32 results about "Dynamic modulus of elasticity" patented technology

A carbon fiber composite material having an elastomer and vapor-grown carbon fibers dispersed in the elastomer. The vapor-grown carbon fibers are rigid fibers having an average diameter of 20 to 200 nm, an average length of 5 to 20 micrometers, and an average value of bending indices defined by the following expression (1) of 5 to 15,Bending index=Lx÷D  (1)Lx: length of linear portion of the vapor-grown carbon fiber, andD: diameter of the vapor-grown carbon fiber.The carbon fiber composite material has a dynamic modulus of elasticity (E′) at 150° C. of 30 MPa or more and an elongation at break (EB) of 140% or more.

An RFID module comprising a transponder covered with a 0.2 to 2 mm thick rubber sheet containing 100 parts by weight of a diene-based rubber, less than 30 parts by weight of carbon black and 5 to 55 parts by weight of silica, having a relative permittivity of 7 or less and having a dynamic modulus of elasticity (E′) of 2 to 12 MPa, which can extend a communication distance with a required installation location and is superior in the durability at the time of being embedded in the tire.

The invention relates to the determination of the dynamic elastic modulus of a material, such as a material comprising a mineral binder like cement, or gypsum, or the like, or a polymer, or ceramic, preferably mortar or concrete, in particular shotcrete, using sound, preferably ultrasound waves which penetrate the material and are continuously measured and analyzed. In particular, the invention relates to an apparatus, to a measuring device, and to a method for determining the dynamic elastic modulus of a material using the apparatus.

The invention discloses a method for measuring mechanical property of a cement-based material. By the method, dynamic modulus of elasticity and poisson ratios of a cement-based material at all age times can be synchronously calculated according to transmission speeds of ultrasonic transverse waves and ultrasonic longitudinal waves by continuously measuring the transmission speeds of the ultrasonic transverse waves and the ultrasonic longitudinal waves in a cement-based material test piece to be measured at all the age times. The invention also discloses a device for measuring the mechanical property of the cement-based material. The device comprises a cubic test die with an opening at the upper part, an ultrasonic longitudinal wave emitter, an ultrasonic longitudinal wave receiver, an ultrasonic transverse wave emitter, an ultrasonic transverse wave receiver and an ultrasonic wave signal processing unit, wherein the cubic test die is used for pouring the cement-based material test piece to be measured; the ultrasonic longitudinal wave emitter and the ultrasonic longitudinal wave receiver are symmetrically arranged in two side walls of the cubic test die; the ultrasonic transverse wave emitter and the ultrasonic transverse wave receiver are symmetrically arranged in the two side walls of the cubic test die; and the ultrasonic wave signal processing unit is connected with the ultrasonic longitudinal wave emitter, the ultrasonic longitudinal wave receiver, the ultrasonic transverse wave emitter and the ultrasonic transverse wave receiver respectively. The dynamic modulus of elasticity and the poisson ratios of the cement-based material in the early age can be measured nondestructively.

A carbon fiber composite material having an elastomer and vapor-grown carbon fibers dispersed in the elastomer. The vapor-grown carbon fibers are rigid fibers having an average diameter of 20 to 200 nm, an average length of 5 to 20 micrometers, and an average value of bending indices defined by the following expression (1) of 5 to 15,Bending index=Lx÷D  (1)Lx: length of linear portion of the vapor-grown carbon fiber, andD: diameter of the vapor-grown carbon fiber.The carbon fiber composite material has a dynamic modulus of elasticity (E′) at 150° C. of 30 MPa or more and an elongation at break (EB) of 140% or more.

An RFID module comprising a transponder covered with a 0.2 to 2 mm thick rubber sheet containing 100 parts by weight of a diene-based rubber, less than 30 parts by weight of carbon black and 5 to 55 parts by weight of silica, having a relative permittivity of 7 or less and having a dynamic modulus of elasticity (E′) of 2 to 12 MPa, which can extend a communication distance with a required installation location and is superior in the durability at the time of being embedded in the tire.

The invention discloses a device and a method for measuring dynamic elasticity modulus in the temperature environment. The technical scheme of the device includes that a beam-shaped test piece is clamped on a fixed rigidity table in a manner of a cantilever state with one end fixed and the other end free; by the aid of a resistance heating device, a thermocouple feeds back temperature and a temperature controller controls heating and temperature of the test piece, a piezoelectric ceramic vibration exciter mounted on the test piece receives excitation signals amplified by a signal amplifier toexcite the test piece, a laser vibration measurer performs modal tests on the test piece in the temperature environment, a computer receives signals of the laser vibration measurer, acquires fixed frequency and modal of each step in the controlled temperature environment through signal analysis and calculates dynamic elasticity modulus of materials in the controlled temperature environment by tested fixed frequency according to the relation between the fixed frequency and the elasticity modulus. The device has the advantages of nondestructive testing, convenience in use and operation, high measuring accuracy and the like.

