106 results about "Tensile strain" patented technology

The invention relates to the technical field of tire processing, in particular to a pattern and rolling resistance simulation evaluation method and system for a rubber engineering tire. The method comprises the following steps: acquiring tire pattern parameters; building a finite element model of tire-road surface contact according to the tire pattern parameters; according to the finite element model, determining deformation distribution, longitudinal tensile strain, grounding pressure distribution and pavement contact rigidity of the tire in the rolling process; and determining a rolling resistance evaluation value according to the deformation distribution, the longitudinal tensile strain, the grounding pressure distribution and the pavement contact rigidity. And rapid parameterization iteration is supported, and modeling errors caused by non-uniform geometric feature description are avoided. And the simulation accuracy and repeatability are ensured. The influence of the pattern structure on the rolling process is reflected, and a foundation is laid for a rolling resistance evaluation value. Quantitative evaluation of the tire rolling resistance is realized, data-driven design optimization is supported, and the simulation efficiency is improved.

The invention belongs to the field of mechanical property testing of metal materials, and relates to a method and a system for detecting tensile strain mark limit, the system applies tensile load to a metal plate sample through a test module, an illumination projection module projects a structured light pattern to the surface of the sample, and an image acquisition module continuously acquires surface images of the sample; and the data processing module is used for carrying out wrapped phase calculation, differential phase calculation, distortion parameter extraction and tensile strain mark initiation judgment on the image sequence, so that accurate positioning at the moment of tensile strain mark initiation and objective and quantitative measurement of the critical strain limit are realized. The method can effectively improve the detection sensitivity and accuracy of the material surface instability characteristics, realizes high-precision judgment at the moment of tensile strain mark initiation, and provides a reliable basis for material performance evaluation and quality control.

The invention discloses a nonvolatile memory device based on CrMoGe2S6 / Ga2O3 heterostructure tensile strain and a construction method, and belongs to the technical field of nonvolatile memory devices. Comprising the following steps: vertically stacking a single layer of Ga2O3 and a single layer of CrMoGe2S6, and constructing two kinds of CrMoGe2S6 / Ga2O3 heterostructures; performing biaxial tensile strain on the CrMoGe2S6 / Ga2O3 heterostructure, calculating a magnetic ground state and an energy band of the CrMoGe2S6 / Ga2O3 heterostructure under different strains, and screening out the CrMoGe2S6 / Ga2O3 heterostructure which is represented as a ferromagnetic state; and on the basis of the screened CrMoGe2S6 / Ga2O3 heterostructures, two CrMoGe2S6 / Ga2O3 heterostructures with the same tensile strain are selected to construct the nonvolatile memory device. Ferroelectric Ga2O3 is introduced to serve as a switch, the electronic property of CrMoGe2S6 is controlled by the polarization state of Ga2O3, the Ga2O3 which is electrically polarized upward P does not change the semiconductor characteristic of CrMoGe2S6, and the Ga2O3 which is electrically polarized downward P enables the CrMoGe2S6 to present semimetallic property; therefore, the non-volatile electric control of the CrMoGe2S6 between the antiferromagnetic semiconductor and the semimetal is indirectly realized; the characteristic is especially important for a memory device, and can significantly reduce energy consumption and improve data stability.

The invention discloses a conjugated polymer film with electrical properties and tensile stability simultaneously improved, and a preparation method and application thereof, and belongs to the technical field of flexible electronic materials. The preparation method comprises the following steps: placing the conjugated polymer film in a solution formed by mixing an electrolyte and a dopant, and soaking for 30-60 seconds to complete ion exchange doping, thereby obtaining the conjugated polymer film with various carrier transport channels. The strategy of increasing the types of carrier transmission channels is adopted, and two main transmission channels of a crystal phase and an accumulation region are formed in the conjugated polymer film through an ion exchange doping method, so that the conjugated polymer film can maintain the electrical property at a high proportion under a stretching external field, and the electrical property of the conjugated polymer film is improved under the same stretching strain. And the tensile stability of the conductivity is far higher than that of a conjugated polymer film which only takes a crystal phase or an accumulation region as a carrier transmission channel.

