CN109117502B - Optimization design method for reducing transient sound radiation of flat plate structure - Google Patents
Optimization design method for reducing transient sound radiation of flat plate structure Download PDFInfo
- Publication number
- CN109117502B CN109117502B CN201810726158.5A CN201810726158A CN109117502B CN 109117502 B CN109117502 B CN 109117502B CN 201810726158 A CN201810726158 A CN 201810726158A CN 109117502 B CN109117502 B CN 109117502B
- Authority
- CN
- China
- Prior art keywords
- flat plate
- plate structure
- boundary
- transient
- matrix
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Computational Mathematics (AREA)
- Civil Engineering (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Architecture (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Building Environments (AREA)
Abstract
The invention provides an optimization design method for reducing transient sound radiation of a flat plate structure, which comprises the following steps: 1. establishing a plate structure transient sound radiation theoretical calculation equation suitable for any boundary condition based on a time domain finite element-boundary element coupling method; 2. setting various known parameters of a flat plate structure and calculating a specific position xi of instantaneous radiation sound pressure; 3. setting an adjustable range of the boundary parameter; 4. giving the initial state and the transient excitation of the flat plate structure; 5. selecting an optimization algorithm, combining a calculation equation of a transient sound radiation theory of the flat plate structure with the optimization algorithm, and searching an optimal solution aiming at the known parameters, the adjustable range of boundary parameters and the initial state of the flat plate structure and the transient excitation to obtain the maximum transient radiation sound pressure level SPL of the flat plate structure max A minimized optimal boundary parameter; 6. and forming a flat plate structure according to the optimal boundary parameters. The invention not only can keep the original structure of the flat plate structure, but also can effectively improve the transient sound insulation and noise reduction performance.
Description
Technical Field
The invention relates to an optimization design method for reducing transient sound radiation of a flat plate structure.
Background
The flat plate structure is one of the most common structures in engineering, and is widely applied to structures of ship and ocean engineering, aerospace engineering, civil and architectural engineering, vehicle engineering and the like. The transient sound radiation characteristic of the flat plate structure is closely related to the overall sound insulation and noise reduction performance of the structure (especially the isolation capability to external transient excitation or transient noise), and has an important effect on the overall sound insulation and noise reduction performance of the structure, and is always concerned by engineering personnel in the fields of buildings, machinery and the like. It is well known that the boundary mounting conditions of a flat panel structure have a significant influence on the transient acoustic radiation characteristics of the structure which is not negligible. If the transient radiation sound pressure of the flat plate structure can be reduced to the maximum extent under the given excitation condition through the optimization design of the boundary condition, the transient sound insulation and noise reduction performance of the flat plate structure is improved (for example, the maximum transient radiation sound pressure when the flat plate structure is excited is reduced), and the method has important significance for engineering application. The design only requires to change the boundary conditions of the structure, and does not need to change the parameters (such as length, width, thickness, materials and the like) of the flat plate, so that the original materials, size and appearance of the flat plate structure can be kept unaffected, and the transient sound insulation and noise reduction performance of the flat plate structure can be effectively improved.
However, at present, no optimal design method exists, and the transient radiation sound pressure minimization of the structure can be realized by effectively guiding the optimal design of the boundary condition of the flat plate structure. The difficulties mainly include: the parameters of the boundary conditions of the flat plate structure are numerous, and the optimization process belongs to the problem of multi-parameter parallel optimization; the variable condition of each boundary parameter is infinite; and so on. These difficulties make it unlikely that the structural characteristics can be calculated one by one using conventional methods (e.g., enumeration) to obtain optimal parameters.
Based on the background, the invention aims to find a better optimal design method for transient sound insulation and noise reduction performance of a flat plate structure, which is used for guiding engineers to quickly determine the optimal boundary condition of the flat plate structure, so that the transient sound radiation of the flat plate structure is reduced to the greatest extent under the given excitation condition, and the optimization of the transient sound insulation and noise reduction performance of the flat plate structure is realized. The optimization design method is to use a flat-plate structure transient acoustic radiation theory to calculate an equation and introduce an optimal solution search theory of an optimization algorithm.
