37results about How to "Little unknown" patented technology

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 electromagnetic scattering analysis method of an ultra-high-speed flying target. Aiming at the non-uniform characteristics of the plasma wrapped around the ultra-high-speed flying target, the volume integral equation method is used to analyze, and the part of the plasma whose equivalent relative permittivity is close to 1 is treated as air, and the equivalent relative permittivity Larger regions are processed with adaptive mesh refinement in order to achieve the required solution accuracy. Compared with the traditional method of subdividing the plasma shell with a unified grid body, the method in the present invention can greatly save computing resources, and at the same time, because the Green's function used in the volume integral equation is the Green's function in vacuum, multi-layer fast multi-level Sub-technologies are used to further speed up the solution, so that the present invention requires less computing memory and computing time for solving the problem of scattering of ultra-high-speed flying targets.

The invention discloses a method for simulating the wide-band electromagnetic scattering property of a conductor target. The method comprises the following steps that the geometric model of the conductor target is built, and mesh generation is conducted on the surface of the conductor target by a curved surface triangle unit; a time domain electric field integral equation of the conductor target is determined; a surface induction current in the time domain electric field integral equation expands through a space CRWG primary function and a time delay primary function; an expanding surface induction current expression is substituted into the time domain electric field integral equation, and then the time domain electric field integral equation in a discrete form is tested in a time and space mode so as to obtain a system impedance matrix equation; singularity integrals are eliminated to obtain a sparse expression of a impedance matrix; the equation of the impedance matrix is solved to determine the distribution of the time domain current of the surface of the conductor target, and wide-band electromagnetic property parameters of the target are obtained according to the distribution of the time domain current so as to finish simulation. The method for simulating the wide-band electromagnetic scattering property of the conductor target has the advantages of being high in simulation precision, little in required time and low in memory consumption, and has wide application prospect.

The invention discloses an electric-heat integrated analysis method for a MESFET under the action of high-power electromagnetic pulses. The method comprises the steps that a drifting-diffusing equation set is solved by taking the electronic quasi Fermi potential, the hole quasi Fermi potential and the electric potential as variables and adopting a time domain spectral-element method to solve the instaneous quasi Fermi potential and electric potential of the metal-semiconductor field effect tube (MESFET) under the action of the high-power pulses, and then the electric field intensity and the current density at the moment are obtained; temperature distribution of all positions at the moment can be obtained under the action of a joule heat source by considering the influences of ambient environment temperature and heat convection; the carrier mobility and the generation-recombination rate are updated according to temperature changes, electric field distribution is recalculated, the steps are repeatedly conducted until the drifting-diffusing equation set meets the convergence precision, and electric field distribution and heat distribution at the moment are to-be-solved electric-heat distribution inside the MESFET at the moment. The method is achieved on the basis of a MESFET physical model, and the distribution conditions, changing along with time, of an electric field and the temperature in a device under the action of the high-power electromagnetic pulses can be clearly obtained.

The invention discloses a manifold mapping algorithm based on a high-and-low-order time domain spectral element method. The algorithm comprises the steps that firstly, an electromagnetic structure geometric model including a plurality of physical variables is established, and variable optimization simulation is quickly conducted through a time domain spectral element method with a first-order vector basis function till a simulated frequency response meets a target frequency response; secondly, according to the optimized variables, simulation is conducted through a time domain spectral elementmethod including a second-order basis function, whether the simulated frequency response meets the target frequency response or not is judged, and if yes, optimization simulation is finished; thirdly,if not, a correction frequency response model including the two simulation frequency responses is constructed, fast variable optimization simulation is carried out again through the time domain spectral element method including the first-order basis function till the correction frequency response meets the target frequency response; the second step is repeated after optimization is finished. Themethod has the advantages of being high in optimization speed, high in calculation precision and the like, and an important value reference can be provided for simulation design of a microwave device.

The invention relates to a closed loop Hall effect current sensor simulation method. The correlated matrix coefficients of closed-loop Hall-effect sensors such as structure matrixes C, K, D and a gradient matrix G are calculated, magnetic core circuit models of the closed-loop Hall-effect current sensors are established, core network table files of the closed-loop Hall-effect current sensors are obtained, circuit network table files of closed-loop Hall effect current sensors are generated through line network table converters, the core network table files and circuit network table files of closed-loop Hall effect current sensors are input into HSPICE software, and the closed-loop Hall effect current sensors are subjected to simulated analysis. The closed loop Hall effect current sensor simulation method can more accurately reflect the influence of factors such as magnetic core structures and air gap positions, the unknown quantity is little, and the simulation process is easily converged.

The invention discloses a time-domain order stepping analysis method for the transient electromagnetic property of an aircraft fleet. According to the method, broadband time-domain electromagnetic pulses serve as excitation to establish a time-domain analysis model of the aircraft fleet; each aircraft is set as a solving sub area, and scattering current of the sub area reaches the equivalent surface surrounding the sub area in an equivalent manner; the equivalent surfaces couples each other to update the equivalent scattering electromagnetic flows at the surfaces continuously till the flows are stable; and the sectional radar scattering area is solved via the final equivalent scattering electromagnetic flows of the equivalent surfaces. Multiple objects can be simulated rapidly in the electromagnetic manner, the method can be used to analyze the transient electromagnetic property of the objects, expansion of an incident field, interaction of the equivalent surfaces and calculation of the sectional radar scattering surfaces all utilize a rotary symmetric moment method, the calculation speed is improved, consumption of memory is greatly reduced, the time-domain order stepping analysis method is post-time stable, and the application value of practical engineering is very high.

The invention discloses a short-gap gas discharge numerical simulation method based on the time-domain spectrum element method. The steps of the method are as follows: establish a structural model of short-gap gas, and discretize it to obtain the structural information of the model; use the GLL basis function based on the spectral element method to discretize, and perform the Galerkin test to obtain the expression of the high-order scheme; for the Stiffness matrix, by eliminating the negative elements outside the diagonal, the expression of the low-order scheme is obtained; the expressions of the high-order and low-order schemes are subtracted to obtain the original back-diffusion flux and pre-limited; the correction factor is calculated, Finally, the limited back-diffusion flux is obtained, and the limited back-diffusion flux is added to the expression of the low-order scheme, time is discretized through the multi-step backward difference scheme, and Newton iteration is used to solve at each time step, Get the electron density and ion density of the gas, calculate the electric field and update the transport parameters. The invention can achieve unconditional stability in terms of time, high calculation precision and good simulation effect.

The invention discloses a method for estimating electromagnetic distribution in a carbon fiber material flying target under lightning pulse. In this method, the lightning pulse with extremely wide spectrum range is simulated by the plane wave in time domain, and the time domain analysis model of the carbon fiber material flying target under the lightning pulse is established. Use the time-domain plane wave algorithm PWTD to realize efficient calculation of the transient far field, apply the equivalent electric dipole model, quickly calculate the time-step time-domain volume integral equation MOT impedance matrix, solve the time-domain matrix equation and extract the electromagnetic characteristics in a wide frequency band . The invention only discretizes the flying target of carbon fiber material, uses the free space Green's function, the equation is simple, can analyze the non-uniform target, has high calculation accuracy and the unknown quantity is small; at the same time, because the time domain method is used to solve the problem, the invention can calculate once The electromagnetic characteristics of all frequency points in a frequency band, compared with the frequency domain method that requires frequency sweep operation, the time consumed for solving is greatly reduced.