Comparison Study of Structural Strength between Longitudinal and

Transverse Modulus on The Hatch Cover using Finite Element

Method

Dony Setyawan

, Septia Hardy Sujiatanti

and Novario Pratama Adiguna

Department of Naval Architecture, Faculty of Marine Technology, Institut Teknologi Sepuluh Nopember, Surabaya,

Indonesia

Keywords: The Longitudinal Modulus, Transverse Modulus, FEM.

Abstract: Container ship carries cargo that mostly container, so cargo hold be designed with the large enough

hatchway to making easy loading and unloading container. Owners usually want to optimize space on cargo

hold. Optimizing space on cargo hold means that if cargo hold is fully loaded by the container, the owner

can still put the container above hatch cover. There are 2 construction members which influence hatch cover

strength, longitudinal & transverse. Finite element method is used to compare strength between longitudinal

& transverse of the hatch cover. The analysis was performed by changing ± 10% & ± 20% longitudinal

modulus and transverse modulus of the model hatch cover. As a result, due to increase 20% longitudinal

modulus, stress is reduced -9.903%, while adding 20% transversal modulus only reduces -5.31% stress.

Reducing 20% longitudinal modulus increase 5.47% stress, while reducing 20% transversal modulus only

increases 4.94% stress. According to the analysis result, it can be inferred that changing the longitudinal

modulus is more influential than changing transversal modulus. e

1 INTRODUCTION

The function of hatch cover on container ships

generally has the same working system and function,

which is used to cover the part of the hatch on the

container ship. However, what distinguishes

between hatch cover on cargo ships and container

ships is that container ships carry commonly called

containers, so container ship must have a wide hatch

for loading space. Owners usually want to optimize

space on cargo hold. Optimizing space on cargo hold

means that if cargo hold is fully loaded by the

container, the owner can still put the container above

hatch cover (Keith, 2001). Hatch cover must have

enough strength to hold the load from the container.

Previous study an analysis was carried out by

comparing 3 variations of hatch cover model. The

first model hatch cover is divided into 3 transverse

partitions. Second model hatch covers without

partition. The third model hatch cover is divided into

5 longitudinal partitions. From three types of hatch

cover, model hatch cover 3 transverse partition is the

most effective model (Fikri and Kurniawati, 2016).

In this comparison study between longitudinal &

transverse construction, most affect construction to

hatch cover stress will be searched with 3 transverse

partitions as a model. The analysis is performed by

changing the longitudinal modulus and transverse

modulus of the hatch cover. From the comparison of

the stress result, the construct will be obtained which

is the most influential to the hatch cover

2 LITERATURE REVIEWS

Hatch cover is a very important equipment in the

ship, which construction and mechanism must

follow Classification rules and International Load

Line Convention (ILLC) 1966. The purpose of the

hatch cover and hatch coaming are to prevent water

from entering through the opening (loading) of the

loading space on the ship deck.

One type of hatch cover is a lift-away hatch

cover (Fikri and Kurniawati, 2016). Hatch cover

using pontoon or lift away hatch cover makes it

easier for the loading and unloading system. Hatch

cover type Lift away hatch cover is good for ships

Setyawan, D., Sujiatanti, S. and Adiguna, N.

Comparison Study of Structural Strength between Longitudinal and Transverse Modulus on The Hatch Cover using Finite Element Method.

DOI: 10.5220/0008375300970100

In Proceedings of the 6th International Seminar on Ocean and Coastal Engineering, Environmental and Natural Disaster Management (ISOCEEN 2018), pages 97-100

ISBN: 978-989-758-455-8

that have multilevel goods (Dewangga and Yulianto,

2012).

Figure 1: Lift-Away Hatch Cover.

2.1 Finite Element Method

Von misses stress is stress that obtained through

calculations involving strains in all axes (x, y, and z)

(Rabbani, et.al, 2017). The theory of the collapse of

von misses yield criterion is used in this study as a

reference in the analysis of stress used. The

following equation for von misses:



















 











 







 



 







(1)

Where,

σx = x-axes stress

σy = y-axes stress

σz = z-axes stress

σ’ = equivalent von misses stress

Finite element method is a numerical calculation

technique that results obtained is the value of the

approach of the actual results. As the size of the

element decreases, the results obtained will be

different and sequential. The calculation approach

will produce a convergent value with the actual

results when the mesh quality is added and the

elements are formed more and smaller in size (Biro

Klasifikasi Indonesia, 2016).

2.2 Hatch Cover Conversion

Hatch cover is considered to have sufficient strength

if the stress value that occurs in each structure does

not exceed the value of equivalent stress σv given by

ship classification for the minimum hatch cover

(Pramono, et.al, 2016).

 (2)

Where,

σv = equivalent stress hatch cover

ReH = minimum nominal upper yield point, 235

N/mm²

Model for this research requires modulus

conversion to get the variation. To find the modulus

can be found by the moment inertia calculation

tabulation which will be divided by the value of the

neutral axis point.

3 METHODOLOGY

In this study, the effectiveness between the

longitudinal and the transversal will be compared.

The analysis is carried out by changing the modulus

of the transverse and longitudinal support of ± 10%

& ± 20%. The next step is modelling. The hatch

cover model is drawn from the deck to the hatch

cover. After modeling, the next step is element

convergence. After obtaining the converging

element size of each model, the model is given a

load and boundary conditions. Stress must be

checked with stress permission from BKI based on

formula (2). Finally, effective construction can be

determined.

3.1 Finite Element Modeling

Finite element models are made from ship decks to

hatch cover. Because the model is complex, then

modeling of hatch cover using CAD (Computer-

Aided Design) assist software.

Figure 2: Geometric Model.

Locking and damping systems are not modeled.

The locking system requires a very detailed model

which can cause an error model. For locking system

modelling and damping systems, it is carried out in

accordance with Figure 3.

ISOCEEN 2018 - 6th International Seminar on Ocean and Coastal Engineering, Environmental and Natural Disaster Management

Figure 3: Locking and Damping System.

Meshing is a process of finite elements to divide

the whole system into smaller elements to obtain a

detailed analysis of the entire system. In this study,

the element types used are solid elements of

Tetrahedron and Hex Dominant because there are

parts of construction that are simple and

complicated, in addition to the geometry modeling

has been given thickness. Solid elements have

quadratic displacement properties and good for

modeling irregular mesh shapes.

Figure 4: Finite Element Model.

Variation of the model is given to compare the

analysis results and get the most effective

construction (longitudinal or transversal). The

analysis is carried out by comparing the construction

hatch cover model as shown in Table 1.

Table 1: Variation of Hatch Cover Model.

Constructi

Initial Profile

Modulus

Change

Profil after

Change

Longitudin

L 100x100x10

+20%

L 100x100x12

+10%

L 100x100x11

-10%

L 100x9+90x10

-20%

L 100x8+100x9

Transversa

T 450x9 +

100x10

+20%

T 450x11 +

100x11

+10%

T 450x10 +

100x11

-10%

T 450x8 +

125x8

-20%

T 450x8 +

125x7

3.2 Loading and Boundary Condition

The type of load applied is a force, which is a static

load on the legs of the container. The amount of the

load is affected by the type of container weight and

container tier placed on the hatch cover. In this case,

containers use BAY 13 where the hatch cover

transports a maximum of 3 tier containers with a

maximum load of 38 tons. The load used is a force

by multiplying gravity becomes 372.4 kN. The

container feet are 4 so that the weight of 372.4 kN is

distributed on 4 feet of the container, 1 container

foot gets a load of 93.1 kN.

Figure 5: Load Distribution.

The parts that are given a support are the ends of

the deck and the deck part that is welded with the

bulkhead. This is done because geometry modeling

for analysis is carried out only on the deck until the

hatch cover.

Table 2: Applied Boundary Condition.

Axis

Displacement

Rotation

Free

4 RESULT AND DISCUSSION

Longitudinal and transverse effectiveness are tested

with the hatch cover model according to the data.

The tests are carried out by reviewing the von misses

model voltage due to changes in modulus of the

transverse and longitudinal.

Comparison Study of Structural Strength between Longitudinal and Transverse Modulus on The Hatch Cover using Finite Element Method

5 CONCLUSIONS

According to the analysis and results, this research

can be concluded that longitudinal construction is

more influential than transverse construction

because of a load of containers. Container load on

the hatch cover is symmetrical so that torque loads

are not too significant. So that transverse

construction has no major effect, while construction

has a big influence.

REFERENCES

Biro Klasifikasi Indonesia, Rules for The Classification

and Construction of Seagoing Steel Ships, Indonesia:

BKI (2016).

D.R. Pramono, A. Imron & M.N. Misbah, Analyze the

Strength of the Lengthening of the Floating Dock

Conversion from the Barge to the Finite Element

Method, Surabaya: Jurnal Teknik ITS Vol. 5, No. 2.

ISSN: 2337-3539, Surabaya: ITS (2016)

D.V. Dewangga & T. Yulianto, Analysis of the Effect of

Flange Angle, Toe Radius, and Preparation Angle on

Deformation and Residual Voltage on Welding Butt

Joint with Double V Campaign Using Finite Element

Method, Jurnal Teknik ITS Vol. 1, ISSN: 2301-9271,

Surabaya: ITS (2012).

International Load Line Convention, International

Maritime Organization, London (1966).

M.U. Fikri & H.A. Kurniawati, Design Livestock Carrier

Makassar - Jakarta Route To Supply Cattle Needs in

Jakarta and Surroundings, Jurnal Teknik ITS Vol. 5.

No. 2. ISSN: 2337-3539, Surabaya: ITS (2016).

T. Keith, Hold and Hatch Cover, London: A.Bilbrough &

Co.Ltd (2001).

Z. Rabbani, A. Zubaydi & S.H. Sujiatanti, Analisa

Kekuatan Sekat Bergelombang Kapal Tanker

Menggunakan Metode Elemen Hingga, Surabaya:

Jurnal Teknik ITS 6 (2), G282-G287, ISSN: 2337-

3520, Surabaya: ITS, (2017).

ISOCEEN 2018 - 6th International Seminar on Ocean and Coastal Engineering, Environmental and Natural Disaster Management

100