113 results about "Strain stiffening" patented technology

The invention belongs to the technical field of metal part surface modification, and relates to a composite strengthening method for a carburized surface of a high-bearing gear of an aero-engine. According to the method, high-hardness and high-density ceramic shots are adopted as media for high-energy mechanical shot peening strengthening, the advantage that the subsurface strain hardening effect of the contact strengthening technology is good and the barb-shaped distribution characteristic of mechanical shot peening residual compressive stress are utilized, extremely high residual compressive stress is introduced to the subsurface position, and the contact fatigue performance of the tooth surface of the gear is improved. High-frequency laser shot peening strengthening is used for secondary treatment, so that the surface layer of the material is subjected to plastic deformation, high-amplitude residual compressive stress is introduced into the surface layer of the material within the depth range of more than 500 microns by utilizing the advantage of large influence depth of laser-induced shock waves, and the residual compressive stress can inhibit fatigue crack initiation, has a certain depth and inhibits fatigue crack propagation; and the bending fatigue resistance of the root of the gear can be effectively improved. And an abrasive flow process is adopted, so that the roughness is reduced to be more than 0.4 mu m.

The present invention relates to the technical field of concrete. Disclosed is a toughening design method for fiber-reinforced concrete. The method of the present invention changes the passive control characteristics of fibers on a concrete crack propagation process in conventional fiber-reinforced concrete. Starting from the origin of composite material design, firstly, an ultrahigh-ductility composite cementitious matrix is designed; and secondly, an aggregate is incorporated. On the basis of a specific combination of matrix and aggregate parameters, a composite material develops meso-scale multiple cracking and strain-hardening behaviors between aggregate particles during external loading. The fiber-reinforced concrete prepared by this method actively disperses brittle damage and failure within the material, and avoids unstable crack propagation caused by weak interfacial bonding between the aggregate and the matrix. Compared to conventional fiber-reinforced concrete design methods, the present invention more accurately establishes relationships between material compositions, microstructures and macroscopic mechanical response, and more efficiently enhances the toughness of the material.

The invention discloses a foundation pit excavation and support cooperative control method based on finite element dynamic feedback, which comprises the following steps: S1, establishing a foundation pit support finite element model, defining constitutive parameters of a soil body small strain hardened soil model HSS and support structure rigidity, and obtaining an initial displacement field and a stress field through step-by-step excavation simulation; and S2, iteratively calibrating parameters based on the simulation result and the field monitoring data, and constructing a construction stage dynamic adjustment threshold library which comprises a displacement warning value (UXmax), a stress safety coefficient (SF is greater than or equal to 1.3) and a support activation time sequence. According to the method, dynamic parameter iteration is achieved, a finite element model is reversely optimized through monitoring data, and the parameter solidification problem of a traditional method is solved; automatic closed-loop control is achieved, manual intervention is reduced, and the response speed is increased to the minute level; and economical efficiency is improved, waste of materials such as steel is reduced through accurate control, and the comprehensive cost is reduced by 15%-25%.

The invention discloses a cold heading forming method for an oil cylinder for a progressive gas spring by upsetting firstly and then gradually extending. The cold heading forming method comprises the following steps: (1) preparing and shaping raw materials; (2) upsetting; (3) indenting; 4) backward extrusion stretching; (5) thin-wall reducing extension one-time forming is carried out; and (6) thin-wall reducing extension secondary forming is carried out. In combination with the characteristics of small overall size, large length-diameter ratio and thin wall and batch production of the oil cylinder for the gas spring, a part with a complex structure is divided into a plurality of simple stations by adopting a method of upsetting first and then gradual extension, and through a process of upsetting, combined extrusion and multi-step diameter-reducing stretching, the length-diameter ratio of the oil cylinder for the gas spring is greatly reduced. And a reducing amount distribution formula based on a strain hardening index and a flow stress model is introduced, so that gradual reduction of the inner and outer diameters of the cylinder body and wall thickness homogenization control are realized. According to the method, on one hand, the product wall thickness uniformity is improved, and the local wall thickness abnormity condition is avoided; and on the other hand, due to the fact that the five-station progressive one-time forming technology is adopted, the auxiliary clamping time is greatly shortened, and therefore the forming efficiency is improved.

