7results about How to "Improve low frequency vibration isolation performance" patented technology

The invention provides a unit cell structure design method and device based on nickel-titanium shape memory alloy, and relates to the technical field of intelligent materials and structures.The method includes the steps that relevant characteristic parameters of nickel-titanium alloy are collected, a mechanical property index, a thermal stability index and a reliability index are generated, and then a phase change temperature index is obtained through comprehensive calculation; and the phase change temperature threshold is corrected, the geometrical shape and the bonding mode of the unit cell structure are determined, and the quasi-zero-stiffness curved beam, the supporting frame and the connecting part of the unit cell structure are optimally designed in combination with the corrected phase change temperature threshold. According to the method, through characteristic parameter pretreatment, mechanical property index calculation and unit cell structure geometric optimization of the nickel-titanium shape memory alloy, the excellent performance under different phase change states is achieved, and the buffering energy absorption and low-frequency vibration isolation functions of the alloy are improved.

The present invention discloses a nonlinear metamaterial vibration isolator with quasi-zero stiffness, which belongs to the technical field of metamaterials and vibration reduction and noise reduction. The vibration isolator is composed of structural parts and vibration isolation components. The vibration isolation components play the role of vibration isolation and buffering. A polymer material with a certain load-bearing capacity is used. The interior of the vibration isolation component has a metamaterial structure formed by periodic arrangement of metamaterial unit cells. The geometric shape of the metamaterial unit cell is similar to a half hexagon. The metamaterial structure is obtained by periodic arrays of metamaterial unit cells in the vertical and horizontal directions. The structural parts are made of metal materials, and the structural parts and the vibration isolation components are connected in a composite manner of mechanical locking and bonding. The present invention can realize the quasi-zero stiffness nonlinear characteristics of the vibration isolator, greatly reduce the natural frequency of the vibration isolator while ensuring the stability of the system, and effectively improve the vibration isolation effect.

The application relates to the technical field of new materials, and discloses a quasi-zero stiffness unit suitable for different tensile loads, a metamaterial vibration isolation structure and a design method, which comprise a first rigid side wall and a second rigid side wall, a positive stiffness unit is arranged in the center of the first rigid side wall, a negative stiffness unit is arranged at the opening of the top of the first rigid side wall, and one end of the second rigid side wall is connected with the vertex of the positive stiffness unit and extends upwards through the negative stiffness unit. The application realizes the regulation and control of the stiffness response of the structure under the action of different loads by parameterizing the design and multi-level combination of the tensile unit configuration and combining the interaction of the positive stiffness and the negative stiffness, the quasi-zero stiffness platform of the structure can be adjusted with the change of the tensile load, so that the stable low dynamic stiffness characteristics of the structure can be maintained within a wide load range, and then the adaptive regulation and control and flexible control of the low-frequency vibration isolation performance are realized.

The three-dimensional vibration isolation device comprises a bottom plate, a top plate, a magnetic isolation sleeve, permanent magnets, springs, excitation coils, a control system and sensors, the top plate and the magnetic isolation sleeve are sequentially connected from the center of the bottom plate to the outer edge of the bottom plate, the magnetic isolation sleeve comprises a first magnetic isolation sleeve and a second magnetic isolation sleeve, the permanent magnets are arranged between the first magnetic isolation sleeve and the top plate, the springs are connected between the first magnetic isolation sleeve and the second magnetic isolation sleeve, the permanent magnets comprise first permanent magnets, second permanent magnets, third permanent magnets and fourth permanent magnets, and a plurality of groups are symmetrically arranged along the circumference of the bottom plate, and the excitation coils are wound on the third permanent magnets. The vibration isolation device can have low dynamic stiffness in three-dimensional directions, can realize quasi-zero stiffness in the horizontal direction, realizes quasi-zero stiffness in the horizontal direction through the parallel connection of magnetic negative stiffness and positive stiffness spring elements, and effectively isolates vibration in multiple directions.

The present application belongs to the field of structural optimization design and vibration control technology, and relates to a bistable quasi-zero stiffness structure reverse topology optimization method based on a double-layer hybrid intelligent algorithm. The method defines material distribution variables within a preset design domain, approximates the optimization target in the form of a target potential energy function, and constructs a multi-objective topology optimization model containing a potential energy deviation term, a volume fraction constraint term and a density gradient penalty term. The outer particle swarm algorithm is used for global search, and the inner gradient descent algorithm is used for local fine convergence, thereby realizing the cooperation of global and local optimization. The method can automatically generate a topology configuration with bistable and quasi-zero stiffness characteristics without explicit geometric assumptions, realize the customized design of structural mechanical properties, and has wide application value for low-frequency vibration isolation, energy absorption and multi-stable mechanism design.

This invention discloses an additive manufacturing-based inertial amplification nonlinear low-frequency vibration isolation metamaterial structure, vibration isolation device, and its performance control method. The vibration isolation metamaterial structure includes a rhombic frame structure, an inertial amplification unit, and a square spring structure. The square spring structure is arranged within the rhombic frame structure, with its two ends connected to a pair of opposite corners of the rhombic frame structure. The elastic extension direction of the square spring structure is parallel to the diagonal of this pair of opposite corners of the rhombic frame structure. The inertial amplification unit has a centrally symmetrical structure, including a rigid rod, two counterweights, and two diagonal rods. The center of symmetry of the inertial amplification unit, the center of the rhombic frame structure, and the center of the square spring structure all coincide in projection. Therefore, the vibration isolation metamaterial structure of this invention significantly widens the bandgap range and enhances low-frequency vibration isolation performance, exhibiting excellent performance in suppressing longitudinal waves in the 0-1000Hz low-frequency range, increasing vibration damping, and energy absorption.

This invention discloses a low-frequency vibration isolator, belonging to the field of vibration isolator technology, possessing quasi-zero stiffness characteristics. It includes an upper end cover, a lower end cover, a negative stiffness vibration isolator assembly, and a positive stiffness vibration isolator assembly. The negative stiffness vibration isolator assembly includes a first spring vertically placed in the central region, which is connected to both the upper and lower end covers and is initially in an extended state. The positive stiffness vibration isolator assembly includes vibration isolation units located around the first spring and spaced circumferentially. Each vibration isolation unit includes a deformable connecting rod structure and a second spring initially in an extended state. The upper and lower ends of the connecting rod structure are connected to the upper and lower end covers, respectively. The connecting rod structure has a left and right half arranged opposite to each other. The second spring is fixedly connected between the left and right half to pull the left and right half inwards to deform. This low-frequency vibration isolator has small size, high load-bearing capacity, and quasi-zero stiffness characteristics, making it suitable for high-end manufacturing platform equipment.