796 results about "Young's modulus" patented technology

The invention relates to the technical field of robot control, in particular to a force control method and system based on an impedance model for a rope-driven robot. Comprising the steps of system dynamics modeling and parameter identification, real-time axial compression sensing and model updating, Cartesian space impedance model design, adaptive impedance parameter adjustment, inner ring position control based on feedback linearization, force error compensation and expected trajectory generation, real-time control circulation and anti-interference processing and experimental verification and iterative optimization. According to the method, through real-time axial compression sensing and equivalent Young modulus dynamic updating, the problem of model mismatch caused by material rigidity sudden change in the phase change process of the hyperelastic material is solved. Specifically, a traditional method depends on static material parameter calibration, and real-time compensation of the nonlinear characteristic of the material is achieved through online estimation of the axial compression amount of the main beam and iterative correction of the Young modulus.

The invention discloses a breakable rock-soil granular material triaxial test simulation method based on a lattice spring-discrete element coupling framework, which comprises the following steps: establishing a triaxial test model rectangular boundary condition, and generating a non-breakable spherical rock-soil granular material in the boundary; replacing the generated non-crushable spherical particle material with rock-soil particles considering particle crushing based on a lattice spring-discrete element coupling frame, and assigning parameters; replacing wall bodies on the two sides of the rectangular boundary condition with a large number of bonded spherical particles to generate a flexible membrane boundary; and applying confining pressure to the boundary of the generated flexible membrane, and carrying out shear simulation. According to the method, the Young modulus and the Poisson's ratio can be matched in a high-precision mode, the heterogeneity of elastic response is reduced, strength degradation and friction characteristics are simulated, and the calculation efficiency is greatly improved.

The invention relates to the technical field of crustal stress measurement, in particular to a rock core three-dimensional crustal stress measurement system and method based on multi-source data. The method comprises the following steps: acquiring well wall damage information, and identifying a damage type in the well wall damage information; multiple sections of core samples are selected based on the well wall damage information, and overburden pressure parameters are determined based on the multiple sections of core samples; a rock mechanics experiment is conducted on the rock core sample, rock mechanics parameters are generated, and the rock mechanics parameters comprise the Poisson's ratio, the Young modulus, the uniaxial compressive strength value and the tensile strength value. According to the method, the difference value of the maximum stress and the minimum stress is combined with the multi-source coupling constraint principal stress interval, the intersection points are identified through the topological visualization graph, the numerical range of the maximum principal stress and the minimum principal stress can be accurately determined, and then the information of the three-dimensional crustal stress is obtained.

The invention discloses an accurate acupuncture positioning method under ultrasonic guidance, which relates to the technical field of medical health and comprises the following steps: acquiring a two-dimensional or three-dimensional ultrasonic image of a target area by utilizing ultrasonic image acquisition equipment; the Young modulus of the target area is calculated by measuring the shear wave propagation speed of the tissue of the target area; a sensor module is adopted to monitor the interaction force between the puncture needle and the tissue in real time, and mechanical data are obtained; according to Young modulus and modulus variance obtained through calculation of the shear wave elastography image and mechanical data fed back by a sensor, a time sequence feature vector is constructed; performing dynamic modeling and prediction on the tissue state in the puncture process by using a long-short-term memory neural network; the path offset of the needle head is judged, a correction signal is generated through a PID controller, and the posture or direction of the needle head is adjusted in real time; the problem of artifacts in a traditional ultrasonic image can be solved, more accurate acupuncture path planning is provided, and the method adapts to the change of tissue elasticity in real time.

A composite structure for a pressure sensor, a pressure sensor, a method of pressure sensing using the pressure sensor, and a method of fabricating a composite structure for a pressure sensor. The method of fabricating a composite structure for a pressure sensor comprises the steps of forming an array of microstructures made from an elastomeric material; and forming a flexible conductive coating on the array of microstructures such that a surface morphology of microstructures is substantially maintained for the coated array of the microstructures; wherein the conductive coating exhibits a Young's modulus that is higher than that of the elastomeric material.

