Overview of FRP Composite Technologies

in Yacht Building

Nguyễn Anh TuấnYacht Designer

TUANSHIPLAND.com

Image source: http://www.boats.com/blog/2011/04/clear-gelcoat-see-beneath-the-surface/

Contents

1. What are composite material, fiber composite and FRP composite?

2. Definitions in Composite Technology (ABS Rules, 2000)3. The Methods of FRP Composite Fabrication of Yacht Builders4. Composite Technology in The Current Yacht Building Practice

(ISSC, 2009)5. Survey of Moulding (ClassNK, 2010)

1. What are composite material, fiber composite

and FRP composite?

Most composite is a multiphase material, most of composite consist of two components that are: (Nguyễn Văn Dán, 2003)1. Reinforcement (Cốt) is the discontinuous phase (pha gián đoạn) to make strength (độ bền) and

elastic modulus (mô đun đàn hồi) of composite. 2. Matrix (Nền) or resin is the continuous phase to transmit the loads, cover the reinforcement and

make bond strength (độ bền liên kết) of composite.

Fiber Reinforced Plastic (FRP, chất dẻo cốt sợi*) is a popular material has been applied widely to build hull boat and deck in yacht industry (Larsson and Eliasson, 2000). Note: * TCVN 6285-2003 (VR, 2003)According to Nghi Tr. C. (2005), FRP for USA and Glass-reinforced Plastic (GRP) for UK

According to 2.33 in Guide for Building and Classing of Motor Pleasure Yachts (ABS, 2000), FRP contains two basic components: 1. A glass-filament (Sợi thủy tinh) or other material fiber, reinforcement filament2. A plastic or resin (nhựa)

FRP Yacht in Thailand ShipyardSource: http://www.amdesign.co.th/In_construction.html

Patrol Boat of Lương Giang Company in VietnamSource: http://luonggiang.com/home.asp?ID=280&langid=1

Fiber Composite (R&G, 2009)

2. Definitions in Composite Technology

Guide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

ReinforcementGuide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

Reinforcement (Cốt) A strong, inert material bonded into the plastic to improve its strength, stiffness and impact resistance, usually fibers of glass or other approved material as aramid or carbon fiber, in a woven or non-woven form, with a strong adhesive bond with the resin

Strand (Bó sợi) a bundle of continuous filament (Sợi liên tục) combined in a single, compact unit

Chopped-strand Mat (CSM, tấm sợi vô hướng*)

a blanket of randomly oriented (xếp ngẫu nhiên) chopped-glass strands held together with binder

Roving (Bó sợi song song) a band or ribbon or parallel strands grouped together

Woven Roving (WR, tấm vải thủy tinh*)

a coarse fabric woven (vải sợi thô) from rovings (sợi*).

Yarn a twisted strand or strands suitable for weaving into fabric

Cloth a fabric woven from yarn

Ply principal axes (hệ trục chính của tấm)

The two principle axes of a reinforcing ply are, the axis that is parallel to the warp and the axis that is parallel to the fill

Binder (chất kết dính) The substance (chất) applied in small quantities (lượng nhỏ) to fibers to hold them lightly together in mat form (liên kết các sợi thành dạng tấm)

Size (dung dịch hồ) A substance applied to fibers at the time of their formation to allow resin to flow freely around and adhere to them and to protect them from abrasion (ăn mòn)

* Translated into Vietnamese by Nghị Tr.C. (2005)

Reinforcement (Cont.)

Finish a substance applied to fabrics to promote wetting of fibers by the resin (tăng độ ướt giữa các sợi bằng nhựa), to improve adhesion (tăng độ bám dính), and to reduce inter-filament abrasion (giảm ăn mòn giữa các sợi)

Uni-directional (đẳng hướng) A woven or non-woven reinforcement with substantially more fibers in one principal axis (nằm cùng 1 trục cơ bản) of the reinforcing ply

Bi-axial A woven or non-woven reinforcement with fibers primarily in the principal axes (nằm trong hệ cơ bản) of the reinforcing ply

Double biased A woven or non-woven reinforcement with fibers primarily at +450 to the principal axes (450 so với hệ trục cơ bản) of the reinforcing ply

Tri-axial A woven or non-woven reinforcement with fibers running in the two principal axes of the ply and in addition, with fibers running at + or – 450 to the warp

Warp (sợi dọc) The roving or yarn running lengthwise in woven fabric

Fill, weft or woof (Sợi ngang) The roving or yarn running at right angles to the warp in a woven fabric

Image source from Composite Meterials – Design and Application (Gray, Hoa and Tsai, 2003)

Kinds of Glass Reinforcement (Larsson and Eliasson, 2000)

Resin A highly reactive synthetic that in its initial stage is a liquid, but upon activation is transformed into a solid

Accelerator (chất xúc tác*) a material that, when mixed with resin, speeds the cure time

Catalyst or Initiator a material that is used to activate resin, causing it to harden

Crazing hairline cracks (vết rạn như sợi tóc), either within or on the surface of resin, caused by mechanical or thermal stresses (ứng suất nhiệt hay cơ)

Cure (đóng rắn) to change resin from a liquid to a solid

Cure time (thời gian đóng rắn) the time required for resin to change from a liquid to a solid after a catalyst has been added

Exothermic (toả nhiệt) the heat given off as the result of the action of a catalyst on resin

Filler (chất phụ gia, chất độn) a material added to resin to modify its working properties or other qualities or to lower costs

ResinGuide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

Image Source: http://www.yachtpaint.com/usa/diy/products/fillers/search.aspx

Epoxy Filler “Watertite”

* Translation obeys TCVN 6285-2003 (VR, 2003)

Resin (Cont.)

