CN104915503A - Simulation method for self-supporting body of amphibious vehicle - Google Patents

Abstract

The invention provides a simulation method for a self-supporting body of an amphibious vehicle. Different objective functions are defined through a typical method, and the self-supporting body is worked out through an optimization process of an algorithm. The simulation method comprises four necessary design procedures of setting of multiple targets in structure topological optimization, determination of an evaluation method of the multiple targets, determination of a simulation method of structure topological optimization, vehicle body structure design based on the optimization result and the like, and the optimal topology of a product is determined based on the result of topological optimization for the targets. The simulation method greatly guarantees that the design size and shape of the amphibious vehicle body structure are carried out under a material distribution optimal initial topological mode, can greatly improve the material utilization rate, determines the optimal layout of a main supporting structural part of the vehicle body, largely saves the design time, obviously improves the structure optimization level of the high-speed amphibious vehicle, and further guarantees a rapid, reliable and stable work state of the amphibious vehicle.

Description

A kind of emulation mode of amphibious vehicle unitary body

Technical field

The present invention relates to a kind of emulation mode of amphibious vehicle, be specifically related to a kind of emulation mode of amphibious vehicle unitary body.

Background technology

High speed amphibious entrucking is that one can voluntarily by water barriers such as rivers,lakes and seas without the utility appliance such as the bridge of boats, ferryboat, and carry out the high speed fighting machine that navigates by water and shoot on the water, whether the structural design of amphibious vehicle, determine amphibious vehicle and can effectively fight.

Current, two kinds of methods are generally adopted in high speed amphibious vehicle vehicle body process, the first is by profile optimization means, the outer car shell of ship shape is determined to reduce wave making resistance for primary goal, adopt with vehicle frame be spirally connected wait form design bodywork system, this method be conducive to dewatering type amphibious vehicle highest speed forecast and drag reduction raise speed.But for alleviate vehicle especially the weight of bodywork system have no idea to offer help, in view of ship shape car shell, for the requirement of satisfied reduction resistance, bodywork system will increase parts, correspondingly increase system weight, the increase of weight has influence on again the reduction of wave making resistance and the raising of velocity on water conversely.Simultaneously cannot meet the maximum requirement of rigidity under static multi-state according to the body frame structure for automotive of ship shape car shell design, and the safe and reliable requirement travelled under the maximum requirement of dynamic vibration low order frequency and land each operating mode.Second method is being reequiped on existing vehicle basis, take weight reduction as primary goal, remove parts unnecessary on vehicle frame, and application structure shape optimum and the technological means such as dimensionally-optimised are by vehicle frame weight saving, connect ship shape shell on this basis, though this method reduces weight, wave making resistance can not get effective control, thus speed over water cannot reach desirable level.

In view of this, a kind of emulation mode of new high speed amphibious vehicle unitary body is badly in need of, to improve stock utilization to greatest extent; And according to different constraint condition, in the design space of a non-individual body, make the layout of the primary load bearing structure part of vehicle body for best.

Summary of the invention

In view of this, the invention provides a kind of emulation mode of amphibious vehicle unitary body, the method ensure that the size and dimension that amphibious vehicle body structure designs carries out under the optimum initial topology form of distribution of material to a great extent, greatly can improve stock utilization.Simultaneously according to different constraint condition, in the design space of a non-individual body, determine the optimal layout of vehicle body primary load bearing structure part; Significantly can save design time, and the structure optimization level of high speed amphibious vehicle can be considerably improved, and then ensure that quick, the reliable and stable duty of amphibious vehicle amount.

The object of the invention is to be achieved through the following technical solutions:

An emulation mode for amphibious vehicle unitary body, described method comprises the steps:

Step 1. sets the objective optimization function in the topological basic structure of described amphibious vehicle unitary body;

Described objective optimization function is changed into evaluation function by step 2., to complete the foundation of described topological basic structure;

Step 3. by the load of described unitary body and the constraint consistency relevant position to described topological basic structure, and optimizes described topological basic structure;

Step 4. designs the structure of described amphibious vehicle unitary body according to the optimum results of described topological basic structure.

