9 results about "Continuum mechanics" patented technology

The invention discloses a method for predicting mechanical properties of ultra-high performance concrete, particularly relates to the technical field of dynamic property analysis of building materials, and aims to solve the problem that sudden brittle failure of materials cannot be accurately predicted under impact and explosion loads in the conventional method. The method comprises the following steps: calculating a macroscopic stress-strain response based on a continuum mechanical equation by acquiring a material ratio parameter and a dynamic load condition; constructing topological features through the strain energy entropy change rate to locate a damage area; determining an interface debonding energy threshold value and a crack growth rate of the damaged area in combination with interface fracture mechanics; utilizing the law of conservation of energy to establish dynamic correlation between interface debonding energy and strain energy density; when the crack growth rate exceeds an interface debonding energy threshold value, correcting macroscopic response data of a sudden stress drop interval based on the dynamic association relationship; the cross-scale coupling of a microscopic damage mechanism and a macroscopic mechanical behavior is realized, and the prediction precision under a dynamic load is remarkably improved.

The application discloses a kind of offshore wind power structure multiscale damage integrated analysis method and system, method includes: based on the principle of continuum mechanics, by representative volume element (RVE) homogenization method, anisotropic elastoplasticity equivalent constitutive model of flange bolt connection is established, to replace the traditional bolt and flange split fine modeling mode.The equivalent flange model established is realized by parameterization calibration Macroscopic mechanical performance characterization of flange connection area, can accurately reflect its stiffness, strength and dynamic characteristics.Using the model can efficiently predict the nonlinear response of the connection part in the overall structure analysis, realize the collaborative analysis of global response and local damage of overall structure.Compared with traditional fine model, the application significantly improves the calculation efficiency under the premise of ensuring calculation accuracy, the analysis time can be reduced by about 62%, and stress distribution and dynamic response characteristics can be accurately reflected.

The application discloses a kind of simulation method of rainfall-induced slope rockfall in the technical field of slope prevention, determine potential slope body to be analyzed, according to engineering geology survey to establish the two-dimensional numerical model of slope body, rockfall and actual rigid protection structure, according to engineering geology survey to determine the material physics and mechanics parameters of slope body, rockfall and actual rigid protection structure, according to meteorological data to summarize the maximum rainfall that can act on slope body and the most dangerous rainfall cycle, then through two-dimensional numerical model based on continuum mechanics using strength reduction method to simulate the limit state of sliding under this maximum rainfall or in the most dangerous rainfall cycle with rockfall slope, and then calculate the safety factor of slope, while through the corresponding simulation slope body, rock layer and simulation rigid protection structure in simulation device are compared and verified.The application is scientific and reasonable, and the simulation accuracy is improved by simulating the potential impact force and impact range of landslide body and rock group interaction through two-dimensional numerical model.

The present application belongs to the field of structural deformation reconstruction, and specifically discloses a structural deformation reconstruction method and system based on a four-node inverse plate shell element containing a drilling degree of freedom, comprising: discretizing the structure into a plurality of four-node inverse plate shell elements, and constructing a shear strain matrix by using a discrete shear gap method; kinematically constraining the drilling degree of freedom by using a continuum mechanics rotation field, solving the continuum medium rotation by deriving the global coordinate system from the natural coordinate system shape function, and supplementing the sixth degree of freedom of the element around the normal line; deriving a coordinate transformation matrix based on the assigned sixth degree of freedom, introducing a node coordinate system, transforming the element stiffness matrix to the node coordinate system, and then transforming it to the global coordinate system; and finally, incorporating the above construction method into the least squares functional framework, assembling the global inverse finite element equation by minimizing the error between the theoretical strain and the measured strain, and reconstructing the full-field displacement of the structure. The present application can realize high-precision deformation reconstruction of complex stiffened plate shells and large-curvature structures.