The invention relates to a defect detection method and system based on multi-modal feature fusion. The method comprises the following steps: acquiring multi-modal data of a transformer; predicting based on the multi-modal data through the fusion prediction model, and outputting an elastic modulus distribution diagram of the insulating material in the transformer; carrying out super-resolution enhancement on the elastic modulus distribution diagram based on a physical constraint diffusion model; and positioning the defects of the transformer through a time reversal algorithm on the basis of the internal Young modulus distribution and the super-resolution elastic modulus distribution diagram of the transformer. According to the invention, the problems of feature loss, large single modal error, fuzzy fractal defect reconstruction, insufficient defect positioning precision and the like caused by signal attenuation in traditional detection are solved. According to the method, the signal-to-noise ratio and modulus distribution prediction precision of the signal is remarkably improved, micron-order super-resolution reconstruction is achieved, winding deformation and insulation layering are accurately distinguished, harm is quantified, traditional imaging limitation is overcome, and a high-precision and physically consistent basis is provided for transformer state evaluation and maintenance.

The invention discloses a meshless EFGM and style migration-based multi-material structure topological optimization method, which comprises the following steps of: (1) inputting material attributes such as Young modulus, shear modulus and Poisson's ratio of a structure, and discretizing a design domain by using meshless nodes; (2) transforming the designed meshless density field to obtain a physical density field, and performing length scale filtering; (3) an alternating active phase algorithm is executed, and the displacement field, the system flexibility and the related sensitivity of the structure are solved based on the meshless EFGM; (4) executing a neural style migration program to calculate the difference between the current topological structure and the reference style image, and calculating the derivative of the physical density field of the topological structure to the network parameter; and (5) updating a design variable by using a moving asymptote algorithm, and judging whether an optimization loop is converged or not. According to the method, based on meshless EFGM and style migration multi-material structure topological optimization, topological structures with different artistic styles can be designed, and the method has engineering application value.

This packaging material has a structure in which a transparent vapor-deposited barrier film, a stretched nylon film, and an unstretched polypropylene film are laminated in this order. The transparent vapor-deposited barrier film and the stretched nylon film are laminated with an adhesive layer formed of a cured product of a solventless adhesive agent therebetween. The ratio of the Young's modulus in the MD direction of the unstretched polypropylene film with respect to the thickness of the unstretched polypropylene film is 9.0 MPa / μm or more.

The invention discloses a welding thermal stress simulation method, device, equipment and medium based on a crystal plasticity finite element, and relates to the technical field of welding thermal stress finite element simulation. The method comprises the steps that a sample is prepared according to a specific multi-phase metal material, and phase distribution and crystal orientation information of a two-dimensional plane of the material are obtained through a metallographic experiment; and a three-dimensional multi-grain model is constructed based on the two-dimensional information. According to the method, a crystal plastic constitutive model is adopted to describe the flowing behavior of the material at high temperature, crystal slippage and polycrystal interaction are considered, the influence on the material performance is reflected from the microstructure evolution level, and the problem that the influence on the macroscopic mechanical performance of a microstructure is difficult to capture in welding multiphase metal material simulation is solved; two-dimensional representation is obtained through a metallographic experiment, the Young modulus and rigidity matrix parameters are accurately calculated by combining forward stretching and shear simulation, the rigidity matrix precision is improved, a temperature field area is divided, stress evolution and residual stress are calculated by combining a thermal-elastic-plastic model, and the welding thermal stress calculation precision is improved.

The invention discloses a method for measuring fan blade root stress based on a fiber bragg grating sensor. According to the method, 6-10 key measurement points are selected in a blade root area of a fan blade, a pair of FBG sensors is installed at each measurement point, one FBG sensor is used for stress measurement (affected by strain and temperature at the same time), the other FBG sensor is used for temperature compensation, and decoupling of temperature and strain signals is achieved. The system adopts a single-mode optical fiber, a broadband light source (the wave band is 1525-1565 nm, and the power is 10-20 mW) and a high-resolution spectrum analyzer (the resolution is smaller than or equal to 1 pm, and the sampling rate is larger than or equal to 100 Hz or 1 kHz) to collect optical signals reflected by an FBG sensor in real time, measured wavelength shift is converted into accurate strain data through temperature compensation and a strain calculation formula, and the optical signals are transmitted to the FBG sensor. And calculating a stress value by combining the Young modulus and Poisson's ratio of the material. The method has the advantages of being high in precision, high in real-time performance, resistant to electromagnetic interference and suitable for seaborne, high-altitude and other severe environments, and reliable data support can be provided for dynamic stress monitoring, fatigue life prediction and fault early warning of the fan blade.

