CN104743086A - Ship whipping motion response prediction method and system under underwater explosion situation - Google Patents

Abstract

The invention discloses a ship whipping motion response prediction method and system under a combined effect of underwater explosive shock waves and bubbles. The ship whipping motion response prediction method comprises the steps that step 1, a ship is equivalent to a uniform cross section free ship body girder, and therefore the prediction of ship motion responses are equivalent to the predication of free ship body girder motion responses; step 2, the load pressure process of the free ship body girder under the underwater explosion effect is divided into five time phases, and a shock wave pressure peak value, a bubble pulsation phase negative pressure peak value and a bubble first time pulsation pressure peak value are collected; step 3, motion displacements in the five time phases of underwater explosion of the free ship body girder are solved. The invention further provides a ship whipping motion response prediction system. The ship whipping motion response prediction method and system comprehensively consider the shock effect of the shock wave and the bubble load on the whole ship, the underwater explosion load pressure is simplified to be five phases, the motion displacements of a ship in different phases are calculated, and therefore project prediction of ship elastic motion or whipping motion responses under medium and distal field explosion effect is achieved accurately, simply and conveniently.

Description

Naval vessel whipping motion response prediction method and system under a kind of underwater explosive damage

Technical field

The invention belongs to blast impulse deformation technology field under naval vessel water resistant, more specifically, relate to naval vessel whipping motion response prediction method and system under a kind of underwater explosive damage.

Background technology

Under underwater explosive damage, naval vessel is first subject to the effect of initial explosion shock wave and deforms, and gas bubble pulsation subsequently and radiation pressure produce subsequent affect to ship structure, the impact that the blast load that now should consider two kinds of forms is out of shape ship structure.Especially, for this longitudinal large-scale structure in naval vessel, the in-service time of shock wave on ship length direction is longer, and naval vessel mass motion distortion that it causes is the basis studying Ship Motion response under shot bubble effect further.And in fact, the impact of underwater blast wave is often ignored in existing research, regard the naval vessel of initial shock wave active phase as quiescence, ignore structure acceleration, speed responsive that shock wave causes, say from physical significance, this kind of simplification causes the Theoretical Prediction Shortcomings of mass motion distortion in naval vessel under underwater explosive damage.

Water surface fight naval vessel mostly is slender type, and it is many within the scope of several hertz that this version determines its single order frequency that wets, and this and the conventional underawater ordnance gas bubble pulsation frequency formed of exploding is identical.Under the explosion condition of middle far field, the coupled resonance motion between shot bubble and naval vessel is more easily excited out, and whipping motion response will occur on naval vessel.Now, although naval vessel is in elastic deformation substantially, global response amplitude is relatively obvious, and the impact of the equipment such as shaft is very important.The research whipping motion response modes of naval vessel under the underwater explosive damage of middle far field, for the design of optimization underawater ordnance and ship structure protection Design all significant.

Summary of the invention

For defect and the technical need of prior art, the invention provides a kind of naval vessel whipping motion response prediction method under underwater blast wave and bubble synergy, the present invention considers explosion wave, gas bubble pulsation and the radiation pressure impact effect to ship structure, Load Characteristics under the lower naval vessel water resistant that tallies with the actual situation during blast impulse and response process, can predict naval vessel whipping motion situation.

For achieving the above object, according to the present invention, provide a kind of naval vessel whipping motion response prediction method under underwater blast wave and bubble synergy, described method comprises step:

S1, naval vessel is equivalent to the free hull beam of uniform cross section, thus the prediction responded Ship Motion is equivalent to the prediction to free hull beam motor imagination;

S2, hull beam load pressure process free under underwater explosive damage is divided into five time phases, gathers shock wave pressure peak value P _m, gas bubble pulsation stage negative pressure peak P _b, bubble first time pulsating pressure peak value P _s; Described five time phases are: 0≤t < t ₁, t ₁≤ t < t ₂, t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅; Wherein t ₁=θ, θ are shock wave attenuation constant; p ₀for explosive place hydrostatic pressure, P _atmfor barometric pressure, c is the velocity of sound in water, r ₀for powder charge radius, R is quick-fried distance; me is powder charge equivalent, ρ _wfor the density of water, g is acceleration due to gravity; $t_5=3290\frac{r_0}{P_0^{0.71}}+t_4;$

