12 results about "Neutral plane" patented technology

Tape for a fabric compacting machine (1), including: an internal base fabric (6) for compaction felts (4); a first layer (7) of felt fixed on a first side of said internal base fabric (6) by a process of needling of felt fibers through a thickness of said internal base fabric (6); a second elastically deformable layer (8) composed of silicone or rubber fixed on a second side of said internal base fabric (6) opposite to said first side, wherein said first layer (7) and said second layer (8) have respective thicknesses determined such that a neutral plane of a bending stress along the thickness of the tape lies within the thickness of said internal base fabric (6).

The present invention relates to an adaptive multi-neutral plane turntable and an adjustment method thereof, belonging to the field of high-precision turntables. It is intended to solve the demand for high-precision and flexible adjustment of turntables in complex measurement and industrial application scenarios. The turntable is provided with multiple neutral planes, and the position of the neutral planes can be matched in real time according to the actual measurement situation. The adjustment method is to match the nearest neutral plane according to the height of the initial centering section, and perform precise tilt adjustment around the center of the sphere of the neutral plane. The advantage is that it can minimize the influence of tilt adjustment on centering, ensuring that the turntable maintains stable and reliable performance in highly precise operations. The design of multiple neutral planes enables the turntable to adapt quickly under different working conditions, greatly improving the measurement efficiency and flexibility of industrial production, and effectively making up for the defect of insufficient adaptability of traditional turntables in complex environments.

The invention relates to the technical field of pile foundation engineering, and discloses a double-speed symmetrical superposition pipe pile integrity detection device which comprises a stress wave measurement assembly, a defect detection device and a calculation component. The defect detection device comprises a fixed part, two pointers are coaxially and rotatably arranged on the fixed part, the two pointers are symmetrically distributed on a neutral plane, the rotating centers of the two pointers are located at the center position of the fixed part, and an angle adjusting assembly is arranged in the fixed part and used for adjusting the two pointers to synchronously and relatively deflect. The device also comprises a speed detection assembly used for obtaining the deflection speed of the two pointers, and the calculation part carries out the calculation and analysis of the values obtained by the speed detection assembly and the stress wave measurement assembly. According to the invention, the low-strain detection precision of the pipe pile can be improved.

The application provides a vibration response calculation method and system of an asymmetric bias stepped beam structure, and belongs to the technical field of vibration reduction and noise reduction. The asymmetric bias stepped beam structure comprises at least two beam sections whose neutral planes are not on the same straight line. The method comprises the following steps: constructing a vibration control equation of each beam section, constructing a continuity condition between two adjacent beam sections by a virtual spring method, and constructing a motion control equation of the asymmetric bias stepped beam structure based on the continuity condition and the vibration control equation; and determining the vibration response of the asymmetric bias stepped beam structure based on the motion control equation. The application achieves the purpose of solving the vibration response of the asymmetric bias stepped beam structure. Moreover, compared with the existing numerical method, the method of solving by the motion control equation has better efficiency and economic benefits.

This invention discloses an attitude control fixture and deployment method for temperature-salinity profile observation. The fixture includes a fixture body, a transversely arranged sensor mounting position, at least two longitudinal cable channels orthogonal to the mounting position and symmetrically arranged about the neutral plane, an array of through-holes (open area ratio 15%–35%) disposed in the connecting section, and a buoyancy adjustment unit for balancing. During assembly, the geometric center line of the cable channel is aligned with the transverse center line of the sensor, with a transverse distance difference Δ ≤ 3 mm; the minimum spatial isolation distance d between the sensor sensitive area and the nearest cable channel is ≥ 25 mm, and a shielding ring and insulating partition can be used to suppress electromagnetic interference. The buoyancy adjustment unit controls the net buoyancy of the system |Fn| within a range not exceeding 5% of the component's wet weight through a sliding float and / or counterweight.

The invention provides a wing deformation reconstruction method based on a flexible plate sensor, and the method comprises the steps: 1, pasting fiber Bragg grating sensors at the symmetrical positions of the upper and lower surfaces of a flexible plate structure, and pasting the flexible plate structure to the upper surface of a wing main beam; 2, under different load working conditions, a load loading experiment is carried out on the surface of the wing structure, and strain values of all FBG measuring points are obtained through FBG sensors; 3, determining the strain of each measuring point of the FBG sensors on the upper and lower surfaces of the flexographic plate, and calculating the position of a neutral surface corresponding to the wing structure; 4, converting the strain value of each measuring point on the lower surface of the flexographic plate into a curvature according to the position of the neutral surface of each measuring point by utilizing a curvature conversion principle; 5, recursively solving vertex coordinates of all the infinitesimal elements based on a curvature coordinate conversion equation, and 6, reconstructing a deformation curve of the wing structure according to the vertex coordinates of all the infinitesimal elements.