To provide a copper alloy excellent in conductivity while having a sufficiently large elastic deformation amount with a low Young's modulus and unlikely to cause a plastic deformation even under a large deformation.SOLUTION: A copper alloy has a composition including 15-57 mass% Zn, 12 mass% or less Al, satisfying A+5×B≥30 and A+3.5×B≤57 in which the Zn content is A mass% and the Al content is B mass%, and a balance Cu with inevitable impurities. A volume fraction in a β phase is 50% or more. an average of KAM (Kernel Average Misorientation) values of the β phase is 2.0° or less obtained when a measurement area of 1 mm2 or more is measured at a measurement interval 1 μm step by an EBSD method and measured excluding a measurement point with a CI value of 0.1 or less analyzed by data analysis software OIM.SELECTED DRAWING: None

To provide a copper alloy excellent in conductivity while having a sufficiently large elastic deformation amount with a low Young's modulus and unlikely to cause a plastic deformation even under a large deformation.SOLUTION: A copper alloy has a composition including 15-57 mass% Zn, 12 mass% or less Al, satisfying A+5×B≥30 and A+3.5×B≤57 in which the Zn content is A mass% and the Al content is B mass%, and a balance Cu with inevitable impurities. A volume fraction in a β phase is 50% or more. When a measurement area of 8 mm2 or more is measured at a measurement interval 8 μm step by an EBSD method and analyzed excluding a measurement point with a CI value of 0.1 or less obtained through an analysis by data analysis software OIM, and an interval between measurement points in which an orientation difference between neighboring measurement points is 5° or more is regarded as a crystal grain boundary, a ratio of each coincidence boundary length of 3≤Σ≤29 to all crystal grain boundary lengths L at which measured β phases are abutting with each other is 4% or more.SELECTED DRAWING: None

The invention relates to the field of pressure sensors, in particular to a triboelectric pressure sensor and a sleep monitoring method and system. The triboelectric pressure sensor comprises a positive friction layer, a negative friction layer, a deformation electrode connected to the negative friction layer and a flexible electrode connected to the positive friction layer. The contact ends of the tips of the multiple micro-cone structures of the positive friction layer all face the negative friction layer, and gaps are formed between the contact ends and the negative friction layer. The Young modulus of the negative friction layer is smaller than that of the micro-cone structure, so that when the negative friction layer approaches the deformed electrode, the negative friction layer sinks and makes contact with the side face of the micro-cone structure. The change amplitude of the contact surface along with the pressure is large, so that the sensitivity of the sensor is improved. Respiration and pulse frequencies are respectively detected by a triboelectric pressure sensor to obtain electric signals, the electric signals are segmented and enhanced into waves, then the waves are classified by a big data method, a learning model for identifying sleep state categories corresponding to the waves is obtained, the categories are further rapidly and accurately identified, and an alarm is given according to the number of abnormal times. The method and the system have high reliability.

The present invention provides a ceramic particle (141) and a coating layer (142) that covers at least a part of the surface of the ceramic particle and contains two or more phases. The coating layer contains a first phase (142a) that is composed of an oxide-based ion conductor, and a second phase (142b) that is composed of an amorphous-containing ion conductor which contains an amorphous phase. The first phase has an ionic conductivity which is higher than that of the second phase. The second phase has a Young's modulus which is lower than that of the first phase.

The invention discloses a method and device for measuring structural parameters of an MEMS cantilever beam, and the method comprises the steps: placing the MEMS cantilever beam on an objective table of a nanoprobe station, and guaranteeing that the thickness direction of the MEMS cantilever beam is perpendicular to a horizontal plane; measuring the length l and the width b of the MEMS cantilever beam by using a microscope; controlling a micro probe of the nano probe station to descend until the micro probe is in contact with the surface of the MEMS cantilever beam; continuously controlling the micro-probe to descend, and recording the displacement X and the loading stress F of the micro-probe at the same time; carrying out linear fitting by utilizing a preset calculation device displacement X and the loading stress F to obtain the deformation rigidity K of the MEMS cantilever beam; and calculating the thickness h of the MEMS cantilever beam based on the deformation stiffness K, the length l, the width b and the Young modulus E. The measuring method is wide in application range and low in testing cost.