Optimization methods and techniques have been applied to solve various engineering problem optimization solutions based on mathematics. The optimization algorithm is a search process and rules, and obtains a near-optimal solution of a problem meeting user requirements through a certain path or rule based on certain ideas and mechanisms. In terms of optimization mechanism and behavior, the currently commonly used optimization algorithms can be mainly classified as: classical algorithms, constructive algorithms, improved algorithms, algorithms based on dynamic evolution of the system, hybrid algorithms, and the like. It is not unique which optimization algorithm is selected as a tool, and various algorithms have advantages and disadvantages of the algorithms. The invention utilizes the idea of optimal solution search of the optimization algorithm, does not limit which specific algorithm is used, and can be selected according to the characteristics and the requirements of actual problems when in application.
Disclosure of Invention
The technical problem to be solved by the invention is to provide an optimization design method for reducing the transient sound radiation of a flat plate structure, so that the optimization design of the boundary condition of the flat plate structure can be guided, and the optimal solution of the boundary condition (boundary parameter) is quickly searched out by utilizing the advantages of an optimization algorithm in the design process, thereby realizing the effect of minimizing the transient radiation sound pressure of the flat plate structure under given transient excitation.
The problem of the invention is realized as follows:
an optimization design method for reducing transient sound radiation of a flat plate structure comprises the following steps:
step 1, establishing a plate structure transient sound radiation theoretical calculation equation suitable for any boundary condition based on a time domain finite element-boundary element coupling method:
the derivation of the above formula is based on the time domain finite element-boundary element coupling method, in which SPL max The maximum instantaneous radiation sound pressure level of the flat plate structure is shown, and p (xi, t) is the instantaneous radiation sound pressure at the position of xi at the time t; s p Is the area of the plate, p 0 For air density, x is the slab nodal coordinate, c is the acoustic velocity, { R } is the transformation matrix used to transform the nodal displacement of the slab structure to transverse deflection, δ is the Dirac function.
Instantaneous node acceleration of the x position of the flat plate structure at the moment tau is obtained; the { M }, { C } and { K } are respectively an integral mass matrix, a damping matrix and an integral rigidity matrix of the flat plate structure,
and { U (t) } is the instantaneous node acceleration, instantaneous node speed and instantaneous node displacement vector of the flat plate structure at the time t respectively,
and { U (t + Δ t) } is the instantaneous node acceleration, the instantaneous node speed and the instantaneous node displacement of the flat plate structure at the moment of t + Δ t respectively; { T } for converting incident sound pressure to equivalent node force, F (T) } for instantaneous external force excitation of the plate structure at time T, and p 0 (t) is of a flat plate structurethe instantaneous incident sound pressure received at the time t, { F (t + Deltat) } is the instantaneous external force excitation received by the flat plate structure at the time t + Deltat, { p 0 (t + Δ t) } is the instantaneous incident sound pressure received by the flat plate structure at the moment of t + Δ t; delta t is a calculation time step length, and eta and beta are time integration constants of a Newmark method respectively;
step 3, setting an adjustable range of the boundary parameter;
step 5, selecting an optimization algorithm, combining the transient sound radiation theoretical calculation equation of the flat plate structure with the optimization algorithm, and searching an optimal solution according to each set known parameter of the flat plate structure, the set adjustable range of the boundary parameter, the given initial state of the flat plate structure and the received transient excitation to obtain the maximum transient radiation sound pressure level SPL of the flat plate structure max A minimized optimal boundary parameter;
step 6, forming a flat plate structure according to the optimal boundary parameters;
wherein, the steps 1, 2, 3 and 4 are not limited to the sequence.
Further, the overall mass matrix { M }, the damping matrix { C } and the overall stiffness matrix { K } of the flat plate structure in the step 1 are obtained by a finite element method, that is, { M } is obtained by a flat plate element equivalent mass matrix { M } p } e Assembled by direct rigidity method, K is a flat plate unit equivalent rigidity matrix K p } e And support boundary element equivalent stiffness matrix K b } e Assembled by a direct rigidity method;
wherein, M p } e ＝ρh∫∫{N} T {N}dxdy；
{K p } e ＝∫∫{B p } T {D p }{B p }dxdy；
Where ρ is the plate material density, h is the plate thickness, { N } is the cell shape function, T transposing symbols for the matrix; { B p Is the strain matrix, { D p The matrix is a bending rigidity matrix; k is a radical of t And k r The parameters for the support boundary, respectively representing the lateral stiffness and the rotational stiffness of the structural support boundary,
is a cell boundary profile, gamma b The unit normal vector of (1);
a damping matrix of the flat plate structure,
wherein mu is a plate damping factor, omega 0 The lowest order natural frequency of the slab.
