UNIVERSITY OF GRONINGEN

BACHELOR THESIS

Export scantlings to Mars2000 fromCADMATIC Hull

Author:Razvan Andrei POINARU

Supervisors:Jirí KOSINKA

Madalina FLOREAN

A thesis submitted in fulfillment of the requirementsfor the degree of BSc Computing Science

in the

University of Groningen

July 14, 2019

ii

UNIVERSITY OF GRONINGEN

AbstractFaculty of Science and Engineering

BSc Computing Science

Export scantlings to Mars2000 from CADMATIC Hull

by Razvan Andrei POINARU

The increase in the complexity of the ship design process and the large variety ofsoftware tools available calls for an immense necessity of optimisation. The solutionto this problem is the use of a holistic approach and links between tools, and the goalis to explore and implement a link between Mars2000 (a scantlings check tool usedfor the Bureau Veritas classification society) and CADMATIC Hull (a basic/detaileddesign 3D modeler used for defining the detailed structural arrangement).

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AcknowledgementsDuring this project, I had the opportunity of not only discovering a completely new field ofstudy (shipbuilding) but also gaining a complete overview in the field of CAD development.The challenge of working in this new environment made me work harder in order to achievemore and gain new knowledge from every obstacle in front of me.

The opportunity to start working on this project was given by my supervisor Madalina Flo-rean (product owner of CADMATIC Hull), who not only gave me the means of working onthis project, but tutored me the whole way through the learning process. On CADMATICgrounds, I had the honour to work among talented programmers, and learn from their waysand their experience. They thought me everything there is to know about the software, andits inner workings, as well as everything that I needed to know about ship building.

The complete field of CAD development was then discovered during the lectures of my pro-fessor and supervisor Jiri Kosinka, who opened my eyes and showed me the inner depths ofthis immense field of study. The knowledge that I received during the Computer Graphicscourse and from his guidance helped me build upon a great foundation and started a greatpassion towards this subject.

Having said this, it would have been impossible to achieve the results of this project alone. Iwant to firstly thank my supervisor Madalina Florean for the opportunity to join a talentedteam and work on this great project. Then I would like to thank the R&D team who guidedme and gave me the means towards a successful project. And lastly, I give my gratitude tomy other supervisor Jiri Kosinka, who helped me to understand and learn more about com-puter graphics and the inner workings of this field.

Thank you all for your outstanding support and trust you put in me.

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Contents

Abstract ii

Acknowledgements iii

1 Export to Scantlings, an introduction 1

2 Background 32.1 Ship design process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.2 Scantlings calculations & class societies . . . . . . . . . . . . . . . . . . 42.3 Mars2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.4 CADMATIC Hull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Analysis & Design 73.1 Problem analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2 Design choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.3 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4 Results 164.1 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5 Conclusion 19

A Design process 20A.1 Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

A.1.1 Use case 1: user wants to export (a) cross section(s) in frameview from CADMATIC Hull to Mars2000 . . . . . . . . . . . . . 20

A.1.2 Use case 2: user wants to set up the main particulars in systemsmanagement application . . . . . . . . . . . . . . . . . . . . . . . 20

A.1.3 Use case 3: user wants to set the project drafts . . . . . . . . . . 21A.1.4 Use case 4: user wants to set the main project data default file

path, xml file destination and file name. . . . . . . . . . . . . . . 21A.2 XML structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

B Working at CADMATIC 24

Bibliography 25

v

List of Figures

1.1 Ship design process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.1 Mars2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.2 Mars2000Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.3 CADMATIC Hull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.1 Grid Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.2 Main Particulars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.3 CAD construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.4 CAD Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.5 Export to Scantlings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.1 Half section hull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.2 Full section hull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.3 shell plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.4 Knuckled plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.5 Transverse Bulkhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.6 Panel in Mars2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

A.1 Excel sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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List of Abbreviations

BV Bureau VeritasIACS International Association of Classification SocietiesCAD Computer Aided DesignHOLISHIP Holistic Optimisation of Ship Design and Operation for Life Cycle 2016-2020R&D Research & Development

1

Chapter 1

Export to Scantlings, anintroduction

The whole process of ship design is vastly increasing in complexity. There are moreand more tools these days that help open up more innovative design, or better de-sign practices. Thus, it is crucial to find an optimal way to work throughout thedifferent stages, and find links between the various software involved in this. In thefollowing pages we will go through, and discover, different key stages in the shipdesign process, and analyse two software tools that play a major role in the basicdesign stage and detail design stage.