This invention discloses a dynamic simulation method, system, computer, and storage medium for a space thin-film antenna system based on the absolute nodal coordinate method. The space thin-film antenna is simplified into a rigid-flexible coupled multibody system composed of a flexible support frame, a tensioned cable net, and a thin-film reflector. Nonlinear cable elements are introduced between the frame and the thin film as connections. The flexible frame and the non-bending stiffness thin film are divided into elements based on the absolute nodal coordinate method. According to the theory of continuum mechanics and the principle of virtual work, a dynamic model of the flexible frame-cable net-thin film coupled multibody system under pretension is established. A form-finding strategy for gentle slope loading is proposed. The generalized -α implicit time integration algorithm is used to solve the dynamic equations of this system, obtaining curves showing the displacement and vibration attenuation of the space thin-film antenna under impact disturbance as a function of time. This invention provides a new dynamic modeling model for large-scale space thin-film antenna systems and offers researchers in this field more comprehensive data and image data.

Disclosed is a numerical simulation method for rainfall-induced flash flood and debris flow, including: obtaining, based on a continuum medium mechanics manner coupled with a hydrodynamic model of a three-phase medium of water, coarse particles, and fine particles, data required for the numerical simulation method. The present disclosure is based on a theory of continuum mechanics, which realizes the numerical simulation method for the flash flood and debris flow considering rainfall conditions by a finite difference manner based on the continuum medium mechanics manner coupled with the hydrodynamic model of the three-phase medium of the water, the coarse particles, and the fine particles. The method in the present disclosure is able to simulate formation, movement, and sediment transport processes of the flash flood and debris flow under different rainfall condition.

The application discloses a kind of underwater vehicle composite structure damage analysis methods considering delamination defect, belong to material damage determination technical field.The method is first based on continuum mechanics theory, constructs the composite orthotropic constitutive model considering humidity effect;By introducing two groups of damage variables in layer and interlayer, respectively matrix / fiber failure and delamination failure are represented;For matrix / fiber failure, three-dimensional Hashin criterion is used as damage initiation criterion, and based on linear displacement damage evolution law and equivalent strain assumption, the stress-strain relationship of coupled damage variable is derived, for delamination failure, the damage initiation and evolution process of interfacial damage is described by using cohesive zone model;Through the secondary development of finite element software subroutine, the damage evolution simulation and residual strength prediction of the structure containing initial delamination defect under static load are realized, which can accurately reveal the damage propagation path and failure mechanism.

The invention discloses a material damage acoustic emission signal identification method and system based on microcosmic energy. The method comprises the following steps: acquiring an acoustic emission signal through high-frequency sampling; calculating a microscopic compression number criterion based on a Rankine-Hugoniot compression relational expression to identify a microscopic compression wave; extracting a pre-compression degree index quantification energy compression feature; material damage fingerprint features are obtained through multi-scale fractal analysis; quantifying a cascade effect, phase coherence and an energy distribution rule; and finally, outputting a damage identification result through a multi-dimensional Bayesian fusion decision. The system correspondingly comprises a signal acquisition module, a microcosmic compression identification module, a feature extraction module, an effect analysis module and a decision output module. The continuous medium mechanics and the quantum theory are combined, accurate recognition of material damage from the atomic scale to the macro scale is achieved, and the accuracy and reliability of damage detection are remarkably improved.

The invention provides a BIM-based concrete wall damage process numerical simulation method, and relates to the technical field of wall damage process numerical simulation methods, and the method comprises the steps: employing a Delaunay triangulation algorithm to generate an initial grid unit, and constructing a damage sensitivity index of the grid unit based on material parameters; temperature and humidity influence factors of the wall bodies of the grid units are constructed through temperature and humidity coupling; the damage energy density of each grid unit is calculated through a continuous medium mechanical method, and the overall damage strength coefficient of the wall is constructed through a weighted energy density method; and setting a maximum dynamic damage strength threshold value of the wall body. Geometric and material parameters of the BIM model are directly extracted, so that errors caused by manual data input are reduced, and the consistency of geometric precision and material attributes is ensured; an overall damage intensity coefficient is constructed by adopting a weighted energy density method, and damage contribution of a high-energy density region is emphasized; and the dynamic maximum damage intensity threshold is adaptively adjusted according to real-time damage distribution, so that the accuracy is improved.