69 results about "Isogeometric analysis" patented technology

A method of Convolution-Hierarchical Deep-learning Neural Network isogeometric Analysis (C-IGA) of a geometric shape of a subject matter comprises performing a first mapping process between a physical domain of a subject matter and a parametric domain of the subject matter; and performing a second mapping process between the parametric domain of the subject matter and a parent domain of the subject matter; wherein the first mapping process comprises constructing an C-IGA interpolation in the parametric domain based on CAD data of the subject matter.

The invention provides a composite material skin isogeometric modeling method considering micro-pores, which comprises the following steps: obtaining internal characteristics of a composite material skin through an SEM scanning electron microscope, and establishing parameterized unit cell microstructure units according to the characteristics; determining a skin deformation area, constructing a constitutive matrix based on different components in the composite material, obtaining and endowing defined material attributes, and obtaining different unit mass matrixes and local stiffness matrixes in the area; and filling into the macroscopic overall matrix through an isogeometric mapping strategy, carrying out inverse mapping fitting on a skin appearance structure, and carrying out applied load calculation. According to the method provided by the invention, through an isogeometric analysis method, three-dimensional curved surface dimension reduction processing is realized, and the calculation cost is reduced; meanwhile, a parameterized microscopic unit is considered to ensure the accuracy of modeling; and the mechanical property of the composite material skin is really simulated. The method is suitable for the structure elasticoplastic deformation state that the skin bears large load, large deformation and the like, and calculation operation is easy and convenient.

The invention discloses an acoustic black hole beam dynamic analysis method, which relates to the technical field of structural dynamics and acoustics, and comprises the following steps: step 1, establishing an acoustic black hole beam theoretical model; 2, according to the Euler-Bernoulli beam theory, the displacement field components of the moment t and the acoustic black hole beam point x can be expressed as # imgabs0 #; and 3, the NURBS function is used for describing the geometry and displacement of the acoustic black hole beam. According to the acoustic black hole beam vibration characteristic and energy transfer analysis method based on isogeometric analysis and the finite element thought, the calculation efficiency is improved while the geometric accuracy is guaranteed, a powerful tool is provided for optimization design and performance evaluation of an acoustic black hole structure, and through deep analysis of energy transfer and distribution characteristics, the method has the advantages that the calculation efficiency is improved; the mechanism of the acoustic black hole effect can be further revealed, and a new thought and method are provided for development of the vibration and noise reduction technology.

An adaptive geometric modeling method for assembled thin-walled component structures oriented to integration of modeling, analysis and optimization, includes firstly, using a multi-level NURBS-based free-form deformation (MNFFD) technique to realize accurate geometric modeling of an assembled thin-walled component structure; secondly, establishing a modeling-analysis unified model suitable for isogeometric analysis of the assembled thin-walled component structure based on an MNFFD method; finally, establishing a modeling-analysis-design unified model suitable for collaborative design of a shape and a stiffened layout of the assembled thin-walled component structure based on the MNFFD method. The present invention fundamentally solves the modeling robustness problem of gaps and overlaps between thin-walled components due to the lack of accurate topological consistency in traditional modeling methods, provides a new tool for optimization design of engineering thin-walled structures. MNFFD is used, so that the geometric dimension reduction transformation from 3D design domain to 2D design domain can be realized.

The invention provides a viscoelasticity isogeometric topology optimization method under transient load based on BESO, and belongs to the technical field of isogeometric topology optimization, and the method comprises the following steps: carrying out isogeometric gridding on a model to be designed, and obtaining a control point and a Gaussian point coordinate corresponding to each unit; constructing a long-term global stiffness matrix and a global quality matrix; determining an optimized target volume; on the basis of constructing a long-term global stiffness matrix, a tangent stiffness matrix and a historical stiffness matrix are obtained, and geometric analysis such as viscoelasticity is carried out. Calculating a target value of the structure according to the optimization problem definition, and calculating the sensitivity of a target function relative to a design variable by adopting an adjoint method; after the sensitivity value of each unit is filtered through a distance filter, the sensitivity value is expanded into sensitivity at a control point through an NURBS filter, and a global sensitivity field is established; and updating the design variables according to the set evolution ratio parameters. According to the invention, the response of the structure under complex dynamic loading can be accurately simulated.

