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1 INTRODUCTION
China's extensive inland navigable water system
determines that inland navigation must be an
important part of China's shipping industry. With the
implementation of the national strategy of country
with strong transportation network, more bridges will
be built in the navigable waters of inland rivers in the
future, and the navigable safety of inland river
Bridges will become an unavoidable topic in the
industry. As an important bridge anti-collision
facility, anti-collision pier will be widely used in
navigable inland waters in the future.
Figure 1. Shape of the anti-collision pier
Analysis on the Process of Ship Striking the Anti-
collision Pier
C. Zhao & H. Yan
Merchant Marine College, Shanghai Maritime University, Shanghai, China
ABSTRACT: China's extensive inland navigable water system determines that inland navigation must be an
important part of China's shipping industry. The collision process of ship striking the anti-collision pier is
analyzed through simulation experiment in this paper. The results show that the collision process usually lasts
less than 2 seconds, and the peak value of the collision force, friction and resultant force appears 0.5 after the
start of the collision.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 16
Number 3
September 2022
DOI: 10.12716/1001.16.03.12
502
Figure 2. Ship attitude after collision
2 PLANE MODEL OF ANTI-COLLISION PIER
In this experiment, anti-collision pier with a width of
5.0 meter, a length of 4.6 meter and a thickness of 2.9
meter was adopted. as shown in Figure 1. Its plane
shape was composed of a 5.0 meter×1.3-meter
rectangle, and a trapezoid with a width of 5.0 meter at
the bottom, 1.72 meter at the top and 2.8 meter at the
top, and a chord tangent circle with a radius of 1
meter and a chord length of 1.72 meter [1-2]. The
shape of one side of the bow as shown in Figure 2.
3 ANALYSIS OF COLLISION FORCE BETWEEN
SHIP AND ANTI-COLLISION PIER
The force perpendicular to the surface in the process
of collision is an elastic force. The relationship
between the force F(t) changing with time and the
change rate of ship's normal momentum (M·δV)
theorem is:
( )
Ft δt M δv =
During the collision process, the velocity vector of
the ship is not parallel to the tangent plane. Besides
the normal velocity perpendicular to the tangent
plane, there is also a tangent velocity parallel to the
tangent plane. The ship has a tendency to slip along
the surface of the anti-collision pier. Affected by the
positive pressure, there is a friction prevents the slip
movement.
( ) ( )
f
Ft μF t=
( )
r
δv
F t t
M
=
The changing of course is:
( ) ( )
( )
( )
( )
( ) ( )
( )
( )
( )
bb
z
f b b
z
180 F t sin T φ 0.5L x cos φ T y
δT
I δt π
F t cos T φ 0.5L x sin T φ y
I δt π
+ − − +
=+
+ − + +
−
The changing of collision point is:
r
180 δv
δφ
πr
=
( ) ( )
δr r φ δφ r φ= + −
The polar coordinates of the bow position
changing with time during collision are as follows:
( )
( )
( )
( )
( )
( )
( )
2
2
bb
b b b b b
yy
r r x y *ctg T φ 2 r x y *ctg T φ cos T φ
sin T φ sin T φ
= + + + + − + + + +
++
( )
( )
( )
( )
( )
( )
22
2
b b b b b
b
b b b
x y *ctg T φ X y *ctg T φ r
φ φ arccos
2r x y *ctg T φ
+ + − + + +
=+
++
4 COLLISION ANALYSIS BASED ON
SIMULATION TEST
At the initial moment of collision, the hull moves
towards the anti-collision pier with a certain radial
velocity. The hull and the side of the anti-collision pier
contact and continue to move, the anti-collision pier
and the surface of the hull resulting in elastic force [4].
MSC. Dytran was used to analysis the structure of
the ship [5,6]. The results of vertical collision between
bow and anti-collision pier are as shown in Figure 3
and Figure 4.
The maximum collision force and damage effect
are produced by vertical frontal collision of bow. The
collision velocity vector can be decomposed into the
direction perpendicular and parallel to the collision
plane. The component perpendicular to the collision
plane is the collision velocity and the collision force is
generated. The component parallel to the collision
plane is the slip velocity, which forms the friction
force. The normal momentum consumption process of
the bow under the collision as shown in Figure 5.
Figure 3. Calculation model
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Figure 4. The change of collision force with time
Figure 5. The changing of impulse coefficient variation with
time
The front of the bow of the test ship struck the
anti-collision pier vertically at a speed of about 4m/s,
the collision time is about 2 seconds. The ratio of
impulse to initial normal vector at any time during
collision is defined as impulse coefficient C(t):
( )
( )
( )
( )
2
0
0
F t dt F t dt
Ct
Mv
F t dt
==
When the bow of the ship struck the anti-collision
pier, the collision force is:
( )
( ) ( )
00
C t Mv C t Mv
Ft
dt δt
=
5 ANALYSIS OF THE RESULTS OF SIMULATING
The test conditions as shown in Table 1, the collision
force, friction and resultant force changing with time
as shown in Figure 6 to 8, the Collision velocity and
slip velocity with time as shown in Figure 9 to 11.
Table 1. Test conditions
_______________________________________________
No. Wind Water flow Angular Ship Heading
D S D S velocity of speed
rotation
_______________________________________________
1 N 4 300 1.4 2.8 6.2 302.9
2 N 5 300 1.4 7.5 5.9 307.7
3 N 6 300 1.4 8.3 5.8 309.4
_______________________________________________
D - direction
S - speed
Figure 6. NO.1 test condition
Figure 7. NO.2 test condition
Figure 8. NO.3 test condition
Figure 9. NO.1 test condition
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Figure 10. NO.2 test condition
Figure 11. NO.3 test condition
6 COLLISION RANGE AND FORCE ANALYSIS
The process of the test ship struck the anti-collision
pier for 2 seconds, and the peak value of the collision
force, friction and resultant force appeared after 0.5
second at the beginning of the collision. During the
collision, the ship's heading Angle changed a little,
not more than 1°. In addition to the deformation and
displacement of the anti-collision pier and hull
structure, there is also a slip relative to the side of the
anti-collision pier, and friction. The resultant force of
friction and collision force increases slightly, but the
increment is not significant.
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