67 results about "Shell element" patented technology

The application belongs to the technical field of electric data processing, and particularly relates to a nonlinear unit construction method based on dimension expansion. The shell unit nodes are classified and information is stored; the normal of the shell unit is calculated; new nodes are expanded on the positive and negative sides along the normal according to the thickness, and corresponding three-dimensional solid units are generated; the junctions at the unit connections are specially processed to maintain the connectivity; and the original constraint conditions are converted and applied to the expanded new nodes. The method significantly improves the calculation accuracy and boundary adaptability, greatly reduces the development complexity of the nonlinear unit, and facilitates the direct coupling analysis of beams, shells, solids and other units in a unified three-dimensional system.

The application discloses a structure nonlinear deformation reconstruction method and system based on isogeometric and reduced basis, and the method comprises the following steps: measuring initial strain data of a ship plate structure surface, constructing a plurality of four-node inverse shell elements of the ship plate based on the initial strain data; assembling the plurality of four-node inverse shell elements to obtain a whole stiffness matrix; reconstructing the whole stiffness matrix based on the measured strain data of the ship plate to obtain a linear reconstruction result of the ship plate; correcting the linear reconstruction result based on the reduced basis, and fusing the correction increment to the linear reconstruction result for nonlinear iteration to complete nonlinear deformation reconstruction. On the basis of the principle of isogeometric analysis, the application combines the inverse finite element method to establish a four-node inverse shell element, realizes high-precision ship structure displacement reconstruction through a small number of strain measuring points, and helps designers to intuitively understand and deeply understand the mechanical properties of the structure and to monitor the safety of the structure in real time.

The invention relates to a wall component (10) for producing a wall and / or a terrace support. The wall component (10) comprises a first plate-type shell element (12) and a second plate-type shell element (14), which is arranged opposite the first shell element (12), wherein the first shell element (12) and the second shell element (14) are connected by at least one reinforcing element (20) and wherein the first shell element (12) and the second shell element (14) are spaced apart from one another such that an interspace (18) for concrete material is formed between the first shell element (12) and the second shell element (14). Furthermore, the wall component (10) comprises a third shell element (16), which is concave at least in some sections and which connects the first shell element (12) and the second shell element (14) at each end such that a portion of the intermediate space (18) is delimited on five sides by means of the first shell element (12), the second shell element (14) and the third shell element (16). The invention also relates to a method for erecting a wall and / or a terrace support.

The invention relates to the technical field of shell unit calculation of a large-curvature curved-surface thin-wall structure. The invention provides a shell unit calculation method suitable for aviation large-curvature skin. The calculation method comprises the following steps: constructing an average plane; determining a local Cartesian coordinate system; obtaining a first balance equation, a second balance equation and a third balance equation based on the moment balance formula in the average plane and the moment balance formula of the actual element; correcting the normal load of the four-node quadrilateral unit to obtain a fourth balance equation; and adding a moment component about an average plane normal at each node i, and performing moment correction on the moment component to finally realize correction on the load of the non-coplanar four-node plate shell element. According to the load correction scheme of the non-coplanar four-node plate shell element, the analysis precision under certain warping configurations is greatly improved.

This invention provides a press forming analysis method, a press forming analysis apparatus, and a press forming analysis program that can predict press forming loads in advance, even for new part shapes and materials. [Solution] The press forming analysis method according to the present invention is a press forming analysis method that predicts the press forming load using a die model 9 having an upper die model 11 and a lower die model 17 modeled with shell elements, using the finite element method, and includes: an elastic element-attached lower die model creation step S1 in which the lower structure 7 of the press device is modeled with elastic elements 15 and attached to the lower die model 17 to create an elastic element-attached lower die model 13; an elastic modulus determination step S3 in which the elastic modulus to be applied to the elastic elements 15 is determined; and a press forming load acquisition step S5 in which press forming analysis is performed using the die model 9 including the elastic element-attached lower die model 13 modeled in the elastic element-attached lower die model creation step S1, and the press forming load is obtained.