The invention belongs to the field of material structure optimization, and particularly relates to an isogeometric topological optimization method based on dynamic response driving, which comprises the following steps of: (1) establishing a thin shell mid-plane geometric representation model based on a T spline and Bessel extraction technology; (2) establishing a frequency response-oriented isogeometric shell unit based on the Kirchhoff theory; (3) solving the aerodynamic response of the surface of the structure based on a high-order panel method of a T spline; (4) constructing a topology description model of the thin shell based on a Bessel unit; (5) establishing a structure dynamic flexibility minimum topological optimization model oriented to the dynamic response of the pneumatic thin shell; (6) dynamic flexibility minimization sensitivity analysis and derivation; and (7) updating optimization model design variables based on an optimal criterion method. According to the method provided by the invention, a pneumatic coupling thin shell dynamic isogeometric analysis framework is constructed, and the problems of poor geometric adaptability, difficulty in complex thin shell dynamic design, lack of pneumatic environment related to optimization and the like in an existing method are effectively solved.

The invention belongs to the technical field of road traffic noise reduction, and particularly relates to a sound barrier shape optimization method based on an isogeometric particle swarm singular boundary method. Comprising the steps of building a sound barrier geometric model, building a sound barrier shape optimization model, building a Burton Miller type singular boundary method program, calculating sound pressure, carrying out particle swarm iterative solution, outputting an optimization result and the like. According to the method, the model is optimized based on the isogeometric singular boundary method of the basic solution of the acoustic control equation for the first time, the model is applied to the optimization design of the sound barrier, the sound barrier is optimized by combining the particle swarm optimization method, only the size of the target function is needed, complex sensitivity derivation is not needed, and when the sound barrier with the complex shape is calculated, the method is simple and convenient to operate. The method has great flexibility and high efficiency, seamless integration between CAD and CAE is realized by introducing isogeometric analysis, namely representing geometric boundaries by using an NURBS function, and a tedious grid division step in an optimization process is avoided, so that the precision and efficiency of sound barrier optimization are remarkably improved.

The invention discloses an isogeometry-based composite material thin shell dynamics prediction method, and belongs to the field of composite material thin shell dynamics behavior prediction. The implementation method comprises the steps that geometric modeling is conducted on the composite thin shell based on an isogeometric analysis method, unification of geometric modeling and numerical analysis is achieved through a non-uniform B spline (NURBS), and a composite thin shell geometric model is obtained; calculating a tensile stiffness matrix, a tensile-bending coupling stiffness matrix and a bending stiffness matrix of the composite material thin shell through the composite material parameters; establishing a kinetic model of the composite material thin shell unit through continuous medium mechanics, assembling the kinetic model to obtain an overall kinetic model of the composite material thin shell, and establishing a kinetic equation of the composite material thin shell based on the overall kinetic model of the composite material thin shell and the stiffness matrix; a kinetic equation is solved based on a generalized alpha implicit time integration algorithm, the kinetic behavior of the composite thin shell under the action of an external force F is predicted, and the stability and precision of thin shell kinetic behavior prediction are improved.

The invention discloses a solver error control development method and system based on isogeometric analysis, and relates to the technical field of computational mechanics and numerical analysis, and the method comprises the steps: building an NURBS primary function according to isogeometric analysis, carrying out the grid division, generating initial grid data, calculating the stress error index of each grid unit through employing a Zienkiewicz-Zhu method, and carrying out the calculation of the stress error index of each grid unit. Grid optimization parameters are generated, local encryption processing is carried out on grid units, the order of an NURBS primary function is improved by adopting a p-refinement method, and an optimized grid structure is obtained; and inputting the optimized grid structure into a solver for iterative calculation, and when a calculation error is smaller than a preset error threshold value, outputting a solving result. According to the method, the optimal balance between the calculation precision and the resource consumption is realized through the precise geometric expression and the self-adaptive grid division of the NURBS primary function in combination with the Zienkiewicz-Zhu posterior error estimation technology.