Preferably, described step 1, comprising:

1-1. standardizes the multiple goal in the topological basic structure of described amphibious vehicle unitary body; Wherein, described multiple goal comprises the wave making resistance of the ship type shell of described unitary body, the static multi-state rigidity of described unitary body and dynamic natural frequency;

1-2. sets up the majorized function of described wave making resistance, the majorized function of described static multi-state rigidity and the majorized function of described dynamic natural frequency respectively.

Preferably, described step I-2, comprising:

1-2-1. sets up the majorized function of described wave making resistance:

The majorized function obtaining described wave making resistance Rw according to profile optimization method is:

In above formula, $I+iJ={\∫}_{-T}^{0}dz{\∫}_{-\frac{\mathrm{\π}}{2}}^{\frac{\mathrm{\π}}{2}}\frac{\∂f}{\∂\mathrm{\ξ}}{k}_0{\sec }^2\mathrm{\θ}(z+i\mathrm{\ξ}cos\mathrm{\θ})d\mathrm{\ξ};$

ρ is fluid density; G is acceleration of gravity; for relative velocity; I, J are outboard shape parameter; θ is the angle of primitive ripple and travel direction; I=1,2 ... ..p; T is the following degree of depth of liquid level; Z is pressure; F is the order needing the low order frequency optimized; ξ is that liquid level is raised; k ₀for basic wave number;

1-2-2. sets up the majorized function of described static operating mode rigidity:

Adopt flexibility method of equal effects, rigidity greatest problem be equivalent to flexibility minimum problem, obtain the objective function of static many rigidity topological optimization:

$\min C\left(\mathrm{\ρ}\right)={\left\{{\mathrm{\Σ}}_{k=1}^m{\mathrm{\ω}}_k^q{\[\frac{C_k\left(\mathrm{\ρ}\right)-C_k^{\min }}{C_k^{\max }-C_k^{min}}\]}^q\right\}}^{\frac{1}{q}};$

In formula, ρ is fluid density; M is load working condition sum; K is some in operating mode; ω _kfor the weights of a kth operating mode; Q is penalty factor, and q>=2; C _k(ρ) be the flexibility objective function of a kth operating mode; be respectively maximal value and the minimum value of a kth operating mode flexibility objective function;

1-2-3. sets up the majorized function of described dynamic natural frequency:

Frequency averaging method is adopted to set up the majorized function of described dynamic natural frequency:

$max\left(\mathrm{\Λ}\left(\mathrm{\ρ}\right)\right)=\{x_1,x_2,...x_n\}={\mathrm{\λ}}_0+s{\left(\underset{i=1}{\overset{f}{\Σ}}\frac{{\mathrm{\ω}}_i}{{\mathrm{\λ}}_i-{\mathrm{\λ}}_0}\right)}^{-1};$

In formula, Λ (ρ) is average frequency; x ₁, x ₂... x _nfor sampling order, λ ₀be the 0th rank characteristic frequency, s is given parameter value, and f is the order needing the low order frequency optimized; I=1,2 ... p; ω _iit is the weight coefficient of the i-th order frequency; λ _ibe the i-th rank characteristic frequency, be used for adjustment aim function.

Preferably, described step 2, comprising:

2-1. chooses described objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p; Wherein, described weight coefficient λ ₁, λ ₂..., λ _pin λ _j>=0 and p is the number of described objective optimization function;

Described weight coefficient corresponding with it for each described objective optimization function is multiplied by 2-2., obtains described evaluation function:

$U\[{\mathrm{\λ}}^{T}f\]=U\[\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_j\left(X\right)\];$

If f _j(X)>=0, then available square of weight function λ ^tfor weight coefficient matrix; F is the order needing the low order frequency optimized; J=1,2 ... ..p; P is the number of described objective optimization function;

2-3. solves the optimum solution X of described evaluation function ^*, X ^*for the efficient solution of multiple-objection optimization.