To easily measure the bend of a cable in the sea.SOLUTION: A sensor unit according to the present invention includes a base portion formed of a synthetic resin, a first tension member disposed along a longitudinal direction of the base portion inside the base portion, a second tension member disposed parallel to the first tension member inside the base portion, a first tape core wire disposed along the longitudinal direction of the base portion inside the base portion and disposed at a position away from a neutral plane of the base portion, and a first spacer disposed between the first tape core wire and the neutral plane.SELECTED DRAWING: Figure 3

In a structure in which a resin fills in gaps between wiring patterns, the resin is adjusted in advance so as to reduce the influence of stress in the filling resin. The resin that is to fill in gaps between wiring patterns of a circuit board is an embedding resin with a coefficient of linear expansion and a Young's modulus such that, in a stack in which a base substrate, an insulating layer and a resin portion formed of the embedding resin are stacked in this order, stress at an interface of the insulating layer that is in contact with the resin portion is at most 13.0 MPa. This stress is calculated by the formula σ=(P / bh)+(Ey / R), which is based on a 4-layer model using a temperature difference between room temperature and a glass transition temperature of the insulating resin. σ represents stress (MPa), P represents axial force (N), b represents a depth measurement of the insulating layer (mm), h represents a thickness of the insulating layer (mm), E represents the Young's modulus (MPa), y represents distance from a neutral plane (mm) and R represents a radius of curvature (mm).

A highly efficient machining method for densely packed hole systems in large conical parts is disclosed. First, the neutral plane projection of each hole in the unfolded state of the steel plate is drawn. Using this projection dimension offset inward by X as the template size, an oxy-fuel cutting template is drawn. Then, the position lines of each hole are marked on the workpiece to be machined. The oxy-fuel cutting template is aligned with each hole position, and the bottom holes of each hole are pre-cut using oxy-fuel cutting equipment. Next, the workpiece is clamped and fixed using a fixing assembly. Rough boring is used to rough-bore each hole in the lower 1 / 3-1 / 2 area of ​​the workpiece. A fine boring tool is then used to machine each hole to the finished size. The fixing assembly is released, and the workpiece is rotated so that its unmachined area is located below the workpiece. After adjustment, the workpiece is aligned using the inner hole at the small end as a reference, and the bottom holes in the remaining 1 / 3-1 / 2 area are machined to the finished size. The workpiece is adjusted again until all holes in all areas are machined. This method is suitable for batch machining of holes on large-angle conical surfaces, providing a reliable theoretical and practical basis for machining this type of part.

The application provides a MEMS structure and a preparation method thereof, and a MEMS piezoelectric microphone. The preparation method comprises the following steps: sequentially depositing a lower electrode layer, a piezoelectric layer and an upper electrode layer on a front surface of a substrate; etching the upper electrode layer and the upper piezoelectric layer from top to bottom to reserve the inner upper electrode layer and the upper piezoelectric layer; and performing deep silicon etching on a back surface of the substrate until the lower electrode layer is reached to form a back cavity of the substrate. The longitudinal section of the piezoelectric layer after etching is in a "convex" shape, the neutral plane of the piezoelectric layer is not coincided with the geometric symmetry plane, the neutral plane is a plane in the piezoelectric layer where the stress and strain are 0, and the geometric symmetry plane is a plane extending along the horizontal direction through the midpoint in the thickness direction of the piezoelectric layer. In the application, the neutral plane is not coincided with the original geometric symmetry plane, the symmetry in the thickness direction is broken, the sensitivity of the structure is greatly improved, the difficulty of adjusting the process parameters to control the residual stress in the structure is reduced, and the accuracy of quantifying the residual stress is improved.

The present disclosure provides a method, device, equipment and medium for obtaining a lattice constant of a wafer; the method can comprise: obtaining a first correction value according to an angle between a normal of a neutral plane of a wafer to be measured and a desired single crystal growth direction; obtaining a second correction value according to X-ray diffraction angles before and after the wafer to be measured is rotated 180° around the center; obtaining a third correction value according to a measurement point position of incident X-rays on the surface of the wafer to be measured and a fitting function; wherein the fitting function is used to describe the relationship between the measurement point position and the system error; obtaining a corrected diffraction angle of the wafer to be measured based on the X-ray diffraction angle of the front surface of the wafer to be measured and the first correction value, the second correction value and the third correction value; and obtaining the lattice constant of the wafer to be measured based on the corrected diffraction angle and the wavelength of the X-rays.

This invention discloses a method for inverting the displacement field of a thick-walled solid structure based on virtual plying, relating to the field of displacement monitoring and inversion technology for thick-walled solid structures. The steps include: embedding a geometrically attached and mechanically isolated virtual ply on the outer surface of the thick-walled solid structure; collecting surface strain as virtual ply membrane strain by arranging measuring points on one side of the virtual ply neutral plane; constructing a weighted least squares functional containing a membrane strain fitting term and bending and shear strain regularization terms; performing variational decomposition of the functional to obtain the virtual ply nodal displacements; and mapping the virtual ply translational displacements to the corresponding nodes of the solid structure to achieve displacement field inversion. This invention solves the problem of high-precision displacement inversion of thick-walled solid structures with single-sided point arrangement without interfering with structural stress, improves the numerical stability of the inversion, adapts to solid element models, is applicable to structures such as pressure vessels, and can be used for structural health assessment.