The invention provides a method for calculating a flexural capacity characteristic value of a steel and UHPC (Ultra High Performance Concrete) composite structural beam. Different constitutive models are adopted according to performance characteristics of UHPC, a T-shaped steel beam and a steel bar in the composite structural beam, and the contribution of material strain hardening performance to the flexural capacity is fully considered; compared with an ideal elastic-plastic model, the real performance of the structure can be better obtained; meanwhile, the cross section curvature, the curvature iterative calculation increment and the neutral axis position iterative calculation increment are given for initial values of conventional bridge calculation, and the neutral axis position and the cross section curvature are searched by adopting an influence coefficient method, so that the search speed is increased, and the problem that convergence cannot be realized due to manual setting of the iterative increment is solved; and finally, the condition that the UHPC top strain reaches the UHPC compression limit strain or the T-shaped steel beam bottom strain reaches the steel limit strain is taken as a judgment condition, and two damage modes of UHPC crushing and the condition that the steel reaches the tensile ultimate strength can be considered at the same time.

The invention discloses a model construction method considering the strain hardening and softening characteristics of a rib-soil interface, and the method comprises the steps: setting normal stress as a single variable, and obtaining a plurality of shear stress-shear displacement curves under different normal stress levels of a to-be-tested soil sample through a pull-out test; a model is established according to the influence rule of normal stress on the characteristics of the rib-soil interface and the change characteristics of the interface shear stress in the shearing process. According to the model considering the strain hardening and softening characteristics of the reinforcement-soil interface, the characteristics of the reinforcement-soil interface in different stress states can be predicted more accurately, the efficiency is high, and the cost is low.

The invention belongs to the technical field of optimization design of concrete materials, and particularly relates to a multi-objective optimization method of a strain hardening alkali-activated concrete material, which comprises the following steps: selecting an experimental material, setting a plurality of alkali-activated mortar mixing ratios, and predicting the performance of alkali-activated mortar based on a response surface method; performing parameter analysis based on the response curved surface model, and constructing a response index prediction model; based on the response index prediction model, defining basic parameters; the response indexes are considered, alkali-activated mortar multi-objective optimization is carried out through an NSGA-II algorithm, and a Pareto leading edge is obtained; determining an optimal compromise solution set based on a Pareto leading edge; based on the optimal compromise solution set, determining the objective weight of each response index by adopting an entropy weight method; based on the determined objective weight of each response index, performing multi-target evaluation on the alkali-activated mortar mix proportion in the optimal compromise solution set by adopting an ideal approximation algorithm to obtain an optimized alkali-activated mortar mix proportion; and the performance optimization of the strain hardening alkali-activated concrete material is indirectly realized.

The invention relates to ultra-low carbon steel, a preparation method thereof and a steel product. The preparation method of the ultra-low carbon steel comprises the following steps: providing a casting blank; sequentially heating and hot-rolling the casting blank to obtain hot rolled steel; the hot rolling comprises rough rolling and finish rolling which are sequentially carried out, the initial rolling temperature of the rough rolling is 990-1040 DEG C, and the outlet temperature of the rough rolling is 900-940 DEG C; the initial rolling temperature of finish rolling ranges from 840 DEG C to 890 DEG C, and the final rolling temperature of finish rolling ranges from 750 DEG C to 830 DEG C; and the hot rolled steel is sequentially subjected to acid pickling, cold rolling and annealing. According to the preparation method, ferrite area low-temperature rolling is adopted, the heating energy consumption is remarkably reduced, the production efficiency is improved, the problem of scale thickening caused by traditional high-temperature rolling is avoided, the surface quality of the strip steel is more uniform, and the pickling cost is greatly reduced. Meanwhile, the ductility, the strain hardening index (n value) and the plastic strain ratio (r value) of the obtained finished product are remarkably improved, and the forming performance is excellent.