S3, solve the moving displacement w (x, t) that free hull beam explodes in five time phases under water:

Wherein, x is the abscissa value at free hull beam at a point place, k ₂=t ₂-t ₁, $\mathrm{\&beta;}=\frac{\mathrm{\&pi;}}{t_3-t_2},k_4=k_5=3290\frac{r_0}{P_0^{0.71}},$ for the intrinsic shape of shaking in free hull beam first rank, wherein ζ ₁for shape amplitude of shaking, μ ₁for beam motion frequency parameter, l is free hull beam length; be the integral constant of five time phases, ω ₁single order for free beam shakes shape natural frequency; φ ₁for integral constant, m is the unit beam length quality considering added mass of entrained water, and p (x) is free hull beam different time staged pressure distribution characteristics function, for 0≤t < t ₁, t ₁≤ t < t ₂time phase, for t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅time phase, $p\left(x\right)=(1-\frac{2x-l}{l})\&CenterDot;\exp [-8{\left(\frac{2x-l}{l}\right)}^2+4{\left(\frac{2x-l}{l}\right)}^3]+{\left(\frac{2l-2x}{l}\right)}^{1.5}\&CenterDot;\left(\frac{2x-l}{l}\right).$

As further preferably, described method also comprises step: S4, according to the moving displacement w (x, t) of naval vessel in the different time stage, calculate its speed, acceleration/accel and moment of flexure.

Correspondingly, the present invention also provides naval vessel whipping motion response prediction system under a kind of underwater blast wave and bubble synergy, and described system comprises:

First module, for naval vessel being equivalent to the free hull beam of uniform cross section, is equivalent to the prediction to free hull beam motor imagination thus by the prediction responded Ship Motion;

Second module, for hull beam load pressure process free under underwater explosive damage is divided into five time phases, gathers shock wave pressure peak value P _m, gas bubble pulsation stage negative pressure peak P _b, bubble first time pulsating pressure peak value P _s; Described five time phases are: 0≤t < t ₁, t ₁≤ t < t ₂, t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅; Wherein t ₁=θ, θ are shock wave attenuation constant; $\stackrel{\&OverBar;}{P_0}=\frac{P_0}{P_{\mathrm{atm}}},n=11.4-\frac{10.6}{{\stackrel{\&OverBar;}{r}}^{0.13}}+\frac{1.51}{{\stackrel{\&OverBar;}{r}}^{1.26}},\stackrel{\&OverBar;}{r}=\frac{R}{r_0},$ P ₀for explosive place hydrostatic pressure, P _atmfor barometric pressure, c is the velocity of sound in water, r ₀for powder charge radius, R is quick-fried distance; m _efor powder charge equivalent, ρ _wfor the density of water, g is acceleration due to gravity; $t_5=3290\frac{r_0}{P_0^{0.71}}+t_4;$

3rd module, for solving the moving displacement w (x, t) that free hull beam is exploded in five time phases under water:

Wherein, x is the abscissa value at free hull beam at a point place, k ₂=t ₂-t ₁, $\mathrm{\&beta;}=\frac{\mathrm{\&pi;}}{t_3-t_2},k_4=k_5=3290\frac{r_0}{P_0^{0.71}},$ for the intrinsic shape of shaking in free hull beam first rank, wherein ζ ₁for shape amplitude of shaking, μ ₁for beam motion frequency parameter, l is free hull beam length; be the integral constant of five time phases, ω ₁single order for free beam shakes shape natural frequency; φ ₁for integral constant, m is the unit beam length quality considering added mass of entrained water, and p (x) is free hull beam different time staged pressure distribution characteristics function, for 0≤t < t ₁, t ₁≤ t < t ₂time phase, for t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅time phase, $p\left(x\right)=(1-\frac{2x-l}{l})\&CenterDot;\exp [-8{\left(\frac{2x-l}{l}\right)}^2+4{\left(\frac{2x-l}{l}\right)}^3]+{\left(\frac{2l-2x}{l}\right)}^{1.5}\&CenterDot;\left(\frac{2x-l}{l}\right).$

As further preferably, described system also comprises: four module, for according to the moving displacement w (x, t) of naval vessel in the different time stage, calculates its speed, acceleration/accel and moment of flexure.