The invention relates to an engine component fatigue life evaluation method based on a structural simulation part, and belongs to the technical field of simulation data processing, and the method comprises the following steps: building a tensile strain energy life prediction model based on elastic strain energy and plastic strain energy, and predicting the fatigue life of a structural part based on the model; optimizing the design parameters of the simulation part of the engine component, manufacturing the simulation part based on the design parameters, performing a low-cycle fatigue test on the simulation part, and analyzing the fatigue life of the simulation part; comparing the fatigue life of the simulation part with the predicted fatigue life of the structural part, and if the requirements are not met, re-optimizing the design parameters of the simulation part; and if the requirement is met, outputting the fatigue life of the structural member. According to the method, the fatigue life of the simulation part is compared with the predicted fatigue life of the structural part, the model is further improved, a closed-loop research method is formed, the accuracy and efficiency of fatigue life prediction are improved, the limitation of a traditional hysteresis energy method is overcome, and the research cost and period are reduced.

A pressure sensor includes a first wafer having a first deflectable diaphragm and a second deflectable diaphragm. The first deflectable diaphragm has a first relationship between deflection and applied pressure, and the second deflectable diaphragm has a second relationship between deflection and applied pressure. The first relationship and the second relationship are different from each other. The second wafer is attached to the first wafer. At least one tensile strain gauge is coupled to the first deflectable diaphragm and at least one compressive strain gauge is coupled to the second deflectable diaphragm. An overvoltage feature is mounted relative to one of the first wafer and the second wafer. The overpressure feature is configured to contact the other of the first wafer and the second wafer during an overpressure condition exceeding a maximum measured pressure of the first deflectable diaphragm and a maximum measured pressure of the second deflectable diaphragm.

A pressure sensor includes a first wafer having a primary deflectable diaphragm and a secondary deflectable diaphragm. The primary deflectable diaphragm has a first relationship between applied pressure and deflection, and the second deflectable diaphragm has a second relationship between applied pressure and deflection. The first and second relationships differ from one another. A second wafer is attached to the first wafer. At least one tensile strain gauge is coupled to the primary deflectable diaphragm and at least one compressive strain gauge coupled to the secondary deflectable diaphragm. An overpressure feature is mounted relative to one of the first wafer and the second wafer. The overpressure feature is configured to contact the other of the first wafer and second wafer during an overpressure condition that exceeds a maximum measurement pressure of the primary deflectable diaphragm and a maximum measurement pressure of the secondary deflectable diaphragm.

This invention discloses a high-performance wood-plastic composite frame structure for building doors and windows, belonging to the field of building materials technology. The frame structure includes a wood-plastic outer wall and an internal cavity. A continuous support mesh structure composed of an array of topological units is integrally formed within the cavity. The topological units are configured with a tensile geometry exhibiting a negative Poisson's ratio effect, including multiple load-bearing members and connecting nodes. When the wood-plastic outer wall experiences axial expansion tensile strain due to heat, the topological units compensate for this displacement through node rotation and member bending, thereby significantly reducing interfacial shear stress and suppressing the arching deformation of the frame. When external fasteners are subjected to axial pull-out force, the topological units undergo centripetal contraction deformation, enhancing the frictional gripping force on the fasteners. This invention resolves thermal stress through microscopic geometric reconstruction, effectively addressing the shortcomings of poor thermal stability and insufficient nail-holding power in wood-plastic profiles.