The invention belongs to the technical field related to structure optimization design, and discloses a topological optimization method and device for a metamaterial microstructure capable of bearing a band gap, and the method comprises the steps: (1) respectively defining an interpolation penalty coefficient of a Young modulus for the homogenization analysis of the microstructure and the band gap problem of an energy band structure according to the performance analysis of the microstructure, calculating an interpolation penalty coefficient of the mass density; (2) carrying out homogenization analysis of the microstructure based on dynamics to obtain equivalent physical property parameters and determine equivalent material modulus; (3) defining an irreducible first Brillouin region wave vector path of the microstructure based on the geometric symmetry constraint of the microstructure, and further calculating a band gap quality factor between adjacent energy band curves of the microstructure; and (4) establishing a topological optimization model which takes the equivalent modulus as a grading constraint and takes band gap quality factor maximization as a target, and performing iterative optimization based on the topological optimization model to obtain an optimal microstructure configuration. According to the invention, efficient and stable design of the microstructure is realized.

Provided is a glass composition which has a low linear expansion coefficient and a high Young's modulus and is suitable for mass production. The present invention provides, in mass%: i) a glass composition containing 56 < = SiO2 < = 70, 0.1 < = B2O3 < = 8, 15 < = Al2O3 < = 24, 4 < = MgO < = 14, 0 < = CaO < = 4, 0 < = ZnO < = 10, 0 < = (Li2O + Na2O + K2O) < = 4, 0.1 < = ZrO2 < = 5, and substantially not containing TiO2; the present invention relates to a glass composition comprising (i) a glass composition containing 56 < = SiO2 < = 70, 0.1 < = B2O3 < = 8, 15 < = Al2O3 < = 24, 4 < = MgO < = 14, 0 < = CaO < = 4, 0.1 < = ZnO < = 3, 0 < = (Li2O + Na2O + K2O) < = 4, and substantially not containing TiO2 and ZrO2, and iii) a glass composition containing 56 < = SiO2 < = 70, 0.1 < = B2O3 < = 8, 15 < = Al2O3 < = 24, 4 < = MgO < = 14, 0 < = CaO < = 4, 0 < = ZnO < = 10, 0 < = (Li2O + Na2O + K2O) < = 4, and 1 < = ZrO2 < = 5.

The invention belongs to the field of carbon product production, and particularly relates to special graphite for ion implantation and a preparation method thereof, and the special graphite is composed of aggregate coke, an additive and a binder; the aggregate coke comprises at least one of low-ash petroleum coke, pitch coke, pitch coke green coke, needle coke and artificial high-purity graphite, the ash content is not higher than 0.2%, the water content is not higher than 0.02%, and the prepared special graphite for ion implantation has excellent comprehensive performance indexes. The volume density is 1.85-1.92 g / cm < 3 >, the porosity is smaller than or equal to 7%, the resistivity is 12-14 mu omega m, the breaking strength is larger than or equal to 85 MPa, the compressive strength is larger than or equal to 180 MPa, the Young modulus is 13-15 GPa, the thermal expansion coefficient is smaller than or equal to 5.0 * 10 <-6 > / DEG C, the total impurity content is smaller than or equal to 50 ppm, the key metal element content is smaller than or equal to 5 ppm, and all the properties reach the industry leading level. The harsh requirements of the ion implantation technology on the special graphite material in the aspects of electric heating performance, mechanical performance, thermal stability and purity can be fully met, and stable operation and efficient work of ion implantation equipment are effectively guaranteed.

The invention provides a flexible pressure sensor array for measuring the airspeed of an unmanned aerial vehicle and a preparation method of the flexible pressure sensor array. The sensor array comprises a net-shaped structure and a plurality of flexible pressure sensors arranged at nodes of the net-shaped structure. The sensor is of a sandwich structure, a sensitive layer is arranged in the middle, a flexible substrate layer and an electrode layer are symmetrically arranged up and down, the sensitive layer is composite conductive foam with a conductive elastomer filling framework, and the composite conductive foam is obtained by dipping foam in a conductive material solution for multiple times. The sensitive layer framework is obtained by forming through holes in composite conductive foam in a laser array mode and filling conductive elastomers with the through holes. According to the sensor array, heterogeneous network porous foam with good conductivity and multi-layer pressure response characteristics is used as a sensitive layer, and the sensor array has a wide pressure response range; the conductive elastomer framework improves the problem that the foam structure is easy to collapse due to compression deformation, and the service life is prolonged; by utilizing the internet design, the Young modulus of the whole structure is reduced, and the device can be closely attached to the curved surface of the leading edge of the wing in a conformal manner.