Tack The degree of stickiness (độ nhớt) of the resin

Thixotropy The property or phenomenon, exhibited by some resins, of becoming jelly-like (dạng keo) at rest but becoming fluid again when stirred (mix, trộn) or agitated (shaked, được khuấy). This facilitates the application of the resin to inclined or vertical surfaces

Inhibitor (chất ức chế)

A material that retards activation (làm chậm phản ứng) or initiation of resin, thus extending shelf life (tăng tuổi thọ) or influencing exothermic heat (tỏa nhiệt) or gel time

Polymerization (polymer hóa)

The reaction that takes place when resin is activated or initiated

Pot life (thời hạn sử dụng của nhựa * )

The length of time that catalyzed resin remains workable

Shelf life (thời hạn sử dụng)

The length of time that an uncatalyzed resins maintains its working properties while stored in tightly sealed, opaque container (container kín và chắn sáng)

Gel (keo) a partially cured resin (nhựa đông đặc 1 phần) in a semi-solid state (trạng thái bán đông, mềm) similar to gelatin (keo) in consistency (độ đặc). Not to be confused with gel coat

Gel time the time required to change a flowable, liquid resin into a nonflowing gel

* Translation obeys TCVN 6285-2003 (VR, 2003)

Image Source: http://www.jamestowndistributors.com/1/1/2251-epoxy-resin-west-system-105-epoxy-resin.html

BRAND: WEST System

Material: Epoxy

Usage: Laminating

Type: Resin

Laminate (plate, sheet) a material composed of successive bonded (được ghép liên tiếp) layers, or plies, of resin and fiber or other reinforcing substances

Bi-directional Laminate A laminate with fibers oriented primarily in the warp and fill directions in the plane of the laminate and where the mechanical properties in the warp (sợi dọc) and fill of the laminate are similar. Bi-directional laminates may be constructed of bi-axial, double bias, tri-axial, mat or uni-directional reinforcing layers, or a combination of any of these

Uni-directional Laminate A laminate with substantially more of the fibers in the plane of the laminate oriented in one of the two principle axis of the laminate plane so that the physical properties along that axis, are appreciably higher than along the other natural axis

Barcol Hardness (Độ cứng Barcol) A measurement of the hardness of a laminate and thereby the degree of completion of the cure

LaminateGuide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

Image Source: Handbook of R&G (2009)

Laminate (Cont.)

Peel Ply A partially impregnated (được tẩm một phần) lightly bonded layer of glass, cloth or woven roving used to protect a laminate in anticipation of secondary bonding (bảo vệ tấm chuẩn bị cho liên kết tiếp theo) , providing a clean, fresh bonding surface

Secondary Bonding The practice (action) of bonding fresh material to a cured or partially cured laminate

Verified Minimum Physical The physical properties verified by the appropriate test given in table 5.1 in Guide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

Laminate Principle Axes The two principal axes of square or rectangular plate panel are for the application of these rules those perpendicular and parallel to the plate panel edges

Gel Coat (Lớp nhựa phủ * ) The first resin applied to a mold when fabricating a laminate. It provides a smooth protective surface for the laminate. For decorative purposes, it usually has a coloring matter added. Not to be confused with gel.

Layup The process of applying to a mold the layers of resin and reinforcing materials that make up a laminate. These materials are then compressed or densified with a roller or squeegee to eliminate entrapped air and to spread resin evenly. Also a description of the component materials and geometry of a laminate and laminate that has been assembled.

Delamination The separation of the layers of the material in a laminate

* Translation obeys TCVN 6285-2003 (VR, 2003)

Encapsulation (~core material)

the containment of a core material such as softwoods, including plywood (ván ép), balsa (gỗ balsa), or plastic foam (xốp nhựa) between two FRP single-skin laminates. The cores may be structurally effective or ineffective

Sandwich Composite Using Honeycomb CoreSource:

http://www.fibre-reinforced-plastic.com/2010/12/sandwich-composite-and-core-material.html

A balsa core sandwich panel with skin connecting 3-dimensional fibersSource: http://www.ebertcomposites.com/news2006.html

Marine plywood panelSource:

http://www.nauticexpo.com/prod/bellotti-spa/sandwich-panels-plywood-balsa-30295-209428.html

Table 5.1 Tests for Physical Properties of FRP Laminatesin Guide for Building and Classing Motor Pleasure Yachts (ABS, 2000)

Properties of Commonly Used Reinforcements (Gray, Hoa and Tsai 2003)

Note: Kevlar 49 là tên thương phẩm của sợi polyamide, có tính chống đâm thủng cao, làm việc ở nhiệt độ nhỏ hơn 200 oC (Dan Ng. V., 2003); E glass ( sợi thủy tinh nhóm E) ứng dụng phổ biến nhất, giá thành không cao, tỉ trọng 2.56, giới hạn bền kéo (tensile strength) 3.4 x 105 N/m2 , modulus of elasticity 72x106 N/m2 (Nghi Tr. C., 2005).

