38 results about "Transfer-matrix method (optics)" patented technology

The invention discloses a method for analyzing the shafting torsional vibration of a turbo-generator set, which belongs to the technical field of power and large rotating machinery manufacture. The method comprises the following steps: firstly, segmenting a shafting body, and determining the external diameter, internal diameter and length of each shaft segment; secondly, calculating equivalent parameters of a shafting, including the rotation inertia and stiffness of each shaft segment; thirdly, calculating the rotation inertia of blades by finite integration technique; fourthly, modeling the shafting of which the shafting body is segmented into a concentrated mass block-spring model; fifthly, calculating the external torque of a shafting torsional vibration model; and finally, calculating shafting torsional vibration response by a Newmark-beta method and a Riccati increment transfer matrix method. The method takes non-linear factors into account during the analysis of shafting torsional vibration, and avoids the influences of the change of torsional vibration patterns with time and space on an analysis result.

The invention aims at providing pipe excitation source identification and a prediction method of vibration response to a pipe excitation source. The steps are collecting a pipe wall acceleration signal and transforming the collected time domain signal into a frequency domain signal through Fourier transform, performing excitation source identification and equivalence and using a linear system superposition method to determine the size of the pipe system equivalent excitation source through comparing the experimental data with the pipe system dynamics calculation result, and using a transfer matrix method for predicting the dynamic response to the vibration of any optional position of the pipe according to the equivalent excitation. According to the pipe excitation source identification and the prediction method of vibration response to a pipe excitation source, an appropriate measuring point easy to measure is chosen according to the specific arrangement of the pipe for the excitation source size identification and the pipe vibration prediction, so that problem of the pipe system excitation source characteristics and the difficult vibration measurement of some portions of the pipe and others can be solved, the experimental measurement points arrangement can be reduced and the flexibility of the pipe vibration measurement can be increased.

The invention provides a statistical energy analysis-based ship cabin noise forecasting method. The method comprises the steps of 1, preliminarily building a statistical energy analysis-based ship cabin noise forecasting model by utilizing ship drawing data; 2, performing local detail optimization on an emphatically assessed cabin and load region in the built model, and constructing an external auxiliary sound cavity; 3, determining a vibration acceleration load and a sound power load of equipment by utilizing an experimental test; 4, performing calculation by utilizing the experimental test or a formula to determine loss factors in a steel plate and the sound cavity; 5, building a microacoustic analysis model of an outfitting material structure by utilizing a transfer matrix method, and obtaining acoustic parameters of an outfitting material through sound absorption and insulation analysis; 6, setting frequency response analysis as a 1/3 octave frequency, and setting a calculation frequency to be 31.5Hz-8kHz; and 7, performing ship cabin noise forecasting analysis by applying statistical energy analysis. The efficiency and precision of ship cabin noise forecasting can be effectively improved; and the method can be applied to ocean platform and ship cabin noise forecasting and control.

The invention provides a multi-cavity direct-through dual-layer perforating silencer capable of eliminating wide-band noise. The multi-cavity direct-through dual-layer perforating silencer capable of eliminating the wide-band noise comprises an inlet end, a silencer body and an outlet end. At least two dual-layer perforating pipes are arranged in the silencer body. The dual-layer perforating pipes are connected in series and separated through partition plates. Each dual-layer perforating pipe comprises an outer pipe body and an inner pipe body, wherein through holes are distributed in the outer pipe body and the inner pipe body, a closed cavity is defined by the outer pipe body, the silencer body and the corresponding partition plate, and another closed cavity is defined by the inner pipe body, the outer pipe body and the corresponding partition plate. The silencer has the advantages that airflow circulates directly from the inlet end to the outlet end, the pressure loss is low, the size is small, the structure is simple, cost is low, and by designing the structure parameters through a multi-cavity one-dimension transfer matrix method, the high-amplitude and wide-band silencing effect can be achieved.

