49 results about "Viscoplasticity" patented technology

The invention discloses a long fiber reinforced thermoplastic composite material multi-scale simulation method to solve the problem of difficult accurate simulation of long fiber reinforced thermoplastic composite material in simulation because of strain rate effect and anisotropic mechanical properties. The method includes the steps of: 1. conducting tensile test on an LFRP plate under different directions and different strain rates; 2. performing x-ray CT scanning on an LFRP plate test area; and 3) carrying out multi-scale simulation verification on the LFRP plate: 1) viscoelastic-viscoplastic material model and failure; and 2) simulation verification: using ABAQUS software and Digimat software coupling to establish a simulation finite element model, conducting simulating calculation of tensile test under three strain rates, wherein 0.001s<-1> and 1s<-1> adopt implicit algorithm, and 100s<-1> adopts display algorithm; fixing one end of the finite element sample model, and applying load to the other end along the length direction, and comparing all the mechanical characteristic curves obtained by simulating calculation with test data.

The present invention discloses a multiaxial creep-fatigue prediction method based on ABAQUS, which comprises: S1: establishing an ABAQUS finite element model, and defining the viscoplastic constitutive equation of the material to be tested by means of the user subroutine UMAT; S2: determining the model parameters required by the viscoplastic constitutive equation; S3: establishing the fatigue damage calculation model and creep damage calculation model of the multiaxial stress-strain state of the material to be tested; S4: establishing an ABAQUS finite element model under the multiaxial stress-strain state, and calculating the stress-strain tensor of each cycle based on the defined viscoplastic constitutive equation and the model parameters; S5: calculating the equivalent stress and equivalent plastic strain by means of the user subroutine USDFLD, and superimposing the fatigue damage and creep damage of each cycle according to the linear cumulative damage criterion to obtain the crack initiation life of the material to be tested based on the fatigue damage calculation model and creep damage calculation model in combination with the stress-strain tensor.

The invention discloses a refractory castable containing viscoplasticity phase, comprising refractory aggregate, refractory fine powder, oxide fine powder, a bonding agent and an additive, wherein the granularity of the refractory aggregate is 1-8mm, the granularity of the refractory fine powder is 0.044-1mm, the granularity of the oxide fine powder is less than 5mum, and the granularity of the bonding agent is less than 0.088 mm. According to the invention, single-substance aluminum powder and single-substance silicon powder are added into the refractory castable; the single-substance silicon powder is liquefied or softened during the material sintering, so that the material can produce liquid-phase sintering at low temperature to improve the bonding strength; the introduced aluminum powder reacts with water to form Al(OH)3 and then forms Al2O3 with big activity after being heated and decomposed; the SiO2 and Al2O3 react to form needle/column-shaped mullite crystals, therefore strength of the castable is improved; and meanwhile, part silicon powder becomes viscoplasticity phase at high temperature, and disperses in the material, thus, the toughness of the material is improved and the thermal shock resistance of the castable is improved.

A method of computationally determining material property changes for a cast aluminum alloy component. Accuracy of the determination is achieved by taking into consideration material property changes over the projected service life of the component. In one form, the method includes accepting time-dependent temperature data and using that data in conjunction with one or more constitutive relationships to quantify the impact of various temperature regimes or conditions on the properties of heat-treatable components and alloys. Finite element nodal analyses may be used as part of the method to map the calculated material properties on a nodal basis, while a viscoplastic model may be used to determine precipitation hardening and softening effects as a way to simulate the time and temperature dependencies of the material. The combined approach may be used to determine the material properties over the expected service life of a cast component made from such material.

The invention relates to the field of heat source radiator technology of an electronic device, in particular to a manufacture method for integrally extruding and forming a graphite-based composite material radiator. The method comprises the manufacture and process steps of: hot-kneading raw materials to prepare a paste with uniform mixing performance and excellent viscoplasticity, arranging the paste into an extrusion press to carry out pre-compression to form a billet, extruding and forming the billet, cooling and cutting the billet after extruding, baking and graphitizing the extruded raw product, and soaking and surface-treating the graphitized product, thus preparing the final radiator product. The manufacture method has the following advantages of (1) being capable of manufacturing graphite radiator with complex section; (2) large flexibility and being capable of producing the graphite radiators with different shapes, specifications and types on the same extrusion press by replacing an extrusion die; and (3) simple process flow and high production efficiency. The graphite radiator manufactured by the method has the advantages of good heat conduction, light weight, etc., and has no pollution during the process, is simple and feasible and has low consumption and high efficiency.