The present invention belongs to the field of manufacturing engineering / digital information, and provides a method for acquiring circumferential mechanical property parameters of a pipe material. In order to obtain a more accurate and comprehensive description of a strain hardening behavior of a material, it is required to use a true stress-strain curve, such that the present invention uses a flexible tensile test fixture to perform a tensile test on a circumferential tensile pipe material sample. The tensile test process comprises: using a non-contact video extensometer and a universal tensile testing machine to obtain tensile measurement data of the pipe material; then preprocessing the tensile measurement data of the pipe material; using the preprocessed data for calculating true stress-true strain data of the circumferential tensile pipe material sample; and setting initial and end strains of a plastic section, and using a linear regression fitting method for calculating a strength coefficient and a strain hardening exponent in the plastic section. The strength coefficient and the strain hardening exponent in the plastic section and the true stress-true strain data of the circumferential tensile sample are used for finite element analysis of pipe systems.

The invention belongs to the technical field of mechanical metamaterials, and particularly discloses an energy-absorbing three-dimensional metamaterial with interactive combination of positive and negative Poisson's ratio structures, which comprises a plurality of microcosmic unit structures, each microcosmic unit structure comprises a reverse four-chiral auxetic structure and a bionic diagonal bracing structure, and the reverse four-chiral auxetic structures and the bionic diagonal bracing structures are arranged in an interactive combination manner. According to the technical scheme, the microscopic unit structures are three-dimensional structures and are simple in structure, the lattice metamaterial obtained by combining the microscopic unit structures has good isotropic characteristics and has three-stage strain hardening characteristics under the compression effect, the plastic deformation capacity is enhanced, the energy absorption capacity of the structures is effectively improved, and the energy absorption efficiency of the structures is improved. And the bearing capacity is relatively high. The structure size of the metamaterial can be flexibly adjusted according to an actual scene, and the metamaterial can be used as a part or a structural member to be flexibly applied to different fields.

The invention discloses a numerical simulation analysis method for a near-river ultra-deep foundation pit under the action of seepage flow, and the method comprises the following steps: S1, constructing a three-dimensional numerical model based on finite element software PLAXIS 3D, and constructing a non-uniform stratum model in combination with a Borehole module; s2, fine modeling is conducted through the underground diaphragm wall, the reinforced concrete supports and the latticed columns; s3, simulating a small strain hardening characteristic and a rigidity attenuation effect of the soil body by adopting an HSS model; s4, simulating underground water flow by combining plastic steady-state seepage analysis, and simplifying the three-axis cement mixing pile into an underground diaphragm wall structure through an equivalent stiffness principle; and S5, step-by-step excavation and support sequential control construction procedures are adopted, and finally, the reliability of the model is verified by comparing a horizontal displacement simulation result of the diaphragm wall with field monitoring data. According to the method, the foundation pit deformation rule is predicted through HSS constitutive model and seepage coupling analysis, and the foundation pit deformation prediction precision is remarkably improved.

A composite copper-based current collector and a preparation method therefor, and a lithium ion battery, relating to the technical field of battery materials. The composite copper-based current collector comprises: a polymer substrate film; and a modified copper layer arranged on at least one surface of the polymer substrate film, wherein the modified copper layer comprises a C-Cu heterogeneous microstructure with dispersed carbon quantum dots. Carbon quantum dots are introduced, and the carbon quantum dots are uniformly dispersed in copper grains and at copper grain boundaries, thereby forming the C-Cu heterogeneous microstructure with dispersed carbon quantum dots; the presence of the carbon quantum dots can exert resistance to grain coarsening, thereby inhibiting grain coarsening and promoting grain refinement, improving the tensile strength of the composite copper-based current collector; the C-Cu heterogeneous microstructure can enhance dislocation storage capacity and strengthen strain hardening, thereby improving the elongation at break of the composite copper-based current collector; and improvements of the tensile strength and the elongation at break jointly enhance mechanical properties of the current collector, and improve the stability of the current collector in the battery.

