JPS59159047A - Fender testing apparatus - Google Patents

Abstract

PURPOSE:To reproduce the state of a vessel coming along a berth with the effect of a collision being lessened by computing the movement of the vessel based on detected signals and driving a pressure member according to the results computed. CONSTITUTION:A computer is used to calculate the movement of a vessel immediately after the vessel has contacted a fender and the results computed are converted into displacement quantities xpm, ypm, psipm and then applied to a control apparatus. A testing apparatus is subjected to the force corresponding to the displacement quantities xpm, ypm, psipm and deformed, whereby it generates reaction force. The displacement quantities xs, ys, psis of an exciting stand, the reaction force of the fender and the moments of the reaction force Rx, Ry, Mfpsi are detected by a displacement detector and a load converter. The control apparatus applies the detected signals to the computer, which computes the movement of the vessel at the time of the detection to obtain the estimated movement of the vessel a minute time DELTAt thenceafter and compute the displacement quantities xpm, ypm, psipm of the fender based on the results computed. As the operation is repeated, the state of the vessel coming along the berth toward the fender can be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fender testing device that can reproduce the phenomenon of a ship coming alongside the fender.

Conventionally, compressive force is applied to the impact-receiving surface of the fender in a direction perpendicular or oblique to this, and in this state, the displacement in the compressive direction and compression mold are measured, and the deformation of the fender is examined. The absorbed energy and physical properties of the material were tested.

However, the berthing phenomenon in which a ship contacts the fender vi and is buffered by the elastic deformation of the corrosion protection H is not static but dynamic; over time, the ship's displacement due to the reaction force of the fender vi changes. The force acting on the fender fluctuates due to changes in speed and speed, and the compression reaction force, shear reaction force, and reaction moment around the vertical axis of the fender row do not act independently on the ship, but are interrelated. Therefore, conventional simple test equipment has not been able to reproduce the actual situation in which a ship collides with a fender.

The invention is related to an improved VC test device for fender rows that overcomes these difficulties, and is capable of performing compression in the direction of compression perpendicular to the impact surface of the fender, in the shear direction along the impact surface, and in the same shear direction. A testing machine that drives a pressure member in the direction of rotation around a perpendicular axis, and a pressure unit built into the testing machine that measures the amount of displacement in each direction and the rotational pressure from the fender. A displacement detector and a load converter detect the reaction forces acting in each direction, and the height detection signal of the detector is used to calculate the berthing movement of the ship while being buffered by the fender. It is characterized by comprising a computer that calculates the movement of the ship after a minute time has elapsed from this, and a shift control device that controls the testing machine so as to drive the pressurizing member according to the calculation result, The purpose of this is to provide a test device for fenders that simulates the shock absorbing conditions of actual ship collisions.

Since the present invention is configured as described above, the fender to be tested is placed in the testing machine, and the position, speed, etc. of the ship immediately before it contacts the fender are measured. If the initial conditions are given to the computer and calculated, and the output of the result is used to operate the quantity control device Z, the test device is operated by a control signal from the control device, and when the ship comes into contact with the fender. The pressure member collides with the fender in a similar state.

Then, the fender deforms and generates a reaction force, causing rJi
The amount of displacement of the pressurizing part (J) is determined by the displacement detector and 7J.
I] fT, the reaction force acting between the parts is detected by a load converter, and its detection signal is transmitted to the control device.

The control device amplifies this detection signal and outputs it to the computer. The computer calculates the movement of the ship based on this voltage signal and the initial conditions, and also roughly calculates the movement of the ship after a minute period of time has elapsed. A signal is sent, a control signal is given from the control device to the test machine, and the test machine is operated to follow the control signal.

These calculations of the ship's motion and the operation of the testing machine are repeated until the pressurizing member separates from the fender, and thus the ship actually collides with the fender'vi and is buffered. The situation is reproduced.