In general, the above technical scheme conceived by the present invention compared with prior art, mainly possesses following technological merit: the present invention considers shock wave and bubble load to the impact effect of Marine campaign system, underwater explosion loading pressure is reduced to double teacher, by setting up corresponding math modeling, calculate the moving displacement of naval vessel in different phase, thus realize the prediction to whipping motion response condition under naval vessel under water explosion wave and bubble synergy.And the parameter of the reaction Ship Motion responses such as ship velocity, acceleration/accel and moment of flexure can be calculated further according to moving displacement.Compared to prior art, the engineering prediction of naval vessel elastic movement or whipping motion response under the detonation of far field during the present invention can realize comparatively accurately and easily, for blast impulse protection Design level under raising naval vessel water resistant, optimizes underawater ordnance signatures generation and attack pattern etc. and all has and instruct reference.

Accompanying drawing explanation

Fig. 1 is the inventive method schematic flow sheet;

Fig. 2 is hull beam of the present invention blast operating mode schematic diagram;

Fig. 3 is underwater explosion loading double teacher schematic diagram of the present invention;

Fig. 4 is one embodiment of the invention central sill model structural form and scale diagrams;

Fig. 5 is hull beam mid point moment of flexure time-history curves schematic diagram in one embodiment of the invention;

Fig. 6 is hull beam neutral displacement time-history curves schematic diagram in one embodiment of the invention;

Fig. 7 is not hull beam length direction deformation comparison diagram in the same time in one embodiment of the invention.

Detailed description of the invention

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.In addition, if below in described each embodiment of the present invention involved technical characteristic do not form conflict each other and just can mutually combine.

The invention provides a kind of naval vessel whipping motion response prediction method under underwater blast wave and bubble synergy, as shown in Figure 1, first Ship Motion is equivalent to the motion of free hull beam by method, consider shock wave and bubble to the impact on naval vessel, hull beam load pressure free under underwater explosive damage is divided into double teacher, and set up corresponding math modeling, and then solve the moving displacement on naval vessel in different phase, its specific implementation thinking is:

Step one, is reduced to the free hull beam of uniform cross section according to longitudinal strength equivalence and principle of similarity by naval vessel, thus the prediction responded Ship Motion is equivalent to the prediction to free hull beam motor imagination;

Step 2, is reduced to double teacher by underwater explosion loading pressure curve, wherein, the Ith, II staged pressure meets linear variability law, the IIIth stage met varies with sinusoidal function relation, and the IVth, V stage met linear variability law;

Step 3, determines the intrinsic shaping function of hull beam;

Step 4, according to shock wave and bubble pulsatile pressure Variation Features, determines the pressure distributed function on hull beam length direction in each stage;

Step 5, according to the pressure distributed function on different pressures stage hull beam length direction, determines the principal coordinate function of hull beam motion deformation;

Step 6, according to shaping function and the principal coordinate function of different pressures stage hull beam, determines the moving displacement function of this stage inner beam;

Step 7, according to initial motion condition and continuous moving condition of each stage, solves hull beam moving displacement in each stage, also can solve ship velocity, acceleration/accel and moment of flexure further, thus prediction hull beam whipping motion response condition.

Below the specific implementation of above-mentioned steps is explained.

Explosion time immediately below explosive is in the middle part of naval vessel, its motor imagination is relatively obvious.In the present invention's specific embodiment, with this typical condition for research object.As shown in Figure 2, under this working condition, the method for calculating of the whipping motion response of naval vessel under water under explosion wave and bubble synergy comprises the steps:

Step one, the hull beam of carrying out ship structure is similar to.

Naval vessel is reduced to the free hull beam of uniform cross section, compared to real yardstick hull beam and contracting than hull model, it simplifies process and meets following two principles:

A () keeps prototype and model always vertical moment of inertia geometrical similarity;

(b) ship structure and explosive by the contracting of same scale geometry than after, keep the model single order frequency that wets to coincide with the shot bubble ripple frequency of contracting than dose.