Further, the specific method for simulating any boundary condition in step 1 is as follows: setting k tb And k rb For the parameters of the support boundary, these boundary parameters may be in complex form, the real part represents the elastic characteristic of the boundary support, the imaginary part represents the damping characteristic of the boundary support, if the elastic boundary support is simulated, the imaginary value takes 0, the boundary parameters are constants or position functions, and the simulation of any boundary condition is realized by changing these boundary parameters.
Further, the transient excitation in the step 4 is transient external force excitation, transient incident sound wave or combined action of the transient external force excitation and the transient incident sound wave.
Further, the known parameters in the step 2 include a plate material, a plate damping factor, a plate size and a plate thickness.
The invention has the advantages that:
1. establishing a plate structure transient sound radiation theoretical calculation equation by combining a time domain finite element-boundary element coupling method, and simulating known parameters (including plate material, plate damping factor, plate size and plate thickness) of any plate structure and plate structure transient sound radiation response under any boundary condition, so that the optimization design of the plate structure transient sound radiation performance is effectively guided, rapid optimization of multiple boundaries and multiple boundary parameters is realized at the same time, and the transient sound radiation of the plate structure under given transient excitation can be effectively reduced;
2. the parameters of the boundary conditions of the flat plate structure are numerous and the variable conditions are infinite, the optimization process belongs to the problem of multi-parameter parallel optimization, and the conventional optimization method cannot be competent. The invention combines the transient acoustic radiation theoretical calculation equation of the flat plate structure with the optimization algorithm, fully utilizes the advantages of the optimization algorithm, can quickly and simultaneously carry out optimal solution search on a plurality of boundary parameters, realizes multi-parameter parallel optimization, further realizes the minimization of the transient radiation sound pressure of the flat plate structure, and is more in line with the actual requirement;
3. the boundary condition of the flat plate structure can be optimally designed within the adjustable range of any given boundary condition, so that the transient radiation sound pressure minimization of the flat plate structure is realized, and the actual requirement is better met;
4. the boundary conditions of the flat structure can be optimally designed for any given transient excitation, so that the minimization of the transient radiation sound pressure of the flat structure is realized. The transient excitation can be transient external force excitation, transient incident sound waves and combined action of the transient external force excitation and the transient incident sound waves, and the actual requirement is met;
5. for a given flat plate structure, the transient radiation sound pressure minimization of the flat plate structure is realized through the optimization design of the boundary condition under the condition that only the boundary condition of the structure is required to be changed and the parameters (such as length, width, thickness, material, appearance and the like) of the flat plate structure are not required to be changed. The original material, size and appearance of the flat plate structure can be kept unaffected, transient sound insulation and noise reduction performance can be effectively improved, and actual requirements are met.
Drawings
The invention will be further described with reference to the following examples with reference to the accompanying drawings.
FIG. 1 is a flow chart of the operation of the present invention.
FIG. 2 is a schematic diagram of a flat panel structure of the present invention.
FIG. 3 is a schematic diagram of an embodiment of the present invention.
Fig. 4 is a schematic time domain waveform of a transient incident sound wave used in the first embodiment.
Fig. 5 is a schematic time domain waveform of the transient external force excitation used in the second embodiment.
Detailed Description
In order that the invention may be more readily understood, preferred embodiments will now be described in detail with reference to the accompanying drawings.
As shown in fig. 1, the present invention is an optimized design method for reducing transient sound radiation of a flat plate structure, and is described by way of example below.