The present invention relates to a textile tool with temporary protection. An anti-abrasion layer (12) is provided on the textile tool (1). The anti-abrasion layer extends and covers a cutting edge (9) or a top end (5). A cap (7) or a cap (11) which is made of protection material is provided for the top end (5) or the cutting edge (9). The protection material is preferably constructed to have viscoplasticity or damping characteristic. Preferably, the cap (7,11) can be easily removed. For instance, in a first using process of the textile tool, the cap is integrally or partially separated from the textile tool (1). Preferably, the protection material is molten impregnated material, such as molten impregnated material based on thermoplasticity.

The invention discloses a method for separating viscosity-elasticity-plasticity characteristic parameters in a triaxial rheological test on a rock. The method comprises the following steps: making a sampled rock body into a standard cylindrical test sample, firstly applying a static water pressure state to the cylindrical test sample to load initial confining pressure of the test sample to reach a rheological test designed value sigma 3, keeping the confining pressure unchanged, performing the triaxial rheological test on the rock in a multistage increment circulated loading and unloading mode till the test sample is damaged, recording deformation characteristics, including an instant strain value epsilon 1, a loading stable strain value epsilon 2, an unloading instant strain value epsilon 3 and an unloading rheology stable value epsilon 4, of the test sample in each stage of axial deviatoric stress level, and identifying according to an elastic-plastic theory to obtain the instant elasticity strain valve epsilon me, the instant plasticity strain value epsilon mp, the viscoelasticity strain value epsilon ce and the viscoplasticity strain value epsilon cp of the test sample. By the viscosity-elasticity-plasticity parameter separation method, the viscosity-elasticity-plasticity rheological characteristics of the rock under different deviatoric stress levels can be identified, and corresponding technical measures are provided for reinforcement of surrounding rock bodies under high ground stress conditions in deep underground engineering.

The invention relates to the building material technical field, in particular to a low grade machine-made sand one hundred elevation pumping concrete, which solves problems that the first grade pumping height of an existing low grade pumping concrete is low and the cost of most adopted river sands with high quality is high. The concrete per cube is made from the raw materials with the following weight ratio of 300-310kg of cement, 90-100kg of fly ash, 750-780kg of machine-made sand, 1000-1100kg of gravels, 170-180kg of water and 3-4kg of compound admixture. The invention adopts the raw materials of the machine-made sand, low content cement, etc. to prepare low grade concrete through a series of optimization tests, which has the advantages of good fluidity, no segregation, small frictional resistance, good viscoplasticity, good pumpability and good construction workability. The first grade vertical pumping height can reach to 100m above. The invention is especially applied to the constructions in mountain areas with precipitous terrain. And the machine-made sand is adopted to replace river sand, which leads to the lower cost.

The invention belongs to the technical field of building materials, and particularly relates to glass fiber reinforced gypsum capable of being used for 3D printing. The glass fiber reinforced gypsum is prepared from phosphorus gypsum, slag powder, cement, glass fibers, a water-reducing agent and an early strength agent. The glass fiber reinforced gypsum with high viscoplasticity, low shrinkage rate, small hydration heat and good working performance can be obtained and directly used for 3D printing to produce a gypsum building material product. By using the glass fiber reinforced gypsum provided by the invention, the problem of resource utilization of the phosphorus gypsum can be effectively solved, and the purposes of high consumption amount of the phosphorus gypsum, low energy consumption and efficient resource utilization of the phosphorus gypsum are realized.

The invention relates to a method for manufacturing an iron-based alloy part and belongs to the technical field of iron-based alloy forming. According to the method for manufacturing the iron-based alloy part, a powder injection forming technology is adopted; firstly, metal and polymer binder powder are mixed into even injection forming feed with viscoplasticity; then, injection is conducted on an injection machine so that an injection blank can be formed; afterwards, the iron-based alloy part is manufactured through the steps of degreasing, sintering and the like. The finished iron-based alloy part product which is good in performance and high in size precision is obtained after heat treatment is conducted on the sintered product. The method for manufacturing the iron-based alloy part has the advantages that the product is formed with a net dimension, subsequent machining is not needed, the production cost is low, and iron-based alloy part products which are complex in shape and good in comprehensive performance can be produced in a batched mode; and the method is suitable for industrial production.

The invention provides a thermo-electric-force coupling field viscoplastic material creep test system. The thermal-electric-force coupling field viscoplastic material creep test system includes a tensile machine, an upper force bar and a lower force bar, and a high Low-temperature environment test chamber; the ends of the upper force rod and the lower force rod in the box are provided with insulating clamping ends oppositely, and the two insulating clamping ends are used to clamp the test piece, and the conductive ring passes through The current leads are connected to the current source, and a force sensor is arranged on the force uploading rod adjacent to the insulating clamping end. Compared with related technologies, the thermo-electric-force coupling field viscoplastic material creep test system provided by the present invention realizes the testing of electronic packaging materials under real extreme working conditions by applying thermal field, electric field and force field to the test piece at the same time. Creep performance observation.