This invention discloses a method and equipment for evaluating the tensile toughness of recycled asphalt mixtures, relating to the field of analytical techniques for recycled asphalt mixtures. The method includes: acquiring variables related to the internal structure and external environment of the recycled asphalt mixture to be evaluated; the variables related to the internal structure include: internal structural state variables, the length of the aggregate-binder two-phase interface transition zone, and the elastic modulus; the variables related to the external environment include: tensile strain ratio, loading frequency, and dynamic modulus; and calculating the tensile toughness evaluation value of the cold recycled asphalt mixture based on a predetermined multi-parameter coupling relationship using the variables related to the internal structure and the external environment. This invention introduces environmental factors and internal structural parameters of the recycled asphalt mixture to establish a multi-parameter tensile toughness evaluation model, fully considering the material composition, microstructural distribution characteristics, load factors, and ambient temperature of the recycled asphalt mixture under stress in the structural layer, enabling accurate evaluation of the tensile toughness of the recycled asphalt mixture.

The application discloses a preparation method of a silica gel-based rigid-flexible coupling pneumatic soft body finger, which comprises the following steps: firstly, preparing a silica gel gas distribution base layer and a silica gel pneumatic expansion joint structure; then, bonding the silica gel gas distribution base layer, the silica gel pneumatic expansion joint structure and a rigid framework into a semi-finished product pneumatic soft body finger; placing the semi-finished product pneumatic soft body finger into a pneumatic soft body finger mold, and placing a flexible tensile strain sensor on the palm of the semi-finished product pneumatic soft body finger, and placing the electric signal lead wire of the flexible tensile strain sensor outside the pneumatic soft body finger mold; finally, injecting silica gel into the pneumatic soft body finger mold to coat the semi-finished product pneumatic soft body finger and the flexible tensile strain sensor into an integral whole by using the silica gel.

The application provides a driving rope and mechanical hand system with force sensing capability, and belongs to the technical field of bionic mechanical hands. The system is composed of a tensile strain sensor and a driving rope. The tensile strain sensor is arranged on the surface of the driving rope and is bonded with the front section by using a flexible adhesive to be arranged in a mechanical hand. The tensile strain sensor and the driving rope are separated at the rear section. The separated driving rope is used for connecting a motor, and the tensile strain sensor is used for connecting a control system. In this way, the tensile strain of the driving rope can be measured in real time while power is transmitted, and the gripping force of a mechanical finger is obtained, so that the "sensing and driving integration" mode of a bionic tendon is realized.

The application relates to the field of household decorative plate industrial production, in particular to a composite method, device, system, equipment and medium for an asymmetric aluminum sandwich plate, which comprises the following steps: determining a loading proportionality coefficient between a first aluminum roll and a second aluminum roll according to a first thickness corresponding to the first aluminum roll and a second thickness corresponding to the second aluminum roll; the loading proportionality coefficient is used for representing a ratio relationship of the required tensile force of the first aluminum roll and the second aluminum roll under the condition of applying the same transverse displacement; calculating a target tensile force corresponding to the other aluminum roll according to a first preset tensile force corresponding to any aluminum roll and the loading proportionality coefficient, and then compositing the two first aluminum rolls and the second aluminum roll according to the corresponding tensile forces to obtain the asymmetric aluminum sandwich plate. According to the application, the tensile forces of the two aluminum rolls with different thicknesses can be determined before the composition, so that the two aluminum rolls have the same tensile strain, and the symmetric aluminum sandwich plate without the stress warping problem can be obtained through the composition.

The invention discloses a negative Poisson's ratio effect energy harvesting device and method suitable for a road structure, and belongs to the technical field of road vibration energy harvesting. The device comprises a substrate with a negative Poisson's ratio structure, piezoelectric ceramic covering and fixed on the substrate, and an excitation rod arranged on the surface of the piezoelectric ceramic. The negative Poisson's ratio structure is formed by periodically arranging a plurality of inwards-concave annular unit cells, and when the negative Poisson's ratio structure is subjected to the action of pressure stress such as traffic load, unique two-way expansion deformation can be generated, so that vertical pressure is efficiently converted into two-way tensile strain in a plane, and the two-way tensile strain is transmitted to piezoelectric ceramics. According to the structure, a traditional d31 working mode is reserved, a d32 mode is more effectively excited, the charge migration path is remarkably widened, and the electro-mechanical conversion efficiency is improved. The device is especially suitable for a low-frequency traffic load environment, solves the problem of low energy collection efficiency caused by resonant frequency mismatch of a traditional cantilever beam structure, and provides an efficient and reliable solution for self-power supply of road infrastructures.