The invention discloses a finite element shell element model modeling method and system considering metal surface corrosion random morphology. The method comprises the following steps: obtaining metal surface corrosion morphology three-dimensional point cloud data of a corroded component through three-dimensional laser scanning; performing dimension reduction on the three-dimensional point cloud data, judging whether the corrosion form of the metal surface is uniform corrosion or not, if so, calculating a physical regression equation based on the expanded point cloud data, and constructing a corrosion random morphology model based on superposition of a corresponding uniform corrosion depth on a corrosion texture generating a corresponding weight loss ratio; if not, constructing a corrosion random morphology model based on the learned corrosion texture; generating a corrosion morphology by using the corrosion random morphology model; performing regular grid division and numbering operation on the corrosion random morphology model; material attribute endowing is completed based on grid partitioning and numbering, and grid encryption division is carried out; and based on the shell element geometric model with the given thickness, parameter setting is completed, and a finite element shell element model is obtained.

The invention discloses a propeller system dynamics analysis method based on a shell unit, and the method comprises the steps: firstly determining the geometric parameters and design conditions of a propeller according to the design task and working condition of an aviation aircraft; and blade chord length distribution and mounting angle distribution are calculated based on an aerodynamic load rule, and an NACA airfoil profile is selected to generate a three-dimensional geometric model. Then, grid division is carried out according to the model, the connection relation between blade nodes and units is established, and a quadrilateral eight-node shell unit grid is formed; a finite element model is established by adopting an isoparametric element theory, a stiffness matrix and a mass matrix are calculated, and then a kinetic equation of the propeller is established. The inherent frequency and vibration mode characteristics of the blade are obtained through modal analysis, and on the basis, aerodynamic loads are applied for dynamic response analysis. According to the method, the parameterized modeling process of the propeller from geometric modeling to kinetic analysis is realized, the aerodynamic coupling vibration characteristics of the blade can be efficiently evaluated, and the method has the advantages of high modeling precision, high analysis efficiency and high adaptability.

The invention relates to a storage system (1) for storing a fluid medium, preferably hydrogen, comprising at least one tank vessel (200) which has a cylindrical basic shape and has two ends (202) for storing fluid medium, in particular hydrogen, wherein the tank vessel (200) comprises: a first shell element (10), which first shell element (10) forms a tank-vessel interior (201); a second shell element (12), which second shell element (12) surrounds the first shell element (10); and an end cap element (18) at each of the ends (202). The end cap element (18) receives the first shell element (10) and the second shell element (12) at the ends (202) of the tank vessel (202). Furthermore, the first shell element (10) is fully inserted into the second shell element (12) and into the end cap element (18), and is fixed therein. The invention also relates to a method for the pressure-tight assembly of the storage system (1).

The invention discloses a parameterized propeller modeling method based on a shell unit. The parameterized propeller modeling method is used for optimizing the design of a propulsion system of an aircraft. According to the method, geometric parameters and design conditions of a propeller are determined according to a design task book and working conditions; then, based on aerodynamic load distribution, chord length changes of the blades are calculated, and the torsion rule of the blades is determined according to the inflow angle and the attack angle; furthermore, a proper NACA airfoil profile is selected, and a three-dimensional geometric section of the blade is generated, so that excellent aerodynamic performance is ensured. On the basis, the connection relation between the nodes and the units of the blades is established through grid division, and a shell unit finite element grid is formed. Constructing a shell unit model by adopting an isoparametric element theory, and calculating a stiffness matrix and a mass matrix of the blade; and finally, in combination with material parameters and boundary conditions, establishing a kinetic equation, and performing modal and dynamic response analysis. According to the method, the blade design and analysis efficiency is effectively improved, the structural strength and the vibration characteristic are guaranteed, and a novel propelling solution with economical efficiency and innovativeness is provided for Boeing aircrafts and other types of aircrafts.

This invention discloses a method for identifying dynamic loads on structures based on dynamic displacement inversion and motion control equations. The method includes: dividing the structure under test into several four-node inverse shell elements; deploying sensors at the centroid positions of the upper and lower surfaces of each element; reconstructing the displacement values ​​of each element node based on the collected strain data; predicting the displacement values ​​at any position of the structure under test using a high-resolution spatial domain reconstruction algorithm based on the reconstructed displacement values ​​of each element node; discretizing the fourth-order spatial deflection derivative of the displacement field of the structure under test using the finite difference method; approximating the second-order derivative of the strain data using the second-order central difference method to obtain the higher-order spatiotemporal deflection derivative; and establishing a model of the relationship between the dynamic displacement and load distribution of the structure under test by combining the motion control equations of the structure under test, thereby achieving dynamic load identification of the structure under test. Given the known geometry and material properties of the structure, this method can not only reconstruct the time history of the dynamic loads on the structure but also simultaneously identify the load application positions.