A method for friction welding of inter alia coarse grain superalloy components, involving conditioning a shear zone of components to be welded by; a) pre-determining temperature profile for which the material of the shear zone of the components approaches viscoplasticity but does not undergo undesirable phase transformations, b) introducing friction at one or both surfaces of the components to be welded to provide a pre-defined quantum of energy sufficient to generate a peak temperature of the temperature profile at that surface whilst simultaneously applying pressure to the surfaces which is below a pressure which will cause upset at the surface, c) withdrawing the friction and/or pressure allowing the heat to disperse by conduction through the shear zone; d) after the temperature at the surface falls below peak temperature, repeating steps b) and c); and repeating step d) as necessary until the pre-determined temperature gradient is achieved throughout the shear zone.

The invention provides intermediate slab connecting equipment. The intermediate slab connecting equipment comprises an outlet clamping device for clamping a front intermediate slab, an inlet clamping device for clamping a back intermediate slab, a friction blade for rubbing the connecting end surfaces of the front intermediate slab and the back intermediate slab, and an upsetting device for applying upsetting force; the friction blade is positioned between the inlet clamping device and the outlet clamping device; and the friction blade is connected with a friction blade vibration device. The friction blade extends between the front intermediate slab and the back intermediate slab for rubbing the end surfaces of the two, so that the end surfaces of the intermediate slabs and near areas are quickly heated to reach a viscoplasticity state; the upsetting device applies the upsetting force to the back intermediate slab; after the friction blade is shifted away, the front intermediate slab is connected with the back intermediate slab. The intermediate slab connecting equipment is simple in structure, high in connecting strength, fast in connecting speed, low in energy consumption and suitable for connecting slabs with different materials.

The invention belongs to the technical field of mechanical manufacturing, and discloses a method for analyzing rotary forging effect based on 3D constitutive model under alternating load comprising the following steps of: performing 3D volume effect and surface effect analyzing on vibration rotary forging visco-elasticity plasticity constitutive model by using MATLAB software, then performing describing on three dimensional contact problem by simulating contact boundary in vibration rotary forging process through multi-parameter coupling; deriving viscoelasticity space matrix and viscoplasticity space matrix respectively by using generalized Hooke law in elastic mechanics and incremental theory in plastic mechanics, then establishing a surface effect analysis model in vibration rotary forging forming; performing finite element simulation analyzing and surface effect analyzing on the vibration rotary forging model under different vibration mode parameters through providing reasonable assumptions. According to the method for analyzing rotary forging effect based on 3D constitutive model under alternating load, vibration forging forming mechanism is disclosed, material vibration forging forming process analysis under the three dimensional constitutive model is perfected, and important theoretical significance and practical value are achieved for building vibration forging formingequipment.

The invention provides a three-dimensional variable parameter full-coupling simulation calculation method for ground subsidence and ground fissures caused by load and underground water exploitation. The problem of calculation of the ground subsidence and the ground fissures under the dual action of overlying load on a soil body and underground water exploitation is solved. The geological conceptual model is established according to the actual background of underground water exploitation. Based on a Biot consolidation theory, full coupling of a seepage field and a stress field is realized, and a three-dimensional full-coupling numerical model for predicting ground settlement and ground fracture development is constructed. According to the calculation method, a mechanism in a rock-soil body compression process is considered, constitutive models of elasticity, viscoelasticity and viscoplasticity are coupled, and a seepage field and a stress field are closely linked by combining changes of rock-soil body parameters, so that the ground settlement amount and the ground fracture extension amount under the conditions of ground load and groundwater dynamic decline can be simultaneously simulated, and a basis is provided for researching seepage field evolution and ground subsidence evolution laws and a fluid-solid coupling action mechanism in the underground water exploitation process.

A method of determining a maximum acceptable alternating stress at a point of a part subjected to cyclic loading: simulating that the part is subjected to constant loading equal to a threshold value during a level period, and assuming that the part has elasto-viscoplastic behavior; from the results of the simulation, determining a final static stress at the point at the end or after the end of the level period; and for the point under consideration, using a Goodman diagram to determine the maximum acceptable alternating stress, which is determined for a static stress equal to the final static stress; the duration of the level period being equal to the duration of the loading of the testpieces that were used to draw up the Goodman diagram.

