89 results about "SHELL model" patented technology

A method for producing a customized helmet including a computer designed composite helmet liner to be incorporated into existing and new helmet designs is provided by scanning a user's cranial region, creating a computer rendering surface model of the scan, modifying the surface model using computer aided design software, overlaying and aligning an outer helmet shell model onto the modified cranial model to define the custom liner three-dimensional space to configure the composite liner with a software algorithm including shock absorbing segments having optimal sizes, shapes, and materials, fabricating the liner in a heat sealing process to include an optional encapsulating or serial air bladder, and assembling the liner and outer helmet shell together.

The invention discloses a preparation method of an oxide ceramic composite shell for precision casting of titanium alloy. The preparation method comprises the following five steps: pressing a wax mold; respectively preparing a surface layer coating, a surface-layer-approaching layer coating, a reinforcing layer coating, a back layer coating and a back layer hardening agent; sequentially dipping the wax mold into the above solutions, and drying to prepare a shell model; dewaxing the shell model; roasting the shell model, and discharging the shell model from a furnace, so as to obtain the shell. The preparation method disclosed by the invention solves the defects that materials are dissolved in water and the air permeability of the shell is poor in existing preparation and dewaxing processes of a shell. The preparation method disclosed by the invention has the advantages that the preparation cycle of the shell is shortened, the production efficiency is increased, dewaxing equipment is simple and is simple and convenient to operate, the surface of the roasted shell is smooth, phenomena such as peeling, shedding, cracking, powder falling and the like on a surface layer are avoided, and the shell is good in air permeability and deformability, and thus a casted titanium alloy casting has a smooth surface, is pollution-free and is low in roughness.

A simulation manual semi-joint body and fabrication technics are provided, which forms a shell model through reverse engineering and 3D design software and the divides the bone layer into three parts, namely upper, middle and lower layer; then designing the internal pipe column negative structure according to the funvtions of each layer and finally combining the model of each layer and the shell model to form the negetive model. The invention shapes the false body model by adopting the speedy shaping and exact photocureable forming machine, fills the ceramics slurry into the false body model and solidifies it in vacuum high temperature stove and then places the solidified ceramics body in polyurethane solution module; then pumping the vacuum, placing the module still and then taking out the ceramics after the polyurethane fully solidified; shaping it, thus achieving the bone layer material serving as the ceramics part; the soft bone layer elastomer is made of manual semi-joint body of the polyurethane elastomer. The invention reduces the rubbing damage for side joints and strengthens the activity capacity of the joints when the soft bone layer contacting the side joints.

The invention discloses an automatic generation method for a quadrilateral finite element mesh of a pitting corrosion damage cylindrical shell. The automatic generation method for the quadrilateral finite element mesh of the pitting corrosion damage cylindrical shell includes that carrying out parameterization set on key geometrical sizes of a pitting corrosion damage cylindrical shell model in a finite element software, constructing three standard basic segments of an end perfecting region, a pitting corrosion region and a pitting corrosion spacer region of the cylindrical shell through segregate expression, constructing the whole geometrical model of the pitting corrosion damage cylindrical shell with a multi-layer pitting corrosion region, the pitting corrosion spacer region and the end perfecting region through copying, translation and division methods, grouping the geometrical model according to pit positions and size characteristics of each region, setting the mesh division number of the region boundary of each grouping object, using mapping MAPPED and AMAP to divide the whole cylindrical shell model, and generating the whole finite element model of the quadrilateral mesh unit. The automatic generation method for the quadrilateral finite element mesh of the pitting corrosion damage cylindrical shell solves the microscopic pitting corrosion damage description problem in a macro-scale structure and improves the solving precision and solving efficiency of the simulating calculation.

The invention discloses a manufacturing method of a brake drum. The manufacturing method mainly comprises the following steps: respectively manufacturing an upper mould shell model, a lower mould shell model and a sprue cup shell model on a core shooting machine, then assembling to form an integral film-coated sand shell model; placing a sand box on a ramming platform; putting dried sand into the sand box, and ramming to form a bottom sand layer; placing the assembled film-coated sand shell model into the sand box, putting the dried sand into the sand box, and ramming; coating a back film, vacuumizing; and pouring, releasing a negative pressure, opening the box, drawing and removing a casting head of a casting of the brake drum. The manufacturing method achieves the characteristic of combining advantages of two processes by combining a V-method casting process and a film-coated sand shell model casting process.