The invention discloses a steel-UHPC (Ultra High Performance Concrete) composite beam and a design system for fine deflection control of the steel-UHPC composite beam. The system comprises a set of complete design method and a composite beam structure optimized for realizing the method. The core of the design system is to provide a dual design methodology: 1, the method is a high-fidelity refined design method based on a UHPC nonlinear stretching constitutive relation; according to the method, the residual tension contribution in the tension area is accurately quantified, and the problem of underestimated rigidity caused by neglecting the contribution in the traditional theory is solved. And secondly, the method is a simplified design method which is based on a traditional conversion section method and is calibrated. According to the simplification method, a creative convenient design tool capable of quickly determining the initial size of the structure is provided for engineers. According to the method, the structural performance is remarkably improved, on the premise that the standard deflection requirement is met, the beam body height can be greatly reduced, the structural dead weight is reduced, and the economic and technical advantages which cannot be achieved through a traditional method are obtained.

The invention relates to a bending test method for an asphalt mixture composite board. The bending test method comprises the following steps: preparing an asphalt mixture composite board test piece; carrying out heat preservation on the asphalt mixture composite board test piece; placing the asphalt mixture composite board test piece subjected to heat preservation on a clamp, vertically and downwards loading the asphalt mixture composite board test piece at a constant speed, and collecting pressure load and midspan displacement when the test piece is damaged; and calculating the flexural tensile strength, the maximum flexural tensile strain and the bending stiffness modulus. The invention provides a special low-temperature crack resistance test method for a multi-layer asphalt mixture structure.

A pressure sensor (200) includes a first wafer (202) having a primary deflectable diaphragm (208) and a secondary deflectable diaphragm (210). The primary deflectable diaphragm (208) has a first relationship between applied pressure and deflection, and the second deflectable diaphragm (210) has a second relationship between applied pressure and deflection. The first and second relationships differ from one another. A second wafer (204) is attached to the first wafer (202). At least one tensile strain gauge (214, 216) is coupled to the primary deflectable diaphragm (208) and at least one compressive strain gauge (218, 220) is coupled to the secondary deflectable diaphragm (210). An overpressure feature (222) is mounted relative to one of the first wafer (202) and the second wafer (204). The overpressure feature (222) is configured to contact the other of the first wafer (202) and second wafer (204) during an overpressure condition that exceeds a maximum measurement pressure of the primary deflectable diaphragm (208) and a maximum measurement pressure of the secondary deflectable diaphragm (210).

This invention discloses a method for controlling welding hot cracks with bilateral symmetrical thermal strain assistance. The method includes preparation before welding and welding. In the welding step, the temperature generated by the two induction coils is stabilized at 302±5℃ before welding begins. During welding, the welding heat source and the two induction coils move synchronously and uniformly from back to front, so that the thermal strain generated by the two induction coils continuously heats the workpieces to be welded on both sides of the weld within the brittle temperature range behind the molten pool until welding is completed. In this way, the thermal strain generated by the two induction coils continuously heats the corresponding workpieces to be welded on both sides of the weld within the brittle temperature range behind the molten pool. The thermal expansion of the workpieces generates a transverse compressive strain pointing towards the weld center in the weld metal within the brittle temperature range (BTR zone) behind the molten pool, thus counteracting the crack-inducing tensile strain generated in the brittle temperature range during welding, thereby effectively controlling the generation of hot cracks.