The invention provides a material constitutive parameter inversion method which can be applied to the technical field of artificial intelligence. The material constitutive parameter inversion method comprises the following steps: acquiring an elastic modulus and an actually measured load depth curve of a to-be-tested material in a single nanoindentation test; performing extrapolation translation preprocessing on the actually measured load depth curve to obtain an equivalent ideal curve; carrying out characterization processing on the equivalent ideal curve to extract input characteristic parameters which comprise press-in rigidity, unloading rigidity and plastic work proportion; the indentation rigidity, the unloading rigidity, the plastic work ratio and the elastic modulus are input into a pre-trained indentation constitutive mapping model to predict the yield strength and the strain hardening index of the to-be-tested material, and the indentation constitutive mapping model is a full-connection back-propagation neural network pre-trained through a finite element virtual test sample. The invention further provides a material constitutive parameter inversion system and device, a storage medium and a program product.

The invention relates to an electric arc additive mixed end plate connecting device and a performance prediction method, and the method comprises the steps: manufacturing a WAAM end plate at the end part of a conventional steel pipe through multi-axis metal 3D printing, and forming a mixed connecting piece; the two mixed connecting pieces are in butt joint through high-strength bolts to form the mixed end plate connecting device; geometric characteristic parameters of the mixed end plate connecting device are obtained by adopting a three-dimensional scanning technology, and the mechanical response of the mixed end plate connecting device is measured by combining a four-point bending test with a digital image correlation technology; and on the basis of the geometrical characteristic parameters and the mechanical response data, the yield bearing capacity is predicted through a correction yield line analysis method, and the ultimate bearing capacity is predicted by adopting an equivalent beam model considering the strain hardening effect. The device and the method have the beneficial effects that geometric characteristic measurement, interface connection characteristic and yield performance test, bearing prediction evaluation and application design of the mixed end plate connecting device combining the electric arc additive manufacturing stainless steel, low-carbon steel and high-strength steel end plates with the conventional steel pipe can be effectively realized.

A method for toughening of fiber-reinforced concrete in the field of concrete technologies is disclosed. The method comprises (1) design of mortar matrix; (2) design of ductile composite mortar with strain-hardening characteristic; (3) iterative design between the ductile composite mortar and aggregate; and (4) load-carrying capacity verification and optimization. In the process of external loading, mesoscale multiple cracking and strain-hardening behaviors are developed in the interstitial matrix between adjacent aggregate particles.

The invention discloses a production method of a 590MPa-grade zinc-aluminum-magnesium-plated dual-phase steel strip for an automobile structure. The production method comprises a smelting-continuous casting production process flow, a hot rolling production technological process; pickling and cold rolling; (4) continuous hot galvanizing and finishing process flow; the steel comprises the following chemical components in percentage by mass: 0.075%-0.120% of C, 0.15%-0.35% of S i, 1.85%-2.2% of Mn, less than or equal to 0.040% of P, less than or equal to 0.015% of S, 0.010%-0.060% of Al t, 0.15%-0.30% of Cr, 0.0008%-0.0025% of Ca and the balance of Fe and impurities. The 590MPa-grade zinc-aluminum-magnesium-plated dual-phase steel strip for the automobile structure has the characteristics of high strength, high strain hardening index, good strength and ductility matching, high corrosion resistance and the like, and meets the requirements of lightweight material selection of automobiles and differentiated application of users.

The invention discloses a high-performance dielectric elastomer film, a driver capable of being driven at low voltage and a preparation method of the driver. According to the preparation method of the high-performance dielectric elastomer film, customization and balance of mechanical properties and electrical properties of a dielectric elastomer are realized by regulating and controlling the proportion of a chemical cross-linking agent, a high-polarity physical cross-linking agent and a monomer; according to the preparation method of the driver capable of being driven at the low voltage, a dielectric elastomer film and a flexible electrode are stacked through an optimized dry stacking method, the dielectric elastomer driver of a multilayer structure is constructed, and the driver has excellent performance under the low driving voltage. The preparation method has the potential of large-batch and large-scale production, and the prepared dielectric elastomer film has low Young modulus and enhanced strain hardening effect, can avoid electromechanical coupling instability, has high dielectric constant, has large-area strain in a low electric field, and can be used for preparing a dielectric elastomer film. The resulting dielectric elastomer driver can have a blocking force of 0.8 N and an energy density of 80 J / kg at a voltage of 500 V.

