38 results about "Mechanical metamaterial" patented technology

The present invention provides meta-materials with an actively controllable mechanical property. The meta-material includes a deformable structure and a set of activation elements. The activation elements are controllable between multiple states. The meta-material includes a first value for a mechanical property when one or more of the activation elements is in the first activation state and includes a second value for the mechanical property when the activation elements have been activated to the second activation state. In one aspect, the meta-material resembles a composite material where the connectivity between the component materials or shape and arrangement of the component materials is dynamically controllable so as to affect a mechanical property of the meta-material.

The invention discloses a novel three-dimensional structure with adjustable Poisson's ratio and thermal expansion coefficient and a design method thereof, and the method comprises the following steps:firstly, selecting different triangular unit geometric parameters and material combinations, designing a triangular unit based on three materials, and then splicing two same triangular units into a parallelogram, constructing a three-dimensional cell element based on four same parallelograms; periodically arranging the three-dimensional cell elements in the direction where the horizontal straightrods are located and repeatedly performing mirroring in the other two directions, and finally obtaining the novel three-dimensional truss structure; and then performing mechanical analysis on a three-dimensional cell element of the three-dimensional truss structure, solving an equivalent formula of elastic parameters and a thermal expansion coefficient of the three-dimensional truss structure through a displacement method and a unit load method, and calculating a corresponding poisson ratio and a thermal expansion coefficient based on the equivalent formula. By selecting reasonable geometrical parameters and material combination, the Poisson's ratio and the thermal expansion coefficient of the three-dimensional mechanical metamaterial can be regulated and controlled in a large range.

Systems and methods for computing linear and non-linear explicit, matrix-free, statics with applications to functionally graded mechanical metamaterials. In some aspects, these systems and methods use an algorithm based on a special finite element formulation called the Jacobian Free Newton Krylov (JFNK) method.

The invention discloses a temperature sensor, and the sensor comprises a substrate, two thermally-driven V-shaped beam structures, a frame-shaped mechanical metamaterial structure and a strain sensitive film. The two thermally-driven V-shaped beam structures are located on the two sides of the frame-shaped mechanical metamaterial structure respectively. The strain sensitive film is located in thecenter of the frame-shaped mechanical metamaterial structure. When the ambient temperature changes, the suspended thermally-driven V-shaped beam expands or contracts under the influence of the temperature, the rigid insulation connecting wire is driven to drive the frame-shaped mechanical metamaterial structure to expand or contract in multiple directions, and expansion or contraction of the mechanical metamaterial structure is transmitted to the strain sensitive film through the rigid insulation connecting wire; the strain sensitive film converts multi-directional strain into resistance valuechange, and the ambient temperature is measured by detecting the resistance change, so the detection sensitivity of the device is greatly improved.

The invention discloses a super-cell and large-range variable stiffness mechanical metamaterial based on a planetary gear system. The mechanical metamaterial is formed by periodically extending a plurality of super-cells in an x-axis direction and/or a y-axis direction, and each super-cell comprises a planetary gear mechanism and a transmission mechanism. Each planetary gear mechanism comprises an outer ring, a sun gear and a planetary gear assembly. Each transmission mechanism comprises a transmission gear and a center shaft, one end of each center shaft is fixedly connected with the center of the corresponding transmission gear, and the other end is fixedly connected with the center of the corresponding sun gear. According to the mechanical metamaterial, on one hand, the defects that in an existing reconfigurable mechanical metamaterial design technology, the adjustment range of elastic parameters is narrow, the number of stable states is small, and adjustment and control robustness is low are overcome; and on the other hand, the defects that a mechanical metamaterial based on a common plane gear is difficult to bear tensile load, the tensile modulus is difficult to adjust, and interference exists between a stress part and regulation and control deformation are overcome.

The invention provides an acceleration sensor based on a mechanical metamaterial structure. The acceleration sensor comprises a substrate, an acceleration sensing unit, at least one strain sensing unit, an anchor point group and a lead group, wherein the acceleration sensing unit, the at least one strain sensing unit, the anchor point group and the lead group are arranged on the substrate. Each strain sensing unit comprises a mechanical metamaterial structure and a resistance strain gauge. One end of each mechanical metamaterial structure is connected with the anchor point group through the lead group, and the other end of each mechanical metamaterial structure is connected with the acceleration sensing unit through the lead group so as to receive a single-direction strain generated by theacceleration sensing unit during acceleration motion and convert the single-direction strain into a multi-direction strain; and each resistance strain gauge is connected with the corresponding mechanical metamaterial structure so as to generate the change of the resistance value under the multi-direction strain and measure the acceleration according to the change of each resistance value. The acceleration sensor has the advantages of high sensitivity, a large measurement range, a small measurement error, a novel structure and the like.