The invention discloses a topological optimization method, device and equipment for material distribution based on particle flow, and relates to the technical field of material structure optimization. According to the method, isogeometric analysis is introduced into the material point method in topological optimization of material distribution, the isogeometric material point method is provided, consistency between geometric modeling and numerical analysis is achieved through a unified primary function of isogeometric analysis, benefit from high-order continuity of the primary function of isogeometric analysis, and the method has the advantages that the method is simple and convenient to implement. The introduction of isogeometric analysis can effectively eliminate and suppress numerical artifacts in topological optimization and unit cross instability in a traditional substance point method. According to the isogeometric material point method, movable particles of material distribution in a physical domain serve as design variables, a set of particle-grid physical information and sensitivity transmission model is established in combination with Lagrange-Euler mixed description, corresponding accurate geometric topology is output while particle evolution is achieved, and the method has the advantages of being high in accuracy and high in reliability. And the accuracy and the flexibility of topological optimization of the material distribution structure are remarkably improved.

The invention provides an isogeometric analysis-oriented high-efficiency fatigue topological optimization method, which belongs to the technical field of geometric analysis and mainly comprises the following steps of: constructing a fatigue problem model, dividing the number of layers of a multi-layer grid method and the size of a design domain according to the requirements of the design domain, and generating an isogeometric node vector of the lowest layer by using h insertion; according to the isogeometric node vector, assembling each level of interpolation operator and continuation operator of the multi-grid method; decomposing and storing independent load components in the load spectrum, and solving a combined weight of each independent load component; an overall stress spectrum is obtained according to weight assembly; evaluating the fatigue constraint of the fatigue damage of the unit; approximately expressing the fatigue constraint topological optimization problem according to an augmented Lagrangian method; and performing updating iteration of the isogeometric analysis design variable until the convergence of the fatigue constraint topological optimization problem is judged according to the design variable variation. According to the scheme, the simplified calculation and counting problems of the multi-cycle general fatigue load spectrum are improved, and the solving cost is reduced.

The invention relates to the technical field of medical image processing, and discloses a temporomandibular joint three-dimensional reconstruction system based on joint imaging diagnosis. The system utilizes CBCT equipment to collect temporal-mandibular joint tomographic image data, and extracts facial feature sites and maxillofacial joint standard model approval sites through a multi-scale residual network. And carrying out space registration by adopting an affine transformation and nonlinear optimization algorithm to generate a synchronous correction parameter, further carrying out deformation interpolation on the standard model of the maxillofacial joint to construct a maxillofacial model, and adjusting the position of a condylar process. And based on the deformed maxillofacial model, generating an occlusal plate structure model by using an isogeometric analysis method, and iteratively optimizing the degree of fit through an edge calculation frame. The system can accurately reconstruct the three-dimensional model of the temporomandibular joint, optimizes the adaptation of the biteplate, provides powerful support for the diagnosis and treatment of temporomandibular joint diseases, and facilitates the improvement of the diagnosis and treatment level.

The invention discloses a motorized spindle thermal characteristic analysis modeling method based on multi-patch isogeometric analysis, which comprises the following steps: S10, carrying out geometric modeling of a high-speed motorized spindle: constructing a multi-patch solid model comprising a motorized spindle stator, a rotor, a bearing and a cooling pipeline of the high-speed motorized spindle by adopting a three-dimensional NURBS patch splicing technology, geometric continuity and parameterization consistency are ensured; s20, performing heat conduction analysis: constructing a transient heat conduction control equation based on a Fourier heat conduction differential equation in combination with high-order smoothness characteristics of the IGA, and solving a temperature evolution process in a time domain through a backward difference method; and S30, performing thermal error modeling: introducing an elastic mechanical constitutive relation and a fixed support boundary, and establishing a thermal-force coupling solving framework.