Provided is a grain-oriented magnetic steel sheet having both low iron loss and low magnetostriction. The grain-oriented magnetic steel sheet has a heat-strained region extending in a direction transverse to a rolling direction, and has closed magnetic domains in the heat-strained region. The heat-strained region has maximum points of tensile strain on both sides of the closed magnetic domains in the rolling direction. In a strain distribution in the rolling direction of the heat-strained region, the strain on both sides of the closed magnetic domains is a tensile strain greater than the strain at the center between the maximum points.

The utility model relates to a clamping test fixture assembly applied to a limit flexural-tensile strain test, and relates to the field of concrete performance detection.The clamping test fixture assembly comprises a clamping bottom frame and a test pressure head, the clamping bottom frame comprises a mounting base and two supporting pieces, and an adjusting sliding groove is formed in the top face of the mounting base in the length direction; adjusting sliding blocks in one-to-one correspondence with the supporting pieces are installed in the adjusting sliding grooves in a sliding mode, adjusting inserting blocks are arranged at the tops of the adjusting sliding blocks, and adjusting inserting grooves allowing the adjusting inserting blocks to be inserted therein are formed in the bottoms of the supporting pieces. The mounting base is further provided with an adjusting mechanism for adjusting the distance between the two adjusting sliding blocks. The supporting device has the effect that the position of the supporting piece on the supporting bottom plate can be conveniently adjusted.

The steel sheet has a TS of 1180 MPa or more and less than 1470 MPa, and has high YS, excellent ductility, excellent press formability of the inside and the ends of the steel sheet, and high crack propagation resistance. A base steel sheet has a predetermined component composition, the Vickers hardness of the base steel sheet is 84% or less with respect to a position 1 / 4 of the sheet thickness from the surface of the base steel sheet, the base steel sheet has a surface soft layer satisfying the following formula (1), the structure in the surface soft layer is within a specific range, and the structure in the position 1 / 4 of the sheet thickness of the base steel sheet is within a specific range. In a 90-degree V bending test having a bending radius of 0.5 mm, the length of a crack progressing in the ridge direction from the end of a bent ridge is 200 [mu] m or less, the El when subjected to a notch tensile test after being subjected to a heat treatment at 170 DEG C for 20 minutes is 6.0% or more, and the El when subjected to a notch tensile test after being subjected to a heat treatment at 170 DEG C for 20 minutes by introducing a 2% tensile nominal strain and then being subjected to a heat treatment at 170 DEG C is 5.0% or more. (1) 20 < = X < = 120-3800 * [Sb]-1900 * [Sn].

The application provides a helicopter landing gear landing load measurement method, the method comprises the following steps: pasting at least 10 strain gauges at the wheel shaft position; obtaining the tensile strain, shear strain, bending strain and torsional strain of the strain gauges; determining the heading load, lateral load and / or vertical load when the helicopter landing gear lands based on the tensile strain, shear strain, bending strain and torsional strain of the strain gauges; the application realizes the analysis and calculation of the transmission of the three-directional ground loads to the landing gear wheel shaft during the landing of the helicopter, the reverse derivation process of strain to load is supplemented by the forward derivation of traditional load to strain, the interference of the nonlinear superposition of combined loads on the solution of ground load calculation is eliminated, the position requirement that the strain gauge layout needs to meet the unidirectional load sensitivity is reduced, and good universality is achieved.

The invention relates to the field of road engineering, in particular to an in-service asphalt pavement thin overlay residual bearing capacity evaluation method and system based on a conversion coefficient and a storage medium, and the method comprises the steps: obtaining the accumulated axle load action frequency at the traffic lane wheel track of an asphalt pavement; the modulus of each structural layer of the asphalt pavement is obtained through FWD inversion; according to the modulus of each structural layer, constructing a mechanical analysis model through a finite element method to obtain the maximum tensile strain of the overlay; acquiring the maximum stress of the finishing coat according to the maximum tensile strain of the finishing coat; performing an indoor splitting fatigue test by adopting the coring test piece to obtain a fatigue life prediction equation of the overlay; obtaining a conversion coefficient according to the overlay fatigue life prediction equation; and obtaining the residual bearing capacity of the thin overlay according to the maximum stress of the overlay and the conversion coefficient. According to the embodiment of the invention, scientific evaluation and accurate prediction of the residual bearing capacity of the thin overlay of the in-service asphalt pavement are realized through a method of fusing the field measured data and the conversion coefficient of the indoor model.