The invention provides a pressure sensor based on a mechanical metamaterial structure. The sensor comprises a substrate, a pressure sensing unit, at least one thermal driving unit, a strain sensing unit, an anchor point group and a lead group, wherein the pressure sensing unit, the at least one thermal driving unit, the strain sensing unit, the anchor point group and the lead group are arranged onthe substrate. The strain sensing unit comprises the mechanical metamaterial structure and a strain sensitive film, wherein the pressure sensing unit is electrically connected with at least one thermal driving unit through the lead group and the anchor point group to form a current path. When a current in the current path changes, the thermal driving unit can generate a single-direction strain, and the mechanical metamaterial structure is connected with each thermal driving unit to convert the single-direction strain into multi-direction strain. The strain sensitive film is electrically connected with the mechanical metamaterial structure so that the pressure is measured by detecting the resistance value according to the multi-directional strain output resistance value, and the sensitivity of the pressure sensor to the pressure is further improved.

The invention discloses a reinforced negative stiffness metamaterial structure, relates to the technical field of mechanical metamaterials, and solves the technical problems that the structure of a negative stiffness metamaterial is not simple enough and cannot be repeatedly used. According to the technical scheme, the metamaterial structure is characterized in that the space is fully utilized through an outer cylindrical surface and an internal periodic structure, and the impact resistance and the self strength of the metamaterial structure are improved. Meanwhile, the negative stiffness and the bistable performance of the metamaterial structure are rapidly calculated or verified through a buckling force displacement expression, the design time of the shock resistance of the reinforced metamaterial structure is shortened, and the structural design efficiency is greatly improved.

The invention discloses a multi-working-condition simulation automation system and method for a rod structure and a metamaterial structure, and the system comprises a definition input module, a structure generation module, a numerical simulation calculation module and a post-processing module. A lattice mechanical metamaterial structure model is generated through a structure generation algorithm, simulation analysis of corresponding working conditions is automatically carried out, and post-processing is automatically carried out according to requirements to extract related data.

The invention belongs to the technical field of metamaterials and relates to a two-dimensional mechanical metamaterial with designable deformation and non-contact control. Each single cell element comprises a deformation unit and a motion unit; each deformation unit comprises an inwards-concave n-angle shape, n connecting rods and n control blocks; one end of each connecting rod is fixedly connected with the concave n-angle shape, the other end of each connecting rod is fixedly connected with the center of one control block; the two ends, far away from the center, of each control block are connected with one movement unit in a sliding mode. In the same single cell element, each movement unit is connected with two control blocks; in the deformation unit, n connecting rods are symmetricallyand fixedly connected to the periphery of the inwards-concave n-angle shape; the deformation unit is of a star-shaped structure with the size controlled by deformation parameters; the movement unit isof a plate-shaped structure with the fixed size; a control groove is formed in a plate-shaped structure and connected with the control blocks and the movement unit in a sliding mode. The material disclosed by the invention can realize negative Poisson's ratio effect, deformation designability and non-contact control.

The invention relates to a step-by-step elasticoplastic deformation mechanical metamaterial suitable for multiple working conditions. The metamaterial comprises a plurality of cells which are periodically arranged in the same plane, and each cell is composed of a vertical rod, two inclined rods and two supporting rods, wherein the two inclined rods are connected, the connecting point between the inclined rods is connected with one end of the vertical rod, the inclined rods and the supporting rod form a rhombus, the slenderness ratio of the inclined rods is not larger than 0.05, and the included angle between the inclined rods and the supporting rod is not larger than 40 degrees. The metamaterial provided by the invention can be used under various working conditions, and step-by-step elasticoplastic deformation is realized. Under a small impact load, the first stress platform can be used for absorbing energy, and elastic deformation correspondingly occurs, so that the material can be repeatedly utilized; under a large impact load, the second stress platform can participate in the energy absorption process, plastic deformation occurs in the stage, the energy absorption efficiency isimproved, and therefore a better buffering effect is achieved.

Disclosed is a method of manufacturing a stretchable substrate according to various embodiments of the present disclosure for realizing the above-described objectives. The method may include generating an auxetic including a plurality of unit structures and adhering one or more elastic sheets to one surface of the auxetic.

A construction system for mechanical metamaterials based on discrete assembly of a finite set of modular, mass-produced parts. A modular construction scheme enables a range of mechanical metamaterial properties to be achieved, including rigid, compliant, auxetic and chiral, all of which are assembled with a consistent process across part types, thereby expanding the functionality and accessibility of this approach. The incremental nature of discrete assembly enables mechanical metamaterials to be produced efficiently and at low cost, beyond the scale of the 3D printer. Additionally, a lattice structure constructed of two or more rigid, compliant, auxetic and chiral part types enable the creation of heterogenous macroscopic metamaterial structures.