Step 2, is reduced to double teacher by underwater explosion loading pressure curve

Underwater explosion loading pressure curve is reduced to I ~ V common double teacher as shown in Figure 3.Wherein, I, II stage is the shock wave load alleviation stage, and it meets linear variability law; The III stage is the flow field negative pressure variation stage that the motion of boundary condition bubble dilation is formed, and it meets sinusoidal function relation; IV, V stage was rising, the decline stage that bubble shrinkage produces secondary pulsating pressure, and it meets linear variability law, then list each staged pressure LOAD FOR formula as follows:

(1) the Ith stage: p (t)=P _m(1-t/k ₁) 0≤t < t ₁

(2) the IIth stages: $p\left(t\right)=P_m/e\&CenterDot;(1-\frac{t-t_1}{k_2})$ t ₁≤t＜t ₂

(3) the IIIth stage: p (t)=P _bsin β (t-t ₂) t ₂≤ t < t ₃

(4) the IVth stages: $p\left(t\right)=P_s\&CenterDot;\left(\frac{t-t_3}{k_4}\right)$ t ₃≤t＜t ₄

(5) the Vth stages: $p\left(t\right)=P_s\&CenterDot;(1-\frac{t-t_4}{k_5})$ t ₄≤t＜t ₅

In formula: $\begin{array}{cc}{P}_m=K_1\&CenterDot;{\left(\frac{{m_e}^{1/3}}{R}\right)}^{A_1}& k_1=\frac{\mathrm{e\&theta;}}{e-1}\end{array},$ t ₁＝θ， $\mathrm{\&theta;}=K_2\&CenterDot;{m_e}^{1/3}\&CenterDot;{\left(\frac{{m_e}^{1/3}}{R}\right)}^{A_2},$ k ₂＝t ₂-t ₁， $t_2=(\frac{850}{{\stackrel{\&OverBar;}{P}}_0^{0.81}}-\frac{20}{{\stackrel{\&OverBar;}{P}}_0^{1/3}}+n)\&CenterDot;\frac{r_0}{c},\stackrel{\&OverBar;}{P_0}=\frac{P_0}{P_{\mathrm{atm}}},$ P ₀＝P _atm+ρ _wgH ₀， $n=11.4-\frac{10.6}{{\stackrel{\&OverBar;}{r}}^{0.13}}+\frac{1.51}{{\stackrel{\&OverBar;}{r}}^{1.26}},$ $\stackrel{\&OverBar;}{r}=\frac{R}{r_0},\mathrm{\&beta;}=\frac{\mathrm{\&pi;}}{k_3},$ k ₃＝t ₃-t ₂， $t_4=T=2.11\frac{{m_e}^{1/3}}{{(P_0/{\mathrm{\&rho;}}_{w}g)}^{5/6}},P_s=\frac{39\&times;{10}^6+24P_0}{\stackrel{\&OverBar;}{r}},$ $P_b=\frac{-3.1\&times;{10}^4{m_e}^{1/3}{(H_0+10)}^{2/3}}{R},$ k ₄＝t ₄-t ₃，k ₅＝t ₅-t ₄， $k_4=k_5=3290\frac{r_0}{P_0^{0.71}}.$

Wherein, m _efor TNT powder charge equivalent, R is quick-fried distance, P _mfor shock wave pressure peak value, K ₁, K ₂, A ₁, A ₂for shock wave constant, k ₁k ₂k ₃k ₄k ₅be respectively the parameter relevant to five pressure stage time lengths, P ₀for explosive place hydrostatic pressure, for dimensionless pressure parameter, P _bfor the negative pressure peak in gas bubble pulsation process, P _sfor pulsating pressure peak value, for characterizing the dimensionless parameter of explosive distance, θ is shock wave attenuation constant, H ₀for shot depth, r ₀for powder charge radius, ρ _wfor the density of water, c is the velocity of sound in water, P _atmfor barometric pressure, g is acceleration due to gravity, and T is the gas bubble pulsation cycle, and β is bubble negative pressure staged pressure function angular frequency value, and each parameter physical quantity all adopts International System of Units.

