37results about How to "Little unknown" patented technology

The invention discloses an electromagnetic scattering analyzing method for superspeed flight targets. For non-uniform characteristics of plasmas around the superspeed flight targets, a part of equivalent relative dielectric constant, approximate to one, of the plasmas is used as the air to be processed by analyzing through a volume-surface integer equation, and areas with larger equivalent relative dielectric constant are encrypted by the adaptive network so as to achieve required solving accuracy. By adopting conventional method of uniform grid subdivision plasma casing, the electromagnetic scattering analyzing method can greatly save computing resources, green function adopted in the volume-surface integer equation is green function in vacuum, multilayer speedy multi-step ion technology is used for accelerating solving, so that fewer internal memory and shorter computing time are required for solving the problem of scattering of the superspeed flight targets.

The invention discloses a metal target transient electromagnetic scattering analysis method based on delay laguerre polynomials. A target is subdivided through curved surface triangle surface elements. Spatial dispersion and time dispersion are carried out on a time domain mixed field integral equation through a CRWG primary function and the delay laguerre polynomials. A test is carried out through a galerkin method. An order-stepped matrix equation is finally formed, and the transient electromagnetic scattering characteristic of the target can be obtained through resolution of the equation and post-processing. As a delay item related to the spatial position of the target is introduced into a time primary function, the time primary function contains the spatial phase information of the target is adopted, and the target can be subdivided with less curved surface triangle surface elements. The unknown calculation amount is greatly reduced, consumption of an inner storage is effectively reduced, the calculation time is shortened, and important reference documents are provided for accurate analysis of the transient electromagnetic scattering characteristic of an electric large-size metal target.

The invention discloses an experimental platform used for verifying vibration isolation effect of active control methods. The experimental platform comprises a force sensor, a bearing plate, a floating plate, an actuator, a linear bearing, shaft supporting bases, a rigidity component, a vibration exciter, and a controller. The rigidity component comprises vertical shafts, a first spring, a second spring, a baffle ring, and nuts. The lower surface of the bearing plate is provided with the force sensor, and the upper surface of the bearing plate is provided with the actuator and the two shaft supporting bases. The actuator is provided with the floating plate, and the vibration exciter is corresponding to the floating plate. The floating plate is provided with the linear bearing, and the various vertical shafts pass through the first spring, the linear bearing, the second spring, the baffle ring, and the shaft supporting bases sequentially, and then are connected with the bearing plate, and in addition, the nuts are in a screwed connection with the vertical shafts, and therefore the two springs are in a compressed state. The controller is connected with the force sensor and the actuator, and according to residual force detected by the force sensor, a compensation signal is determined, and according to the compensation signal, actuating force output by the actuator is adjusted. The experimental platform is used for the experimental verification of the vibration isolation effect of the different active control methods.

The invention discloses a rapid analysis method for an electromagnetic property characteristic model of a repetitive structure considering carrier platform coupling. The method comprises the followingsteps: firstly, integrally modeling the repetitive structure conformal on the surface of a carrier platform; then, for the integrated structure, fully utilizing repetitive characteristics in the structure, introducing a characteristic mode global basis function method to reduce the impedance matrix dimension of the repetitive structure part, and greatly reducing the number of unknown quantities to be solved; then, fusing the multi-layer fast multipole with a feature mode, accelerating a reduced-order impedance matrix filling process and an iteration process, and improving the efficiency; andfinally, using a parallel order reduction technology based on MPI (Message Passing Interface) and OPENMP mixing to reduce the memory consumption and shorten the calculation time. An efficient and accurate analysis tool is provided for numerical optimization and design of a conformal repetitive structure and carrier platform integrated target.

The invention discloses a frequency-domain electromagnetic scattering characteristic analysis method for a dielectric object with cylindrical periodic characteristics. When the electromagnetic scattering characteristics of the dielectric object with a cylindrical periodic structure is calculated by adopting a surface area integral equation (PMCHW), the whole object with the periodic structure needs to be subjected to electromagnetic modeling, and a modeling mode is relatively cumbersome especially for a complicated structure with more cycles. For the object with the cylindrical periodic characteristics, the object can be calculated with a discrete rotational symmetric method (DBOR) and only one complete periodic region in the periodic structure needs to be modeled, so that the establishment of a complicated model is avoided, the unknown quantity of subdivision is reduced, the matrix filling time is greatly shortened, and a memory is saved.