The invention relates to a method and apparatus for generation of a radial polarized cosine Gaussian Shell Model (GSM) light beam. The method comprises the steps: performing beam expanding on laser, and modulating the correlation characteristics of the light beam through a spatial light modulator to obtain a light beam with the correlation characteristics of cosine Gaussian; performing space polarization regulation and control on the light beam to obtain a radial polarized beam; reducing the spatial correlation characteristics of the radial polarized beam to obtain a noncoherent cosine Gaussian correlation beam; obtaining a linearly polarized cosine Gaussian correlation Gaussian beam after the noncoherent cosine Gaussian correlation beam is focused through a lens and is filtered through a Gaussian amplitude filter plate; and obtaining a radial polarized cosine GSM light beam after the linearly polarized cosine Gaussian correlation Gaussian beam passes through a radial polarized light converter. The invention provides a novel light beam generation method, further promoting the research on transmission, imaging and matter interaction for a special coherence light beam, and expanding the types of light beams.

A fatigue life estimating method for a spot welded structure is provided comprising the steps of providing a shell model of a spot welded structure for a finite element method analyzing process, calculating the nominal structural stress on a nugget as the center of the spot welded structure using a disk bending theory and a two-dimensional elastic theory of the elastodynamics with the partial loads exerted on the nugget and the deflection on the circumference of a circle, D in diameter, in which the nugget is located, which have been calculated by the finite element method analyzing process of the shell model, and estimating the fatigue life of the spot welded structure from the nominal structure stress.

According to the method, the fatigue life of the spot welded structure can be estimated easily, readily, and accurately.

The invention relates to the technical field of FSS (Frequency Selective Surface) radome manufacturing, and specifically discloses a manufacturing method of a curved frequency selective surface array.The manufacturing method comprises the steps of S1, respectively performing three-dimensional modeling on a substrate dielectric shell and a three-dimensional exposure mask shell through three-dimensional modeling software; S2, respectively inputting a substrate dielectric shell model and a three-dimensional exposure mask shell module into 3D printing equipment for molding; S3, coating the outersurface of the substrate dielectric shell with a photoresist, attaching the three-dimensional exposure mask shell to the molded substrate dielectric shell, enabling the two layers to be tightly laminated, and performing exposure processing through exposure equipment; S4, performing development processing, cleaning and drying on the substrate dielectric shell; and S5, preparing a metal film layer on the surface of the processed substrate dielectric shell, and removing the left photoresist by using a photoresist removing liquid, cleaning and drying. The manufacturing method not only can manufacture a hole unit array, but also can manufacture a patch unit array, and has good universality.

The invention provides a parametric modeling method of a folded plate reticulated shell based on grasshopper, which is used for solving the problems of modeling difficulty, low modeling efficiency andlow repetition utilization rate of the existing space folded plate reticulated shell with complex modeling. The invention comprises the following steps: expressing the geometrical parameters of a lattice shell model to be established by corresponding input plug-ins; generating a flap surface or quasi-spherical surface by using the application plug-ins according to geometrical relation; selectingone of the planes and using an isoparametric method or subdivision method to mesh a folded surface to generate local meshes; gridding all the planes by the circumferential array plug-in, and generating the single-layer folded latticed shell by connecting the bars with the plug-in. The invention has the advantages of simple design method, new model can be established by changing the parameter valuein the model, the modeling efficiency can be improved, the force analysis and the structural design optimization of the complex space reticulated shell structure under different types and different parameters are improved greatly and conveniently, and the use of the complex space reticulated shell structure is promoted.

The invention discloses a method for detecting air gap on a blast furnace shell. The method comprises steps of: establishing a blast furnace shell model; dividing the blast furnace shell into a plurality of regional units; collecting reference configuration information and finite element reference position information in the regional units, and measuring reference temperature; calculating to obtain a reference heat transfer coefficient of the blast furnace shell model based on the above reference configuration information, the finite element reference position information and measured reference temperature; determining an air gap parameter of the blast furnace shell based on the blast furnace shell model; collecting on-site configuration information, finite on-site element position information in the regional units, and measuring an on-site temperature; calculating to obtain an on-site heat transfer coefficient based on the on-site configuration information, finite on-site element position information and measured on-site temperature; and comparing the on-site heat transfer coefficient with the reference heat transfer coefficient to obtain air gap parameter of the blast furnace shell. The method provided by the invention can effectively and timely reflect the air gap parameter of the blast furnace shell, show the change of the heat transfer coefficient of the blast furnace shell, and provide direct evidence for gap detection.