The ship design process has six major steps (Figure 1.1): initial design, concept de-sign, basic design, functional design, detailed design, and production information. Allthose steps come together and bring the ship from an idea/concept to a fully de-signed ship ready to be produced in the shipyard. During the first two phases (initialand concept design), engineers determine the ship purpose, they draft the concept,plan milestones for the process ahead of them and they shape up their (or theirclient’s) idea. After the ship concept is defined, the basic design phase begins. Dur-ing this process, engineers start defining the right shape, make calculations, createa general design and prepare the ship for classification societies approvals. Whenthe approval has been given, and the basic design stage is finished, the engineersstart adding detailed design structures and construction items (plates, profiles, faceplates, brackets, etc.). When this design is satisfactory, they start defining the pro-duction information and the required documents that will be sent to the shipyard inorder to start producing the elements and building the ship.

Mars2000 is a tool made by Bureau Veritas (a classification society), and helps theuser to check the scantling of plating and stiffening in cross section based on BureauVeritas Rules and IACS Common Structural Rules for Bulk Carriers and Tankersduring basic design stage [2]. During the design proccess, the ship needs to meetthe requirements from BV (Bureau Veritas) or from other classification societies, andalso has to take into acount the scantling regulations. Using this tool, the engineerhas the possibility to check and modify the parts that do not meet those regulations.

However, CADMATIC Hull is a tool that allows the user to make a detailed de-sign of the ship by defining topological elements and to complete the process all theway to production information stage. Using this tool, engineers can easily modifyand create the model in 2D and 3D, and generate drawings, sheets, input files forfactory machines, that are later on used in the shipyard.

Of course, in most of the cases, engineers already did the required calculations when

2 Chapter 1. Export to Scantlings, an introduction

FIGURE 1.1: Ship design process (an overview)[3].

they arrive at this stage, but sometimes, big design decisions might affect the originalcalculations, and they have to go back to software tools like Mars2000, and recreatethe cross sections in order to do the calculations again. This has a great impact inefficiency, and a link between CADMATIC Hull and Mars2000 will open up newpossibilities for the engineers.

In this thesis we investigate and implement a one-way link from CADMATIC Hull toMars2000 that allows the engineers to export certain cross sections, and use them im-mediately in Mars2000 to perform the required calculations without having to drawthe construction from scratch all over again. We go further into the ship design pro-cess, how this implementation optimises this process, and discover the differencesand similarities between the two software tools.

3

Chapter 2

Background

In September 2016, the HOLISHIP (Holistic Optimisation of Ship Design and Op-eration for Life Cycle 2016-2020) [1] started, with the whole purpose to advanceand improve the ship design process by implementing, between various partners,holistic ship design methods in which tools in the process will be linked through in-tegrated features by each of them [6]. This need for optimization became more andmore important for the ship designers and engineers, since nowadays there are alot of software packages and work is distributed to different design offices betweenstages, i.e., if a design office is doing the basic design stage, it is not necessary tohave the same company do the detailed design. This need for optimization is alsocaused by the ever-increasing computerization of design processes, development ofAI, etc. [4].

2.1 Ship design process

In order to fully grasp the concept of this thesis, we take a brief look at the ship de-sign process. This process has the following stages: initial & concept design stage,basic design stage, functional design stage and the detailed design stage.

In the initial and concept design stage, the engineers transform the idea into a real-istic concept. They create technical specifications, look into stability, etc., and createa general plan in order to fully describe the ship that will be produced. This is wherethe ship type, dead weight, type of propulsion, etc. are taken into account for furthercalculations.

After this stage is finished, the basic design stage follows. During this phase the en-gineer extends the initial design. A general arrangement is refined (or defined), thebasic design for the shape of the ship is drafted, the systems and their arrangement,compartments are designated, and the ship design is prepared for the classificationsocieties1, in order to receive approval.

After the shape is defined, together with a general arrangement and design vali-dated by the classification society, the detailed design stage begins, where the en-gineers have a strongly defined plan, and start adding details and constructing theship. In this phase, plates and shell plates are added, together with the requiredstiffeners (profiles, face plates, pillars, etc.) and all the required construction items.

When this stage is finished, the production information is defined, sheets are cre-ated and sent to shipyards to start manufacturing the required parts and start the

1i.e. Mars2000, DNV-GL, IACS, etc.

4 Chapter 2. Background

building process.

Throughout this whole process, a concept is defined, the general arrangement andthe shape of the ship are validated by the classification societies, and then the con-struction items, together with the ship schematics are sent to the shipyard, conclud-ing the ship design flow (Figure 1.1).

2.2 Scantlings calculations & class societies

Classification societies are non-governmental organisations that establish and main-tain technical standarts for construction and operation of marine vessels and off-shore structures, having the primary role to classify ships and validate their design.

IACS (International Association of Classification Societies) [5] is a international asso-ciation that puts together ship standards and provides unified interpretations of theinternational regulations of their members. Currently, thirteen of the largest marineclassification societies are members of IACS.