The invention provides a dynamics forecasting method of a random branch structure. The dynamics forecasting method comprises the following steps of: (1) selecting a main transmission path, i.e. for a system which comprises the random branch structure, firstly, selecting one chain-type main transmission path from one boundary end to the other boundary end; (2) establishing each branch point model, i.e. by the influence of adsorbing each sub branch, establishing the model between state vectors of both front and rear ends of each branch point on the main transmission path; (3) establishing an integral model, i.e. establishing the integral model between state vectors of both initial and tail ends by an arrangement sequence of transfer elements and point elements of each field on the main transmission path; and (4) forecasting a structural dynamics problem, i.e. introducing a boundary condition and an external acting force which serve as definite conditions and applying a transfer matrix method to forecast the dynamics problem of a chain system. The dynamics forecasting method has wide application range, has simple and convenient implementing process, is very beneficial to programming calculating and has high forecasting accuracy; the integral solving process cannot cause the increase of a variable freedom degree value; and the forecasting efficiency is ensured high.

The invention discloses a calculation verification method for the torsional vibration modal of a gas turbine pull-rod type rotor, comprising the steps of: (1) establishing a transfer matrix equation of a pull-rod rotor contact section, and then introducing a contact section torsional rigidity correction coefficient in the equation; (2) calculating the torsional rigidity correction coefficient of the pull-rod rotor contact section in the equation; (3) calculating the modal frequency and the modal vibration mode of the rotor via a transfer matrix method by utilizing the transfer matrix equationand the torsional rigidity correction coefficient value of the pull-rod rotor contact section, wherein the contact effect of the rotor contact section is considered in the calculation; and (4) testing the torsional vibration modal frequencies of an experimental pull-rod rotor under different pre-tightening forces via a torsional vibration modal experiment, and comparing with the calculated result. According to the method disclosed by the invention, the influence of the contact effect on the calculation of the torsional vibration modal of the pull-rod type rotor can be efficiently considered and the torsional vibration modal frequency of the pull-rod type rotor can be more accurately calculated, thus a reliable basis is provided for reasonably designing the torsional vibration characteristics of the rotors of the type.

The invention discloses a truck dynamic modeling method based on transfer matrixes. The method comprises the steps of establishing transfer matrixes of dynamic elements in a truck dynamic model; carrying out reasonable assumption on a truck, thereby obtaining a rigid-flexible coupled dynamic model with truck features; on the basis of a transfer matrix method theory, determining truck element serial numbers, transmission directions and cutting locations; modularly establishing a transfer matrix method of the truck, scattering the elements in each module, establishing sub-module transfer matrixes, obtaining a total transfer matrix of the truck dynamic model through splicing, and establishing the truck dynamic model; and in a frequency domain, through road surface spectrum input, and carryingout inherent characteristic and dynamic characteristic analysis on the established model according to a random vibration theory. According to the method provided by the invention, the modeling efficiency and accuracy and a code reuse rate are improved, and the theoretical basis for truck ride comfort analysis is provided.

The invention belongs to the field of diesel engine air distribution system researches and relates to a diesel engine air distribution system dynamic calculation method based on a multi-body system transfer matrix. The diesel engine air distribution system dynamic calculation method based on the multi-body system transfer matrix comprises the following steps of: building a cam profile Nth harmonic fitting function, selecting a state vector, a boundary condition, an initial input quantity and the like required by a multi-body system transfer matrix method, analyzing the mechanical properties of all components of an air distribution system, deducing a transfer matrix which reflects the mechanical properties, integrating all parameters to obtain a total transfer equation, solving the total transfer equation to obtain the dynamic response situation of each part, drawing the dynamic characteristic curve of each part and the like. The diesel engine air distribution system dynamic calculation method based on the multi-body system transfer matrix has the advantages that the mechanical response situations of all parts during the movement of the air distribution system can be intuitively reflected through the dynamic characteristic curves, the dynamic response results and the like of all parts, the method is suitable for air distribution systems of diesel engines with different speed types, the measuring and modeling time needed for building a three-dimensional model is greatly saved, and the obtained results are more effective than the results obtained through solution by using the traditional multi-rigid-body differential equation set.