The invention relates to a method adopting a ring type low frame rate camera array to catch a high-speed moving object and model, belonging to the technical field of a computer multimedia. The method includes that: the ring type camera array is divided into groups in a uniform spacing; each group of cameras acquires the moving object in a ring type field; an acquisition time difference between the adjacent groups of cameras is 1/(fm) second; by utilizing a bi-directional optical flow prediction method, a (group count-1) frame is interpolated out between the adjacent two frames of a sequence shot by each camera; a contour constraint is added to a result of the interpolation to improve the result of the interpolation; at each moment, a visual shell model is established and rendered by using an image of each visual angle and the interpolation image. The method which adopts the ring type low frame rate camera array to catch the high-speed moving object and model is capable of using the low frame rate camera to realize the catching of the high-speed movement and the modeling of a three-dimensional dynamic scene.

The invention discloses an optical system for generating a hollow beam by focusing a Bessel-Shell model light field through axicons.The optical system comprises an optical platform.A laser device is placed on the optical platform.A collimation and beam expanding system, an aperture diaphragm, the first axicon, a first thin lens, rotary ground glass, a second thin lens and the second axicon are sequentially placed along an optical path of the laser device.By means of the technology, the hollow beam of the size increasing along with increase of the distance can be generated, and the hollow beam has a self-reconstruction characteristic.The optical system has the advantages that the optical structure is simple, optical elements are cheap, and the generated hollow beam is high in quality; a powerful means will be provided for people to trap particles of different sizes and numbers on multiple layers.

The invention belongs to the casting field, relates to a composite mold shell preparation method for reducing the recrystallization tendency of a high-temperature single-crystal alloy casting. The preparation method is suitable for preparing a shell of the investment precision casting high-temperature alloy casting for investment casting. The preparation method comprises the following steps: pressing a wax mold; preparing a surface layer coating, a transition layer coating, a middle layer coating and a back layer coating; sequentially immersing the wax mold into the coatings, scattering corresponding sand and preparing a shell model after the wax mold is dried; dewaxing the shell model; and roasting the shell model. According to the technical scheme, the defects of poor deformability and collapsibility of an existing shell are overcome, after a composite mold shell is used as a mold shell of the investment precision casting, the casting residual stress of the shrinkage blocking area of the high-temperature single-crystal alloy casting is remarkably reduced, and therefore the casting recrystallization defect caused by subsequent heat treatment is eliminated, the single crystal integrity of a casting blank is ensured, and the qualification rate of the casting is remarkably improved.

The invention discloses a Gaussian Shell model (GSM) shaping method. After a GSM beam is expanded through a beam expanding mirror and the size of a light spot is changed, the GSM beam vertically enters a first thin lens, and is focused on an amplitude attenuation piece. The light beam from the amplitude attenuation piece is outputted through a second film lens in a collimation manner, thereby obtaining a special part coherent beam. The method can achieve the simultaneous or independent modulation of the light intensity and coherence of the GSM beam, can obtain a result that the distribution of the light intensity and coherence is non-Gaussian distribution, and greatly increases the types of light beams. The invention also discloses a GSM shaping system.

The invention discloses a boundary simulation device and method for a thin-walled cylindrical shell structure experiment. The device comprises a central support bar, an upper ring plate and a detachable lower ring plate. A thin-walled cylindrical shell model is manufactured with the upper ring plate and the lower ring plate as templates, and a glass cement is coated on the bottom boundary of the thin-walled cylindrical shell model, The lower ring plate is shifted inward by loosening bolts on the detachable lower ring plate, and then the same glass cement is coated at the inner side of the model by a circle to create a bottom fixed boundary condition. The top of the thin-walled cylindrical shell model is fixed on the upper ring plate by adopting an aluminium strip at the top of the thin-walled cylindrical shell to create a top fixed boundary condition. The device can be detached flexibly, and plays the roles of serving as a template in the manufacturing process of a test piece and creating the bottom and the top boundary conditions for the test piece. The device can simulate a floating roof shell when the top boundary is loosened, and simulate a fixed roof shell when the top boundary is restrained.