Scantling calculations are the backbone of the ship structure, taking care of the rightmaterial thicknesses and the strength of the general arrangement, based on the weightof the ship, global hull strength, the drafts in different conditions (harbour, sea go-ing, etc.) and other details regarding the ship. These calculations are based on therules and standards of the classification societies that the ship has to uphold and aredefined and calculated during the basic design stage, using the right software basedon the classification society that the engineer has to follow (Mars2000 - BV, DNV-GLhaving their own tool with the same name, etc.).

2.3 Mars2000

Mars2000 is a 2D tool that allows the engineer to define a basic ship model, in orderto perform scantling calculations based on the Bureau Veritas and IACS rules.

In Mars2000 (Figure 2.1), the user can quickly define plates and structures, by defin-ing panels. Panels are defined similar to how oriented graph are defined, havingnodes (vertices) and segments (edges) to connect them. Strakes (plates) are appliedto panels by defining a start node and a distance from that start point on the panelfollowing its segments. Stiffeners are defined in a similar way by giving the rightproperties (body and flange direction, size and type, etc.) and a distance from thestarting point of the panel (Fig. 2.2). Strakes are plates of material that can be usedas decks, walls, etc., whereas stiffeners are used for strengthening different areas ofthe ship.

2.4 CADMATIC Hull

The CADMATIC Hull (Figure 2.3) module is a 3D modelling tool that allows theuser to create the hull structure from basic design up to detailed design and produc-tion information. The application can generate 2D drawings where users can addconstruction items, and relate them with each other topologically, and generate a 3Dmodel output based on them.

2.4. CADMATIC Hull 5

FIGURE 2.1: Mars2000, the main panel (left) with the drawing editorused for drawing strakes and stiffeners (right).

FIGURE 2.2: Nodes, Panels, Strakes and Stiffeners in Mars2000.

FIGURE 2.3: CADMATIC Hull, 3D Contek application (left) and HullViewer (right).

6 Chapter 2. Background

In CADMATIC Hull, plates in cross section are defined by regular lines with an endpoint and a start point, or by a poly-line in case of curved shapes. Profiles in crosssection together with their position can be read from the drawing. CADMATIC Hullhas multiple applications within itself (Shell, Hiltop, Hull Viewer, etc.), but in thescope of this thesis we will focus on 3D Contek and on Systems Management Appli-cation (where general data about the ship or the project is stored).

7

Chapter 3

Analysis & Design

3.1 Problem analysis

In order to start designing the right link between the two software tools, first weneed to take a deep look at what information Mars2000 needs, what is available inCADMATIC Hull, how to translate this information, and the differences betweenthem.

Before exporting the cross sections, there are a number of data sets that need to beprovided to Mars2000, that contain general data about the vessel, about the param-eters of the calculation, and about the project. We go through them one by one andsee what is present in Hull, what can be determined by the system, and what has tobe provided by the user

Main Particulars represent the general data about the vessel and the ship drafts1

and has to be provided in the export. In Hull, this data is not calculated, it is pro-vided by the user at the start of the project.

Besides the Main Particulars, the engineer needs to provide the SWBMSFDistri-butions which are the shear forces and bending moments distributions in differentconditions (sea going or harbour conditions). These data entries (can be multiple oneach frame position) are relevant for the calculations. The data is provided by theuser by means of an excel file which will be read during the export.

After the main particulars and distributions are defined, another set of data is re-quired regarding the properties of construction. There are three types of propertydata:

• Materials are defined by a name of the material, their Young modulus and theiryield stress.

• Stiffener types are defined by a name2, a type, a standard and their dimensions.

• Strake (plate) types are defined by a name 3 and their thicknesses.

In the case of materials, they are present in Hull, but they don’t have a Young mod-ulus and a yield stress, therefore this additional data has to be provided by the user.

1’Draft’ (or ’Draught’) of a ship’s hull is the vertical distance between the waterline and the bottomof the hull(Wikipedia).

2This is standardized in the form of “Type of stiffener - Dimension x Dimension”, e.g. B - 120 x 10represent a Bulb profile

3This is in the form of "Thick*Thickness of the plate*", e.g. "Thick12.00" is the name of a plate with12.00 mm thickness

8 Chapter 3. Analysis & Design

TABLE 3.1: Mapping of stiffeners (profiles) between CADMATICHull and Mars2000.

ProfileCADMATIC

HullMars2000

Bulb (Type 401) Bulb (B type)

T Bar (Type 408) T bar (T type)

Equal/Unequalangle bar (Types

402 & 403)Angle (L type)

Flat bar (Type400)

Flat (F type)

But for stiffener types and strake types, all the data necessary for exporting exists.