The invention discloses a high-temperature structure dangerous point stress-strain calculation method, aims to solve the problem of notch stress-strain overestimation in the Neuber criterion, adopts an effective stress concentration coefficient to calculate pseudo stress, and improves the calculation method of the effective stress concentration coefficient. In addition, the proposed notch correction method is combined with a Caboch unified viscoplasticity constitutive model, and the stress-strain state of the dangerous point under the heat engine load is estimated. In order to evaluate the reliability of the method, an estimated result is compared with a nonlinear finite element analysis result, and the result shows that the method can accurately estimate the notch stress and strain underthe multi-axis thermal-mechanical cyclic load. The method is of great significance in guaranteeing the life prediction accuracy of structural parts in actual engineering, safety service of various important devices and accurate life extension.

The invention relates to a prediction method for aluminum alloy thermal deformation behaviors and yield strength after forming. The prediction method comprises the following steps that S1, solving a constitutive model of the aluminum alloy through tensile data; S2, converting the engineering stress-strain curve into a real stress-strain curve; S3, establishing a unified viscoplasticity constitutive model of the aluminum alloy to obtain the dislocation density and hardening of the aluminum alloy in the deformation process and the relationship between the grain size and the viscoplasticity flow behavior; S4, making DSC analysis on the deformed aluminum alloy; S5, making XRD analysis of deformed aluminum alloy; S6, obtaining the element concentration, the precipitated phase volume fraction and the precipitated phase size according to the calculation result; S7, establishing a yield strength prediction model; and S8, solving model parameters. The calculation and analysis process involved in the method is simple, parameters are few, application and popularization are convenient, the model precision is high, and verification can be conducted through an aluminum alloy hot stamping experiment.

The invention relates to a device for conveying discharged mud cakes of a plate-and-frame filter press. The device comprises a mud hopper and a conveyor under the mud hopper, and the lower portion ofthe mud hopper is provided with gratings. By additional arrangement of the gratings, with large mud cake breaking power, on the lower portion of the mud hopper, the mud cakes are cut into small-size blocks by the gratings under the action of gravity so as to achieve convenience in transporting. The conveyor conveys cylindrical rollers through a chain-sprocket structure and is less prone to slipping or deflecting and low in operating noise. The multiple cylindrical rollers are arrayed to form an uneven transporting surface which is capable of withstanding direct impact of mud blocks with certain weights, and the concave-convex surface enables increasing of a contact area, so that convenience in mud block conveying is achieved. By arrangement of a roller brush and a cleaning procedure, the whole device for conveying is low in requirement on intrinsic weights of the mud cakes, the conveyor is slightly affected by the moisture content or viscoplasticity of the mud cakes, and the device forconveying is less prone to failure caused by mud accumulation.

The invention relates to an upright magnetorheological polishing device. The device comprises a polishing mechanism and a clamping mechanism; the polishing mechanism comprises a magnetic frame, a coiland a vertically arranged liquid storage pipe; the inner hole of the liquid storage pipe fits a workpiece and contains magnetorheological liquid; the workpiece is clamped by the clamping mechanism tofit the position of the liquid storage pipe; a magnetic field is formed in the inner hole of the liquid storage pipe by the coil, and a flexible polishing film is formed by the magnetorheological liquid; the workpiece and the polishing film move relatively in the vertical direction and rotate relatively along the axis of the workpiece. According to the upright magnetorheological polishing deviceand an upright magnetorheological polishing method, a rheologic effect is generated by the magnetorheological liquid to shear the polishing film with higher yield stress and apparent viscosity and viscoplasticity, the relative movement of the magnetorheological liquid and a to-be-processed surface is utilized to perform material removing on the surface, the polishing process is not limited by theshape of the surface of the workpiece, the polishing efficiency is high, and damage is not generated. The device has a simple structure and is easy to control, and workpieces with different characteristics and demands can be polished.

The invention provides a method for calculating viscoplastic tensile deformation of a columnar crystal structure in a steel solidification process, and relates to the technical field of metallurgical continuous casting. The method comprises the following steps: based on a two-dimensional columnar crystal growth CA-FVM model, calculating a columnar crystal structure growth morphology; extracting growth morphology data of the columnar crystal structure under a specific solid fraction, and establishing a geometric model and a finite element model of the columnar crystal structure; based on the finite element model of the columnar crystal structure, setting viscoplasticity attributes of the columnar crystal structure, and establishing a constitutive model, namely a columnar crystal structure viscoplasticity model, representing the viscoplasticity mechanical behavior of the columnar crystal structure; setting conditions for calculating viscoplastic deformation of the columnar crystal structure; calculating viscoplastic deformation of the columnar crystal structure in finite element software, and carrying out visualization and data post-processing. The method can qualitatively characterize the deformation evolution condition of the columnar crystal structure under the tensile effect in the steel solidification process and the overlarge stress and strain concentrated distribution part, and can also qualitatively characterize the viscoplastic deformation mechanical behavior of the secondary dendritic crystal arm well.