The invention belongs to the field of automobile steel manufacturing, and particularly relates to 400 MPa-grade high-strength cold-rolled automobile inner and outer plate steel based on an ultra-fast heating and continuous annealing technology and a preparation method of the 400 MPa-grade high-strength cold-rolled automobile inner and outer plate steel. The steel comprises the following chemical components in percentage by mass: 0.003%-0.008% of C, 0.3%-0.7% of Mn, 0.01%-0.08% of Si, 0.02%-0.06% of Ti, less than or equal to 0.03% of P, less than or equal to 0.002% of N, less than or equal to 0.005% of S and the balance of Fe and inevitable impurities. The yield strength of the steel plate is 240-320 MPa, the tensile strength is 400 MPa or more, the percentage elongation after fracture A80 is 36% or more, the plastic strain ratio r is 2.0 or more, and the strain hardening index n is 0.2 or more.

The present application relates to the technical field of ultra-high performance concrete, and particularly relates to a light sand modified ultra-high strain hardening ultra-high performance concrete. The light sand modified ultra-high strain hardening ultra-high performance concrete comprises the following raw materials in parts by mass: cementitious material 55-65 parts, fine aggregate 0-48 parts, light sand 0-5 parts, steel fiber 6-10 parts, and water 10 parts; the volume ratio of the fine aggregate to the light sand is 0-18:18-0, and the sum of the volume of the fine aggregate and the volume of the light sand is always the same. The present application improves the strain hardening grade of UHPC to more than 1.5 times, thereby obtaining an ultra-high strain hardening UHPC, which has a stronger crack width control ability compared with the traditional strain hardening type UHPC, and is particularly suitable for UHPC structure application in marine environment.

The application provides a battery device and a power utilization device. The battery device comprises a box body, a battery monomer and a protection plate. The battery monomer is contained in the box body, and the protection plate is connected to the box body. The protection plate comprises a first fiber resin layer and a reinforcing plate. The first fiber resin layer is arranged on at least one side of the reinforcing plate along the thickness direction. The elongation after fracture e1 of the reinforcing plate is greater than or equal to 28%, and the strain hardening index N of the reinforcing plate is greater than or equal to 0.27. The battery device provided by the application is beneficial to reducing the risk of deformation of the protection plate and the risk of fracture of the protection plate.

The invention relates to the field of UHPC material constitutive model calculation, in particular to a UHPC uniaxial stretching constitutive model calculation method based on the fiber mixing amount and orientation, and the method comprises the following steps: S1, constructing a three-dimensional mesoscopic numerical model of UHPC; s2, performing uniaxial tensile simulation on the sample by using the three-dimensional mesoscopic numerical model to obtain a stress-strain curve data set of the sample; s3, dividing the application range of the constitutive model according to the stress-strain curve data set; and S4, based on the volume fraction of the steel fibers in the UHPC and the orientation angle of the steel fibers, a constitutive model is constructed, and the constructed constitutive model is a strain hardening type constitutive model or a strain softening type constitutive model or a displacement softening type constitutive model. According to the method, the UHPC uniaxial tensile constitutive model considering the steel fiber mixing amount and orientation is constructed, the calculation precision of the UHPC tensile strength is effectively improved, and the problem that an existing UHPC tensile constitutive model is insufficient in precision in macroscopic finite element analysis calculation is solved.

The invention belongs to the technical field of material performance evaluation, and provides a metal material cavitation erosion incubation period prediction method based on surface plastic deformation analysis. The method comprises the following steps: carrying out cavitation erosion test on a sample; measuring the surface profile length of the sample in the cavitation environment, and calculating the surface area increment rate of the sample; drawing a surface area increment rate-time change curve, and obtaining an incubation period demarcation point and an incubation period end point of the sample; predicting the incubation period of the actual equipment according to the incubation period demarcation point and the incubation period end point; by analyzing the surface area increment rate of the material exposed in the cavitation environment, the incubation period is divided into two stages dominated by hardness and strain hardening indexes, a quantitative relation with the material performance is established, and non-destructive life prediction is achieved.