The invention relates to a vibration reducing and sound insulating material, in particular to a development method of a phonon crystal the vibration reduction initial frequency of which is not higher than 200 Hz. The invention comprises the following steps. Metal material with 10e10 elastic modulus magnitude order and large density and rubber material with 10e6 elastic modulus magnitude order are chosen. The period size of the phonon crystal is 0.04m according to the stability condition. According to a transfer matrix method, equivalent density is obtained through calculation. The equivalent density method is adopted and when the vibration reduction initial frequency is lower than 200Hz, the height ratio the metal material and the rubber material is approximate to 1 to 1. The sectional areas of the metal material and the rubber material are calculated. The metal material and the rubber material are spliced periodically and then the phonon crystal the vibration reduction frequency of which is not higher than 200Hz can be obtained. The invention has the beneficial effects that the invention can obtain the band gap of low frequency when the periodical size is small, is applicable to low frequency vibration and noise reduction and has simple manufacture technology and strong designability.

The invention relates to a linkage type row pile isolation structure. The structure is provided with a periodic row pile structure on the walking direction of row piles, and pile tops of the row piles are in mutually rigid linkage through linkage beams. Each pile in the same row of the piles is a concrete pile with arbitrary cross section, and is provided with same geometry material parameters; and piles in different rows can have different parameters. The linkage beams in the same groups have same geometry material parameters, and the linkage beams in different groups can have different parameters. Floquet transformation and a boundary element method are adopted, and a pile-soil boundary element model in a wave number domain is built. The linkage beams on the upper portion are processed through a transfer matrix method. The pile-soil boundary element model, coupling conditions and periodic conditions of the pile tops and the beams are adopted, and a calculation model of the linkage type row piles is built. Compared with free type row piles with pile tops not restricted, the linkage type row pile isolation structure can effectively reduce vibration isolation coefficients and improve vibration isolation effects.

The invention relates to a multilayer constraining and damping implementation method for vibration damping of a case of an aeroengine. The method comprises the following steps: (1) taking lightweight aluminum foil as a constraining material, sequentially sticking a viscoelastic material and the constraining material, carrying out multilayer constraining and damping processing on the case of the aeroengine, and establishing a multilayer constraining and damping case vibration analysis model; (2) determining the number of layers of a multilayer constraining and damping structure by adopting an improved transfer matrix method; (3) enabling the surface to be stuck of the case to keep a certain temperature; (4) gradually sticking a constraining and damping material to the case starting from one end of the constraining and damping material; (5) verifying the vibration damping effectiveness of the multilayer constraining and damping processed case. The method has the advantages that the method is simple and is easy to implement, and the vibration stress of the case can be effectively lowered, so that the fatigue damage resistance of the case is improved; multiple layers of constraining and damping have very good bonding performance and are firm in sticking, so that the case has a good vibration damping suppression effect.

The invention provides a test bench for acoustic performance development and verification of an intake and exhaust system, comprising a standing wave tube assembly, a gas source system, an airflow control and acquisition system, an acoustic data acquisition system and a post-processing software platform. A sound source system is provided on both sides of the standing wave tube assembly. The gas source system, the airflow control and acquisition system are connected to the sound source system. The acoustic data acquisition system and the post-processing software platform are connected to the standing wave tube assembly. The sound source system emits sound waves, and the air source system generates airflow. The sound waves and the airflow enter the standing wave tube assembly, and the airflow is monitored by the airflow control and acquisition system. A sound signal is collected by the acoustic data acquisition system, and the obtained data is transmitted to the post-processing softwareplatform for calculation processing. According to the test bench for acoustic performance development and verification of intake and exhaust system, a proven dual source transfer matrix method is used, he frequency range of the test process can be customized, commonly used intake tuning components and exhaust mufflers are tested with low frequency, and broadband muffler of turbocharger is tested with the high frequency.