Step 3, determines the normal vibration mode function of underwater explosive damage lower hull beam vibration

When underwater explosion loading is less, free hull beam makes elastic movement under explosion pressure P (x, t) effect, and its motion control equation is

$\mathrm{EI}\frac{{\&PartialD;}^{4}w}{{\&PartialD;x}^4}+m\frac{{\&PartialD;}^{2}w}{{\&PartialD;t}^2}=P(x,t)---\left(1\right)$

Its general solution is

Wherein, x is the abscissa value at free hull beam at a point place, and w is moving displacement function, and E is modulus of elasticity, and I is beam moment of inertia of cross-section, and m is the unit beam length quality considering attached water.

Wherein, the intrinsic shapes of shaking in beam i-th rank, H _it () is that beam i-th rank shake principal coordinate corresponding to shape.In order to determine the moving displacement function of beam, the principal coordinate of intrinsic shake shape and correspondence first should be determined respectively.

The general expression of the intrinsic shape of shaking of beam is

Wherein, μ is the variable relevant to beam natural frequency, and l is beam length, ζ ₁, ζ ₂, ζ ₃, ζ ₄for constant.

For free boundary beam, two ends bending and shearing is zero, therefore meets as downstream condition when x=0 and x=l

Formula (3) is substituted into above-mentioned boundary condition, and derivation can have ζ ₁=ζ ₃, ζ ₂=ζ ₄, and

$\left\{\begin{array}{c}{\mathrm{\&zeta;}}_2(\mathrm{ch\&mu;}-\cos \mathrm{\&mu;})+{\mathrm{\&zeta;}}_1(\mathrm{sh\&mu;}-\sin \mathrm{\&mu;})=0\\ {\mathrm{\&zeta;}}_2(\mathrm{sh\&mu;}+\sin \mathrm{\&mu;})+{\mathrm{\&zeta;}}_1(\mathrm{ch\&mu;}-\cos \mathrm{\&mu;})=0\end{array}\right.---\left(5\right)$

For constant ζ ₁and ζ ₂, a particular solution of above-mentioned set of equations requires that determinant of a matrix coefficient equals zero, namely

(chμ-cosμ) ²-(sh ²μ-sin ²μ)＝0 (6)

Above-mentioned non trivial solution determines the natural frequency of free beam.In addition, the natural frequency of beam also meets

$\mathrm{\&omega;}={\left(\frac{\mathrm{\&mu;}}{l}\right)}^2\sqrt{\frac{\mathrm{EI}}{m}}---\left(7\right)$

When μ gets first untrivialo solution μ ₁when=4.730, the single order of beam shakes shape natural frequency now ζ ₂/ ζ ₁=(sin μ ₁-sh μ ₁)/(ch μ ₁-cos μ ₁) ≈-1, then the single order shaping function of beam can approximate representation be

Step 4, determines the pressure distributed function of underwater explosion loading at hull beam length direction

For underwater blast pressure function P (x, t), it meets P (x, t)=p (t) p (x), wherein p (t) is beam midpoint pressure time-process decay curve, and p (x) is the blast load Pressure Distribution function relative to beam mid point.

For the shock wave load alleviation stage (I, II stage), beam upward pressure distribution characteristics function p _sx () can be characterized by

$p_s\left(x\right)=\frac{R^{1.13}}{{\sqrt{R^2+{(x-l/2)}^2}}^{1.13}}---\left(9\right)$

For the gas bubble pulsation stage (the IIIth-V stage), beam upward pressure distribution characteristics function p _bx () can be characterized by

$p_b\left(x\right)=(1-\frac{2x-l}{l})\&CenterDot;\exp [-8{\left(\frac{2x-l}{l}\right)}^2+4{\left(\frac{2x-l}{l}\right)}^3]+{\left(\frac{2l-2x}{l}\right)}^{1.5}\&CenterDot;\left(\frac{2x-l}{l}\right)---\left(10\right)$

Determine the Pressure Distribution function p in shock wave and bubble stage hull beam respectively _s(x) and p _bafter (x), in conjunction with in double teacher pressure time-process change formula p (t), pressure function P (x, t).

Step 5, determines the principal coordinate function of hull beam motion in the different pressures stage

For the principal coordinate H under forced vibration condition _it (), can be expressed as

$H_i\left(t\right)=a_i\cos {\mathrm{\&omega;}}_{i}t+b_i\sin {\mathrm{\&omega;}}_{i}t+\frac{1}{{\mathrm{\&omega;}}_i}{\&Integral;}_0^t{f}_i\left(\mathrm{\&tau;}\right)\sin {\mathrm{\&omega;}}_i(t-\mathrm{\&tau;})\mathrm{d\&tau;}---\left(11\right)$

In formula for the broad sense disturbance force corresponding with generalized mass, a _i, b _ifor integral constant, determined by initial condition (IC) (displacement and speed are zero) and the motion condition of continuity.