The specific optimization steps of the first embodiment (the structural schematic diagram is shown in fig. 2 and fig. 3) are as follows:
step 1, establishing a plate structure transient sound radiation theoretical calculation equation suitable for any boundary condition based on a time domain finite element-boundary element coupling method:
the derivation of the above formula is based on the time domain finite element-boundary element coupling method, in which SPL max The maximum instantaneous radiation sound pressure level of the flat plate structure is shown, and p (xi, t) is the instantaneous radiation sound pressure at the t moment and xi position; s p Is the area of the plate, p 0 For air density, x is the slab nodal coordinate, c is the acoustic velocity, { R } is a transformation matrix for transforming nodal displacements of the slab structure into transverse deflection, δ is the Dirac function,
instantaneous node acceleration of the x position of the flat plate structure at the moment tau is obtained; the { M }, { C } and { K } are respectively an integral mass matrix, a damping matrix and an integral rigidity matrix of the flat plate structure,
and { U (t) } is the instantaneous node acceleration and instantaneous node of the flat plate structure at the time t respectivelyThe point velocity and the instantaneous node displacement vector,
and { U (t + Δ t) } is the instantaneous node acceleration, the instantaneous node speed and the instantaneous node displacement of the flat plate structure at the moment of t + Δ t respectively; { T } is a conversion matrix for converting incident sound pressure received by the unit into equivalent node force, { F (T) } is instantaneous external force excitation received by the flat plate structure at time T, and { p } 0 (t) is the instantaneous incident sound pressure to which the plate structure is subjected at time t, { F (t + Δ t) } is the instantaneous external force excitation to which the plate structure is subjected at time t + Δ t, { p 0 (t + Δ t) } is the instantaneous incident sound pressure received by the flat plate structure at the moment of t + Δ t; delta t is a calculation time step length, and eta and beta are time integration constants of a Newmark method respectively;
specifically, the overall mass matrix { M }, the damping matrix { C } and the overall stiffness matrix { K } of the flat plate structure are obtained by a finite element method, namely { M } is obtained by a flat plate element equivalent mass matrix { M } p } e Assembled by direct rigidity method, K is a flat plate unit equivalent rigidity matrix K p } e And support boundary element equivalent stiffness matrix K b } e Assembled by a direct rigidity method;
wherein, M p } e ＝ρh∫∫{N} T {N}dxdy；
{K p } e ＝∫∫{B p } T {D p }{B p }dxdy；
Where ρ is the plate material density, h is the plate thickness, { N } is the cell shape function, T transposing symbols for the matrix; { B p Is the strain matrix, { D p The matrix is a bending rigidity matrix; k is a radical of t And k r The parameters of the supporting boundary respectively represent the transverse rigidity and the rotational rigidity of the structural supporting boundary, and the specific method for simulating any boundary condition comprises the following steps: setting k tb And k rb For supporting boundariesThe boundary parameters can be in a complex form, a real part represents the elastic characteristic of the boundary support, an imaginary part represents the damping characteristic of the boundary support, if the elastic boundary support is simulated, the imaginary part value takes 0, and the boundary parameters are constants or position functions, and the simulation of any boundary condition is realized by changing the boundary parameters.
Is a cell boundary profile, gamma b The unit normal vector of (1); a damping matrix of the flat plate structure,
wherein mu is a plate damping factor, omega 0 The lowest order natural frequency of the slab.