The invention belongs to the technical field of fan blade structure analysis, and particularly relates to a parametric modeling method and system for a composite fan blade section. According to the method, an airfoil profile is reconstructed with high precision by adopting an arc length parameterization and segmented cubic Hermite shape-preserving interpolation algorithm; extruding the two-dimensional contour along the spanwise direction based on an isoparametric mapping grid generation method to generate a three-dimensional shell unit grid; dividing unit sets of skin, web plates and paving layer transition areas; defining a layering sequence and optimizing the transition distribution of the thickness and the angle in the transition area; parametrically integrating the geometric model, the grid, the material attribute and the layering definition, and generating a finite element solver input file; and outputting a geometric comparison diagram, a layering distribution diagram and a grid quality evaluation diagram through a visualization system. According to the method, full-process parameterization integration of the fan blade section from geometric modeling to finite element analysis is achieved, the modeling precision and efficiency are improved, and reliable support is provided for optimization design of the blade structure.

The invention relates to an air guide element (100) for a ventilation system of a vehicle headlight, comprising at least one component body (1) with at least one internal air guide channel, wherein the component body (1) is designed as a composite of at least two shell elements (11, 12). According to the invention, the shell elements (11, 12) are manufactured from a foamed plastic by thermoforming.

The application discloses a panel identification method and device of a three-dimensional finite element model. The method comprises the following steps: obtaining a three-dimensional finite element model; traversing the element edges of shell elements, identifying the panel boundary in the element edges according to a panel boundary judgment condition, and determining the shell elements constituting the panel; determining the nodes corresponding to the panel according to the corresponding relationship between the shell elements and the nodes and the corresponding relationship between the shell elements and the panel; determining the type of the panel according to the nodes corresponding to the panel, identifying the contour nodes of different types of panels, and the type of the panel comprises a planar panel and a curved panel; traversing the contour nodes, grouping the contour nodes according to a node grouping condition, and making each group of contour nodes correspond to the same panel edge of the panel. The application determines the contour nodes of the panel and the type of the panel by identifying the shell elements and the nodes included in the panel, and can identify all types of panels included in the three-dimensional finite element model.

The invention relates to a parametric modeling method for a plane truss of an end expansion support node, and is suitable for the field of steel structure design. The method comprises the following steps: generating a corresponding overall line unit model based on a structure type of a plane truss in combination with overall size parameters; on the basis of component size parameters of the side columns and the chord members and corresponding line segments of the overall line unit model, section feature points are determined, and then a section profile curve is generated; based on the section profile curves of the side columns and the chord members, generating shell unit models of the side columns and the chord members in combination with the corresponding line segments of the integral line unit model; determining contour feature points based on the component size parameters and the node size parameters of the support and the overall line unit model line segments corresponding to the support, and further generating a contour line of the support; based on the contour line of the support, a support web model and a support flange model are generated, and a support model is obtained; and obtaining an integral shell unit model of the plane truss based on the shell unit model of the side columns and the chord members and the supporting model.

The present application belongs to the technical field of engineering structure optimization design, and discloses a kind of topological optimization method and equipment of three-dimensional curved surface composite material thin shell structure, steps are as follows: S1, using conformal geometric mapping algorithm three-dimensional curved surface grid is mapped to the parameterization coordinate of two-dimensional plane parameter domain angle-preserving, obtain the mapping relationship of three-dimensional curved surface composite material thin shell structure from three-dimensional curved surface to two-dimensional plane;S2, construct shell element stiffness matrix of finite element grid;S3, in two-dimensional plane parameter domain, with the relative density of shell element and the direction of element as design variable, establish the topological optimization model of finite element grid based on conformal mapping;S4, based on moving asymptote method and topological optimization model to update design variable;S5, based on the design variable and mapping relationship of updated inversion mapping back original three-dimensional curved surface, thus obtain the three-dimensional configuration of optimal material distribution of three-dimensional curved surface composite material thin shell structure.The present application improves optimization efficiency.