The invention relates to a shafting load preadjusting method of a metered spring base. The method sequentially comprises the following steps of (1) collecting the elevation hi of a rigid base bearing and a spring with the rigid Ki of a spring base corresponding to the bearing; (2) obtaining a relation between a bearing load and the elevation hi at a constant speed under the rigid base by adopting a transfer matrix method; (3) obtaining the stroke of the spring; (4) solving a reynolds equation by adopting a finite element method so as to obtain the floating amount of a shaft neck under a bearing load condition; (5) obtaining the elevation of the bearing; (6) replacing hi by use of the elevation of the bearing according to the f(hi) obtained in the step (2) so as to obtain an iterated bearing load; (7) returning to the steps (3)-(7) in due time; (8) obtaining the real load and practical elevation of the bearing at a constant speed under the spring base; and (9) obtaining the preadjusting amount delta of the elevation of the bearing. The method provided by the invention can be used for effectively improving the stability of the bearing and reducing the low-frequency vibration of the bearing and is wide in application prospect.

Multilayered nanoparticles and methods of producing same are provided for controlling plasmon-exciton distance. The nanoparticles include a silver core, a polyelectrolyte spacer layer exterior to the silver core, and a J-aggregate cyanine dye outer shell. This multilayer architecture served as a framework for manipulating the dual coupling of localized surface plasmon resonance exhibited by the silver core with the molecular exciton exhibited by the J-aggregate outer shell. The polyelectrolyte spacer layer promotes the formation of an excitonic J-aggregate while serving as a means of controlling the plasmon-exciton coupling strength through changing the distance between the core and the shell. An analytical expression based on Mie Theory and the Transfer Matrix Method is provided for describing the optical response of these multilayered nanoparticles. Computational and experimental results illustrate that the absorption wavelength of the J-aggregate form of the dye is dependent on both the distance of the dye layer from the silver core and the degree of dye aggregation.

The invention discloses a calculation method for the dynamic additional stress of the roadbed under the load effect of vehicles. The calculation method includes the following steps: (1) according to actual conditions of the roadbed and surface of a road, establishing a two-dimensional elastic layered body model, and transforming stress and displacement in an elastodynamic control equation into state vectors under modal coordinates; (2) separating and eliminating a time variable in a dynamic additional stress expression; (3) subjecting the state vectors to Laplace transformation, and acquiringa stiffness matrix of layered foundations by a transfer matrix method; (4) according to initial conditions and boundary conditions, establishing a dynamic additional stress quantitative model of a layered roadbed and road surface system; (5) subjecting the model to Laplace inverse transformation by a Durbin method to obtain the dynamic additional stress of the roadbed under the load effect of thevehicles. The calculation method for the dynamic additional stress of the roadbed provided by the invention is suitable for selection of road and rail roadbed fillers and the structural combination design of the roadbed.

The invention discloses a straight pile vertical impedance calculation method, which comprises the following steps: vertically dispersing a pile body of the straight pile and foundation soil accordingto the horizontal layering condition of a soil body, and dispersing the foundation soil in the radial direction according to the disturbance condition of soil around the pile; solving a wave equationof each soil ring layer and calculating the dynamic stiffness on the pile-soil contact surface through a radial transfer matrix method; and calculating the vertical impedance of the straight pile through a vertical transfer matrix method after solving the equation. The straight pile vertical impedance calculation method has the advantages that the vertical impedance of the straight pile under theradial heterogeneous condition of saturated soil around the pile caused by the construction disturbance effect in the layered foundation is calculated and considered; radial heterogeneity of layeredsaturated soil under a construction disturbance effect is considered through a bidirectional transfer matrix method, and meanwhile, a fractional derivative operator is adopted to describe a stress-strain relationship of foundation soil so as to improve calculation precision; and a Rayleigh rod vibration theory is adopted to describe vertical vibration of a pile body so as to consider a transverseinertia effect of pile body vibration. By means of the straight pile vertical impedance calculation method, the calculated vertical impedance of the straight pile better conforms to engineering practice.

