CN103979086A - Determination method of launching sliding force of variable gradient berth - Google Patents

Abstract

The invention discloses a determination method of launching sliding force of a variable gradient berth. The method comprises the following steps: S1, for a the ship built from stern to bow by segments, respectively calculating the weight of each ship segment corresponding to the berth segment through design and measurements: WS1, WS2, WS3...; S2, respectively calculating sliding force of each ship segment on each gradient of the berth: for a ship segment SL with the gradient of a, the coefficient friction between the launching subject and the berth is u, then the sliding force is SL1 of WSL1sina-u WSL1cosa; and using the same method to obtain the sliding force on other berth segment SL2, SL3, SL4...; and S3, acquiring sliding force on each gradient of the berth and the each gradient of the berth of the whole launching subject: for a berth segment SL with the gradient of a, the sliding force SL is SL1+sliding force SL2+sliding force SL3+sliding force SL4 +... The invention aims to obtain accurate launching sliding force of variable gradient berth in the design or construction phases, so as to guarantee the security of the project enforcement.

Description

A kind of sliding force that becomes gradient slipway launching is determined method

Technical field

The sliding force that the present invention relates to ship design or construction stage slipway launching is determined, more particularly, relates to the sliding force becoming in gradient slipway launching process and determines.

Background technology

Boats and ships or ocean engineering product can be built on dock or building berth, if built on building berth, after main construction work completes, just need to slide into mooring in water and on bank, proceed follow-up construction work.This process sliding in water from building berth is just called lower water.

Before the lower water of boats and ships or ocean engineering product (hereinafter to be referred as lower water thing), need to establish anti-skid device with opposing sliding force, to avoid the landing and cause Important Project accident under the effect of sliding force, in uncontrollable situation of lower water thing.Different depending on lower water thing yardstick, sliding force may be from several tons to hundreds of ton not etc.

By building berth by different sections, formed, the gradient of different sections is different, is referred to as to become gradient building berth.In order to illustrate, the lower water schematic diagram of grade building berth as shown in Figure 4.The present invention becomes the lower water schematic diagram of gradient building berth as shown in Figure 5 again.

In sliding force is determined, the method conventionally adopting is only according to center of gravity place slope of slipway and the disposable definite sliding force of lower water thing total weight.As shown in Figure 3, hull center of gravity is A point.Generally, the gradient of launching platform is a definite value, and this method obtains sliding force can guarantee precision.Specifically with reference to prior art shown in figure 6, calculate the mode of sliding force, establishing u is coefficient of sliding resistance, and a2 is the center of gravity place gradient, and w is lower water thing weight, and sliding force is

w*sin(a2)-w*cos(a2)*u

Note: sin (a2) is the sinusoidal function of grade angle a2,

Cos (a2) is the cosine function of grade angle a2.

Shipyard is in design during anti-skid device, the above formula of usining calculate sliding force be multiplied by certain safety factor as the design value of on-slip power.

For becoming gradient building berth, the method for this disposable definite sliding force still obtains general employing.But in fact can not get accurate sliding force data, can make engineering be in danger.

And definite method of change gradient slipway launching sliding force, process is more complicated, and result is more true, and engineering construction is safer.

Summary of the invention

For the problems referred to above, the present invention aims to provide the sliding force of a kind of ship design or construction stage change gradient slipway launching and determines method, by actual measurement or design ship weight parameter and building berth parameter, obtain accurate sliding force, thereby guarantee the safety of engineering construction.

In order to achieve the above object, the invention provides a kind of sliding force that becomes gradient slipway launching and determine method, comprise the steps:

S1, the boats and ships from stern to bow sectional construction, the weight that obtains each body section of building berth section correspondence by design, measurement means by calculating is respectively: W _sL1, W _sL2, W _sL3, W _sL4

S2, ask for respectively the sliding force of each body section on each gradient building berth: for building berth section SL, its gradient is a, and the friction coefficient between lower water thing and building berth is u, sliding force _sL1=W _sL1sina – u W _sL1cosa; Use the same method and obtain the sliding force in other building berth sections _sL2, sliding force _sL3, sliding force _sL4

S3, obtain the sliding force on each gradient building berth, the sliding force of whole lower water thing:

For building berth section SL, its gradient is a, sliding force _sL=sliding force _sL1+ sliding force _sL2+ sliding force _sL3+ sliding force _sL4+ ...

The present invention is intended to design or the construction stage obtains the sliding force that becomes accurately gradient slipway launching, thereby ensures the safety of engineering construction.

Accompanying drawing explanation

Fig. 1 is that sliding force is determined basic principle schematic.

Fig. 2 is the schematic diagram of a certain weight center of gravity in lower water thing.

The schematic diagram of Fig. 3 when to be a certain ocean engineering product lay on becoming gradient building berth.

Fig. 4 is grade slipway launching schematic diagram.

Fig. 5 is that the present invention becomes gradient slipway launching schematic diagram.

Fig. 6 is that prior art becomes the principle schematic that gradient slipway launching calculates sliding force.

Fig. 7 is that the present invention becomes the principle schematic that gradient slipway launching calculates sliding force.

The specific embodiment

As shown in Figure 1, the angle of establishing building berth and horizontal surface is a, and lower water thing weight is w, and the friction coefficient between lower water thing and building berth is u.

For lower water thing, along building berth direction, be subject to the effect of two power:

(1) gravity is along the downward component w sina of building berth

(2) pressure=u w cosa of water thing to building berth under friction force=u* building berth bearing capacity=u*

Sliding force=w sina – u w cosa

This is the fundamental formular of calculating sliding force.