The invention discloses a web bonding state determination method and device and a computer storage medium. The method comprises the following steps: constructing a shell unit model of the wind power blade to determine a load parameter of an external load acting on each position of a web of the wind power blade, and determining a risk position in each position according to the load parameter of each position and a preset load threshold value; constructing a three-dimensional entity model of each risk position according to the preset layering information of each risk position; and according to the three-dimensional entity model of each risk position, the web bonding state of each risk position is determined. According to the method, stress distribution nonuniformity is considered, a risk position is determined through a shell model, and a three-dimensional entity model of a local position is constructed, so that the calculated amount is reduced, and meanwhile, the accurate web bonding state is obtained.

The invention discloses a hyperelastic constitutive calculation method compatible with three-dimensional and shell elements, which comprises the following steps: establishing a unified theoretical framework of an elastic constitutive as a basis by strictly deducing a unified solution process of the hyperelastic constitutive, and representing stress and a consistent tangent stiffness matrix as a deformation gradient; a user only needs to provide a small number of expressions or parameters such as first two-order derivatives of a strain energy function about an invariant or a main tensile value, a unit dimension, a stress objective rate type and the like, and outputs stress and consistent tangent stiffness, so that the user input is minimized, and the user experience is improved. The successful implementation of the hyperelastic constitutive structure with different unit types, different stress objective rates and different strain energy forms under a unified solution system in a finite element is realized.

The invention discloses a virtual shell method for ship vibration forecast attached water calculation, which comprises the following steps of: establishing a virtual ship hull shell unit on a node of an original ship hull shell unit based on a whole ship finite element model; the grid size of the virtual hull shell unit is larger than that of the original hull shell unit; the virtual hull shell unit is used for a grid unit for carrying out attached water mass calculation. According to the method, the workload of attached water mass calculation can be greatly reduced, the calculation time is greatly shortened, calculation resources are saved, and the vibration forecasting precision is guaranteed.

The application provides a corrugated box finite element modeling method for simulating package falling, comprising the following steps: S1: determining equivalent elastic mechanics parameters of corrugated paperboard; S2: verifying whether the equivalent plate anisotropic elastic mechanics parameters are accurate, and if yes, entering S3, otherwise, returning to S1 until the equivalent plate anisotropic elastic mechanics parameters pass the verification; S3: establishing a paper box geometric model, decomposing the paper box into six surfaces of upper, lower, left, right, front and back, modeling each surface by adopting a shell element, and setting topology sharing; S4: respectively giving each surface of the paper box corresponding material properties; S5: dividing the paper box grid model by adopting a quadrilateral, and completing contact setting of the paper box and other PART, setting boundary conditions and load, and solving setting. The method solves the problem that the simulation calculation result of the package falling is not accurate and reliable due to the modeling error of the paper box by combining mechanical test and theoretical formula.

The invention relates to a thin-wall structure model generation method and device, engineering machinery and a medium, and relates to the technical field of engineering machinery. The model generation method comprises the following steps: discretizing a thin-wall structure into a plurality of shell units by utilizing a finite element analysis method, wherein each shell unit in the plurality of shell units comprises a plurality of nodes; dividing the first mass value of the thin-wall structure into a second mass value corresponding to each node in the plurality of nodes, and determining the translational inertia force of each shell unit according to the second mass value and the position vector of each node in the global coordinate system; dividing the first rotational inertia value of the thin-wall structure into a second rotational inertia value corresponding to each node, and determining the rotational inertia force of each shell unit according to the second rotational inertia value and the angular velocity vector and the angular acceleration vector of each node under the global coordinate system; and generating a dynamic model of the thin-wall structure according to the translation inertia force and the rotation inertia force.

The application belongs to the technical field of aircraft thin-walled structure design, and particularly relates to a correction method of quadrilateral shell element in finite element analysis of aircraft thin-walled structure, which comprises the following steps: step one, establishing an element coordinate system for the quadrilateral shell element; step two, establishing a balance equation of a plane stress element related to in-plane deformation under the element coordinate system, and calculating a plane stress element stiffness matrix; step three, establishing a balance equation of a bending plate element related to out-of-plane deformation under the element coordinate system, and calculating a bending plate element stiffness matrix; step four, applying an in-plane rotation penalty term to the rotational stiffness of the quadrilateral shell element, calculating the influence of the in-plane rotation penalty term on the strain energy function of the quadrilateral shell element under the element coordinate system, and obtaining an in-plane rotation stiffness matrix; step five, calculating the stiffness matrix of the quadrilateral shell element under the element coordinate system; and step six, performing coordinate transformation to obtain the stiffness matrix of the quadrilateral shell element under the overall coordinate system.