The invention provides a pointing accuracy calculation method for a spaceborne deployable antenna system. The deployable antenna system comprises a feed source and a reflection surface, wherein the feed source is fixedly mounted on a satellite body, and the reflection surface is connected with the satellite body through M cascaded deployment arms. The method includes the following steps that: (1)a feed source body coordinate system SigmaF, each of deployment arm body coordinate systems Sigma1 to SigmaM, and a reflection surface body coordinate system SigmaA are defined; (2) with the reflection surface adopted as a datum, an ideal parabolic antenna system is established, so that the theoretical pointing of the deployable antenna system can be obtained; (3) the installation accuracy of thefeed source and the first-stage deployment arm is measured, and the actual pointing of the deployable antenna system is calculated through a transfer matrix method according to inherent error transferrelationships between various components of the deployable antenna system, inherent error being angular error which is brought by manufacturing tolerances after the deployment arms are deployed, andthe actual pointing of the deployable antenna system is determined; and (4) the actual pointing and theoretical pointing of the deployable antenna system are compared with each other, so that the pointing accuracy of the antenna system can be obtained.

The invention relates to a multi-cavity insert tube type double-layer perforated silencer capable of eliminating broadband noise of a supercharging air intake system. The silencer comprises an inlet end, silencer main bodies and an outlet end. The silencer main bodies are internally provided with at least two double-layer perforated tubes. All the double-layer perforated tubes are connected in series and partitioned through partition plates. Each double-layer perforated tube comprises an outer tube body and an inner tube body which are provided with perforated holes, the outer tube bodies, the corresponding silencer main body and the corresponding partition plate form a closed cavity, the inner tube body extends from the inlet side to the outlet side, and the inner tube body, the corresponding outer tube body and the corresponding partition plate form an unclosed cavity. The silencer is low in pressure loss, compact in structure and low in manufacturing cost, and structural parameters are designed through a multi-cavity one-dimensional transfer matrix method to achieve the high-amplitude broadband silencing effect.

The invention discloses a Chinese text named entity recognition method which comprises the following steps: when a named entity recognition request is received, analyzing the named entity recognitionrequest to obtain a to-be-recognized Chinese text; respectively extracting character features, word features and whole sentence features in each sentence of the to-be-recognized Chinese text by takingthe sentence as an analysis unit; respectively splicing the character features and the word features of each word in the Chinese text to be recognized and the sentence features of the sentence wherethe word features are located to obtain a feature sequence respectively corresponding to each word; extracting a context feature of each feature sequence to obtain a context feature extraction result;and according to a context feature extraction result, labeling each named entity of the to-be-recognized Chinese text from each word by utilizing a Markov transfer matrix method. According to the method, the named entity recognition performance is greatly improved, and the recognition accuracy is improved. The invention furthermore discloses a Chinese text named entity identification apparatus and device, and a storage medium, which have corresponding technical effects.

The present invention provides an analyzing method of the dynamic characteristics of a biomimetic seal whisker sensor. The analyzing method comprises the following steps of : dividing a biomimetic seal whisker into a plurality of continuous Timoshenko beam sections; according to the kinematical equation and the dynamic balance equation of the Timoshenko beam sections, calculating the frequency-response function H00 of the linear displacement in accordance with shear force, the frequency-response function N00 of the angular displacement in accordance with the shear force, the frequency-response function L00 of the linear displacement in accordance with the bending moment, and the frequency-response function P00 of the angular displacement in accordance with the bending moment, of any point on the biomimetic seal tentacle. The analyzing method of the dynamic characteristics of the biomimetic seal whisker sensor adopts a multi-section Timoshenko beam theory and a transfer matrix method to analyze the dynamic characteristics of the biomimetic seal whisker in the free state, and reveals the influence rules of elasticity modulus, shear coefficients, damping ratios, sectional dimensions and the like on structural natural vibration characteristics, so that the analyzing method disclosed by the present invention has an important significance in the development of the biomimetic seal whisker sensor.