However, there is a small difference in the names and types for profiles betweenMars2000 and CADMATIC Hull, and this can be observed in Table 3.1.

Of course, because Hull is a detailed design software tool there are many of othertypes of profiles present in the application, together with user defined profiles, com-posite profiles, etc. For profiles that are not available in Mars2000, they are exportedas a flat bar of 0x0 dimensions, in order to not have any affect on the calculations.Moreover, a warning is showed, so the user can be aware of this and change it ac-cordingly in Mars.

Besides the data necessary about the ship, Mars2000 requires a frame grid, whichis the grid with certain positions on the ship that is used by engineers to refer to thelength of the ship. This grid is defined differently between the two software tools.In Mars2000 grids are defined by having a starting frame number, and then addingintervals: “starting from frame -2 until frame number 12, there is a spacing of 600millimeters, from frame 12 until frame 20, there is a spacing of 650 millimeters, etc.”.In Hull, the grid is represented differently (Figure 3.1) but has the same meaning.Therefore, here is another place where a mapping needs to be made in the export.

After all the required data is added, the cross sections need to be added. The crosssections in Mars2000 are defined and drawn from panels. Panels, as mentionedearlier, work like ordered graphs, and define the 2D drawings inside the software.

3.1. Problem analysis 9

FIGURE 3.1: Grid manager in the CADMATIC Hull Systems Manage-ment Application. The grid defined by a table, and each entry has aframe number (Num.), a value (Value), and the step to the next frame

(Step).

Panels have nodes which serve as vertices and segments which serve as edges. Pan-els can have multiple strakes and stiffeners attached to them and, as a whole, theydefine a construction area.

Strakes in Mars2000 are defined by the distance from the starting node of the panel,a material code, a strake property, and the hole properties. In case there are multiplestrakes on the same panel, the distance from the starting point is still required, butthe actual strake will be defined from the end position of the latest strake, i.e. if theengineers defines a strake with a distance of 2 meters from the starting point, andanother one with a distance of 3 meters from starting point, the second strake willhave 1 meter and will start where the first one ends. In Hull, having the 3D positionpoints of the plates, it makes it easier to draw the panels and calculate their positionwith respect to the panels and the last node on them. Besides the information that Imentioned above, in Mars2000 the engineer can also define holes in cross section thatmight affect calculations, this is done by defining the position on the panel wherethe hole starts, and another position where the hole ends. This, however is differentin CADMATIC Hull, and we look into the problem in the following chapter.

In case of shell plates however, there are extra steps that need to be considered. InHull, they are drawn as poly-lines, with lots of points defining them, because accu-racy is important in the detailed design stage. However, in basic design stage andin Mars2000, this accuracy is not a priority since the calculations done are usuallyjust approximations, and also Mars cannot handle that many points inside a panel.Another issue is that the distance from the starting node is not a simple problem asfor plates (just a distance between to points), but the distance along the poly-lineto the desired position has to be calculated. Therefore, when designing, two factorsneed to be taken into consideration: one is simplifying the poly-line, and the otherone is finding the correct distance from it is starting and end points.

Stiffeners in Mars2000 are defined by the distance from the starting node, similarto what is seen in strakes, material and stiffener property, a direction (which is the

10 Chapter 3. Analysis & Design

direction in respect to the plate, i.e., perpendicular to the plate, to the Y axis, etc.),a flange direction (in respect to the direction of the panel, can be forwards or back-wards) and a side (can be on the right or left side of the panel in regards to thedirection. Most of the data can be retrieved from Hull but, since the body and thick-ness direction do not consider the contour direction but have different standardsand are regarded as 0 for standard and 1 for non standard4, the information has tobe mapped accordingly [7].

After the drawing is done in Mars2000, the engineer needs to add the Compart-ments of the structure (i.e., tankers, void spaces, living spaces, etc.), which affectthe calculations because the purpose of the compartment has different requirements(for example a tank has thicker walls then a living compartment). Those are definedas connected graphs that start and end in the same node. Unfortunately this infor-mation is nonexistent in CADMATIC Hull, and the solutions for these issues arepresented in the following chapter.

Having said that we can conclude the whole process analysis of defining a crosssection successfully in Mars, and now we have an overview of all the informationrequired by the software and a mapping between CADMATIC Hull and Mars2000.Now we can move on to designing the right architecture and the design choices wetook during the development process.

3.2 Design choices

In order to successfully export cross section drawings from CADMATIC Hull toMars2000, an XML structure is used that is readable by Mars2000. This structureis presented in detail in Appendix A.3, but is important to go through the mainparts presented in the previous chapter, and how those relate to the XML file thatneeds to be imported to Mars2000. Therefore, in order to export cross sections, theinformation is exported in the following structure:

• Main Project Data, which contains the Main Particulars and the SWBMSFDis-tributions.