The application discloses a kind of based on boronene and its strain regulation and control broadband terahertz wave absorber and its design method, the designed wave absorber includes metal bottom plate and dielectric substrate silicon, sheet boronene is arranged on the surface of silicon lining, and thin dielectric layer silicon is arranged above boronene.The optical conductivity of boronene in terahertz frequency band is calculated by first principle, and then through design and simulation by finite-difference time-domain method, a broadband terahertz wave absorber is obtained.The boronene based on different uniaxial tensile strain is calculated, the designed wave absorber under different polarization directions, the working bandwidth of wave absorber is widened or reduced respectively, the wave absorber changes from isotropic to anisotropic, solves the problem that existing broadband terahertz wave absorber is difficult to actively control, simultaneously expands the terahertz working bandwidth of wave absorber, realizes the characteristics of active control in broadband terahertz wave absorption work.

This application discloses a design and construction method for a sealing system of an underground artificial cavern for compressed air energy storage, relating to the field of computer-aided architectural design. The technical solution includes: obtaining cavern engineering design parameters; establishing a numerical model to simulate the inflation condition and obtain the maximum tensile strain of the reinforced concrete lining; determining the selection of carbon fiber fabric based on strain compatibility conditions; calculating the load sharing of each structure and the circumferential stress of the carbon fiber composite layer based on the theory of multi-layer thick-walled cylinders; calculating the conditions under different combinations of surrounding rock conditions and thicknesses to form a circumferential stress dataset, which is then analyzed and classified using a clustering algorithm; finally, determining the thickness and number of carbon fiber composite layers from the classification based on the actual surrounding rock conditions. This application achieves digitalization, precision, and intelligence in sealing layer design, ensuring optimal structural safety and economy from the source.

The invention discloses a boron arsenide indirect-direct band gap transformation method based on deep strain regulation and application, the boron arsenide indirect-direct band gap transformation method based on deep strain regulation is characterized by comprising the following steps: S1, applying uniaxial tensile strain to a boron arsenide crystal; s2, directional transformation of boron arsenide from an indirect band gap to a direct band gap is achieved by controlling the strain direction, the strain range and the relaxation condition after strain loading, the uniaxial tensile strain is applied in the [111] crystal orientation of boron arsenide crystals, the tensile strain is controlled within the elastic limit range, and the tensile strain is applied in the [111] crystal orientation of the boron arsenide crystals; the band gap type transformation is completed when the tensile strain reaches the critical transformation strain, indirect-direct band gap transformation can be completed only by applying 0.12 tensile strain in the [111] direction, the transformation condition is clear and controllable, and the photoelectron transition efficiency is greatly improved.

The application discloses a kind of ceramic matrix composite temperature-related mechanical properties inversion method, specifically related to the field of composite material performance characterization.It includes: the ceramic matrix composite to be measured is divided into multiple test pieces;Each test piece is heated to target temperature, and the measured thermal strain of multiple points on the surface of each test piece is obtained;For each test piece, at its target temperature, the test piece is uniaxially stretched by loading end, and the measured tensile strain of multiple points on the surface of the test piece during uniaxial stretching, the measured stress-strain curve is obtained;A parameterized function of the mechanical property parameter vector of the ceramic matrix composite to be measured changes with temperature is constructed, to minimize the error function as the goal, the hyperparameter vector is inverted and identified, to obtain the optimal hyperparameter vector, and the mechanical property parameter vector of the ceramic matrix composite to be measured is obtained in combination with the parameterized function.Based on the above method, the mechanical property parameters of microscale component materials can be obtained.