Specify the Pressure Distribution function p in underwater blast each stage _safter (x), for simplifying the parameter expression form of the follow-up derivation of equation, special introducing parameter

Step 6, determines the moving displacement function of different pressures stage inner beam

Considering that explosive mainly evokes the low order motor imagination of beam in the middle part of beam during explodes beneath, for simplifying problem, supposing that now hull beam mainly presents first order motion mode.Shaping function is determined respectively according to formula (8), (11) with the principal coordinate function H of its correspondence ₁t, after (), the approximate displacement function that can obtain beam is

Because underwater explosion loading is divided into 5 different phases, the shaping function in each stage be consistent, and the forced vibration principal coordinate function H of correspondence ₁t () is different, according to the calculation of pressure formula of different phase, can obtain the moving displacement function of its correspondence for (respectively being formula (13) to formula (17))

Ith stage:

IIth stage:

IIIth stage:

IVth stage:

Vth stage:

Step 7, determines the kinematic parameter of different pressures stage inner beam, according to motion parameter predictive hull beam whipping motion response condition.

In formula (13) ~ (17) time t with the initial time in each pressure stage for zero point, coefficient determined by initial motion condition (displacement and speed are zero) and continuous moving condition of each stage, parameter phi ₁pressure Distribution function according to different phase is determined.

After the displacement function w (x, t) in each stage determines, the speed of beam, acceleration/accel and moment of flexure can ask partial derivative to obtain to time t or variable x by displacement function, can predict hull beam whipping motion response condition further according to above parameter.

In the present invention's specific embodiment, choosing certain beam model is analytic target, and its relative dimensions parameter is: beam length 2.8m, wide 0.3m, high 0.08m, thickness of slab 1mm, and beam plastic limit bending moment 1.8e4Nm, specific constructive form as shown in Figure 4.Choose TNT dose 5g, the quick-fried blast operating mode apart from 1m to analyze the mass motion response process of beam.

Fig. 5 gives hull beam mid point moment of flexure time-history curves.Can find out, in gas bubble pulsation process, beam mid point moment does not exceed plastic limit bending moment M _s, whole beam presents elastic movement process; Moment during beam sagging condition is greater than initial hogging condition, and a new peak has appearred in the moment but bubble is crumbled and fall during the hogging distortion of back rest second time, and visible bubble in bubble pulsating pressure is very important to the overall damaging action of beam.

Fig. 6 gives hull beam neutral displacement time-history curves.Can find out, hull beam presents significantly up and down periodic motion, and the beam single order frequency that wets is 26Hz, and close with bubble first time ripple frequency (21Hz), now both coupled resonances motions are excited out, present the response of similar whipping motion; The low pressure flow field formed in bubble motion make beam occur certain in hang down distortion, but due to quick-fried distance comparatively large, meiobar sphere of action, time length are all relatively little, and causing hanging down in beam distortion is still not obvious.In addition, as can be seen from the kinematic velocity that displacement curve obtains, beam mid point maximum distortion velocity amplitude is no more than 3m/s.

Fig. 7 gives typical time hull beam length direction deformation contrast situation.Can find out, beam totally presents single order elastic deformation, beam around two stationary points occur hogging, in hang down distortion; For a certain particular moment, the moving displacement at beam two ends even exceedes neutral displacement value.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (4)

1. a naval vessel whipping motion response prediction method under underwater blast wave and bubble synergy, it is characterized in that, described method comprises step:

S1, naval vessel is equivalent to the free hull beam of uniform cross section, thus the prediction responded Ship Motion is equivalent to the prediction to free hull beam motor imagination;