Take accompanying drawing 3 as example, and lower water thing is distributed on the building berth of several sections of different gradient.The method generally adopting is now the slope of slipway a that finds center of gravity place corresponding, supposes that lower water thing weight is w,

Sliding force=w sina – u w cosa

Method of calculating of the present invention is as follows:

1. calculate the lower water thing weight on different gradient building berth

The weight of lower water thing generally forms to 30 multinomial weight by five or six, and every weight has a definite distribution limit, all can be expressed as the figure of accompanying drawing 2.The rearmost end coordinate that wherein A is this weight, B is coordinate foremost, and C is areal coordinates, and weight W 1 is area.It is longitudinally abscissa that system of axes be take boats and ships, and the weight of take on unit area is ordinate, and take boats and ships 0 station is the origin of coordinates.

The a certain section of S1 that becomes gradient building berth of only take is example, and its rearmost end coordinate is L1, and coordinate is L2 foremost.Try to achieve L1 in figure to the area of part between L2, obtain this weight how much weight that distributed on this section of building berth.

(1) the right-angled trapezium left side in supposition figure is long is a, and the right is long is b

(a+b)(B-A)/2＝W

(B-C)＝(B-A)*(2a+b)/[3(a+b)]

Can obtain a and b.

(2) supposition L1 is l1 to the right-angled trapezium left side length of L2, and the right is long is l2

(L1-A)/(B-A)＝(l1-a)/(b-a)

(L2-A)/(B-A)＝(l2-a)/(b-a)

Can obtain l1 and l2.

The weight that this weight distributes on this section of building berth is

W1’＝(l1+l2)*(L2-L1)/2

According to the method, can draw all weight project W2 ' that distribute on this section of building berth, W3 ' ..., summation can obtain the lower water thing weight on this section of building berth

W _SL1＝W1’+W2’+W3’+…

Use the same method and can obtain the lower water thing weight in other building berth sections.

In addition, the lower water thing weight on different gradient building berth also can and be measured according to actual design and obtain, and wherein part weight project must obtain by actual design and measurement.

2. calculate respectively the sliding force on each gradient building berth, the final sliding force that accurately obtains whole lower water thing

For building berth section SL, its gradient is a, and the friction coefficient between lower water thing and building berth is u, sliding force _sL1=W _sL1sina – u W _sL1cosa

Use the same method and can obtain the sliding force in other building berth sections _sL2, sliding force _sL3, sliding force SL4 ...

To these sliding force summations, can obtain the sliding force of this lower water thing _sL

Sliding force _sL=sliding force _sL1+ sliding force _sL2+ sliding force _sL3+ sliding force _sL4+

A specific embodiment, as shown in Figure 7, does not calculate the sliding force on each gradient building berth, the final sliding force that accurately obtains whole lower water thing.The weight w of whole lower water thing is added and is obtained by w1, w2, w3, lays respectively on the building berth that the gradient is a1, a2, a3.

For w1 part, its gradient is a1,

Sliding force 1=w1*sin (a1)-w1*cos (a1) * u;

For w2 part, its gradient is a2,

Sliding force 2=w2*sin (a2)-w2*cos (a2) * u;

For w3 part, its gradient is a3,

Sliding force 3=w3*sin (a3)-w3*cos (a3) * u.

Sliding force=sliding force 1+ sliding force 2+ sliding force 3 of whole lower water thing

3. the bright actual effect of we

Take certain lower water thing is example, supposes that its weight is 10700 tons, is distributed in the gradient and is on the change gradient building berth of 3 °, 2.8 °, 2.6 °, 2.4 °, and it is in the building berth section of 2.6 ° that center of gravity is positioned at the gradient.

By method of the present invention, calculating its weight being distributed on each section of building berth is 3600 tons, 3000 tons, 1700 tons, 2400 tons.

Adopt the method generally adopting now, calculate 485.4 tons of sliding forces; Adopt method of the present invention, calculate 512.6 tons of sliding forces, than more than 485.4 tons 27 tons more than, exceed 5.6%.Can find out, the result precision that conventional algorithm calculates is poor, and numerical value is less than normal, may cause on-slip power deficiency and generation engineering accident.Therefore, calculate the sliding force that becomes gradient slipway launching according to method of the present invention, engineering construction is safer.

The above; it is only the preferably specific embodiment of the present invention; but protection scope of the present invention is not limited to this; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses; according to technical scheme of the present invention and inventive concept thereof, be equal to replacement or changed, within all should being encompassed in protection scope of the present invention.

Claims (1)

1. the sliding force that becomes gradient slipway launching is determined a method, it is characterized in that, comprises the steps:

S1, the boats and ships from stern to bow sectional construction, the weight that obtains each body section of building berth section correspondence by design, measurement means by calculating is respectively: W _sL1, W _sL2, W _sL3, W _sL4

S2, ask for respectively the sliding force of each body section on each gradient building berth: for building berth section SL, its gradient is a, and the friction coefficient between lower water thing and building berth is u, sliding force _sL1=W _sL1sina – u W _sL1cosa; Use the same method and obtain the sliding force in other building berth sections _sL2, sliding force _sL3, sliding force _sL4

S3, obtain the sliding force on each gradient building berth, the sliding force of whole lower water thing:

For building berth section SL, its gradient is a, sliding force _sL=sliding force _sL1+ sliding force _sL2+ sliding force _sL3+ sliding force _sL4+ ...