Therefore, it is possible to know the deformed shape of the fender at each given time from a strobograph photograph, etc., and also to know the reaction force of the fender and the displacement of the pressure member at each given time from a display. The fender's absorbency and other physical properties can be tested under conditions close to the real thing.

An embodiment of the present invention illustrated in the drawings will be described below.

In Figures 1 and 2, 1 is a short column-shaped fender which is the object to be tested.The fender 1 is attached so that its surface 1a is integrally attached to the horizontal movable table 3 of the testing machine 2. ing.

In addition, the horizontal movable table 3 of 4 m2 for the test has a guide rail 4
It is designed to be driven in the horizontal direction It is interposed between the cylinder 5 and the cylinder 5.

A pedestal 7 is installed above the horizontal movable table 3, and an axial hydraulic cylinder 8 is attached to the top horizontal member 7a of the pedestal 7 so as to be oriented vertically. An axially movable table 10 is integrally attached via a load converter 9 for detecting axial reaction force, and the axially movable table 1o supports the fender 1 by the operation of the coaxial multi-thickening front pressure cylinder 8. It is designed to be driven freely.

In addition, brackets 11 are integrally provided on both left and right sides of the coaxial moving table 10 and project downwardly.
1, a pressure plate 12 is pivoted freely around a pin 15 which is oriented in the horizontal direction perpendicular to the guide rail 4. A pressure plate 12 is mounted between the coaxial moving table 1o and the front and rear of the pressure plate 12. Each pair of swing hydraulic cylinders 13 and a load converter 14 for detecting swing reaction force are interposed, and when one of the swing hydraulic cylinders 13 is extended by 10,000 and the other is shortened, the pressure plate 12 changes. The VC is driven to rotate around Vin] 5.

Further, the hydraulic cylinder 5.8.13 includes the cylinder 5.
．． 8.13 expansion/contraction amount? A displacement detector is built in to detect the horizontal reaction force of the horizontal moving table 3 - the amount of axial displacement of the axial moving table 107. s and the amount of rotational displacement ys of the pressure plate 12 about the center of the bottle 15 are detected.

The hydraulic cylinder is controlled by operating a servo valve using an operating voltage from a control device.

Here, the reason why the fender impact surface is moved parallel to the fender impact surface relative to the direction of movement of the ship is because it is the best method for the structure of the testing machine.

The control 11 is interposed between the reciprocating signals between the testing machine and the computer, and controls the output signals. In other words, the output voltage from the computer is converted into a voltage for the vibration operation of the testing machine, and the detection signals from the load converter and displacement detector of the testing machine are amplified and sent to the computer as voltage signals. It is outputting.

The computer stores various external conditions and ship's initial conditions, calculates the ship's movement, and calculates the ship's movement.
Outputs the voltage signal necessary for operation. At this time, the actual displacement and reaction force of the test object are fed back to the computer and used to calculate the ship's movement.

The display displays the reaction force of the fender, the calculated trajectory of the ship's center of gravity, speed, etc.

If we follow the above signal movements among the test object, test machine, control device, and computer in order according to the block diagram in Figure 3, we can see that the movement of the ship immediately after contact with the fender 7 is calculated by the computer. , the movement is expressed as the displacement of the fender in the 1, z-/direction Zp
Convert to m-ypm-ypm, roughly it 7 city signal V
It is output to the control device as ix, Viy, and Viψ. The control device uses these voltage signals Vix, Viy, Vi
Voltage signal Vi required to stop the vibration table of the ψ test machine
x・Viy・■Convert to 1ψ and output to the test machine.

In the test machine, the vibration table is operated by the voltage signal, and the fender O receives forces corresponding to the displacement differences pm, 7pm, and ψpm, deforms, and generates a reaction force.