The invention discloses a preparation method of a shape memory polymer nanorod array, and belongs to the technical field of bionic adhesive materials. According to the method, on the basis of an anodic aluminum oxide template, hydrophilic or hydrophobic chemical modification is carried out on the surface of the anodic aluminum oxide template, the surface wettability of a template pore channel is adjusted, and then the permeation behavior of an epoxy resin precursor in the pore channel is controlled. The preparation method comprises the following specific steps: modifying an AAO template, preparing and defoaming an epoxy resin mixture, filling the template, curing, removing an aluminum substrate, dissolving an aluminum oxide layer, and finally obtaining the shape memory polymer nanorod array with high Young modulus (1-20 GPa). According to the method, a template method is combined with chemical modification, the process steps are clear, the conditions are mild, the method is particularly suitable for preparing a hard micro-nano composite structure matched with the mechanical property of a gecko script characteristic material, and an effective technical support is provided for research of a high-performance dry adhesive material.

A three-dimensional elastography method based on a vision-based tactile sensor. The method comprises several steps, which respectively involve: performing system construction and data processing, and acquiring contact deformation data collected by a vision-based tactile sensor; performing forward simulation; performing inverse optimization; calculating gradient information inside a target object, deriving the derivative of an objective function with respect to Young's modulus, calculating the partial derivative of a resultant force with respect to an elasticity distribution, and calculating the overall gradient of the objective function with respect to Young's modulus distribution; and outputting a Young's modulus distribution obtained by means of reconstruction and outputting a quantization reliability index. The method can realize accurate reconstruction of a Young's modulus distribution inside soft objects under robotic tactile sampling, and can output a corresponding reliability index, thus having high levels of practicability.

An orthosis for support of a joint, adapted to the thumb or wrist, having sleeve-like main member made of an elastic material, adapted to envelop the joint and distal and proximal limb portions on either side of the joint, elastically deformable panel housed in a pocket formed in the main member, and non-elastic bracing device for bracing the main member and a proximal portion of the panel around the proximal limb portion, the panel being configured such that, over at least 50 % of the length of the main member along the limb portions, including a limb portion covered by the bracing device, the panel has a cross-section occupying more than 30 % of the perimeter of the underlying limb, the panel having a stiffness defined by a Young's modulus between S and 10 MPa, while the material forming the main member has a stiffness of a lower order of magnitude.

The invention discloses titanium-rare earth synergistic alkali-free glass with an ultrahigh strain point and high resistance and a preparation method of the alkali-free glass, and belongs to the technical field of glass. According to the alkali-free glass, a unique titanium-rare earth synergistic enhanced network is constructed, two key control parameters, namely, a high temperature performance index (HTPI) and a resistance synergistic factor (RCF), are defined for the first time, and when the HTPI is controlled to be 5.8-7.2 and the RCF is controlled to be 3.5-4.85, the strain point of the glass is larger than or equal to 745 DEG C, and meanwhile, the glass has the advantages that the glass has the good heat resistance and heat resistance; according to the glass substrate prepared by the preparation method disclosed by the invention, the resistivity at 1620 DEG C can be accurately regulated and controlled within an ideal interval of 50-150 omega.m, meanwhile, the Young modulus is greater than or equal to 88 GPa, the liquidus temperature is less than or equal to 1260 DEG C, the comprehensive performance is far better than that of the prior art, and the strict requirements of high-generation LTPS and IGZO display panel manufacturing on the glass substrate are perfectly met.

The invention discloses a manufacturing method of a flexible piezoresistive sensor, which comprises the steps of conductive composite material preparation, sensitive layer microstructure forming, sensor integrated assembly and the like, and is characterized in that conductive particles and an elastic polymer matrix are uniformly compounded to form an integrated sensitive layer structure; an interface problem caused by Young modulus mismatch in a traditional two-layer structure is eliminated from a material source, meanwhile, a micro geometric structure is elaborately designed and copied on the surface of the sensitive layer, and an externally applied pressure signal is ingeniously converted into effective local stress concentration. According to the structural design, the change rate of the contact area between the sensitive layer and the electrode can be amplified, so that the sensor can generate remarkable electric signal response to tiny pressure change.

An optical component including: a substrate on which an optical element is mounted; a transparent sealing member disposed above the substrate and configured to seal the optical element; and a bonded portion in which a plurality of metal films are laminated, and which is configured to bond the transparent sealing member and the substrate. The bonded portion includes: one or more stress relaxation layers constituted by one or more metal films having a Young's modulus of less than or equal to 150 GPa, the one or more stress relaxation layers having a total thickness of greater than or equal to 1.2 μm; and a diffusion prevention layer disposed on each of both sides in a thickness direction of each of the one or more stress relaxation layers, and configured to prevent diffusion of metal constituting the stress relaxation layer.