step 3, setting the adjustable range of the boundary parameter, as shown in the following table:
Step 5, selecting a proper optimization algorithm, combining the transient acoustic radiation theoretical calculation equation of the flat plate structure with the optimization algorithm, and searching an optimal solution according to each set known parameter of the flat plate structure, the set adjustable range of the boundary parameter, the given initial state of the flat plate structure and the transient excitation so as to obtain the maximum transient radiation sound pressure level SPL of the flat plate structure max A minimized optimal boundary parameter; the specific optimization algorithm is not limited, and the specific steps of the design method of the invention are respectively illustrated by taking a genetic algorithm and a complex shape algorithm as examples:
A. adopting a genetic algorithm as an optimization algorithm:
the genetic algorithm comprises three main operation operators of selection, intersection and mutation, wherein N groups of solutions are randomly generated at the beginning of the algorithm, each group of solution is called as an individual, the set of the solutions is called as a population, then the fitness of each individual is calculated, the selection operation enables the individual with high fitness to have higher replication probability, the convergence speed of the algorithm can be accelerated, the intersection operation generates more optimal individuals by performing gene exchange on two parents, and the mutation operation can bring new genes to the population to avoid falling into local optimization. Through the operation of the three operators, the optimized population is continuously evolved generation by generation, and finally converges to an optimal state. The genetic algorithm comprises the following operation steps:
(1) initialization: selecting a population, i.e. selecting a set of strings or individuals b i N, this initial population, i.e., the set of problem hypothesis solutions, typically produces a set of strings or individuals b in a random manner i N, · i ═ 1, 2; the optimal solution to the problem will be solved by these initial hypothesis solution evolutions;
(2) selecting: selecting next generation individuals according to the survival principle of the fittest, taking the fitness as the selection principle during selection, giving an objective function f according to the natural law that the fittest lives and the fittest eliminates, and then f (b) i ) Referred to as individual b i The fitness of the propagation method is high, and the number of the propagated next generation is high for individuals with high fitness; the degree of adaptability is relatively highSmall individuals, fewer numbers of propagated next generations; even eliminated, thus, the offspring with stronger environmental adaptability is generated, and for the problem solving, the intermediate solution which is closer to the optimal solution is selected;
(3) and (3) crossing: for individuals selected for breeding the next generation, the same positions of two individuals are randomly selected according to the cross probability P c The exchange is carried out at the selected position, which reflects the random information exchange, with the aim of generating new combinations of genes, i.e. new individuals, and during the crossover, a single-point crossover or a multi-point crossover can be carried out, generally speaking, the crossover probability P c The value is 0.25-0.75;
(4) mutation: according to the principle of gene variation in biological genetics, the variation probability P is used m Performing mutation on certain bits of certain individuals, and negating corresponding bits of the string in which mutation is performed, namely changing 1 into 0 and 0 into 1, wherein the mutation probability P is m It is consistent with the case where the biological variation is extremely small, so that P m The value of (2) is small, generally 0.01-0.2, and the method cannot obtain benefits in the solution by means of variation alone, but can ensure that an algorithm process cannot generate a single population which cannot be evolved, because when all individuals are the same, new individuals cannot be generated by crossing, and only the new individuals can be generated by means of variation, namely, the variation increases the characteristics of global optimization;
(5) globally optimal convergence: when the fitness of the optimal individual reaches a given threshold value or the fitness of the optimal individual and the population fitness do not rise any more, the iterative process of the algorithm is converged and the algorithm is ended; otherwise, replacing the previous generation population with the new generation population obtained through selection, crossing and mutation, and returning to the step (2), namely, continuing to circularly execute at the selection place.
The optimization algorithm of the genetic algorithm specifically comprises the following steps:
(1) initializing control parameters: setting population size N, cross probability P c And the mutation probability P m ；
(2) Randomly generating an initial population within a variable setting range;
(3) the following operations are carried out on the existing population:
calculating fitness f (x) of each individual in the population i )，i＝1，2，...，N；
Selecting operation is carried out according to a game machine system, and the probability of selecting individuals with high fitness is obtained;
③ two individuals x are randomly selected i And x j As a parent, according to the probability P c Performing a crossover operation to generate two new individuals x i And x j Calculating the fitness of the four individuals, and selecting the two individuals with the maximum fitness;
fourthly, the probability P of the crossed individuals is calculated m And (4) carrying out mutation operation, receiving a new solution after mutation, exiting the evolution process if the convergence condition is met, and otherwise, turning to the step (3).