A pneumatic vehicle tire having a radial carcass, an at least single-layer belt and a tread that is composed of two layers, a tread cap and a tread base, which are made from different rubber mixtures, in a radial direction, the tread base having a central portion and two lateral portions that extend at least in a radially outward direction from an axial perspective. The two lateral portions are made from a rubber mixture that has a lower dynamic modulus of elasticity E′ at 55 ° C. in accordance with DIN 53513 (measured at an extension of 8%) and a lower hysteresis than the central portion of the tread base for a lower rolling resistance without worsening the handling behavior of the vehicle tire.

A pneumatic vehicle tire for passenger cars, vans or the like has a radial carcass, a multi-ply belt, and a profiled tread that, as viewed in the axial direction, has a central portion and two shoulder portions. The shoulder portions include a rubber mixture that has a lower dynamic modulus of elasticity E′ (at 55° C. and 8% elongation according to DIN 53513) than the central portion. The central portion has extensions at the base thereof, running laterally substantially parallel to the tread substructure and radially inside and across the width of the shoulder portions.

A pneumatic tire having an inner liner includes a specified rubber compound on the inner surface of the tire, maintaining air retainability and improved with road noises without deteriorating a rolling resistance or a durability, in which the ratio (E′r / E′p) of the dynamic modulus of elasticity E′r in the axial direction of the tire and the dynamic modulus of elasticity E′p in the peripheral direction of the tire of an inner liner rubber sampled from the tire is 1.1 or more.

The invention discloses a concrete life prediction method based on a standard Wiener process. The method comprises the steps of firstly, enabling Tb=inf{t:W(t)=b, t>0}, enabling W(t) to represent a durability degradation amount of concrete at a t moment; detecting an initial dynamic modulus of elasticity Ed of a concrete material, enabling a safety margin b=40%*Ed; inputting the safety margin b and a time length t, calculating a failure probability Pf of the concrete dynamic modulus of elasticity based on the standard Wiener process within the time of [0,t) according to a formula as shown in the specification, calculating and drawing a concrete life distribution prediction curve according to calculation formula programming through computer software MATLAB, thereby evaluating a service lifethereof. The concrete life prediction method with wide application range, high reliability, convenient calculation, efficiency and low prediction cost is established.

The invention belongs to the technical field of large-span underground engineering mining stability prevention and treatment, and particularly relates to a dynamic elastic modulus detection method ofthe large-span underground cavity mining roof stability. The dynamic elastic modulus detection method comprises the following steps that 1, physical and mechanics parameters of underground cavity rockmass are determined; 2, initial ground stress of the central axis of an underground cavity roof and ground stress in the dynamic process are determined; 3, an initial rock mass dynamic elastic modulus of a detection profile of the underground cavity roof and the rock mass dynamic elastic modulus in the dynamic process are detected; 4, roof damage variables after different excavation stages of anunderground cavity are determined; 5, a criterion of the underground cavity roof structural stability is determined; and 6, evaluation of the underground cavity roof stability and a safety limit of anexcavation span of the underground cavity roof are determined. According to the dynamic elastic modulus detection method, the dynamic modulus of elasticity of the rock mass underground cavity roof ismeasured through hole drilling, the parameter of the dynamic modulus of elasticity serves as a parameter of large-span underground space mining roof stability evaluation, the dynamic stability, the strength and the like of the large-span underground cavity mining roof under the effect of external dynamics are evaluated and predicated by applying the parameter, and a quantitative basis can be provided for optimization design of the large-span underground space mining roof.

A tire which has a bead filler (5) arranged on the outside in the tire radius direction of one pair of bead sections provided at the right and left thereof, one pair of side wall sections (6) provided in the right and left of a tread section, and a rubber reinforcing layer (7) arranged in the side wall section (6), characterized in that the rubber composition constituting the bead filler (5) or the rubber reinforcing layer (7) comprises a conjugated diene based polymer having a vinyl bond content of 25% or more, a weight average molecular weight (Mw) of 200,000 to 900,000 and a molecular weight distribution (Mw / Mn) represented by the ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1 to 4 in an amount of 50 mass % or more of the rubber component thereof, and a resin and a curing agent therefor in a total amount of 3 parts by mass or more relative to 100 mass parts of the rubber, and exhibits a modulus of elasticity at 100% elongation at 25° C. of 5 MPa to 20 MPa and a dynamic modulus of elasticity at room temperature of 10.5 MPa or less.