The amount of displacement of the vibration table at this time is s, ! ts, Ts and reaction force and reaction moment of fender) Rx, Ry, Mf
(p is detected by a displacement detector and a load converter, and this detection signal V'x, y, ■>, E'c, E'y, E'
is output to the control device. The control device amplifies this detection signal to generate voltage signals VX, Vy・■ψ, Ex, Ey,
Output to the computer as Eψ. The computer converts the input voltage signals Vx, vy, vψ・F2X・EV, Eψ into engineering values ″l
:Ls,...@s, ψs, Rx, Ry, Mf9) to calculate the movement of the ship at the detection time. σ) Based on the calculation results, calculate the displacement Zpm of the fender M in the sky, f, and y directions,
'tpm, 7pm'Y calculation and voltage signal Vix,
It is output to the control device as Viy to Viψ. The same operation is repeated again using the voltage signals V i x-, V i V, 1ψ. By repeating this series of closed-loop operations, the movement of the ship is simulated, and the phenomenon of the ship berthing against the fender is reproduced. - This repeated action causes the ship and the fender to separate from the start of contact. Do the steps up to

Next, I will explain the movement of the ship. In general, six degrees of freedom are considered: three types of translation in the directions of the principal axes of inertia (front and back, left and right, up and down) and three types of rotation around these axes, but in the case of berthing, translational movement In the vertical and rotational directions, the longitudinal and horizontal axes and the movements around the horizontal axes can be ignored, so in the end there are three types of in-plane movements: longitudinal and horizontal translational movements, and rotational movements around the vertical axes. These three types of motion ultimately correspond to the direction of pressure applied to the fender.

Therefore, the motions of the three types of ships will be analyzed and explained based on the three coordinate systems shown in FIG.

G-ξηψ thread: main axis of inertia ξ of the ship fixed at the ship's center of gravity G
・η direction and around the vertical axis ψ o-xYy system Space-fixed coordinate system F-xy system: Center FV of the impact surface of the fender under no load
r - A fixed coordinate system, here parallel to the spatially fixed coordinate system.

The operating equations of the ship in the ξ, η, and ψ directions while berthed are given by the following equations.

(1) In the equation, M', Mξ, M, 7 are the ship's mass and ξ, η direction clause addition M (t0n□°ekatsu), engineering ψ, > Jψ is the ship's moment of inertia and additional moment of inertia (ton -sec-m) 1 u, V\r is ξ, η direction velocity (Tle c ) and.

Directional angular velocity (/5ea) ☆, ÷, ξ, η direction acceleration <72> and se
c Angular acceleration in the ψ direction (rzu4°.2) F (ξ, Foyy, M, 9. is the ξ~η direction component (ton) of the external force due to the relative flow velocity acting on the ship and the moment in the ψ direction (t o n -m) P″Wξ, I' W 77, Mwψ are the ξ, η direction component (ton,) of the wind force acting on the ship VC and the moment (ton-m) in the ψ direction Fpay, M c tpc”i ship η-direction component (ton) of the steady force due to waves acting on the wave and its ψ-direction moment) (ton-m) Rξ, Rη, M (pc
'i component of the reaction force of the fender acting on the ship in the ξ and η directions (to
n) and its reaction force in the ψ direction moment (ton・-m
) Here, the external force C: i due to tidal currents, wind, and waves is generally determined by the following formula, assuming that it is stationary within a relatively short berthing time.

Mp9. -F D 7 , X c, )
・--('+) (2), (3), (4) In the formulas, Wo is 7 per unit volume of water (//n13) VClV,
ξ is the relative velocity between the tidal current speed and the hull speed and its ξ direction rO] component (m/sea) Cξ-〇77・Cψ is the flow pressure coefficient and the flow pressure moment coefficient Sl, S2 is the surface area and side surface of the flooded part of the hull Projected area (m') Lpp is the vertical length of the hull (m) M c ψ is the turning resistance of the hull vL (ton-m) RW is the resultant force of wind force Angle (rad)
Xw is the distance (m) between the position of action of the resultant force RW and the ship's center of gravity G
Wa is the unit volume weight of air σ0113) Cw is the wind force coefficient Vw is the wind speed (m). S^, SB are the projected areas of the front 15 and side surfaces of the hull above the water surface (
m2) θW is the angle between the wind direction and the ξ axis (rad) (is the wave amplitude @ (m), D is the relative oblique angle (rad), Kt is the drifting force coefficient due to waves, XC, is the center of gravity G and the hull It is the distance (m) from the center.