B. Adopting a complex shape algorithm as an optimization algorithm:
the complex algorithm of the invention comprises the following specific steps:
(1) initialization: selecting a set X k Wherein k is 1, 2, r, r > n +1, n is the dimension of the optimization problem;
(2) the fitness function is f; to find
To obtain X g ；
To obtain X b ；
(3) If d is less than or equal to epsilon, outputting X * ＝X g ，f * ＝f(X * ) Stopping, otherwise, continuing the step (4);
(4) to find
f(X 0 )＝f 0 If f is 0 ＜f(X b ) If not, entering the step (5), otherwise, entering the step (6);
(5) if g is i (X 0 ) 0 ≦ 0(i ≦ 1, 2., r), then X b By X 0 Replacing, and turning to the step (2), otherwise, entering the step 5.1;
(5.1) taking eta ═ eta 0 ，t＝0；
(5.2) obtaining
If g is i (X 0 ) No more than 0(i ═ 1, 2.., r), then step 5.3 is entered, otherwise step 5.4 is entered;
(5.3) obtaining f (X), if f (X) < f (X) b ) Then X b Replacing with X, and entering the step (2), otherwise, entering the step (6);
(5.4) let η ═ η 0 η, t ═ t + 1; if t is more than or equal to N (N is a large number considered to be set), the step (6) is carried out; otherwise, turning to step 5.2;
(6) to find
If it is
Then X b By using
Replacing, and turning to the step (2), otherwise, entering the step (7);
(7) let X k ＝βX g +(1-β)X k And (k ═ 1, 2., r), and proceeds to step (2).
In this embodiment, a genetic optimization algorithm is selected, and the transient acoustic radiation theory calculation equation and the optimization algorithm are combined, and for each set known parameter of the flat plate structure, the set adjustable range of the boundary parameter, the given initial state of the flat plate structure, and the received transient excitation, after an optimal solution search, a boundary parameter optimization result shown in the following table is obtained:
step 6, forming a flat plate structure according to the optimal boundary parameters; wherein, the steps 1, 2, 3 and 4 are not limited to the sequence.
The design effect is as follows: in the first embodiment, a flat plate structure is formed according to the boundary parameter optimization results shown in the above table. The optimized effect is SPL max The result ratio is not optimized, and the SPL of the flat plate structure at the upper limit value and the lower limit value of the adjustable range of the boundary condition is directly taken max The values are reduced by 3.16dB and 7.25dB, respectively.
Example two:
step 1, establishing a plate structure transient sound radiation theoretical calculation equation suitable for any boundary condition based on a time domain finite element-boundary element coupling method;
and 2, setting various known parameters of the flat plate structure, including flat plate materials, flat plate damping factors, flat plate sizes and flat plate thicknesses, and setting a specific position xi for calculating instantaneous radiation sound pressure. Xi is set at the position 1m away from the flat plate structure on the central normal line of the flat plate structure in the embodiment; the specific parameter values of the set flat plate structure are shown in the following table:
step 3, setting the adjustable range of the boundary parameter, as shown in the following table:
and 4, giving the initial state of the flat plate structure and the transient excitation. The true bookExample given an initial State of
The central position of the flat plate structure is excited by transient external force, and the time domain waveform is shown in fig. 5.
And 5, selecting a complex algorithm, combining the transient acoustic radiation theoretical calculation equation with an optimization algorithm, and searching for an optimal solution aiming at each set known parameter of the flat plate structure, the set adjustable range of the boundary parameter, the given initial state of the flat plate structure and the received transient excitation to obtain a boundary parameter optimization result shown in the following table:
step 6, forming a flat plate structure according to the optimal boundary parameters; wherein, the steps 1, 2, 3 and 4 are not limited to the sequence.
While specific embodiments of the invention have been described, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, as equivalent modifications and variations as will be made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the appended claims.