The invention discloses a cement concrete pavement cavity drop hammer type Benkelman beams deflectometer comprehensive detection method. The method comprises the following steps that S1, preparation work is done, in specific, a Benkelman beams deflectometer is conditioned, detected, aligned and turned on; S2, testing is conducted, a bearing board falls down, a drop hammer device is started, a sensor and the bearing board are lifted up, calculation is conducted, heavy hammers with different levels of mass of the drop hammer type Benkelman beams deflectometer fall the certain height to generateimpact load, instant deformation occurs on the pavement surface, and the dynamic deflection and deflection basin generated under the dynamic load effect are tested. The dynamic modulus of elasticity of each layer of the pavement is calculated inversely, and serves as the void determination parameters of the cement concrete pavement, when any one of the intercept, the single-point deflection and the deflection different does not meet the requirement, it is deemed that voids exist beneath a board block, and the device is convenient to operate and suitable for being widely popularized.

The invention relates to a method for protecting the safety and stability of a movable museum collection in an earthquake. The method comprises the following steps: a museum collection imitation is subjected to a material characteristic test in a laboratory, so that tensile and compression resistance limit stress, shear resistance limit stress and a dynamic modulus of elasticity and a dynamic modulus of shearing of a material are obtained; after a stress reduction factor K is fetched, the tensile and compression resistance limit stress and the shear resistance limit stress of the imitation are multiplied by the K, and the product serves as allowable dynamic stress of the museum collection; allowable acceleration is calculated according to the D'Alembert's principle; the stability of the museum collection is classified into three stability levels according to the allowable acceleration, the friction factor and the height-width ratio (namely the allowable vibration index)of the museum collection; finally, an exhibition stand is designed and arranged, and the museum collection is placed according to a classification result. The discriminating method is simple and practicable, and the result is accurate; the allowable vibration index provides a scientific basis and a quantitative criterion for control cover the safety guarantee of the museum collection in an earthquake.

The invention discloses a test method for detecting a kinetic parameter of artificial polycrystalline ice. Based on a low-temperature dynamic triaxial test, a constitutive relation and a kinetic parameter index of the artificial polycrystalline ice under the action of a rail transit step cyclic load are researched. Under different negative temperatures and frequencies, an axial dynamic stress-stain relation curve of a test piece is considered, and an abstract of the invention 1 of the artificial polycrystalline ice is obtained: the dynamic constitutive relation can be described by using a linear viscoelasticity model, dynamic modulus of elasticity is lowered with the increase of the temperature and is increased with the increase of the frequency; and the coefficient of viscosity is increased with the increase of the temperature and is reduced with the increase of the frequency, therefore, a comprehensive expression among the kinetic parameter index, the dynamic modulus of elasticity, the coefficient of viscosity, and the temperature and the frequency is established.

The invention relates to the determination of the dynamic elastic modulus of a material, such as a material comprising a mineral binder like cement, or gypsum, or the like, or a polymer, or ceramic, preferably mortar or concrete, in particular shotcrete, using sound, preferably ultrasound waves which penetrate the material and are continuously measured and analyzed. In particular, the invention relates to an apparatus, to a measuring device, and to a method for determining the dynamic elastic modulus of a material using the apparatus.

The invention relates to the field of methods for testing or analyzing concrete by means of measuring chemical or physical properties of materials, in particular to a method for evaluating self-repairing effects of self-repairing cement-based materials. A self-healing effect evaluation method for self-healing cement-based materials, characterized in that: evaluation indicators include relative dynamic elastic modulus, fracture behavior (stress intensity factor recovery rate, fracture toughness recovery rate), constitutive behavior comparison, bending resistance Stiffness recovery rate and strength recovery rate. Follow the steps below: Step 1: Prepare specimen; Step 2: Prefabricate local cracks and scattered cracks; Step 3: Test various parameters; Step 4: Complete self-repair; Step 5: Test various parameters; Step 6: Calculate Treatment and evaluation of restoration effects. The present invention is comprehensively evaluated.

The invention provides a free lossless audio codec (FLAC) finite difference software-based method for generating dynamic elasticity coefficient. On the basis of FLAC finite difference software, the method comprises the following main steps: inputting the number of nodes on the boundary of a hole; generating a command stream file which can be identified by the FLAC finite difference software; calling in the generated command stream file in the FLAC finite difference software; acquiring counter force acted on each node on the boundary of the hole calculated by the FLAC finite difference software according to the command stream; inputting coordinates of arbitrary two vertexes on diagonal lines on the periphery of the hole; and calculating the elasticity coefficient of a hole peripheral structural plane according to the steps above, and outputting a result. The easy input and output of the method provides important basis for underground structure power calculation.

The invention provides a free lossless audio codec (FLAC) finite difference software-based method for generating dynamic elasticity coefficient. On the basis of FLAC finite difference software, the method comprises the following main steps: inputting the number of nodes on the boundary of a hole; generating a command stream file which can be identified by the FLAC finite difference software; calling in the generated command stream file in the FLAC finite difference software; acquiring counter force acted on each node on the boundary of the hole calculated by the FLAC finite difference software according to the command stream; inputting coordinates of arbitrary two vertexes on diagonal lines on the periphery of the hole; and calculating the elasticity coefficient of a hole peripheral structural plane according to the steps above, and outputting a result. The easy input and output of the method provides important basis for underground structure power calculation.