A deformable wheel with non-pneumatic load bearing intended to equip a vehicle for rolling under extreme conditions such as those encountered on the moon and on Mars, includes a hub, a laminated annular strip including a plurality of concentric ferrules which are assembled with the interposition of interposing layers each composed of a material whose Young's modulus is 600,000 to 1,000 times lower than that of the ferrules, and a plurality of metal cables. Each cable connects the hub to the laminated strip while being fixed, on the one hand by an external end to the laminated strip, and on the other hand by an internal end to the hub by means of an elastic member making it possible to modulate the radial stiffness of the cables. Each elastic member is associated with an abutment able to limit its deformation.

The invention relates to the field of sensors, and discloses an acoustic sensor and a preparation method thereof. The acoustic sensor comprises an upper support body, an acoustic sensing layer and a lower support body; the acoustic sensing layer comprises a first electrode layer, a flexoelectric material layer and a second electrode layer which are stacked in sequence; the flexoelectric material layer contains a two-dimensional layered material and an ion regulator; the two-dimensional layered material is selected from at least one of graphene oxide, boron nitride, vermiculite, molybdenum disulfide, tungsten diselenide, tungsten disulfide, black phosphorus, Mxene, molybdenum ditelluride and tungsten trioxide; the ion regulator is selected from one or more than two of polystyrolsulfon acid, polyethylene glycol, poly (diallyldimethylammonium chloride), carboxyl ethylene copolymer, polyethylene sulfonic acid, polymethylacrylic acid, polyethylene phosphoric acid, polyvinylamine, sodium alginate, silk fibroin and carboxylated nanofiber. The acoustic sensor operates by using the flexoelectric effect, and has higher sensitivity and high Young modulus.

The invention discloses a quantitative evaluation method for shale brittleness based on bedding characteristics, and relates to the field of petroleum and natural gas engineering, in particular to the quantitative evaluation method for the shale brittleness based on the bedding characteristics in the exploration and development process, and the quantitative evaluation method comprises the following steps: taking a rock sample from shale at a target layer to obtain the maximum Young modulus of a block; calculating a macroscopic brittleness index; processing the rock sample into a cuboid rock block for a nanoindentation experiment, calculating an interlayer heterogeneous coefficient between two corresponding adjacent probes according to mechanical parameters at the same transverse position between stratums so as to obtain a microscopic brittleness index, and calculating the total brittleness index of the rock by combining the microscopic brittleness index with the macroscopic brittleness index; microcosmic rock mechanics experimental data between different stratums of shale are tested on the basis of nanoindentation for the first time, heterogeneity between different stratums is quantitatively calculated, quantitative evaluation of shale rock microscopic brittleness is achieved, and compared with a conventional macroscopic evaluation method, quantitative evaluation is further improved.

Provided are an optical fiber, a ribbon optical fiber, and a method for manufacturing an optical fiber, whereby it is possible to align an optical fiber having directivity with respect to the rotational direction with high precision. An optical fiber is provided with: a fiber which includes at least one core and a cladding covering the core, and which extends in the longitudinal direction; a primary resin layer covering the outer periphery of the fiber; and a secondary resin layer covering the outer periphery of the primary resin layer. The fibers are directional with respect to a rotation direction about the longitudinal direction as an axis. The primary resin layer includes, in the longitudinal direction, a plurality of first regions having a first Young's modulus and a plurality of second regions having a second Young's modulus, the second Young's modulus being higher than the first Young's modulus.

An information recording medium disc according to an embodiment is a disc having a plate thickness of 0.51 mm or less, and is provided with a substrate and a cover layer. The substrate has one main surface and another main surface, and also has a side wall surface connecting the two main surfaces. A cover layer covers both main surfaces and side wall surfaces of the substrate. The disk has a specific elastic modulus E / d [106 m2 / s2] of 40 or more as calculated from a Young's modulus E [GPa] and a density d [g / cm3]. When 30 [G] impact of 2 [m seconds is applied to the disk in the normal direction of the main surface of the disk substrate in a state in which the inner peripheral end of the disk is fixed, the maximum amplitude caused by vibration in the thickness direction of the outer peripheral end of the disk substrate is 0.25 mm or less.