The invention discloses an efficient Catmull-Clark subdivision volume isogeometric analysis method, which comprises the following steps of: S1, for a CC subdivision volume initial grid input file in an. Inp format, reading geometric information, topological information, load information, constraint information and material information of a CC subdivision volume grid through a data structure; s2, applying a Catmull-Clark subdivision scheme to subdivide the initial grid of the CC subdivision body into a hierarchy suitable for analysis, and calculating an equivalent constraint and an equivalent load; s3, for each hexahedron unit in the subdivided CC subdivision body grid, calculating a CC subdivision body unit primary function of the hexahedron unit according to grid information and unit mapping; s4, solving a stiffness matrix of the subdivided CC subdivided volume unit according to a primary function calculation method of the CC subdivided volume unit; and S5, assembling the CC subdivision volume element stiffness matrix and the linear equation set to obtain a displacement field U of all degrees of freedom, and writing the displacement field U into a vtk file to visualize the displacement field. According to the method, the physical simulation speed of the CC subdivision body is improved on the premise of ensuring the precision.

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 belongs to the technical field related to robot machining, and discloses an optimal design method and equipment for a three-dimensional complete continuous functional gradient lattice extension rod, and the method comprises the steps: constructing a mapping relation between geometric and physical properties of a lattice structure; by combining the continuous, smooth and locally controllable characteristics of the NURBS body, the completely continuous characterization and regulation of the property distribution of the functionally gradient lattice structure are carried out, the completely continuous smooth transition of the lattice structure in a three-dimensional space is realized, and compared with an incomplete continuous functionally gradient lattice structure, the preparation method has the advantages that the preparation cost is reduced; the completely continuous functional gradient lattice structure has higher structural strength and optimization potential; a high-order shear beam theory and an isogeometric analysis method are combined to construct a dynamic model of a three-dimensional complete continuous functional gradient lattice structure, and a theoretical basis is provided for subsequent robot system dynamic modeling of an additional lattice extension rod; on the basis of the method, distribution characterization-regulation and control design-performance analysis of the three-dimensional completely continuous functional gradient lattice structure can be realized.

The invention discloses a B-spline finite element analysis topological optimization method based on a neural network, which fuses a non-uniform rational B-spline (NURBS) and a physical information neural network (PINNs), and comprises the following steps of: performing geometric region and structural density representation by using the NURBS, inputting a control point of a geometric region into an isogeometric neural network based on the PINN, and outputting a density control point; then, isogeometric analysis is used for displacement calculation, and a structural performance index is calculated as loss. And finally, performing sensitivity analysis by using a built-in back propagation mechanism so as to optimize density field distribution. The optimized density field is obtained through continuous forward propagation, performance index (such as flexibility) calculation, back propagation and weight updating until a preset convergence condition or the maximum number of iterations is reached. According to the method, the modeling capability of the neural network and the accuracy of finite element analysis based on the B-spline can be effectively combined, and efficient and accurate topological optimization is realized.

An adaptive geometric modeling method for combined thin-walled component structures with integrated modeling-analysis-optimization. First, the free deformation technology MNFFD based on multi-level NURBS is used to realize accurate geometric modeling for combined thin-walled component structures. Secondly, a unified modeling-analysis model suitable for geometric analysis of combined thin-walled component structures is established based on the MNFFD method. Finally, a unified modeling-analysis-design model suitable for the collaborative design of the structural shape and reinforcement layout of combined thin-walled components is established based on the MNFFD method. The present invention fundamentally solves the modeling robustness problem of gaps and overlaps between thin-walled components caused by the lack of precise topological consistency in traditional modeling methods, provides a new tool for the optimal design of engineering thin-walled structures, can greatly improve product design accuracy and shorten the development cycle; the use of MNFFD can realize the geometric dimensionality reduction conversion from three-dimensional design domain to two-dimensional design domain, and breaks through the problem of adaptive updating of design models, and realizes the decoupling of design domains of combined thin-walled component structures with complex assembly relationships.