Preferably, described step 2-1 chooses described objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p, comprising:

2-1-1. tries to achieve each described objective optimization function f respectively ₁(X), f ₂(X) ..., f _p(X) constrained optimum solution X _j ^*;

2-1-2. is respectively according to p described optimum solution X _j ^*calculate the functional value f of each described objective optimization function _ji=f _j(X _i ^*), obtain the matrix { f of a target function value _ji} _{p × p}:

2-1-3. solve linear equations $\left\{\begin{array}{c}\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_{\mathrm{ji}}=c\left(i=1,2,...,p\right)\\ \underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j=1\end{array}\right.,$ I=1,2 in formula ... p; Try to achieve each described weight coefficient λ ₁, λ ₂..., λ _pvalue.

Preferably, described step 3, comprising:

The fixed part of described unitary body is mapped on corresponding curved surface in described topological basic structure and unit by 3-1., and loads the load corresponding with described fixed part and solidify, and makes described fixed part in optimizing process as fixed cell;

Described fixed part comprises motive power part, transmission intermediate portions, hangs emphasis junction and marine propulsion unit;

3-2. using the adjustable part of described unitary body as optimization unit; And by the geometric parameter in described adjustable part each cross section in described topological basic structure, determine described optimization unit original depth value, and retain the structural symmetry of described unitary body;

Described optimization unit comprises wave making resistance unit, static multi-state rigidity unit and dynamic natural frequency unit;

3-3. chooses the state variable optimizing described topological basic structure, and the displacement that described state variable comprises model key position is done, had the supporting place node representing meaning, the vertical direction displacement of each node of described topological basic structure, the largest score of the manifold shared by final structure material and minimum score;

3-4. reduces each described state variable respectively, and described optimization unit of all singing in antiphonal style after it reduces at every turn is recombinated, and optimizes described topological basic structure; Wherein, the scope of described state variable is 0 to initial design values.

Preferably, be optimized in described step 3-4 to described topological basic structure, if described topological basic structure is non-individual body, then adopt density variable method optimization, described density variable method comprises:

3-4-1. by discrete for described non-individual body be finite element model;

3-4-2. specifies the density value in each described optimization unit;

3-4-3. with the density of each described optimization unit for design variable, minimum for target with the compliance of described topological basic structure, consider quality of materials constraint or volume constraint and equilibrium condition;

Assuming that the nonlinear dependence of density and material behavior is:

E＝η _i ^αE ₀；

In formula, 0 subscript represents the material behavior of actual use material, i=l, and 2,3 ... n is the pseudo-density optimizing unit, η _ibe the parameter value between 0 ~ 1, penalty factor α be greater than 1 round values.

As can be seen from above-mentioned technical scheme, the invention provides a kind of emulation mode of amphibious vehicle unitary body, the method defines different target function by utilizing typical method, and the unitary body system that the optimizing process of algorithm calculates; Comprise multiobject setting in structural Topology Optimization, the determination of multi-objective assessment method, the determination of structural Topology Optimization emulation mode, based on four necessary design links such as body structure design of optimum results, determines the optimum topology of product to the result of target topological optimization.Emulation mode of the present invention ensure that the size and dimension that amphibious vehicle body structure designs carries out under the optimum initial topology form of distribution of material to a great extent, greatly can improve stock utilization.Simultaneously according to different constraint condition, in the design space of a non-individual body, determine the optimal layout of vehicle body primary load bearing structure part; Significantly can save design time, and the structure optimization level of high speed amphibious vehicle can be considerably improved, and then ensure that quick, the reliable and stable duty of amphibious vehicle amount.