The invention provides a method for evaluating the health indexes of a harbor concrete member based on the analytic hierarchy process. The method for evaluating the health indexes of a harbor concrete member based on the analytic hierarchy process comprises the following steps: confirming the target layer, the criterion layer and the decision layer and structuring a judgment matrix; calculating the weight coefficients of the six variables of the criterion layer assigned on the basis of the target layer; and calculating the score of the target layer according to the consistency weight distribution equation to measure the health status of concrete. By means of the analytic hierarchy process provided by the invention to evaluate the health indexes of a harbor concrete member, the working performances of the harbor concrete members can be monitored accurately, and the defects that the calculation amount is large, the calculation time is long and the calculation is difficult to use in routine conditions in the evaluation of concrete health indexes in engineering practice can be solved effectively, and the method for evaluating the health indexes of a harbor concrete member based on the analytic hierarchy process has the advantages of less unknown quantity, small calculation scale, high accuracy and convenient application.

The invention discloses a nanostructure extinction characteristic simulation method based on a moment method in combination with an adaptive cross approximation fast algorithm. According to the method, a moment method in an integral equation method is adopted for solving, and compared with a traditional numerical method such as a finite element method based on a differential equation method, dispersion errors do not exist, and the accuracy is high. According to the method, the extinction characteristic of the large-scale nanostructure can be solved by combining the adaptive cross approximation fast algorithm on the basis of the moment method, transplantation can be conveniently carried out under different background media, and the application range is wide.

The invention relates to an identification method of random structural damage based on genetic algorithm and static force measurement data. The identification method of the random structural damage based on the genetic algorithm and the static force measurement data comprises the following steps: (1) preliminarily obtaining statistical properties of random structural damage indexes; (2) defining the probability of unit damage as the random rigidity before occurrence of the damage or the probability that an elastic modulus Kai is larger than Kdi; (3) introducing damage probability indexes, determining several units of the damage probability indexes as non-damage units, and conducting corresponding adjustment on the statistical properties of the damage indexes; (5) going back to the governing equation of the initial damage identification in the step (1), and obtaining the objective function of the structural damage indexes after rearranging; and (6) solving the minimum value of the objective function in the step (5) by means of the genetic algorithm, and obtaining the statistical properties of the damage indexes. The identification method of the random structural damage based on the genetic algorithm and the static force measurement data has the advantages that multiple damage identification of different damage degrees can be carried out due to the fact that the genetic optimized algorithm has little limit on the type, the quantity and the size of the parameter.

The invention discloses an electric field analysis method of an electromagnetic pulse nano semiconductor device. The steps of the method are as follows: in the first step, the solution model of MOSFETis established, and the model is divided by using the curved hexahedrons to obtain the structural information of the model, including the element information and node information of the hexahedron; in the second step, starting from the carrier current continuity equation, Poisson equation and carrier quantum correction equation, the backward Euler time difference is used firstly, then the discontinuous Galerkin method is used to test the equation, and the electric field boundary condition is imposed to obtain the electric field and current distribution of each node. On the premise of the samecalculation amount, Under the action of electromagnetic pulse and voltage, the distribution of the internal electric field with time can be obtained more clearly, which can reduce the computational load when the convergence accuracy is the same. In addition, the method has the advantages of flexible modeling and convenient dissection, and the formed matrix has good sparsity and high efficiency ofsolution.

The invention discloses an integral equation direct solving method for analyzing electromagnetic characteristics of a medium target. The method comprises the steps of dispersing a medium target surface by adopting triangular units; layering and grouping according to the electrical size of the medium target, and building an octree structure; establishing a current-magnetic current mixed integral equation for the surface of the medium target; separating a near field and a far field according to an octree structure, and compressing the far field part by adopting a hierarchical adaptive cross approximation algorithm, orthogonal triangular decomposition and singular value decomposition; and then, constructing an H-matrix of the JMCFIE impedance matrix, decomposing the H-matrix by adopting an up-down triangular decomposition algorithm, then, solving current and magnetic current coefficients by utilizing forward and backward back substitution, and finally, obtaining electromagnetic characteristic parameters of the medium target. The invention is wide in application range, has the advantage of being controllable in precision, and can solve the multi-excitation problem efficiently.

The invention discloses a large-scale quasi-periodic structure electromagnetic scattering characteristic analysis method based on a sub-global basis function method. The method makes full use of the physical characteristics of a quasi-periodic structure and extracts a main characteristic current mode as a sub-global basis function through a characteristic model, thereby greatly reducing the complexity of solution and improving the calculation efficiency.

The invention provides a complex cable bundle distribution parameter modeling method based on a moment method. By combining a Maxwell equation set with the physical characteristics of a cable bundle,the complex cable bundle distribution parameter modeling method solves the charge distribution on the surface of a cable so as to obtain the potential distribution of charges and the voltage distribution among cables in the cable bundle, obtains the distributed capacitance parameter of the cable bundle based on the relationship among the capacitance C, the voltage and the charges, and then acquires other distribution parameters of the complex cable bundle according to the relationship among the capacitance C, the inductor L and the conductance G. The complex cable bundle distribution parametermodeling method based on the moment method has the advantages of being high in universality and capable of accurately extracting the distribution parameters of the multi-conductor transmission cablebundle.