• Properties, which contains the materials, strake properties and stiffener prop-erties.

• Compartments.

• Cross Sections, which contain a list of all the Nodes defined in the drawings,and a list of Panels, encompassing the respective strakes and stiffeners attachedto them.

For the Main Project Data, a newly introduced dialog is introduced to add and editthis information in the Systems Management Application under the properties of theproject, since all these data sets are related to the whole vessel and the project in gen-eral. As for the distributions and materials, a spreadsheet is made available whichthe user can use during the export, in order to pass the required data (Figure 3.2).In this way, the system administrator can set up this data once when setting up theproject, and then the engineers do not have to take care of this anymore.

4Standard is downwards for the body direction and towards center line for the flange direction

3.2. Design choices 11

FIGURE 3.2: Newly added UI panels for Main Particulars (left) andProject Drafts (right) in the Systems Management Application.

In case of the SWBMSF Distributions and Materials, the user is able to pass a spread-sheet, with a required structure (see Fig A.1). For the distributions (see Appendix A),the software will go through cells and add all the distribution points according to thedata inside the cell until a full empty row is found. But for the materials, Mars2000has a limit of six input materials that the user can use inside a project, therefore thislimit will be enforced in CADMATIC Hull during the export as well. The parsing ofthe excel sheet will go through specific columns: columns A to C for bending mo-ments distributions at sea going conditions, columns E to G for bending moments atharbour conditions, etc.

The frame grid will be taken from the Systems Management Application, and will beconverted to the Mars2000 convention, using a map. The map will have the framenumber as the key and the position as the value. After the map is initialised, eachelement is parsed, and another entry is added when the spacing is changed.In order to read a cross section, the user will need to define a drawing inside CAD-MATIC Hull, and then all the elements are parsed inside the drawing using theEagle5 API to get all the elements present in the drawing. If either a plate, profile, shellplate or a shell frame6 is found (Fig. 3.3), they will be handled in a different matters:

• A plate in the drawing is represented by two lines (Fig. 3.4), one is the mouldedside and the other is the thickness side (parallel lines with a distance betweenthem equal to the thickness of the plate). The moulded side line is taken intoaccount, because it is more accurate for the calculation.

• For shell plates, all the points on the moulded side are taken and stored as apoly-line (using an internal library that handles geometry), which is simplifiedafterwards using the library.

• If a profile or a shell frame is found, the construction type is set as profile andhandled in a later step.

To draw the plates and shell plates in Mars2000, first a panel is added (or retrieved,if there is an existent one) and then nodes and segments are added to it. That is doneby going through the points of the line, take the first point add a node, or retrieve if

5outsourced technology used for 2D rendering and presentation6profile on a shell plate

12 Chapter 3. Analysis & Design

FIGURE 3.3: Plates, shell plates, profiles and shell frames in CAD-MATIC Hull (3D CONTEK).

FIGURE 3.4: Molded side and thickness side of a plate.

3.2. Design choices 13

already existent, check if there is a panel ending with that node, if not, a new one iscreated. After the starting node, and a panel, are initialized, for each following pointon the line, a segment from the last node to the next one is added. But at this mo-ment, in the XML structure, only panels, nodes, and segments are added to the project.

After the firs part is done, for one construction item, the element is drawn (if it isa plate of a shell plate), its construction type is initialized and retrieved the construc-tion’s database key number. With this key number, using the CADMATIC databaseAPI, the construction’s properties and the required data can be accessed and re-trieved.

• In case of plates and shell plates, the only thing needed at this point is thethickness.

• But in case of profiles and shell frames, the type, the body and thickness direc-tion, the position, the plate number of the plate on which it is attached and thestiffener’s orientation with regard to the plate will be retrieved and processed.

For each stiffener the following mapping is done:

• The position is retrieved from the starting point as a set of 3D coordinates.Since only stiffeners in cross section are taken into account, the length (x) is ir-relevant. Therefore the (y, z) coordinates are used in order to find the stiffener’sposition in the drawing. After the position is found, the panel is retrieved us-ing the plate number, and the distance from the start of the panel until theposition of the stiffener is calculated. If the stiffener is a profile, the distancefrom the starting point and the position is calculated and if it is a shell frame,the distance along the poly-line to the position given has to be determined.The later is done using current functionality in the geometry library.

• The type is mapped using following Table 3.1, and the dimensions are taken.The dimensions come as an array of four dimensions, in case of bulb, flat barand angle bar only the first two are relevant, but for the others, all 4 are re-quired.

• The side, thickness direction and body direction is found using the standardsmentioned earlier and the direction of the panel.

• For the stiffener property, if there is no property with the same type and di-mensions already existent in the export at this point (when no other profile ofthe same type was exported already) a new property is created and added tothe property part.