With immediate prior art ratio, technical scheme provided by the invention has following excellent effect:

1, in technical scheme provided by the present invention, bodywork system provided by the invention is by utilizing typical method to define different target function, and the unitary body system that the optimizing process of algorithm calculates; Ensure that the size and dimension that amphibious vehicle body structure designs draws under the optimum initial topology form of distribution of material to greatest extent, greatly increase stock utilization.According to the vehicle body of different constraint condition design, in the design space of non-individual body, vehicle body primary load bearing structure part layout is best; Significantly can save design time, and the structure optimization level of high speed amphibious vehicle can be considerably improved, and then ensure that quick, the reliable and stable duty of amphibious vehicle amount.

2, in technical scheme provided by the present invention, in view of setting multiobject in structural Topology Optimization, the determination of multi-objective assessment method, the determination of structural Topology Optimization emulation mode, based on the setting of four necessary design links such as body structure design of optimum results, drastically increase stock utilization.Simultaneously according to different constraint condition, in the design space of a non-individual body, determine the optimal layout of vehicle body primary load bearing structure part; And then ensure that amphibious vehicle amount in quick, reliable and stable duty.

3, in technical scheme provided by the present invention, by using body structure rigidity as high request index, and the displacement of Selection Model key position is as state variable with choose the supporting place node that has and represent meaning as state variable, considerably improve the structure optimization level of high speed amphibious vehicle.

4, technical scheme provided by the invention, is widely used in military field, has significant military benefit and economic benefit.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the emulation mode of amphibious vehicle unitary body of the present invention;

Fig. 2 is the schematic flow sheet of the step 1 in emulation mode of the present invention;

Fig. 3 is the schematic flow sheet of the step 2 in emulation mode of the present invention;

Fig. 4 is the schematic flow sheet of the step 3 in emulation mode of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on embodiments of the invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

As shown in Figure 1, the emulation mode of a kind of amphibious vehicle unitary body provided by the invention, method comprises the steps:

Step 1. sets the objective optimization function in the topological basic structure of amphibious vehicle unitary body;

Objective optimization function is changed into evaluation function by step 2., thus completes the foundation of topological basic structure;

Step 3. by the load of unitary body and the constraint consistency relevant position to topological basic structure, and is optimized topological basic structure;

Step 4. is according to the structure of the optimum results design amphibious vehicle unitary body of topological basic structure.

As shown in Figure 2, step 1, comprising:

1-1. standardization is for the multiple goal in the topological basic structure of amphibious vehicle unitary body; Wherein, multiple goal comprises the wave making resistance of the ship type shell of unitary body, the static multi-state rigidity of unitary body and dynamic natural frequency; Multiobject mathematical programming problem canonical form such as formula:

min F(x)＝[F ₁(x),F ₂(x),...,F _p(x)] ^T；

g _i(x)＝0，i＝1,2，…q；

g _i(x)≤0，i＝q+1，q+2，…，m；

Due in practical problems, the dimension of possible target is different, so if necessary, needs each target to standardize in advance.

1-2. sets up the majorized function of the majorized function of wave making resistance, the majorized function of static multi-state rigidity and dynamic natural frequency respectively.

Wherein, step I-2, comprising:

1-2-1. sets up the majorized function of wave making resistance:

According to profile optimization method, the majorized function of wave making resistance is:

In above formula, $I+iJ={\∫}_{-T}^{0}dz{\∫}_{-\frac{\mathrm{\π}}{2}}^{\frac{\mathrm{\π}}{2}}\frac{\∂f}{\∂\mathrm{\ξ}}{k}_0{\sec }^2\mathrm{\θ}(z+i\mathrm{\ξ}cos\mathrm{\θ})d\mathrm{\ξ};$

ρ is fluid density; G is acceleration of gravity; for relative velocity; I, J are outboard shape parameter; θ is the angle of primitive ripple and travel direction; I=1,2 ... ..p; T is the following degree of depth of liquid level; Z is pressure; F is the order needing the low order frequency optimized; ξ is that liquid level is raised; k ₀for basic wave number; Application prior art, selects f (ξ, z) to make Rw minimum, namely by optimizing hull shape, reduces shape to the impact of wave making resistance;