Claims (5)
1. An optimization design method for reducing transient sound radiation of a flat plate structure is characterized by comprising the following steps: the method comprises the following steps:
step 1, establishing a plate structure transient sound radiation theoretical calculation equation suitable for any boundary condition based on a time domain finite element-boundary element coupling method:
the derivation of the above formula isBased on the time domain finite element-boundary element coupling method, wherein, SPL max The maximum instantaneous radiation sound pressure level of the flat plate structure is shown, and p (xi, t) is the instantaneous radiation sound pressure at the position of xi at the time t; s p Is the area of the plate, p 0 For air density, x' is the slab nodal coordinate, c is the acoustic velocity, { R } is a transformation matrix for transforming nodal displacements of the slab structure into transverse deflection, δ is the Dirac function,
instantaneous node acceleration of the x' position of the flat plate structure at the moment tau is obtained; the { M }, { C } and { K } are respectively an integral mass matrix, a damping matrix and an integral rigidity matrix of the flat plate structure,
and { U (t) } is the instantaneous node acceleration, instantaneous node speed and instantaneous node displacement vector of the flat plate structure at the time t respectively,
and { U (t +. DELTA.t) } is the instantaneous node acceleration, instantaneous node speed and instantaneous node displacement vector of the flat plate structure at the moment of t +. DELTA.t respectively; { T } is a conversion matrix for converting incident sound pressure received by the unit into equivalent node force, { F (T) } is instantaneous external force excitation received by the flat plate structure at time T, and { p } 0 (t) is instantaneous incident sound pressure received by the flat plate structure at the time t, { F (t +. DELTA.t) } is instantaneous external force excitation received by the flat plate structure at the time t +. DELTA.t, { p 0 (t +. DELTA.t) } is the instantaneous incident sound pressure received by the flat plate structure at the time of t +. DELTA.t; delta t is a calculation time step length, and eta and beta are time integration constants of a Newmark method respectively;
step 2, setting various known parameters of the flat plate structure, and setting and calculating a specific position xi of instantaneous radiation sound pressure;
step 3, setting an adjustable range of the boundary parameter;
step 4, giving the initial state and the transient excitation of the flat plate structure;
step 5, selecting an optimization algorithm,combining the transient sound radiation theoretical calculation equation of the flat plate structure with an optimization algorithm, and searching an optimal solution according to each set known parameter of the flat plate structure, the set adjustable range of the boundary parameter, the given initial state of the flat plate structure and the received transient excitation to obtain the maximum instantaneous radiation sound pressure level SPL of the flat plate structure max A minimized optimal boundary parameter;
step 6, forming a flat plate structure according to the optimal boundary parameters;
wherein, the steps 1, 2, 3 and 4 are not limited to the sequence.
2. The optimization design method for reducing the transient sound radiation of the flat plate structure according to claim 1, wherein the optimization design method comprises the following steps: the overall mass matrix { M }, the damping matrix { C } and the overall stiffness matrix { K } of the flat plate structure in the step 1 are obtained by a finite element method, namely { M } is obtained by a flat plate element equivalent mass matrix { M } p } e Assembled by direct rigidity method, K is a flat plate unit equivalent rigidity matrix K p } e And support boundary element equivalent stiffness matrix K b } e Assembled by a direct rigidity method;
wherein, M p } e ＝ρh∫∫{N} T {N}dxdy；
In the formula, rho is the density of a flat plate material, h is the thickness of the flat plate, { N } is a unit shape function, and superscript T is a matrix transposition symbol; { B p Is the strain matrix, { D p The matrix is a bending rigidity matrix; k is a radical of t And k r The parameters for the support boundary, respectively representing the lateral stiffness and the rotational stiffness of the structural support boundary,
is a cell boundary profile, gamma b Is a unit normal vector;
a damping matrix of the flat plate structure,
wherein mu is a plate damping factor, omega 0 The lowest order natural frequency of the slab.
3. The optimization design method for reducing the transient sound radiation of the flat plate structure according to claim 2, wherein the optimization design method comprises the following steps: the specific method for simulating any boundary condition in step 1 is as follows: setting k t And k r For the parameters of the supporting boundary, the boundary parameters are in complex form, the real part represents the elastic characteristic of the boundary support, the imaginary part represents the damping characteristic of the boundary support, if the elastic boundary support is simulated, the imaginary part value takes 0, the boundary parameters are constants or position functions, and the simulation of any boundary condition is realized by changing the boundary parameters.
4. The optimization design method for reducing the transient sound radiation of the flat plate structure according to claim 1, wherein the optimization design method comprises the following steps: the transient excitation in the step 4 is transient external force excitation, transient incident sound waves or the combined action of the transient external force excitation and the transient incident sound waves.
