; the cable protection sleeve is provided with an opening structure, both sides of the opening structure are provided with sealing parts, the sealing parts on both sides can be adapted to abut to seal the installation cavity of the inner layer from the outside, and the sealing parts are made of rubber material; the inner wall surface of the inner layer is provided with a plurality of rubber support rings, the rubber support rings protrude from the inner wall surface of the inner layer, and the rubber support rings are provided with heat conduction grooves.

This invention provides a hybrid vibration reduction method for large-span steel space frames in wind tunnels based on TMD and viscous dampers, belonging to the field of wind tunnel technology. This invention involves installing magnetorheological elastomer variable stiffness devices and temperature-compensated viscous dampers within each tuned mass damper unit. It collects signals using triaxial accelerometers and performs frequency domain decomposition algorithm mode identification, establishing a two-layer game optimization model to output the optimal frequency distribution vector and optimal damping force distribution vector. Based on the optimization results, the stiffness coefficient and damping coefficient are adjusted using a current controller. The vibration reduction effect is evaluated using a sliding time-window power spectral density analysis method, and the optimization model is re-executed to update the control parameters based on the evaluation results. This solves the technical problem of vibration reduction failure in large-span steel space frame structures due to frequency detuning of tuned mass dampers caused by multimodal coupled vibration under wind load excitation.