1-2-2. sets up the majorized function of static multi-state rigidity:

Adopt flexibility method of equal effects that rigidity greatest problem is equivalent to flexibility minimum problem, namely the objective function of static many rigidity topological optimization is obtained, the i.e. optimum structure topology of the corresponding rigidity of each operating mode, in general, different load working conditions will obtain different structural topologies.Therefore, many rigidity topology optimization problem belongs to multiobjective topology optimization problem.This method adopts flexibility method of equal effects research multiobjective topology optimization problem.Rigidity greatest problem is equivalent to flexibility minimum problem to study, and flexibility then defines by strain energy.So the objective function of static many rigidity topological optimization can be obtained:

$\min C\left(\mathrm{\ρ}\right)={\left\{{\mathrm{\Σ}}_{k=1}^m{\mathrm{\ω}}_k^q{\[\frac{C_k\left(\mathrm{\ρ}\right)-C_k^{\min }}{C_k^{\max }-C_k^{min}}\]}^q\right\}}^{\frac{1}{q}};$

In formula, ρ is fluid density; M is load working condition sum; K is some in operating mode; ω _kfor the weights of a kth operating mode; Q is penalty factor, and q>=2; C _k(ρ) be the flexibility objective function of a kth operating mode; be respectively maximal value and the minimum value of a kth operating mode flexibility objective function;

1-2-3. sets up the majorized function of dynamic natural frequency:

Frequency averaging method is adopted to set up the majorized function of dynamic natural frequency, namely dynamic natural frequency topological optimization objective function is set as that the maximization of several rank important frequencies in low order is as objective function, wherein using vehicle body volume as constraint function, in actual computation, each order frequency values can not reach maximal value simultaneously, objective function there will be oscillatory condition, needs to adopt " frequency averaging method " to define the objective function of natural frequency topological optimization:

$max\left(\mathrm{\Λ}\left(\mathrm{\ρ}\right)\right)=\{x_1,x_2,...x_n\}={\mathrm{\λ}}_0+s{\left(\underset{i=1}{\overset{f}{\Σ}}\frac{{\mathrm{\ω}}_i}{{\mathrm{\λ}}_i-{\mathrm{\λ}}_0}\right)}^{-1};$

In formula, Λ (ρ) is average frequency; x ₁, x ₂... x _nfor sampling order, λ ₀be the 0th rank characteristic frequency, s is given parameter value, and f is the order needing the low order frequency optimized; I=1,2 ... p; ω _iit is the weight coefficient of the i-th order frequency; λ _ibe the i-th rank characteristic frequency, be used for adjustment aim function; This method has considered each order lower mode to the contribution margin of objective function, and average frequency defines a smooth objective function.

As shown in Figure 3, step 2, comprising:

2-1. chooses objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p; Wherein, weight coefficient λ _j>=0 and p is the number of objective optimization function;

Weight coefficient corresponding with it for each objective optimization function is multiplied by 2-2., obtains evaluation function:

$U\[{\mathrm{\λ}}^{T}f\]=U\[\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_j\left(X\right)\];$

If f _j(X)>=0, then available square of weight function λ ^tfor weight coefficient matrix; F is the order needing the low order frequency optimized; J=1,2 ... ..p; P is the number of described objective optimization function;

2-3. solves the optimum solution X of evaluation function ^*, X ^*be the efficient solution of multiple-objection optimization.