5. The optimization design method for reducing the transient sound radiation of the flat plate structure according to claim 1, wherein the optimization design method comprises the following steps: and each known parameter in the step 2 comprises a flat plate material, a flat plate damping factor, a flat plate size and a flat plate thickness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810726158.5A CN109117502B (en) | 2018-07-04 | 2018-07-04 | Optimization design method for reducing transient sound radiation of flat plate structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810726158.5A CN109117502B (en) | 2018-07-04 | 2018-07-04 | Optimization design method for reducing transient sound radiation of flat plate structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109117502A CN109117502A (en) | 2019-01-01 |
| CN109117502B true CN109117502B (en) | 2022-09-02 |
Family
ID=64822929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810726158.5A Active CN109117502B (en) | 2018-07-04 | 2018-07-04 | Optimization design method for reducing transient sound radiation of flat plate structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109117502B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103308157A (en) * | 2013-05-24 | 2013-09-18 | 南京大学 | Estimation method for structure low-frequency radiation sound power under vibration distributed undersampling condition |
| JP2013258557A (en) * | 2012-06-12 | 2013-12-26 | Canon Inc | Radiography device, and control method and program of radiography device |
| CN107562993A (en) * | 2017-07-25 | 2018-01-09 | 华侨大学 | A kind of slab construction Optimization Design for improving sound insulation room performance |
-
2018
- 2018-07-04 CN CN201810726158.5A patent/CN109117502B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013258557A (en) * | 2012-06-12 | 2013-12-26 | Canon Inc | Radiography device, and control method and program of radiography device |
| CN103308157A (en) * | 2013-05-24 | 2013-09-18 | 南京大学 | Estimation method for structure low-frequency radiation sound power under vibration distributed undersampling condition |
| CN107562993A (en) * | 2017-07-25 | 2018-01-09 | 华侨大学 | A kind of slab construction Optimization Design for improving sound insulation room performance |
Non-Patent Citations (2)
| Title |
|---|
| Acoustic topology optimization of sound power using mapped acoustic radiation modes;Yilin Zhang等;《Wave Motion》;20160930;第70卷;第90-100页 * |
| 基于声压测量的结构模态参数辨识;夏茂龙 等;《振动与冲击》;20171231;第36卷(第22期);第232-238页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109117502A (en) | 2019-01-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107562993B (en) | Flat plate structure optimization design method for improving low-frequency sound insulation performance | |
| CN104317997A (en) | Optimized design method for modelling of end wall of high load fan/compressor | |
| CN103810341B (en) | Predicating method for wind turbine blade airfoil fluttering | |
| CN107491585B (en) | Structural topology optimization design method taking random displacement response variance as target | |
| CN107590325A (en) | A kind of fiber-reinforced composite materials structures optimization method based on Shepard interpolation | |
| Jiang et al. | An improved whale algorithm and its application in truss optimization | |
| CN110516318A (en) | Airfoil Design method based on radial basis function neural network agent model | |
| Fenton et al. | Discrete planar truss optimization by node position variation using grammatical evolution | |
| CN112926025A (en) | Method for solving weapon target allocation problem based on cross entropy genetic algorithm | |
| Fan et al. | A novel hybrid algorithm for solving multiobjective optimization problems with engineering applications | |
| CN109117502B (en) | Optimization design method for reducing transient sound radiation of flat plate structure | |
| CN109101752B (en) | Method for calculating natural vibration frequency of local structure of complex hydraulic structure | |
| CN111368970A (en) | Sensor optimal arrangement method based on deep reinforcement learning | |
| CN103699778B (en) | Flat plate structure optimization design method considering fluid load effect | |
| CN117688807A (en) | Structural deformation and damage analysis method based on indirect bond finite element method | |
| CN114841095B (en) | Incompressible flow disturbance domain propulsion method | |
| CN109977520B (en) | Two-degree-of-freedom dynamic vibration absorber joint optimization method | |
| CN111785274A (en) | Black box anti-sample attack method for voice recognition system | |
| CN108763641B (en) | Optimized design method for flat plate structure for improving transient vibration isolation performance | |
| Alshabatat et al. | Design of in-plane functionally graded material plates for optimal vibration performance | |
| CN112307684A (en) | Fixed-point fast scanning method combining multi-resolution WENO format with ILW boundary processing | |
| CN116776470A (en) | Ship structure total vibration calculation method based on variable cross-section beam dynamic stiffness method | |
| Zhou et al. | Moving least square Ritz method for vibration analysis of plates | |
| CN110826155A (en) | Multi-branch pipeline design method based on genetic algorithm | |
| CN102323983B (en) | Method for automatically providing optimized synthetic jet parameters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |