The Application of Sandwich Plate System Material on a Tanker
Ship’s Construction
Muhammad Musta’in
1,a
, Heni Siswanti
b
, and Alfan Rahmatullah
1
Department of Shipbuilding, State Polytechnic of Madura, Sampang, Indonesia
Keywords:
Deformation, Double Bottom, FEM, SPS, Stress .
Abstract: Secondary stiffeners and intersections on ship construction cause a lot of spots with high potential of
structural breakdown, such as fatigue crack on the corners of weld part. Those could be fixed by removing
the secondary stiffeners by applying a new construction technology by using sandwich plate system
material technology. SPS material consists of two steel plates bonded to elastomer material on the
middle part using injection. This research has analysed the replacement of inner bottom plate with SPS
material on KM X 3557 DWT’s double bottom construction. Methodology in this research is to
calculate SPS material construction to analyse the strength of existing double bottom construction and
SPS double bottom that varied with ASTM (AH36, A36, and Grade D), and to calculate estimation
weight of double bottom construction. The maximum stress on SPS material with ASTM (AH36, A36,
Grade D) material variation is 99.18, 99.81, 97.87 MPa. Those values are 46.91-47.95% lower than the
existing double bottom which has 188 MPa of maximum stress. The average stress on SPS material
variation is 20.47, 20.53, 20.42 MPa which mean 69.16-69.3% lower than the existing double bottom
that has 66.5 MPa of average stress value. The maximum deformation is - 7.23-7.39 mm, lower than the
existing double bottom that has 8.31 mm of maximum deformation.
1 INTRODUCTION
The development of technology and science
unceasingly gave birth to many innovations. One of
which is in the field of ship construction (Utomo,
2016). The use of secondary stiffener in conventional
steel ship construction results in
intersection/intersection between construction
components. Secondary stiffener and intersection are
critical parts which are vulnerable to structural
problems on the ship, such as fatigue cracks that
occur at welding angles (Kennedy, 2002; The Royal
Institution of Naval Architects, 2004). Therefore, new
construction technology is needed that can eliminate
the use of secondary stiffener in ship construction
(Al-Qablan, 2010; Ramakrishnan, 2016).
Sandwich plate system (SPS) is one of the
technologies that can be applied to overcome these
problems because it can eliminate the use of
secondary stiffener (Baidowi, 2015; Zubaydi, 2017).
SPS is a composite material consisting of two steel
plates joined together with a core material in the form
of an elastomer in the middle using the injection
method (The Royal Institution of Naval Architects,
2004). The use of SPS material for ship construction
has been approved by the Lloyd’s Register
classification board. Research conducted by
Intelligent Engineering (IE) in 2004 concluded that
the use of SPS material was able to eliminate the use
of secondary stiffeners, so as to reduce critical points
that are prone to structural damage to ships such as
fatigue cracks (Intelligent Engineering, 2018).
In this research, a sandwich plate system (SPS)
material is applied to the KM X 3557 DWT tanker
construction which still uses conventional
construction. The application is carried out on the
ship's double bottom construction by replacing the
inner bottom plate with SPS material. The output of
this research includes SPS material construction
design for use on the KM Bot 3535 DWT tanker
bottom, and the feasibility of using SPS material for
use in the KM X 3557 DWT tanker double bottom
construction.
122
Musta’in, M., Siswanti, H. and Rahmatullah, A.
The Application of Sandwich Plate System Material on a Tanker Ship’s Construction.
DOI: 10.5220/0010855300003261
In Proceedings of the 4th International Conference on Marine Technology (senta 2019) - Transforming Maritime Technology for Fair and Sustainable Development in the Era of Industrial
Revolution 4.0, pages 122-127
ISBN: 978-989-758-557-9; ISSN: 2795-4579
Copyright
c
 2022 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved

2 LITERATURE REVIEW
2.1 the Sandwich Plate System
The Sandwich Plate System (SPS) is a composite
material consisting of two steel plates joined together
with a core material in the form of an elastomer by
injection method The Royal Institution of Naval
Architects, 2004). The SPS material construction
consists of top plate, core and bottom plate as shown
in Figure 1. In the figure it is also known that the use
of SPS material can simplify construction by
eliminating the use of stiffeners (Feldmann, 2007).
Each thickness of the SPS material construction
components can be adjusted to meet specific strength
requirements or requirements. The SPS material
dimensions standard has been determined by
Intelligent Engineering Ltd. as a patent owner and
producer of SPS materials as shown in Figure 2. This
figure shows that SPS material has standard
dimensions ranging in length from 20 'to 40' and
width 5 'to 8' (1 '= 0.304 m).
Figure 2: Standard Dimensions of SPS Materials
(Intelligent Engineering, 2018).
The core part of the SPS material construction
component consists of an elastomer specifically
formulated by Intelligent Engineering Ltd with its
partner, Elastomer GmbH (Intelligent Engineering,
2018). Technical testing of SPS material that has been
carried out produces mechanical property data as
shown in Table 1.
Table 1 shows the results of technical tests that
have been carried out on elastomeric materials which
have a specific gravity of 1150 kg / m3. The test is
carried out in several operating temperature
conditions (-80°C to 80°C) so as to produce varied
mechanical properties.
Table 1: Mechanical Properties of Elastomeric Materials.
Property -80°C -60°C-40°C -20°C 23°C60°C 80°C
Tensile
Strength
(MPa)
38.9 29.5 28.4 23.0 16.1 8.1 6.2
Yield
Strength
(MPa)
52.1 33.5 30.9 21.4 18.0 10.2 7.9
Shear
Modulus
(MPa)
1,386 955 559 429 285 180 135
Density :1,150 kg/m³; Poisson Ratio,  = 0.36
2.2 Calculation of Construction
Material Sandwich Plate System
Material
The calculation of sandwich plate system material
construction has been regulated in Lloyd’s Register
regulation "Provisional Rules for the Application of
Sandwich Panel Construction to Ship Structure"
(Lloyd Register, 2015). The equations used to
calculate SPS material construction are:
𝑅0.01𝐴

0.1
𝑏

𝑑

𝑡

𝑡


 11.7
𝑏

𝑑


.
𝑘𝑃
,
(1)
Where:
A
R
= (a/b)
0.65
α = length of SPS panel on its longest side
b = length of the SPS panel on its shortest side (mm)
P
eq
R = 0.0017
𝑍

𝑙

d = 0.5(𝑡
1
+ 𝑡
2
) + 𝑡
𝑐
Z
rule
 Equivalent section modulus N/mm
2

t
1
 0.3𝑡
𝑟𝑢𝑙𝑒
 𝑡
𝑎𝑅
  𝑡
𝑎1
t
2
 0.3𝑡
𝑟𝑢𝑙𝑒
 𝑡
𝑎𝑅
 𝑡
𝑎2

t
rule
 Plate thickness
l  Panel length m
t
aR
 Rule thickness allowance
tc = Core material thickness
k = Material factor = 1
R ≤ 1
3 METHODOLOGY
3.1 Calculation of Construction Material
Sandwich Plate System Material
The data needed in this study include:
a. The Principal's Dimension
b. General Settings
c. Midship Section
The Application of Sandwich Plate System Material on a Tanker Ship’s Construction
123

Ta
Table 2: 3556 DWT tanker dimensions.
LOA 89.98
m
LPP 85.56
m
B 15
m
H 7.2
m
T 5
m
Vs 11 knot
Gross Tonnage 2,755 ton
Net Tonna
g
e 1,116 ton
Dead Weight Tonnage 3,557 ton
Tank Ca
p
acit
y
4,759 m
2
3.2 Calculation of SPS Material
Construction
The next stage is processing the results of data
collection to calculate the construction of the
sandwich plate system (SPS) based on regulations
from the Lloyd’s Register. The results obtained in this
stage are the SPS material construction design which
includes the thickness of top plate, core and bottom
plate which will be used to replace the inner bottom
plate in the existing double bottom construction of the
KM X 3557 DWT tanker.
The first step in calculating SPS material
construction is to determine the value of equivalent
rule thickness (trule) and equivalent section modulus
(Zrule), trule value is the thickness of the existing
construction material from ship calculation that will
be replaced with SPS material. Whereas Zrule is the
modulus section value on the secondary stiffener
from ship calculation, in this case the longitudinal
inner bottom modulus on the KM X 3557 DWT
tanker. Next, the thickness allowance value is
determined using the conditions in Table 3. The value
of the rule thickness allowance (taR), top plate
thickness allowance (ta1), and bottom plate thickness
allowance (ta2) are determined based on the part of
the ship construction that will be replaced with SPS
material. In this final project, the construction part of
the KM X 3557 DWT tanker which is replaced with
SPS material is the inner bottom plate. This value is
only used as a parameter to get the thickness value of
the spedific SPS material construction component.
The next step is to calculate the specific thickness
value for the top plate (t1), core (tc), and bottom plate
(t2). The minimum thickness requirement for each
component of the SPS is as shown in Table 4. Here,
it can be seen that the minimum thickness for top plate
(t
1
) and bottom plate (t
2
) for new construction is 3
mm, while the minimum thickness for core material
(t
c
) is required at 15 mm.
Table 3: Thickness allowance material SPS.
Structural Elements t
aR
t
a1
t
a2
Bottom shell 1.00 0.00 1.00
Side shell 1.00 0.00 1.00
Inner bottom, hopper plating 2.00 1.00 1.00
Inner bottom, crown of tan
k
3.50 1.00 2.50
Strength decks 2.50 2.50 0.00
Internal decks 0.00 0.00 0.00
Superstructure dec
k
0.00 0.00 0.00
Waterti
g
ht bulkheads 0.00 0.00 0.00
Deep tank bulkheads 2.50 0.00 2.50
Dee
p
tank crowns which is also dec
k
3.50 1.00 2.50
Vehicle deck clear of tanks 2.00 2.00 0.00
The next step is to calculate the strength index
value (R) of SPS material. Based on regulations, the
SPS material strength index value that must be met is
R≤1. This is to ensure that the strength of the
sandwich plate system (SPS) material is equivalent to
the strength of the existing construction on ships
which will be replaced with SPS material. If the R
value does not meet the requirements, then an
additional thickness is added to the SPS material
construction, then a re-calculation is made until the R
value meets the requirements of the regulation.
Table 4: Minimum top plate and bottom plate thickness in
SPS material (Lloyd Register, 2015).
Ite
m
New Construction Overlay Construction
t
1
(Min) 3 3
t
2
(Min) 3
50% of the as built
thickness
3.3 Double Bottom Construction
Design
After the calculation process of the SPS material
construction is completed, the next step is to make a
3D design of the double bottom construction based on
the ship image data that has been obtained. In this
study, 4 variations of the double bottom construction
were made, including:
1) Double Bottom (A) is the existing double bottom
construction of the ship with the type of material
used is ASTM A36.
2) Double Bottom (B) is a SPS double bottom
construction with top plate and bottom plate
material using ASTM Grade AH36 steel.
3) Double Bottom (C) is a SPS double bottom
construction with top plate and bottom plate
material using ASTM Grade A36 steel.
4) Double Bottom (D) is a SPS double bottom
construction with top plate and bottom plate
material using ASTM Grade D steel.
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The results of this stage are the 3D design of the
existing double bottom construction of the ship and
double bottom construction using SPS material.
3.4 Strength Analysis of Double
Bottom Construction
After the design of the ship's double bottom
construction is complete, the next step is to analyze
the strength of the construction of the four variations
of the double bottom construction that have been
made. Analysis of the strength of this construction
with the 2016 SOLIDWORKS software.
The analytical method used is the Finite Element
Method (FEM) by running a simulation in the form of
providing a static force of 95 kN on the inner bottom
plate. The steps in the analysis phase of the strength
of the double bottom construction include:
1) Determine the type and thickness of the material
in the double bottom construction.
2) From the 3D design of the double bottom
construction that has been made, a definition of
the type and thickness of the material in each
construction component is made in that section.
3) Giving load on double bottom construction
After determining the thickness and type of
material, the next step is to provide a static load
of 95 kN on the inner bottom plate.
4) The meshing processes
Meshing is the most important thing in
conducting analysis using FEM. Meshing
process to break analysis objects into finite
elements.
5) Stages of simulation
After the meshing process is successfully
carried out, the next step is to run a simulation
on the double bottom construction design. The
results of doing this stage are the parameters of
the strength of the double bottom construction
which includes: the value of the maximum stress
(maximum stress), the average stress (average
stress), and the maximum value of the
deformation (maximum deformation) that
occurs on the inner bottom plate due to the effect
of loading.
3.5 Calculation of Estimated Weight of
Double Bottom Construction
After the construction strength analysis phase is
completed, the next step is to calculate the estimated
weight of the double bottom construction. This was
done to determine the difference in weight of the
double bottom construction at the time of the existing
condition and after the application of the sandwich
plate system (SPS).
This stage is done by calculating the volume of
each construction component contained in the double
bottom, then multiplying by the specific gravity and
the number of construction components whose
weight is calculated. The result of this stage is the
ratio of the weight of the existing double bottom
construction using ASTM A36 material, with the
double bottom using SPS material.
4 ANALYSIS AND DISCUSSION
Figure 3: Midship section tanker KM X 3557 DWT.
Figure 4. Double bottom tanker KM X 3557 DWT.
Figure 3 and 4 show the shape of the existing
construction
in the double bottom of the KM X 3557 DWT tanker.
Based on this picture, it can be seen that the type of
construction in the double bottom of the ship uses the
elongated type. In the inner bottom plate has a
thickness of 10 mm with a frame distance between
longitudinal 640 mm. In addition, there are several
other existing conditions in the section that are
needed for the final project including the material
thickness, size, and modulus of the longitudinal all of
which have been summarized in Table 5.
Table 5: Material Thickness
Inner Bottom Plate 10 mm
Inner Bottom Lon
g
itudinal 200 x 44 x 10
(
mm
)
250 cm
3
Bottom Plate 10 mm
Bottom Lon
g
itudinal 200 x 48 x 11
(
mm
)
250 cm
3
Side Girde
r
12 mm
Center Girde
r
12 mm
Solid Floo
r
9 mm
Bracket Floo
r
9 mm
The Application of Sandwich Plate System Material on a Tanker Ship’s Construction
125

Based on the calculation, the strength index value
of the SPS material meets the requirements (R≤1), so
that the SPS material construction design that can be
used to replace the inner bottom plate on the 3557
DWT tanker is SPS (4-15-4), with material details as
shown in Figure 5.
Figure 5: SPS material construction design result of
calculation.
The SPS double bottom construction variations
are made based on the type of top plate and bottom
plate material used. This was done to find out how the
difference in mechanical properties in each variation
of material used in the construction of SPS material
affects the results of the analysis of the strength of the
construction being carried out.
1) Double Bottom A, an existing double bottom
construction with the type of material on the inner
bottom plate is ASTM A36. The material has
mechanical properties; tensile strength of 550
MPa and yield strength of 250 MPa.
Figure 6: SPS double bottom 3D design results.
2) Double Bottom B is a SPS double bottom
construction with the type of material used on the
top plate and bottom plate is ASTM AH36. The
material has mechanical properties; tensile
strength between 620 MPa and yield strength of
more than 350 MPa.
3) Double Bottom C is a SPS double bottom
construction with the type of material used on the
top plate and bottom plate is ASTM A36.
4) Double Bottom D, a SPS double bottom
construction with the type of material used on the
top plate and bottom plate is ASTM Grade D. The
material has mechanical properties; tensile
strength between 490 MPa and yield strength of
220 MPa.
Figure 7 shows the dynamics or changes in
voltage values that occur in elements 0 to 200 for each
double bottom variation. Overall, the maximum stress
that occurs in the SPS double bottom variations (B,
C, and D) is lower than 46.91% to 47.95% of the
maximum stress that occurs in the existing double
bottom of the ship (A). The average stress on all SPS
double bottom variations is also lower from 69.16%
to 69.3% from the average stress on double bottom A.
The weight calculation in the SPS double bottom
construction obtained a construction weight value of
28.02 tons without the use of the longitudinal inner
bottom. The core part of the SPS material in the form
of an elastomer has a density of 1150 kg / m3. The
results of comparison of construction weight
estimates of the two types of double bottom can be
seen in Figure 8 and Figure 9.
Figure 8: Graph of maximum stress comparison an
d
avera
g
e stress on double bottom variations.
Figure 7: Comparison of stress distribution charts in double
bottom variations.
senta 2019 - The International Conference on Marine Technology (SENTA)
126

Figure 9. Graph of comparison of estimated weight of
double bottom construction.
5 CONCLUSIONS
After analyzing Material Sandwich Plate System in
Tanker Construction, with the object of study is the
KM X 3557 DWT tanker, it can be concluded that:
1) The design of the sandwich plate construction
system (SPS) on the KM X3557 DWT double
bottom is to use a plate (top plate & bottom
plate) with a thickness of 4 mm, and a filler
material (elastomer) with a thickness of 15 mm.
2) The use of ASTM AH36, ASTM A36, and
ASTM Grade D material variations for SPS,
maximum stresses of 99.18 MPa, 99.81 MPa
and 97.87 MPa are obtained, these values are
lower than the maximum stress in the existing
construction of 188MPa. Likewise in the
average stress value, the SPS material variations
obtained values of 20.47 MPa, 20.53 MPa, and
20.42 MPa, these values are lower than the
average stress in the existing construction of
66.5MPa.
3) While the maximum deformation that occurs in
SPS material variation is 7.23-7.39 mm, the
value is smaller than the maximum deformation
that occurs in existing construction which is
8.81 mm. This proves that the material sandwich
plate system with ASTM AH36, ASTM A36
steel material variations, and ASTM Grade D,
has the feasibility/possibility to replace
conventional construction on the KM X 3557
DWT tanker double bottom.
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