′:J:′r-ξ of the reaction force from the fender, η direction component Rξ
, and its reaction force (moment in the ψ direction) Mψ is the reaction force of the fender. −f direction strength Rx, By, Mfy
All you have to do is convert it in the ξ, η, and ψ directions, and you can find it using the following formula.

(5) In the formula, 16 is the distance (m) between the contact point C and the center of gravity G.
It is the angle (rad) formed with the axis.

The above are the analysis and calculation formulas for the elements necessary for the ship's equation of motion (1).

Therefore, if the reaction force of the fender RX' Ry = ' M f y is given, the initial speed of the ship is U. ,■. , r6,
Also, according to the predicted speed of the hull 'ip % Vp, r, the acceleration of the hull is also calculated by formulas (2), (3), (4), (
5) It can be found by substituting it into equation (1).

The speed of the hull U・■・ri The cospeed for the hull just found Era・÷
, can be found by integrating the ox.

u(t):=-8(t)at, v(t,)-/'
:(t)dt=r(t)−/,'r(t)dt
-16) If these hull speeds u(t), v(t), r(t) are found, then at a certain time t during y dust, the trajectory of the ship's center of gravity G xCf(t), Ye(t), ψ (1) can be obtained from the following equation.

Since the integral calculations of equations (6) and (7) are nonlinear, they will be performed by numerical approximation integration. From the locus xe(t), Y6(t), and ψ(1) of the ship's center of gravity G, the ship's contact point The locus of C, XC(t), Yυ(1), can be calculated using the following formula in terms of Ikunomachi.

Furthermore, the velocity Vcy/Vcy of the hull y contact point C in the X and Y directions can be determined using the following equation.

Here, Vx(t) and vy(t) are the velocity of the center of gravity of the ship,
The velocity component in the Y direction is given by the following equation: ξ η6 is the position of the hull contact point C in the hull-fixed coordinate system, and is equal to the above l and g. It is given by the following formula.

ξ<, = (3cos〆o1 η, =lSin
$, ・−, −−−−([1) Therefore, the hull speed U・■,
If r and the rotation ψ of the hull are given, X, Y of the hull contact point C
Obtain the velocity component in the direction.

Based on the above calculation, the point of contact with the ship (C, i.e., the fender σ) is 11σ based on the spatially fixed coordinate system of the point of contact with the ship.
Then, we can obtain Yc and velocity Vc(, VC, Yn.

Next, a method for predicting the movement of the ship and the movement of the ship's contact point C after a short time Δ after time t will be described.

First, there are various methods for calculating the predicted value u (t+Δt) of the hull acceleration, but here we will calculate it by extending the line representing the change in acceleration from time t-Δt to time t. That is, u (10Δt) = 2u(t) 1 unit (−Δt)・01
1. ...Find it using the formula for σ2. ÷(t+Δt),
The same applies to r (t+Δt). 1, the hull comes into contact with the fender, and immediately after L σ), the predicted acceleration is the acceleration immediately before the j-th dimension Φ.

The predicted value of the hull acceleration is also (10Δt), v (10Δt)
) Wealth (t-1-Δt)t If you find it in this way, then
Predicted values of hull speed u (t+Δt), v (t+Δt
), r (10Δt) is the predicted value of the trajectory of the ship's center of gravity X, (10Δt) −Y, (10Δt
), y(t+Δt) is determined by equation (7), and the movement of the hull contact point C.

The predicted value of the track x, (10Δt), Yc(t+Δt) is calculated from equation (8) by (′),′E, and the measured T value of the velocity in the X and Y directions of the hull contact point C is V Q X(t+Δt) ,V(,y
(10Δt) is (9), and 0. You can find the mouth blow for Nili using the Qυ formula.