A truck / bus tire has an internal surface covered with an air-seal layer that has an end in a region within 120 mm as measured from a toe tip of a bead portion along a bead base line and is configured of a stack of layers of polymers including a first layer of an elastomer composition containing a SIBS and having a thickness of 0.05-0.6 mm and a second layer of an elastomer composition containing at least one of a SIS and a SIB, having a thickness of 0.01-0.3 mm, and positioned adjacent to a carcass ply. The first and second layers have the elastomer compositions with a dynamic modulus of elasticity (E*) of 2-5 MPa. A pneumatic tire can be provided that includes an air-seal layer having limited variation at an internal surface of the tire for enhanced air permeation resistance and increased rolling resistance.

The invention relates to a Cr-containing high-strength constant expansion alloy. The weight percentage of each component of the alloy is: C≤0.08; Si≤0.40; Mn≤1.0; S≤0.010; P≤0.010; Ni: 35.0~ 38.0; Cr: 0.8-2.5; Nb≤1.0; Co: 0.5-1.5; the balance is Fe. The alloy has high mechanical strength at room temperature and dynamic modulus of elasticity, and is used in precision instruments and equipment with special requirements and other precision instruments and equipment with such requirements.

A carbon fiber composite material comprising 100 parts by mass of an elastomer, and 20 to 100 parts by mass of carbon nanofibers that have been oxidized and reduced in number of branch points. The carbon fiber composite material has a dynamic modulus of elasticity (E′) at 200° C. and 10 Hz of 10 to 1000 MPa, and a volume resistivity of 106 to 1018 ohms·cm.

The invention discloses a concrete prism test block elasticity modulus detecting method based on impact echo. The method comprises the steps that a concrete prism test block is cut into a test piece with the slenderness ratio being larger than or equal to 2; two end faces of the cut test piece are polished to be smooth in the length direction; the dynamic modulus of elasticity of the test piece isdetected by utilizing the impact echo method; and the static modulus of elasticity of the test piece is deduced by utilizing the detected dynamic modulus of elasticity according to a dynamic-static elasticity modulus numerical relationship, and the static modulus of elasticity of the concrete prism test block is obtained. The method can rapidly and accurately detect the existing real-time staticmodulus of elasticity of the concrete prism test block, and avoids a large amount of redundant test block static pressure tests. The method is easy to operate and low in cost, can avoid to purchase test equipment such as large-size pressure testing machines, and can effectively lower the project cost. The used formula can reduce the errors caused by deduction through indirect data.

The invention discloses continuous wood dynamic elastic modulus eccentric pressure roller detection equipment and a method, belonging to the technical field of wood strength grade detection. The invention aims to solve the problem that the detection error exists in the existing wood dynamic elastic modulus detection technology, and the anisotropy of the wood will further enlarge the error value. The frame of the testing equipment is provided with at least six sets of support rollers along its length direction, two sets of main support rollers are located in the middle of the frame, at least four sets of auxiliary support rollers are arranged on both sides of the main support rollers, and the indenter frame is set On the frame, the eccentric roller head is rotatably installed on the frame of the head, and a pneumatic cylinder and a sensor are arranged in the frame. Detection method: Apply a load to the midpoint of the effective length of the wood specimen by a pneumatic cylinder, detect the deformation and load change value, bring it into the elastic modulus, and obtain the elastic modulus value. The invention is used for continuous wood dynamic elastic modulus detection.

The invention relates to a self-positioning dynamic elasticity modulus test apparatus for determining elasticity modulus property of a material in the instrument industry. A purpose of efficiently andaccurately testing the elasticity modulus of the material can be realized. According to the technical scheme, one end of a connecting plate is hinged with the end portion of a fixed plate by virtue of a rotating shaft assembly, and the other end of the connecting plate is hinged with the end portion of an adjusting plate by virtue of a supporting shaft assembly; a constraint bracing wire a, a constraint bracing wire b, the inner side edge of the fixed plate and the inner side edge of the adjusting plate are parallel to one another, a distance from the constraint bracing wire a to the inner side edge of the fixed plate is equal to a distance from the constraint bracing wire b to the inner side edge of the adjusting plate, and the distance from the constraint bracing wire a to the inner side edge of the fixed plate is equal to 0.224 times of the distance from the inner side edge of the fixed plate to the inner side edge of the adjusting plate. By adopting the dynamic test method, the elasticity modulus parameter of a test piece material can be rapidly and accurately determined; and by adopting a parallelogram structure, the positioning of constraint points of different test pieces of different lengths can be rapidly realized, and the efficiency and accuracy can be greatly improved.