The invention is suitable for the technical field of heat conduction analysis, and relates to an underground granary heat insulation performance simulation method based on axisymmetric geometric analysis, which utilizes a non-uniform rational B-spline (NURBS) primary function to accurately represent a geometric shape and approximate a physical field, realizes the unification of modeling and analysis data, and improves the heat insulation performance of an underground granary. The axisymmetric characteristics and boundary conditions of the granary are fully utilized, geometric analysis system equations and solving formats such as the axisymmetric heat conduction problem are deduced in a cylindrical coordinate system from an axisymmetric steady-state heat conduction problem control equation on the basis of the variational principle, and a general three-dimensional problem is reduced into a two-dimensional problem; efficient utilization of the degree of freedom of calculation is achieved, then temperature field and heat flux density distribution characteristics of a granary body-soil body system are analyzed, the influence rule of different conditions on underground granary heat conduction is revealed through parameterization research, and a high-order continuous interpolation basis function is introduced to obtain a high-order continuous interpolation basis function; the calculation precision and calculation efficiency of underground granary temperature field analysis are effectively improved.

The invention discloses a shape optimization method of a pipeline support structure based on isogeometric analysis, and belongs to the technical field of pipeline shape optimization. The problem that an existing pipeline support structure is poor in vibration reduction performance is solved. The method specifically comprises the following steps: step 1, identifying edge information of a pipeline support from an image containing the pipeline support, extracting a contour line from the edge information, and extracting a contour point from the contour line as a control point; parameterization description is carried out on the coordinates of the control points, and a two-dimensional plane parameterization model of the pipeline support is obtained; 2, taking the abscissa of a control point in the two-dimensional plane parameterized model as a design variable, and establishing a target function according to the design variable; step 3, establishing a shape optimization mathematical model based on the objective function and the system balance equation; and 4, solving the shape optimization mathematical model, and completing the shape optimization of the pipeline support structure according to the abscissa optimization result of each control point. The method can be applied to shape optimization of the pipeline support structure.

The invention relates to the technical field of electrical equipment fault prediction, and discloses a converter valve weak link solving method and device, a storage medium and computer equipment, and the method comprises the steps: building a substructure model corresponding to a system of a to-be-discriminated converter valve, and carrying out the interpolation optimization, and obtaining a plurality of reduced-order substructure models; distributing the reduced-order substructure model to a plurality of processors for parallel processing, calculating an analysis result by using an isogeometric analysis method, solving the analysis result by using a multi-objective evolutionary algorithm, and performing optimization iteration on a solution of each finite element model by using a Pareto transfer strategy to obtain an optimal parameter set; and constructing a nonlinear equation according to the operation data of the converter valve to be discriminated, solving the nonlinear equation by using the optimal parameter set, and identifying a temperature abnormal point of the converter valve to determine a weak link. According to the method, the weak link identification speed and precision of the converter valve are improved, the temperature abnormal region is accurately positioned, and clear fault diagnosis information is provided for maintenance personnel.

The invention discloses a method for generating a quadrilateral curved surface grid, the quadrilateral curved surface grid can cover the curved surface of a three-dimensional object so as to analyze the three-dimensional object, and the method comprises the following steps: obtaining a curved surface digital geometric model of the three-dimensional object; constraint on grid singular point configuration on the curved surface is received, the singular point configuration comprises at least one designated position and a target price number of the designated position, and the price number represents the number of edges connected with grid vertexes; on the basis of the Riemannian-Rooch theory, a finite-dimensional quadrilateral grid generation space is constructed within the range meeting singular point configuration constraints, and construction comprises calculation of a primary function of a sub-pure function linear space L (D) corresponding to singular point configuration; selecting a specific grid generation parameter combination from the quadrilateral grid generation space; a quadrilateral curved surface grid is generated and output according to the grid generation parameter combination, and singular point distribution of the grid conforms to the received constraint; and the quadrilateral curved surface grid is provided for a finite element analysis or isogeometric analysis solver and is used for carrying out simulation analysis of mechanics, thermotics or fluid dynamics on a three-dimensional object.