The invention discloses a strain simulation method and a board card, and relates to the technical field of computers, in the method, when strain simulation is carried out on the board card, the maximum tensile strain of each sub-region of a board card model is searched based on the tensile strain distribution of the last frame of multiple analysis steps, and a maximum tensile strain cloud picture is constructed based on the maximum tensile strain; and based on the compressive strain distribution of the last frame of the plurality of analysis steps, searching for the minimum compressive strain of each sub-region of the board card model, and based on the minimum compressive strain, constructing a minimum compressive strain cloud picture. Compared with strain nephograms obtained by superposing a plurality of analysis steps in some technologies, the total strain nephogram obtained by superposing the maximum tensile strain nephogram and the minimum compressive strain nephogram achieves similar effects. And under the condition of similar effects, only two cloud pictures need to be superposed, so that the superposition times of the strain cloud pictures can be greatly reduced, and the simulation efficiency can be further improved.

The invention discloses a liquid metal fiber stretchable strain sensor and a preparation method and application thereof, and relates to the technical field of stretchable strain sensors. A coaxial layered structure of an elastic fiber core, a PDA adhesion layer, an Ag seed layer, a Cu functional layer, a liquid metal (LM) conductive layer, an SEBS packaging layer and an inert electrode interface (MWCNT / SEBS-PEDOT: PSS) is adopted, and a liquid metal material is combined with a composite fiber structure, so that the electrical property stability and the response speed of the sensor in a high strain state can be remarkably improved; meanwhile, the chemical stability of the sensor in a wet, ion-containing or biological fluid environment is ensured, long-time stable work is ensured, and the wearable biological monitoring requirement is met. The structure of the sensor is optimized, the sensor can be better attached to the skin or soft tissue, the wearing comfort is enhanced, the stability of sensing signals is guaranteed, and the problems that an existing sensor is prone to falling off and poor in air permeability are solved.

This invention discloses a method for monitoring shear cracks in reinforced concrete beams based on digital image technology, comprising the following steps: Step 1, acquiring a surface image of a reinforced concrete beam specimen and using the DIC digital image detection method to obtain the principal tensile strain across the entire field in the reinforced concrete beam specimen; Step 2, generating a crack skeleton line corresponding to the crack based on the principal tensile strain across the entire field; Step 3, setting multiple sets of crack measurement reference points on both sides of the crack skeleton line and calculating the motion vector of the cracked area on both sides of each set of crack measurement reference points; Step 4, generating the overall motion of the corresponding crack based on the motion vectors of the multiple sets of crack measurement reference points and outputting the corresponding motion vector result image based on the motion. This invention also provides a device for monitoring shear cracks in reinforced concrete beams. The method provided by this invention can effectively assess the safety and residual life of concrete structures.

To produce a polystyrene-based resin extruded foam plate in which shrinkage after production is suppressed even when the density is low.SOLUTION: A method for producing an extruded polystyrene foam board having an apparent density of 10kg / m3 or more and 40kg / m3 or less and a volume 20000cm3 or more, the method comprising the step of extruding and foaming a foamable melt obtained by melt-kneading a polystyrene resin-containing base material and a physical blowing agent, and forming the foamable melt into a board shape with a forming tool, wherein the polystyrene resin component has a stress-relaxation time τ of 100 seconds or more as measured by the following tensile stress-relaxation test (I): Tensile stress relaxation test (I) In accordance with JISK7127:1999, when a 20% tensile strain is applied to a 0. 4-mm-thick dumbbell-shaped test piece type 5 made of polystyrene resin at a tensile speed of 50m / min in an atmosphere of 80 °C, and the tensile strain is maintained for 4 minutes from the point in time at which the 20% tensile strain is applied, the initial stress at the point in time at which the 20% tensile strain is applied is set as a reference value, and the time required until the stress reaches one tenth of the reference value is set as a stress relaxation time τ.SELECTED DRAWING: None