Wherein, step 2-1 chooses objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p, comprising:

2-1-1. tries to achieve each objective optimization function f respectively ₁(X), f ₂(X) ..., f _p(X) constrained optimum solution X _j ^*, j=1,2 ... ..p;

2-1-2. is respectively according to p optimum solution X _j ^*calculate the functional value f of each objective optimization function _ji=f _j(X _i ^*), obtaining an objective function is worth matrix { f _ji} _{p × p}:

2-1-3. solve linear equations $\left\{\begin{array}{c}\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_{\mathrm{ji}}=c\left(i=1,2,...,p\right)\\ \underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j=1\end{array}\right.,$ I=1,2 in formula ... p; Obtain each weight coefficient λ ₁, λ ₂..., λ _pvalue.

As shown in Figure 4, step 3, comprising:

The fixed part of unitary body is mapped to corresponding curved surface in topological basic structure and unit by 3-1., and loads respective loads and solidify, and makes fixed part in optimizing process as fixed cell;

Fixed part comprises motive power part, transmission intermediate portions, hangs emphasis junction and marine propulsion unit;

3-2. using the adjustable part of unitary body as optimization unit; And by the geometric parameter in adjustable part each cross section in topological basic structure, determine to optimize unit original depth value, and retain the structural symmetry of unitary body;

Optimize unit and comprise wave making resistance unit, static multi-state rigidity unit and dynamic natural frequency unit;

3-3. chooses the state variable optimizing topological basic structure, and the displacement that state variable comprises model key position is done, had the supporting place node representing meaning, the vertical direction displacement of each node of topological basic structure, the largest score of the manifold shared by final structure material and minimum score;

3-4. reduces each state variable respectively, and optimization unit of all singing in antiphonal style after it reduces at every turn is recombinated, thus is optimized topological basic structure; Wherein, the scope of state variable is 0 to initial design values.

Wherein, be optimized in step 3-4 to topological basic structure, if topological basic structure is non-individual body, then adopt density variable method optimization, density variable method comprises:

3-4-1. by discrete for non-individual body be finite element model;

3-4-2. specifies the density value in each optimization unit;

3-4-3. with the density of each optimization unit for design variable, minimum for target with the compliance of topological basic structure, consider quality of materials constraint or volume constraint and equilibrium condition;

Density variable method has nonlinear relationship between the Macroscopic physical constant of artificial supposition material and its density η i.By discrete for non-individual body be finite element model after, the density in each unit is appointed as identical, with the density of each unit for design variable, minimum for target with the compliance of structure, consider quality of materials constraint (or volume constraint) and equilibrium condition.

Assuming that the nonlinear dependence of density and material behavior is:

E＝η _i ^αE ₀；

In formula, 0 subscript represents the material behavior of actual use material, i=l, and 2,3 ... n is the pseudo-density optimizing unit, η _iget the value between 0 ~ 1, penalty factor α be greater than 1 round values; E=η _i ^αe ₀assuming the relation between the elastic modulus E of material and density of material μ, by introducing penalty factor α, material intermediate density being punished, intermediary density values is assembled to 0 or 1 two ends.

Wherein, body structure rigidity is the index higher compared with requirement of strength, when vehicle body design and optimization, and should to meet rigidity requirement for main target.In order to the control of body torsional rigdity in ensureing to optimize simultaneously, the displacement of Selection Model key position, as state variable, chooses the supporting place node that has and represent meaning as state variable.In addition, consider that the element thickness change that may occur in optimizing process causes local displacement to increase, using optimizing the vertical direction displacement of each node of basic structure also all as state variable.Obtain optimal layout, using the largest score of manifold shared by final structure material and minimum score as state variable, namely must define volume fraction as state variable, can iteration time be shortened like this.

Close section bar is selected for elongated units in optimization change part, is divided into each parts design, adopts welding afterwards, be spirally connected, the form connection such as riveted joint is fastening.Curvature portion adopts different materials according to stressing conditions difference, stem stress surface adopts formed sheet metal design, both sides non-stress and pass to payload segment and use nonmetallic materials design, nonmetallic materials use be spirally connected, rivet with the form such as bonding with carry main body and be connected, periphery is closed.