The invention discloses a method for controlling the consistency of vibration of the surfaces of shell structures on the basis of neural networks. The method includes firstly, constructing vibration consistency control architectures on the basis of a neural network optimization algorithm; secondly, deducing weight and threshold iterative formulas of identifiers and controllers on the basis of a gradient descent process; thirdly, further computing global errors and frequency-point errors, combining the global errors and the frequency-point errors with one another and creating a novel error judgment criterion for judging difference between control effects and targets; fourthly, synchronously controlling the consistency of vibration response of multiple points of the surfaces of the shell structures so as to cooperatively controlling the vibration response of the multiple points of the surfaces of the shell structures. Each control architecture mainly comprises two core modules which are the corresponding identifier and the corresponding controller respectively, the identifiers are used for identifying controlled shell models and predicting the vibration response, and the controllers are used for implementing excitation parameter optimization and control targets. The weight and threshold iterative formulas are used for optimizing and updating loop parameters.

The invention provides a parametric modeling method of a spatial reticulated shell based on grasshopper, which is used for solving the modeling difficulty of the existing complex-shaped spatial latticed shell structure, the modeling efficiency is low, and the repeated utilization ratio is low. The method comprises the following steps: determining the geometric parameters of the spatial lattice shell model by using the geometric relationship, and expressing each geometric parameter by using the corresponding input plug-in; based on the two-point adjustment method, generating the corresponding fork-cylinder surface or shell surface by using the application plug-in; using the isoparametric method to mesh the surface of the ridge to generate the local mesh; generating a single-layer fork-cylinder reticulated shell or a single-layer shell reticulated shell by gridding all the curved surfaces of the ring array plug-in. The invention can greatly improve the generation and modification speed of the model by using the parametric modeling, and improves the working efficiency. The design method is simple and efficient. It is very convenient for the analysis and optimization of spatial latticed shell structure with complex shape under different types and different parameters by using finite element design software.

The invention discloses a GIS (Gas Insulated Switchgear) shell circulating current and transient grounding potential rise (TGPR) modeling and analysis method based on a PEEC method. On the basis of the circulating current and transient grounding potential rise generation mechanism in the GIS system, the PEEC method is adopted to build a GIB busbar and shell model, an equivalent model is further built for simulation, the relation curve between amplitude of GIS inter-phase circulating current and grounding grid circulating current and a grounding point is obtained, and according to the relationcurve, influence factors for the shell circulating current and the TGPR are determined. Power grid protection and control adjustment are facilitated.

The invention discloses a method for correcting numerical simulation of atmospheric turbulences and belongs to the field of interdisciplinary branches of aviation and mechanics. The method includes: firstly, implementing numerical simulation of atmospheric turbulences for a traditional Dryden model by iteration; secondly, performing shell model numerical simulation to obtain a physical quantity capable of reflecting turbulence singular scale features, namely energy transfer rate; and thirdly, introducing the energy transfer rate and correcting the traditional Dryden model numerical simulation signals. The defects of traditional atmospheric turbulence signals are made up, the actual features of atmospheric turbulences are more conformed, and more reasonable atmospheric turbulence signals can be provided for simulation modeling of a flight simulation system of a flight simulator.

The invention discloses an assessment method for residual stress relaxation effect of steel box girder top plate-longitudinal rib welding details under a vehicle-mounted effect. The method comprises the following steps: establishing a top plate-longitudinal rib solid model, and carrying out simulation analysis on top plate-longitudinal rib welding detail residual stress by using finite element analysis software; verifying a simulation result through a top plate-longitudinal rib test piece residual stress experiment; embedding the top plate-longitudinal rib solid model into the steel box girder shell unit model to obtain a steel box girder solid-shell model; loading a verified simulation result serving as an initial load to the steel box girder entity-shell model, and setting a material cyclic plasticity constitutive relation; and on the basis, applying a vehicle load to the steel box girder entity-shell model, and obtaining the top plate-longitudinal rib welding detail residual stress relaxation degree through calculation. The method can be used for objectively and accurately evaluating the residual stress relaxation level of the steel box girder top plate-longitudinal rib welding details under the vehicle-mounted effect, and is greatly helpful for the anti-fatigue design of a large orthotropic steel bridge deck and the fatigue life prediction of the welding details.