A press forming analysis method according to the present invention uses a finite element method, and predicts a press forming load using a die model 9 having an upper die model 11 and a lower die model 17 modeled by shell elements. The press forming analysis method comprises: an elastic body element-imparted lower die model creation step S1 in which a lower structure 7 of a press device is modeled by an elastic body element 15 and imparted to the lower die model 17 to create an elastic body element-imparted lower die model 13; an elastic coefficient determination step S3 of determining an elastic coefficient to be imparted to the elastic body element 15; and a press forming load acquisition step S5 of performing press forming analysis using the die model 9 including the elastic body element-imparted lower die model 13 modeled in the elastic body element-imparted lower die model creation step S1, to acquire the press forming load.

The invention belongs to the technical field of corrugated steel plate shear wall simulation, and particularly provides a construction method of a corrugated steel plate shear wall structure simplified model, and the simplified model is established in ABAQUS finite element software. The corrugated steel plate is equivalent to an orthotropic flat steel plate with the same thickness, and an S4R shell unit is used for modeling; selecting a 3-node B32 beam unit to represent an edge component; frame beams and frame columns are simplified into line units, the line units of the frame beams and the line units of the frame columns form a two-dimensional frame through optimized semi-rigid connection or rigid connection, and the line units are provided with section parameters. The initial rigidity and the ultimate bearing capacity of the semi-rigid connection corrugated steel plate shear wall analyzed by the simplified model and the refined model are well matched, and load-displacement curves basically coincide.

The invention provides a bidirectional coupling simulation calculation method, device and equipment for ship local slamming upwave water elasticity, and the method comprises the steps: determining a structure node hydrodynamic load of a local structure grid of a ship local structure based on the displacement and flow field effect generated by the ship local structure during slamming upwave and a preset shell unit model; in each solving time step, determining a structure node displacement update value of the local structure grid based on a structure node hydrodynamic load; based on the structure node displacement update value, determining a boundary node displacement update value of a surface fluid grid of the ship local structure and a flow field computational domain grid update value; and performing flow field iteration simulation calculation based on the flow field calculation domain grid update value until a comparison result of two adjacent iteration simulation calculation results is smaller than a preset threshold value or the number of iterations is larger than an iteration number threshold value. According to the scheme provided by the invention, refined simulation of load distribution and local structure response of the ship local structure under the action of the slamming load is realized.

The invention discloses a nuclear power cooling tower structure safety analysis intelligent agent operation and maintenance method based on an industrial physics AI engine, relates to the technical field of nuclear power, and provides a method for simulating concrete and double-layer two-way reinforcing steel bar layers by adopting a common-node multi-layer shell unit, and considering normal bias of each reinforcing steel bar layer relative to the middle surface of a tower wall; according to the method, three-dimensional solid modeling of a reinforced concrete structure is replaced with a traditional method, the number of degrees of freedom of the model is reduced on the premise that real structure composition is reflected, and in the aspect of material nonlinearity, a nonlinear damage model and a linear hardening model are adopted for simulating mechanical behaviors of concrete and steel bars respectively; the integration of the independent nonlinear constitutive model of the reinforced concrete, the superposition calculation of the total tangent stiffness matrix and the separation and extraction of the stress result of the reinforced concrete are realized, so that the solving efficiency and precision are improved, a more efficient finite element industrial engine is accessed to the AI intelligent operation and maintenance service flow of the nuclear power cooling tower, and the stability and damage condition of the cooling tower are intuitively predicted.