Above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; although with reference to above-described embodiment to invention has been detailed description; those of ordinary skill in the field still can modify to the specific embodiment of the present invention or equivalent replacement; and these do not depart from any amendment of spirit and scope of the invention or equivalent replacement, it is all being applied within the claims of the present invention awaited the reply.

Claims (7)

1. an emulation mode for amphibious vehicle unitary body, is characterized in that, described method comprises the steps:

Step 1. sets the objective optimization function in the topological basic structure of described amphibious vehicle unitary body;

Described objective optimization function is changed into evaluation function by step 2., to complete the foundation of described topological basic structure;

Step 3. by the load of described unitary body and the constraint consistency relevant position to described topological basic structure, and optimizes described topological basic structure;

Step 4. designs the structure of described amphibious vehicle unitary body according to the optimum results of described topological basic structure.

2. emulation mode as claimed in claim 1, it is characterized in that, described step 1, comprising:

1-1. standardizes the multiple goal in the topological basic structure of described amphibious vehicle unitary body; Wherein, described multiple goal comprises the wave making resistance of the ship type shell of described unitary body, the static multi-state rigidity of described unitary body and dynamic natural frequency;

1-2. sets up the majorized function of described wave making resistance, the majorized function of described static multi-state rigidity and the majorized function of described dynamic natural frequency respectively.

3. emulation mode as claimed in claim 2, it is characterized in that, described step I-2, comprising:

1-2-1. sets up the majorized function of described wave making resistance:

The majorized function obtaining described wave making resistance Rw according to profile optimization method is:

In above formula, $I+iJ={\∫}_{-T}^{0}dz{\∫}_{-\frac{\mathrm{\π}}{2}}^{\frac{\mathrm{\π}}{2}}\frac{\∂f}{\∂\mathrm{\ξ}}{k}_0{\sec }^2\mathrm{\θ}(z+i\mathrm{\ξ}cos\mathrm{\θ})d\mathrm{\ξ};$

ρ is fluid density; G is acceleration of gravity; for relative velocity; I, J are outboard shape parameter; θ is the angle of primitive ripple and travel direction; I=1,2.....p; T is the following degree of depth of liquid level; Z is pressure; F is the order needing the low order frequency optimized; ξ is that liquid level is raised; k ₀for basic wave number;

1-2-2. sets up the majorized function of described static operating mode rigidity:

Adopt flexibility method of equal effects, rigidity greatest problem be equivalent to flexibility minimum problem, obtain the objective function of static many rigidity topological optimization:

$\min C\left(\mathrm{\ρ}\right)={\left\{{\mathrm{\Σ}}_{k=1}^m{\mathrm{\ω}}_k^q{\[\frac{C_k\left(\mathrm{\ρ}\right)-C_k^{\min }}{C_k^{\max }-C_k^{\min }}\]}^q\right\}}^{\frac{1}{q}};$

In formula, ρ is fluid density; M is load working condition sum; K is some in operating mode; ω _kfor the weights of a kth operating mode; Q is penalty factor, and q>=2; C _k(ρ) be the flexibility objective function of a kth operating mode; be respectively maximal value and the minimum value of a kth operating mode flexibility objective function;

1-2-3. sets up the majorized function of described dynamic natural frequency:

Frequency averaging method is adopted to set up the majorized function of described dynamic natural frequency:

$max\left(\mathrm{\Λ}\right(\mathrm{\ρ}))=\{x_1,x_2,...x_n\}={\mathrm{\λ}}_0+s{\left(\underset{i=1}{\overset{f}{\Σ}}\frac{{\mathrm{\ω}}_i}{{\mathrm{\λ}}_i-{\mathrm{\λ}}_0}\right)}^{-1};$

In formula, Λ (ρ) is average frequency; x ₁, x ₂... x _nfor sampling order, λ ₀be the 0th rank characteristic frequency, s is given parameter value, and f is the order needing the low order frequency optimized; I=1,2 ... p; ω _iit is the weight coefficient of the i-th order frequency; λ _ibe the i-th rank characteristic frequency, be used for adjustment aim function.