The invention provides an isogeometric analysis control grid-oriented graph neural network Poisson equation solving method. The method comprises the following steps of S1, matching data set acquisition and input formats; s2, carrying out proportion division on the data set; s3, constructing a graph neural network model; s4, performing model training and parameter initialization; training a model by using a training set, and monitoring a training effect through a verification set by taking Poisson solution error minimization and operation speed maximization as targets; step S5, Poisson solution and performance verification: executing Poisson solution by using the test set, calculating a solution error and a running speed which need to be superior to a file specified standard, and returning to adjust model parameters and retraining if the standard is not reached; and S6, outputting a result. Step S7, Main file integration and interface implementation: writing Main file integration functions from the step S1 to the step S7; according to the method, the problem that the compatibility of a data set and input of an existing method is limited remarkably in the engineering simulation and scientific calculation process can be solved.

This invention discloses a structural thermo-mechanical coupling method and apparatus considering isogeometric analysis, belonging to the field of thermodynamics. The method includes: S1. Establishing an isogeometric NURBS model: providing the basis for expressing geometric and physical fields for thermo-mechanical coupling analysis, achieving seamless integration of CAD and CAE; S2. Calculating the transient temperature field based on the central difference method: obtaining the temperature distribution of the structure at different times, providing temperature input for subsequent thermo-mechanical coupling; S3. Transforming the temperature field into equivalent temperature loads: converting the thermal effects caused by temperature changes into equivalent loads identifiable by structural mechanics analysis; S4. Solving the stiffness equation of the structure under the combined action of external forces and temperature: obtaining the displacement matrix of the structural control points; S5. Solving the structural coupling field based on the displacement matrix: obtaining all key physical quantities in the thermo-mechanical coupling field, completing the coupling analysis. This invention can verify the feasibility of applying isogeometric analysis in coupled fields.

The application relates to the field of artificial intelligence, and particularly discloses an industrial design parameterized design system with multidimensional simulation feedback, which comprises a parameterized modeling module, a multidimensional simulation module, a simulation agent model construction module, a multidimensional feedback fusion and optimization module, an iterative convergence discrimination module and an interactive visual feedback module; the parameterized modeling module is used for generating an integrated parameterized three-dimensional model containing geometric features, material distribution and topological structure according to input design parameters. The application constructs an integrated parameterized three-dimensional model fusing geometric features, material distribution and topological structure, realizes millisecond-level real-time updating of the model through an incremental constraint solver, adopts an isogeometric analysis method based on NURBS, unifies the discretization process of modeling and simulation, avoids model conversion errors and realizes seamless connection of parameterized modeling and multi-physical field simulation.

The invention discloses an assembly joint surface contact deformation prediction method based on an enhanced depth operator network. Comprising the following steps: firstly, establishing an isogeometric analysis model of an assembly joint surface, and constructing a joint surface deformation data set by changing the rough morphology of the joint surface of the isogeometric analysis model and changing different loading forces; then, constructing an enhanced depth operator network, and training the enhanced depth operator network by using the joint surface deformation data set to obtain an assembly joint surface contact deformation prediction model; and finally, inputting the rough morphology and the loading force of the to-be-measured assembly joint surface into the assembly joint surface contact deformation prediction model, and outputting an assembly joint surface contact deformation result by the model. According to the method, the image generator is used as a backbone network of the depth operator network, so that the prediction precision of the depth operator network on the contact deformation of the assembly joint surface is enhanced. The method can be used as a rapid evaluation tool for the product part assembly joint surface rough morphology optimization design effect.