When the export starts, a ScantlingsManager instance is created and the data retrievedand processed is added to it. At the end, the class has its own mechanism of render-ing the data in the required XML structure and is used to output it in a file at thedesired file path. The file path, file name and the default location of the excel sheetused (the user has the possibility to use another file) are set up by the system admin-istrator in the Systems Management application.

To sum up, at the user level, the user will have the possibility to chose from thedrawings available inside the active block, chose the main project data sets s/hewants to use, or use the default one, and export them to a file path set up in theproject (see Fig. 3.5).

14 Chapter 3. Analysis & Design

FIGURE 3.5: Export to scantlings dialogue in CADMATIC Hull.

3.3 Implementation

During the implementation of the project there were more obstacles, from program-ming restrictions, problems regarding the difference between Mars2000 and CAD-MATIC Hull and more regarding my lack of experience in the shipbuilding and shipdesign field. Here is an overview of the key design and implementation decisionstaken during this project:

1. Holes were not implemented because of the output from the drawings. Thedifference was that two different plates were sent back even though there werethe same plate with a hole and usually there are rare cases when the user wantsto export a drawing with a hole in cross section.

2. Compartments were not implemented because at the detailed design stageand in CADMATIC Hull there are no references to those compartments, hencethey were impossible to determine. However, they are easy to define once thewhole drawing is exported successfully.

3. The decision between the moulded side and thickness side was one of the firstkey decisions that we took.

4. Even though we are able to attach multiple plates to the same panel in the end,an internal decision was taken to have each plate on its own panel in order toavoid extreme edge cases that would make the export fail.

5. Because there are a lot of types of stiffeners in Hull that are not available inMars2000 we made the decision to export it as a flat bar with zero dimension inorder to preserve the outcome calculation, after we received input from users.

6. There are also cases when the user does not add all the materials in the excelsheet. When this case happens, another material is added with the name avail-able in hull and a default Young modulus and yield stress which represent anormal steel material.

3.3. Implementation 15

7. After finding out that usually those calculations are done with multiple distri-bution conditions, we found the solution to the nonexistent data by definingthe excel sheet because engineers usually prefer a ’copy-paste’ solution to thistypes of issue and not inputting the data manually.

8. Because the order in which the elements in the drawing are retrieved cannotbe predicted, we had cases when a profile was found before the plate, causinga loss of data or crashes. In order to solve this, all the profiles and shell framesfound that did not have a plate to be attached were stored on the stack andwhen the export was done they were assigned to the right panels.

9. The use of poly-lines and the decision to simplify them came after we exporteddifficult and highly curved shapes and finding out that Mars2000 cannot han-dle that many points. We received feedback about this not being that importantfor Mars2000 since it is an approximate calculation. Therefore, we decided tosimplify the lines.

All these decisions were based on either user input, or made by the product owner, inorder to preserve the users need and to arrive to a feature that, in the end, optimizesthe process.

16

Chapter 4

Results

First we see as a result how a normal basic shaped half section is exported (see Fig-ure 4.1), which is the usual case. In Mars2000, most commonly, engineers only drawhalf of the section because the tool considers the other half mirrored, therefore thiswill be the first case covered. It can be observed in the figure that there are multipletypes of profiles of different sizes with different directions. As a reference, there arealso profile types that are not available in Mars2000 added.

The results can be observed in Figure 4.1. The profiles were exported successfullyand the shape and construction items were kept during the export. The same resultscan be observed in Figure 4.2 in which a full section was exported. Even thoughprofile standards might change on the left side of the center line, after the exportthey preserve their position. The following key points in the export can be seen inthe two cases:

1. Not only did all the profiles keep their directions, sizes and types, this was alsothe case with the shell frames. Although they are usually constructed insidethe ship, this case presents a so called “bilge keel”1.

2. The two decks on the top are two plates joined by a knuckle2, even thoughthey are two different plates, in reality they will be produced as one plate bentin that knuckle point.

3. The shell frames had 90 degrees on the shell plate itself and were exported inMars as perpendicular (to the panel).

1bilge keel (noun) - each of a pair of plates or timbers fastened under the sides of the hull of a ship toprovide lateral resistance to the water, prevent rolling, and support its weight in dry dock. (Wikipedia)

2knuckle (noun) - a convex portion of a vessel’s figure where a sudden change of shape occurs, asin a canal boat, where a nearly vertical side joins a nearly flat bottom (Wikipedia).

FIGURE 4.1: Half of section in Hull (left) and the result in Mars2000(right).

4.1. Evaluation 17

FIGURE 4.2: A full section in Hull (left) and the result in Mars2000(right).

FIGURE 4.3: Exported shell plate as poly-line in Hull (top) and as apanel in Mars2000 (bottom).

4. Profile types that were not available in Mars2000 can be observed as normalflat bars.

5. The shell plate form was preserved quite nicely and the poly-line was greatlysimplified before creating the panel (see Figure 4.3).

4.1 Evaluation

The feature shows satisfactory results, and the following restrictions and edge casesare present:

• During the testing process, an issue was found when a user tried to simulateshell plates, in a scenario with a simple shape, by using normal plates andknuckling them together with a radius (see Fig 4.4). In this case, the shell

FIGURE 4.4: Two perpendicular plates (left) that are knuckled withan inner radius of 100mm (right).

18 Chapter 4. Results

FIGURE 4.5: Transverse bulkheads, or profiles in cross section inCADMATIC Hull.

FIGURE 4.6: Nodes (represented by squares) connected by Segments(grey lines) defining a Panel (red number) in Mars2000.

frames are not exported because they require a shell plate to be attached to andthe plates will be drawn perpendicular, because knuckles are not processed.

• Transverse bulkheads (see Fig. 4.5) are not handled and remain an objectiveunder future developments.

• Usually when panels are defined in Mars2000, the main objective is the min-imum number of nodes used. However, in some cases, because the order inwhich the items are passed from CADMATIC Hull is unpredictable, this is notthe case. For example, in Fig. 4.6, the node at the end of panel 27 will also be apart of panel 7, but this will not be taken into account.

As for future implementation, the goal of CADMATIC is to cover and implementmore classification society tools (e.g. DNV-GL, LADS, etc.) and continue develop-ment on the current functionality in case another need is raised.

19

Chapter 5

Conclusion

During this thesis an innovative way to optimize the design process in the ship-building field was found and implemented. All the steps involved in this processand the importance of this issue were investigated. Many projects, like HOLISHIP,are actively trying to improve this long and costly process by introducing more linksbetween the existent software tools. This is not always achieved because of the dif-ferences in the architectures, cultural differences (e.g. U.S. shipbuilding / Europeanshipbuilding), many emerging software tools, etc. But despite the challenge, a suc-cessful one-way link between CADMATIC Hull and Mars2000 was created, and nowthe process of redesigning, in case of key design decisions, is optimized. The usercan easily retest, and do the calculations, not having to redraw everything from onesoftware tool to another. In the future CADMATIC plans to develop more links be-tween software tools for scantling calculations (like DNV-GL), trying to cover all themain classification societies present on the market.

To sum up, even though the process is getting more complex due to the rise oftechnology and the variation of the available tools in the market, companies (likeCADMATIC) are actively trying to create links between tools in order to optimizeand create a faster process. In the end, as shown above, a holistic approach in ship-building needs to be taken into consideration, and many more links between today’ssoftware tools need to follow this because of the need of increase in efficiency andits advantages.

20

Appendix A

Design process

A.1 Use cases

A.1.1 Use case 1: user wants to export (a) cross section(s) in frame viewfrom CADMATIC Hull to Mars2000

Use case: Export cross section in frame view from CADMATIC Hull to Mars2000Goal in context: Export cross section into an xml format file readable to Mars2000Primary actor: Hull userScope: 3D-CONTEKPreconditions: System administrator (Systems Management Application):

• Main particulars are set. (Projects -> Properties -> Main Particulars)

• Project drafts are set. (Projects -> Properties -> Project Drafts)

• Ship name and service notation are set. (Projects -> Properties -> Settings)

• The XML file name and file path are set. (Import/Export -> Scantlings)

• The path to the main particulars file is set. (Import/Export -> Scantlings)

Main success scenario:

1. User: Enters a block.

2. User: Accesses Export to Scantlings feature. (File -> Export -> Scantlings ->Mars2000)

3. System: Returns the dialog with a list with all the frame views, and the paththat the administrator set for the main Particulars.

4. User: Selects the view(s) he wants to export

5. User: Triggers the export

6. System: Reads the settings, adds the data from the main particulars file, pro-cesses the drawings and creates the XML (in the file path set by the systemadministrator).

A.1.2 Use case 2: user wants to set up the main particulars in systemsmanagement application

Use case: Set main particulars.Goal in context: User wants to set up the main particulars of the ship.Primary actor: Hull system administrator

A.1. Use cases 21

Scope: System Management ApplicationPreconditions: User has access to the System Management ApplicationSuccess end condition: Main particulars are set and the data is added under thenorms folderMain success scenario:

1. Use: Launches System Management Application.

2. User: Requests to change the main particulars. (Projects -> Properties -> MainParticulars)

3. System: Returns a dialog with the settings available. (length overall, lengthbetween perpendiculars, etc.)

4. User: Fills in the data

5. System: Saves the data to the norms file.

A.1.3 Use case 3: user wants to set the project drafts

Use case: Set project drafts.Goal in context: User wants to set up the project drafts of the ship.Primary actor: Hull system administrator.Scope: System Management Application.Preconditions: User has access to the System Management ApplicationSuccess end condition: Project drafts are set and the data is under the norms folder.Main success scenario:

1. User: Launches System Management Application.

2. User: Requests to change the project drafts. (Projects -> Properties -> ProjectDrafts)

3. System: Returns a dialog with the settings available. (scantling draft, heavyballast draft, etc.)

4. User: Fills in the data.

5. System: Saves the data to the norms file.

A.1.4 Use case 4: user wants to set the main project data default file path,xml file destination and file name.