4. emulation mode as claimed in claim 1, it is characterized in that, described step 2, comprising:

2-1. chooses described objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p; Wherein, described weight coefficient λ ₁, λ ₂..., λ _pin λ _j>=0 and p is the number of described objective optimization function;

Each the described weight coefficient corresponding with it is multiplied by 2-2., obtains described evaluation function:

$U\[{\mathrm{\λ}}^{T}f\]=U\[\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_j\left(X\right)\];$

If f _j(X)>=0, then available square of weight function λ ^tfor weight coefficient matrix; F is the order needing the low order frequency optimized; J=1,2 ... ..p; P is the number of described objective optimization function;

2-3. solves the optimum solution X of described evaluation function ^*, X ^*for the efficient solution of multiple-objection optimization.

5. emulation mode as claimed in claim 4, it is characterized in that, described step 2-1 chooses described objective optimization function f ₁(X), f ₂(X) ..., f _p(X) corresponding weight coefficient λ ₁, λ ₂..., λ _p, comprising:

2-1-1. tries to achieve each described objective optimization function f respectively ₁(X), f ₂(X) ..., f _p(X) constrained optimum solution X _j ^*;

2-1-2. is respectively according to p described optimum solution X _j ^*calculate the functional value f of each described objective optimization function _ji=f _j(X _i ^*), obtain the matrix { f of a target function value _ji} _{p × p}:

2-1-3. solve linear equations $\left\{\begin{array}{c}\underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j{f}_{ij}=c(i=1,2,\mathrm{...},p)\\ \underset{j=1}{\overset{p}{\Σ}}{\mathrm{\λ}}_j=1\end{array}\right.,$ I=1,2 in formula ... p; Try to achieve each described weight coefficient λ ₁, λ ₂..., λ _pvalue.

6. emulation mode as claimed in claim 1, it is characterized in that, described step 3, comprising:

The fixed part of described unitary body is mapped on corresponding curved surface in described topological basic structure and unit by 3-1., and loads the load corresponding with described fixed part and solidify, and makes described fixed part in optimizing process as fixed cell;

Described fixed part comprises motive power part, transmission intermediate portions, hangs emphasis junction and marine propulsion unit;

3-2. using the adjustable part of described unitary body as optimization unit; And by the geometric parameter in described adjustable part each cross section in described topological basic structure, determine described optimization unit original depth value, and retain the structural symmetry of described unitary body;

Described optimization unit comprises wave making resistance unit, static multi-state rigidity unit and dynamic natural frequency unit;

3-3. chooses the state variable optimizing described topological basic structure, and the displacement that described state variable comprises model key position is done, had the supporting place node representing meaning, the vertical direction displacement of each node of described topological basic structure, the largest score of the manifold shared by final structure material and minimum score;

3-4. reduces each described state variable respectively, and described optimization unit of all singing in antiphonal style after it reduces at every turn is recombinated, and optimizes described topological basic structure; Wherein, the scope of described state variable is 0 to initial design values.

7. emulation mode as claimed in claim 6, is characterized in that, be optimized in described step 3-4 to described topological basic structure, if described topological basic structure is non-individual body, then adopt density variable method optimization, described density variable method comprises:

3-4-1. by discrete for described non-individual body be finite element model;

3-4-2. specifies the density value in each described optimization unit;

3-4-3. with the density of each described optimization unit for design variable, minimum for target with the compliance of described topological basic structure, consider quality of materials constraint or volume constraint and equilibrium condition;

Assuming that the nonlinear dependence of density and material behavior is:

E=η _i ^αE ₀；

In formula, 0 subscript represents the material behavior of actual use material, i=l, and 2,3 ... n is the pseudo-density optimizing unit, η _ibe the parameter value between 0 ~ 1, penalty factor α be greater than 1 round values.