S2, hull beam load pressure process free under underwater explosive damage is divided into five time phases, gathers shock wave pressure peak value P _m, gas bubble pulsation stage negative pressure peak P _b, bubble first time pulsating pressure peak value P _s; Described five time phases are: 0≤t < t ₁, t ₁≤ t < t ₂, t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅; Wherein t ₁=θ, θ are shock wave attenuation constant; p ₀for explosive place hydrostatic pressure, P _atmfor barometric pressure, c is the velocity of sound in water, r ₀for powder charge radius, R is quick-fried distance; me is powder charge equivalent, ρ _wfor the density of water, g is acceleration due to gravity; $t_5=3290\frac{r_0}{P_0^{0.71}}+t_4;$

S3, solve the moving displacement w (x, t) that free hull beam explodes in five time phases under water:

Wherein, x is the abscissa value at free hull beam at a point place, k ₂=t ₂-t ₁, for the intrinsic shape of shaking in free hull beam first rank, wherein ζ ₁for shape amplitude of shaking, μ ₁for beam motion frequency parameter, l is free hull beam length; be the integral constant of five time phases, ω ₁single order for free beam shakes shape natural frequency; φ ₁for integral constant, m is the unit beam length quality considering added mass of entrained water, and p (x) is free hull beam different time staged pressure distribution characteristics function, for 0≤t < t ₁, t ₁≤ t < t ₂time phase, for t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅time phase, $p\left(x\right)=(1-\frac{2x-l}{l})\&CenterDot;\exp [-8{\left(\frac{2x-l}{l}\right)}^2+4{\left(\frac{2x-l}{l}\right)}^3]+{\left(\frac{2l-2x}{l}\right)}^{1.5}\&CenterDot;\left(\frac{2x-l}{l}\right).$

2. naval vessel whipping motion response prediction method under underwater blast wave as claimed in claim 1 and bubble synergy, it is characterized in that, described method also comprises step:

S4, according to the moving displacement w (x, t) of naval vessel in the different time stage, calculate its speed, acceleration/accel and moment of flexure.

3. a naval vessel whipping motion response prediction system under underwater blast wave and bubble synergy, it is characterized in that, described system comprises:

First module, for naval vessel being equivalent to the free hull beam of uniform cross section, is equivalent to the prediction to free hull beam motor imagination thus by the prediction responded Ship Motion;

Second module, for hull beam load pressure process free under underwater explosive damage is divided into five time phases, gathers shock wave pressure peak value P _m, gas bubble pulsation stage negative pressure peak P _b, bubble first time pulsating pressure peak value P _s; Described five time phases are: 0≤t < t ₁, t ₁≤ t < t ₂, t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅; Wherein t ₁=θ, θ are shock wave attenuation constant; p ₀for explosive place hydrostatic pressure, P _atmfor barometric pressure, c is the velocity of sound in water, r ₀for powder charge radius, R is quick-fried distance; me is powder charge equivalent, ρ _wfor the density of water, g is acceleration due to gravity; $t_5=3290\frac{r_0}{P_0^{0.71}}+t_4;$

3rd module, for solving the moving displacement w (x, t) that free hull beam is exploded in five time phases under water:

Wherein, x is the abscissa value at free hull beam at a point place, k ₂=t ₂-t ₁, for the intrinsic shape of shaking in free hull beam first rank, wherein ζ ₁for shape amplitude of shaking, μ ₁for beam motion frequency parameter, l is free hull beam length; be the integral constant of five time phases, ω ₁single order for free beam shakes shape natural frequency; φ ₁for integral constant, m is the unit beam length quality considering added mass of entrained water, and p (x) is free hull beam different time staged pressure distribution characteristics function, for 0≤t < t ₁, t ₁≤ t < t ₂time phase, for t ₂≤ t < t ₃, t ₃≤ t < t ₄, t ₄≤ t < t ₅time phase, $p\left(x\right)=(1-\frac{2x-l}{l})\&CenterDot;\exp [-8{\left(\frac{2x-l}{l}\right)}^2+4{\left(\frac{2x-l}{l}\right)}^3]+{\left(\frac{2l-2x}{l}\right)}^{1.5}\&CenterDot;\left(\frac{2x-l}{l}\right).$

4. naval vessel whipping motion response prediction system under underwater blast wave as claimed in claim 3 and bubble synergy, it is characterized in that, described system also comprises:

Four module, for according to the moving displacement w (x, t) of naval vessel in the different time stage, calculates its speed, acceleration/accel and moment of flexure.