The invention discloses a non-pneumatic tire topological optimization method based on isogeometric analysis in the technical field of wheel design, and aims to solve the problems of low analysis precision and low solving speed due to the fact that finite element analysis is generally adopted for optimization work in the prior art. The method comprises the following steps: performing parametric modeling on a non-pneumatic tire based on an NURBS curve to obtain a parametric model, performing grid division on the parametric model, obtaining units, a design domain and a structure model, dividing the units into multiple types of units under a fixed equidistant geometric background grid, and introducing boundary conditions under different working conditions based on the parametric model and the multiple types of units to obtain a design domain of the non-pneumatic tire. Analyzing the stress distribution and the displacement vector of the non-pneumatic tire to obtain a stress distribution matrix; according to the method, the situation that a straight line segment and an arc are discontinuous in traditional finite element analysis is overcome, the topological optimization precision is improved, the calculation time is shortened, the service life of the non-pneumatic tire is prolonged, the performance of the non-pneumatic tire is improved, and meanwhile the working efficiency of structural design optimization is guaranteed.

The present invention discloses a three-dimensional CAD reconstruction method for pixel-based topology optimization results, comprising the following steps: S1, performing a smoothing operation on the discrete voxel model generated from the topology optimization result; S2, extracting the triangular mesh on the surface of the smoothed discrete voxel model to generate a skeleton line of the triangular mesh model; S3, simplifying the skeleton information of the triangular mesh model; S4, generating a coarse skeleton model; S5, performing a Catmull-Clark volume subdivision operation on the coarse skeleton model and projecting the surface vertices onto the surface triangular mesh generated in step S2 to generate a Bézier volume model, which can conveniently and efficiently convert the discrete hexahedral mesh model generated by topology optimization into a Bézier volume model. It has a significant advantage in the number of generated Bézier volume models, and at the same time eliminates the jagged structure of the discrete hexahedral mesh model, having application value in the field of topology optimization. The model reconstructed by CAD can also be applied to isogeometric analysis and has application value in the field of isogeometric analysis.

The invention provides a porous structure-oriented dynamic fracture process simulation and fracture toughness evaluation method, and relates to the technical field of fracture toughness and safety evaluation of structures under the action of dynamic loads. According to the method, an existing second-order phase field dynamic fracture simulation method is expanded to a fourth-order method, so that a C1 continuous primary function is constructed by adopting a PHT spline based on isogeometric analysis; in order to improve the calculation efficiency, a grid adaptive refinement strategy is introduced into a numerical value implementation scheme, a transmission scheme comprising a node field quantity and an integral point field quantity is formulated, most of the existing adaptive phase field fracture methods based on isogeometric analysis neglect the field quantity on a transmission integral point, and the field quantity on the transmission integral point cannot be reduced. Therefore, the phenomenon of crack healing possibly occurring in the loading process of the structure is caused. Compared with a method for carrying out calculation by adopting a fixed grid, the method can greatly improve the calculation efficiency; the calculation result of the method converges to grid refinement and time increment step reduction, and the stability of the calculation result can be effectively guaranteed.

The application discloses an isogeometric analysis simulation method of a hyperelastic material model based on body subdivision. The isogeometric analysis adopts the division of a spline model parameter domain and the mapping of the parameter domain to a physical model, avoids the time consumption of mesh division in a finite element, and realizes an integrated process from modeling to simulation in combination with a CC subdivision method. The application comprises the following steps: converting a CC subdivision body into a spline body model, and establishing a mapping relationship of control points of the subdivision body and the spline body; establishing a hyperelastic material constitutive model according to geometric boundary conditions and material parameters; establishing a discrete balance equation of the model according to an isogeometric method; in combination with the balance equation, establishing a model motion equation and a nonlinear solving system; using a Newton iteration method to solve the nonlinear system, obtaining displacement solutions at each time step, and mapping the displacement solutions back to the subdivision body, so as to realize deformation simulation of the subdivision body.