The invention relates to the field of bridge damping, in particular to a near-fault bridge anti-seismic toughness improving device and a test method thereof.The bridge comprises T-beams, a cover beam, a diaphragm plate between every two adjacent T-beams and an ECC column located between the two T-beams; two pairs of SMA disc spring devices are arranged on the ECC column body, one pair of SMA disc spring devices are arranged towards the T beam, and the other pair of SMA disc spring devices are arranged towards the transverse partition plate; the SMA disc spring devices are used for enabling the T beams to recover to the initial positions through the recovery characteristic of the SMA disc spring devices after relative displacement of the bridge in the transverse bridge direction occurs, and the ECC column is arranged between the two T beams of the bridge, so that the T beams can be recovered to the initial positions. The limit tensile strain of the ECC (fiber cement-based composite material) material can reach more than 200 times that of the traditional concrete, and the ECC material is accompanied by the multi-crack cracking phenomenon of fine cracks, so that the strain hardening characteristic of a similar metal material under the tensile effect is formed, and the structural deformation caused by earthquakes can be effectively dealt with.

The invention provides a quantitative evaluation method for micro-area comprehensive mechanical properties of an electron beam welding joint, and belongs to the technical field of material mechanical property evaluation.A load-displacement curve is obtained through a nanoindentation test, and a data processing method combining numerical integration and high-order derivative calculation is adopted, so that the comprehensive mechanical properties of the electron beam welding joint are evaluated. Meanwhile, three performance parameters of strength, plasticity and strain hardening are extracted, and a quantitative mapping relation between the three performance parameters and the microcell structure is established. The method solves the problem of mechanical property quantitative evaluation of gradient structures of a fusion zone, a heat affected zone and a base metal zone of a welding joint, and the problems of high cost, low efficiency, single parameter and the like in the existing evaluation technology.

The application discloses a kind of unbound post-tensioned prestressed fabricated column foot and post-earthquake rapid repair method, belong to building structure seismic and fabricated steel structure technical field.The column foot includes base plate, steel column, friction layer, strain hardening cement-based composite sleeve, vertical prestressed steel bar and cover plate;The friction layer uses block type structure, and is spliced by several friction layer monomers;Vertical prestressed steel bar is threaded through strain hardening cement-based composite sleeve and cover plate, and is fixed cover plate and applies prestress to vertical prestressed steel bar by disc spring group and anchor nut being set to its top end, realizes the unification of " high seismic, easy construction, fast repair ".The application also discloses the post-earthquake rapid repair method of the column foot, including post-earthquake evaluation, elastic self-resetting, installing temporary support, in-situ jacking, lateral replacement, resetting tensioning and the like steps, using unbound characteristics, without lifting off steel column can be completed in 3-4 hours friction layer replacement.

The invention relates to the technical field of tunnel reinforcement, in particular to an active supporting and reinforcing method for a tunnel face. The reinforcing method comprises the following steps that a tunnel is excavated in stratum surrounding rock with the strain hardening characteristic; after the tunnel is excavated, stability parameters of surrounding rock are monitored in real time; a reinforcing mesh is applied to the tunnel face, and the edge of the reinforcing mesh is connected with the edge of the tunnel face; tightening the reinforcing mesh through a concentrator until the reinforcing mesh is completely tightened, so that the reinforcing mesh actively applies pressure to the tunnel face; and after the surrounding rock reaches the self-stabilization state, the reinforcing mesh is removed, and excavation operation of the next cycle is carried out. According to the reinforcing method, pressure is actively applied to the tunnel face by tightening the reinforcing mesh, so that the fractured rock mass is re-compacted under the combined action of the vertical load and the active pressure, self-healing of the fractured rock mass is achieved, and safety and stability of tunnel construction are guaranteed. According to the reinforcing method, the bearing capacity of the surrounding rock is utilized to the maximum extent, tunnel face supporting work can be reduced, and supporting materials are saved.