Use case: Set main project data default file path, xml export path and the xml filenameGoal in context: User wants to set up the main project data default file path, xml filedestination and file name for the exportPrimary actor: Hull system administratorScope: System Management ApplicationPreconditions: User has access to the system management applicationSuccess end condition: Data is set and added under the norms folderMain success scenario:

1. User: Launches System Management Application

2. User: Requests to change the properties. (Import/Export -> Scantlings)

22 Appendix A. Design process

3. System: Returns a dialog with the settings requested.

4. User: Fills in the data

5. System: Saves the data under the norms folder

A.2 XML structure

• Main Project Data

– Main Particulars: Bilge Keel, Maximum service speed, Water plane coef-ficient ballast draft, water plane coefficient scantling draft, block coeffi-cient scantling draft, heavy ballast draft, minimmum ballast draft, scant-ling draft, dead weight, bulkhead deck, freeboard deck, depth at strengthdeck, breath moulded, load line length, AE rule from frame 0, rule length,length between perpendiculars, length over all, service notation, shipname

– SWBMSF Distributions

∗ BMDistributionSeaGoing∗ BMDistributionHarbour∗ SFDistributionSeaGoing∗ SFDistributionHarbour

– Frame Table : Frame Group

• Properties

– Material : Material (yield stress, Young modulus, material type, name)

– Strake properties: StrakeProp (name, thickness)

– Stiffener properties: StiffProp (name, dimensions, standard, stiffener type)

• Compartments

• Cross Sections: CrossSection (name, local breadth, local depth, distance fromframe 0)

– Nodes: Node (Y, Z)

– Panels: Panel (name, primary structure spacing, start node)

∗ Segments: Segment (postion, radius, segment type, end node)∗ Strakes: Strake (strake property, material, distance from start node,

hole start position, hole end position)∗ Stiffeners: Stiffener (stiffener property, material, side, flange direc-

tion, body direction, position)

A.2. XML structure 23

FIGURE A.1: Spreadsheet used for distributions and materials. Thefirst 4 tables represent the SWBMSFDistributions (the first two,BMDistributionSeaGoing and BMDistributionHarbour, is used forbending moments and the other two, SFDistributionSeaGoing and

SFDistributionHarbour, is used for shear forces).

24

Appendix B

Working at CADMATIC

During my time at CADMATIC, I worked as a summer trainee in the R&D Team forHull applications. I was tutored by my supervisor Madalina Florean, and I imple-mented the feature following the official team guidelines. I was part of the SCRUMteam, I followed and participated actively in daily stand ups, sprint review meetingsand kick off meetings. I was also guided by my co-workers, especially the lead de-velopers, who not only assisted me in the inner workings of the whole system, butalso taught me the ship building notions and ways of working.

The code was done entirely in C++ and the following tools were used in the pro-cess:

• Visual Studio 2017

• Google test

• Git/Sourcetree

• CADMATIC internal API

• Jira

25

Bibliography

[1] URL: http://www.holiship.eu/ (visited on 06/08/2019).

[2] Bureau-Veritas. Mars2000 - Ship structure calculation software. URL: https : / /marine-offshore.bureauveritas.com/mars-2000-ship-structure-calculation-software (visited on 06/08/2019).

[3] C-Job. C-Job explained: ship design process. URL: https://c-job.com/services/ship-design-engineering/c-job-design-process/ (visited on 06/08/2019).

[4] N. Maniar B. Baret Y. Homma W. Trafalski D. Catley E. Lehmann. “DesignOptimization: A State-of-the-Art Review”. In: Marine Structures 3 1 (Jan. 1990),pp. 1–2.

[5] Classification Society IACS. Classification Society IACS (International Associa-tion of Classification Societies). URL: http://maritime-connector.com/wiki/classification-society/ (visited on 06/08/2019).

[6] Habil. Apostolos Papanikolaou. A Holistic Approach to Ship Design. Volume 1:Optimisation of Ship Design and Operation for Life Cycle. 2019.

[7] Bureau Veritas. CSR for Bulk Carriers and Oil Tankers assessment within MARS.July 2015.