σ) Operate the test machine within the calculation results, /,
), so when extracting the π required curve/f element, at time t the hull Jz contact point 0 (7) (3z gxc, (t),
Y, (t) O, J: (Q(t) and (H;+r interval t+Δt predicted value xc(t
Mo Δt), Yc (10Δt), J (10Δt)
and its prediction method f V CX (t + J t ),
V c Y (t+Δt), 7” (10Δt).

Roughly detected value of actual displacement ``11-s, , @s,
There is fs/Cholera σ) Displacement f that causes begging Q and test i: 'CI T' ”” 2 p”” f T
'''Y will be asked.

Here, the symbol ゲi'aj is abbreviated to the ship body contact point at time t (N position i1 is omitted, 7, f ~ time is set to 10Δt/,), and the predicted value of the position It of contact point C and the speed. beggar p,y
p・'f'Po, J2bivc, p-vcyp-ipto replacement thio〈.

First, the positioning work that falls on the time, 7-f and the actual displacement ``l:
l-s, , j/s='j' s difference Δ711-(
-Beauty-Xs), Δ! <=7-, @s), Δa<-y-
zoS) as a displacement prediction value of 4k, and a correction value of 1Jll.
Calculate the difference % (-., % + Komata) Jp (-j (, 1 ΔV), 'J'i <-zof+j%) 7r.

After time Δ based on this value Bi reference vcVc, XglΔC1V*
(f'iΔ and f AAj(, rub) so that they appear sequentially to receive the changes in (・rubbing. In other words, considering the displacement 271 for operating the test machine, about 0.1 seconds is desirable.

A system diagram of the above calculation process is shown in FIG.

When actually reproducing the phenomenon from when a ship contacts the fender Vi to when it leaves the fender Vi, the elements that should be entered into the computer as initial conditions are: The speed μO%11O%, etc., the distance between the ship's center of gravity G and the contact point C of the fender Io, and the angle da of the contact point C from the ξ axis. There are other factors such as the shape of the ship, the nature of seawater, tidal currents, wind power, and wave properties.

Figure 6 shows an example of the movement of the ship's center of gravity, the speed of the ship, and the reaction force on the fender up to a certain time after the ship came into contact with the fender using the untested equipment.

(σ) As usual, it changes from moment to moment from the time the ship berths (a)
Since it is possible to simulate the ship's movement and the deformation reaction force of the fender indoors, it is better to evaluate the fender in a more realistic manner.

[Brief explanation of drawings]

Figure 1 is a front view of the test machine, Figure 2 is a side view of the test machine, Figure 3 is a block diagram of the test equipment, Figure 4 is a schematic system diagram of the calculation process, and Figure 5 is a diagram of the hull and fender. An example of the movement, FIG. 6, is an example of the results obtained by an untested machine. 1... Fender, 2... Test machine, 3... Horizontal moving platform, 4... Guide rail, 5... Front and rear hydraulic cylinders,
6... Front-back direction load converter, 7... Frame, 8...
Axial direction M■Iff cylinder・9...Axial load converter, 10...Axial direction moving table・11...Bracket, 12
...Pressure plate, 13...Swivel hydraulic cylinder, 14...
Swing load converter, 15...bin. Agent Patent attorney Nozomi Ehara 1 person Kuro 1 Figure 3 Figure 21

Claims (1)

[Claims] A load transducer is used as a displacement detector that detects the compression direction perpendicular to the impact surface of the fender, the shear direction along the same impact surface, and the reaction force in the axial direction perpendicular to the shear direction. a computer that calculates the movement of the ship as it approaches the berth while being buffered by the fender based on the detection signal of the ship; and a computer that calculates the movement of the ship after a minute elapsed time; A testing device for fender materials, characterized in that the testing device is comprised of a control device for controlling the driving force.