The invention relates to the technical field of material basic mechanical property testing, in particular to a method for obtaining an intrinsic stress-strain relation of a material under the action of residual stress, and the method comprises the following steps: step 1, obtaining the surface residual stress sigma R of a to-be-tested area of a test material; 2, two diamond conical pressure heads with different angles are adopted, half cone angles are set to be theta 1 and theta 2, quasi-static press-in tests are completed on the to-be-tested area on the surface of the sample respectively, and a continuous press-in force-depth (F-h) curve is obtained; 3, respectively fitting press-in force-depth curves of the two types of half-cone angle pressure heads to obtain test loading curvatures CE-theta1 and CE-theta2; and 4, according to the sigma R obtained in the step 1 and the CE-theta1 and CE-theta2 obtained in the step 3, sequentially carrying out iterative calculation to obtain intrinsic indentation responses CN-theta1 and CN-theta2 of the material, a strain hardening index np, a nominal yield stress sigma y-p and a nominal yield strain epsilon y-p, and obtaining a stress-strain relationship of the material.

The present invention provides an ionomer having high strain-hardening properties and excellent moldability.　The ionomer contains: a structural unit (A) derived from at least one member selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one member selected from the group consisting of a carboxyl group and a dicarboxylic acid anhydride group; and a structural unit (C) having a carboxylic acid metal salt group. The ionomer has 50 or fewer methyl branches per 1,000 carbon atoms or has a total number of ethyl and butyl branches of less than 4.2 per 1,000 carbon atoms. When the maximum elongation viscosity after strain hardening is defined as ηmax(t1), a time t in question is defined as t1, and an approximate straight line of the elongation viscosity before stain hardening is defined as ηlin(t), ηmax(t1) and ηlin(t1) satisfy ηmax(t1)> ηlin(t1), and further satisfy formula (α) or (β).　Formula (α): ηmax(t1)>1.9 ηlin(t1)1.1 Formula (β): ηmax(t1)≥1.9 ηlin(t1)0.7

The application provides a tunnel surrounding rock grouting reinforcement process simulation analysis method and system, relates to the tunnel surrounding rock reinforcement simulation technical field, and effectively improves the spatial resolution of the surrounding rock deformation state monitoring through the arrangement of multiple evaluation interfaces in the tunnel axis direction and the multi-point synchronous strain collection; the volume strain hardening index normalization analysis can dynamically and quantitatively reflect the mechanical property evolution of the surrounding rock after being compressed; the volume strain of the surrounding rock is dynamically coupled with the rheological test parameters of the grouting material, the timeliness and accuracy of the slurry permeability and pressure correction are improved; the linear interpolation method is used to realize the continuous distribution calculation of the grouting pressure in the tunnel axial direction, and the simulation analysis is significantly improved in the refinement and practicability.

The application discloses a method for analyzing nonlinear dynamics and stress wave propagation characteristics of a dielectric elastomer actuator structure. The method considers the strain hardening effect and viscoelasticity of the dielectric elastomer material, establishes a dynamic model of the dielectric elastomer actuator structure from linear damping assumption and considering material viscoelasticity respectively, calculates the equilibrium deformation and inherent frequency of micro-vibration near the equilibrium state, studies the nonlinear dynamic response of the structure under alternating voltage load, explores the influence law of the constitutive parameters on the nonlinear dynamic response, and analyzes the internal relationship between material viscoelasticity and structure vibration damping. In addition, considering compressibility, the stress wave propagation characteristics in the finite deformation state are studied, the separation phenomenon of transverse wave and longitudinal wave is analyzed, and the influence of the constitutive parameters and strain hardening effect on the stress wave propagation characteristics is explored. The application can provide a theoretical basis for the fine design of the dielectric elastomer actuator and the control of stress wave propagation by adjusting the electric field.