The invention discloses a kinetic parameter prediction method, system and equipment in the mirror image milling process of a thin-walled workpiece, a medium and a product, and relates to the technical field of machining.The method comprises the steps that in the mirror image milling process of the thin-walled workpiece, for the thin-walled workpiece in any milling state, any milling state serves as the current milling state, and the current milling state serves as the current milling state; taking the thin-wall part in any milling state as a to-be-predicted thin-wall part in the current milling state; discretizing the to-be-predicted thin-wall part in the current milling state into a plurality of to-be-measured shell units in the current milling state by adopting a finite element analysis method, and determining the thickness value of each to-be-measured shell unit in the current milling state; and inputting the thickness values of all the to-be-measured shell units in the current milling state into the thin-wall part mirror image milling kinetic parameter prediction model to obtain predicted values of kinetic parameters of the to-be-predicted thin-wall part in the current milling state. According to the invention, the prediction precision and prediction efficiency of the time-varying kinetic parameters are improved.

The application discloses a kind of based on pile soil coupling's fan tower structure safety evaluation method and equipment, belong to offshore fan operation technology field.The application of a kind of based on pile soil coupling's fan tower structure safety evaluation method, by constructing fan monitoring model, fan load simulation model, tower response calculation model, monitoring data are handled, obtain the load that fan bears;Again using soil spring algorithm and shell element simulation algorithm, simulate the response of tower under the action of the load that fan bears, so that simulation model is closer to real scene, effectively avoid the error caused by excessive simplification, improve simulation precision and evaluation result.Further, the application can analyze the source of fan load, and accurately calculate the fan load, so that the uneven distribution of load and stress on the local section of fan tower can be fully considered, so that the fan load can be accurately simulated, and the evaluation of offshore fan tower is more accurate.

This invention belongs to the field of structural optimization technology. It discloses a full-scale design method for porous stiffened shells based on multi-piece isogeometric topology optimization. The steps are as follows: (1) Divide the thin shell structure and the stiffening region into high-order NURBS element meshes respectively; (2) Use isogeometric Kirchhoff-Love shell elements to describe the thin shell structure and three-dimensional solid elements to describe the stiffening region. Decompose the high-order NURBS element mesh into Bézier elements, and then construct solid-shell coupled elements; (3) Set the equivalent density as a design variable on each solid element. Transform the design variable into the equivalent density on the control points of the thin shell by applying mapping constraints. At the same time, introduce local volume constraints on the design variable to obtain bone-like porous stiffening, and then construct a full-scale multi-piece isogeometric topology optimization model for porous stiffened shells, and finally obtain the optimized porous stiffened shell structure. This invention improves applicability.

The invention provides a finite element model dynamic analysis and conversion method and system based on MATLAB. The method comprises the steps that an Abaqus INP file is read, and node coordinates, unit connection relations, unit grouping and section parameters are dynamically recognized and extracted; aiming at a shell unit, analyzing a node connection relation of the shell unit, establishing a mapping table from unit ID to thickness, generating a unique thickness list, writing the unique thickness list into SECTIONHELL of LS-DYNA, and forcibly setting the thickness values T1-T4 to be the same; the method comprises the following steps: aiming at a beam unit, analyzing a generate parameter in Elset to generate a continuous unit ID sequence, extracting a section parameter according to Beam Section, and mapping the section parameter to SECTIONBEAM of LS-DYNA; and an LS-DYNA K file is generated according to the sequence of the nodes, the shell units and the beam units, and corresponding section attributes and grouping information are associated. According to the method, the finite element model file of Abaqus is dynamically analyzed, complete reservation of unit grouping information, accurate extraction of complex section parameters and consistency processing of shell unit thickness are achieved, the unit grouping information is efficiently and accurately converted into the K file format of LS-DYNA, and the efficiency and reliability of multi-software co-simulation in the ship and ocean engineering field are improved.

The invention provides a structural member residual stress compensation analysis method and device. When the method is executed, simulation data of a structural part formed by stamping a simulation plate of stamping simulation software is obtained firstly, and the simulation data comprises a residual stress field stored in a shell unit node stress tensor form; mapping the residual stress field to a static strength grid of the structural member, and constructing a static strength model of the structural member; then correcting a stress-strain curve of the local material of the structural member based on the mapped residual stress value; and finally, based on the static strength model and the stress-strain curve of the local material of the structural member, in combination with the test working condition and the assembly constraint of the structural member, performing statics solution to obtain failure data, and based on the failure data, determining whether the structural member has a failure risk. In this way, the stress-strain curve of the local material of the structural member is corrected and adjusted based on the residual stress value, and failure analysis is conducted on the structural member more accurately.