Properties of Commonly Used Resins (Gray, Hoa and Tsai 2003)

Properties of Commonly Used Core Materials (Gray, Hoa and Tsai 2003)

Comparison of core material in yacht building (Larsson and Eliasson, 2000)

3. The Methods of FRP Composite Fabrication

of Yacht Builders

Molding Process (Qui trình tạo hình) in Composite Production (Gray, Hoa and Tsai, 2003)

Layup Methods in Composite TechnologyRules for Material and Welding (ABS, 2006)

Chapter 6 Materials for Hull Construction – Fiber Reinforced Plastics (FRP)

Lay-up Methods

Hand layup or contact

process

Vacuum Bagging

Resin Impregnation

Resin Transfer Molding (RTM)

Resin Infusion

Pre-preg

Wet/Hand layup

Image Source: http://www.netcomposites.com/education.asp?sequence=56

Advantages * Disadvantages*

Very economical process Final quanlity depends heavily on the skills of laminators

Low investment Be dangerous for human health and workshop enviroment due to open mould technique

Used for complicated shaped pieces

* Source from ISSC (2009) ; ** Source: http://www.netcomposites.com/education.asp?sequence=56

Material Options **Resin: Any, e.g. epoxy, polyester, vinylester, phenolicFibers: Any, although heavy aramid fabrics can be hard to wet-out by handCores: Any

Spray layup method

Image Source: http://www.netcomposites.com/education.asp?sequence=55

Advantages * Disadvantages*

Very economical process Final quality depends heavily on the skills of laminators

Low investment Be dangerous for human health and workshop environment due to open mould technique

Used for complicated shaped pieces Not suitable for high strength structures

Material Options **Resin: Primarily polyesterFibers: Glass roving onlyCores: None. These have to be incorporated separately (Phải được đưa vào một cách riêng lẽ)

* Source from ISSC (2009) ; ** Source: http://www.netcomposites.com/education.asp?sequence=55

Hand layup method with vacuum compression in the TÛRANOR PlanetSolar PlanetSolar projectSource: http://www.reinforcedplastics.com/view/10751/carbon-composite-materials-in-modern-yacht-building

To improve the hand layup methods is application of vacuum bagging. Usually, this method is used in conjunction with pre-preg (bán thành phẩm) laminates that are pre-impregnated with resin and strictly obey the manner of the material suppliers. (ISSC, 2009)

Image Source: http://www.netcomposites.com/education.asp?sequence=57

Vacuum Bagging

Material Options **Resin: Primarily epoxy and phenolic. Polyesters and vinylesters may be have problems due to excessive extraction of styrene from the resin by the vacuum pump.Fibers: The consolidation pressures mean that a variety of heavy fabrics can be wet-out.Cores: Any.

** Source: http://www.netcomposites.com/education.asp?sequence=57

Resin Infusion is a general term. In yacht production, builders refer to Vacuum Infusion or Seeman Composite Resin Infusion Molding Process SCRIMP. Resin Infusion includes Resin Transfer Moulding (RTM) and Vacuum Assisted Resin Transfer Moulding (VARTM) (ISSC, 2009).

Resin Infusion/ Infusion Process

Image source: http://www.netcomposites.com/education.asp?sequence=61

Material Options **Resin: Generally epoxy, polyester and vinylesterFibers: Any conventional fabrics. Stitched materials work well in this process since the gaps allow rapid transport.Cores: Any not including honeycombs (Ngoại trừ dạng tổ ong)

** Source: http://www.netcomposites.com/education.asp?sequence=61

Advantages * Disadvantages *

Greatly reduced emissions due to applying closed-mould techniques

Complicated set up (vacuum tubes and resin inlet placement)

Better fiber to resin ratio Easy to ruin a part (Difficultly correct any errors)

Ability to mould complex structural and hollow shapes

Trial and error (Because of the complexity and ease to error, resin infusion should be viewed as trial-and-error process)

Sandwich structures can be laminated in one hit

Consideration of Infusion Process Application in Yacht Building (ISSC, 2009)

* Source from ISSC (2009)

Resin Transfer Moulding (RTM)

Image Source: http://www.netcomposites.com/education.asp?sequence=60

RTM is in which dry fibers are injected with resin under high pressure in a mold of very stiff male and female parts. This method effectively applies for large production, it is not found in mega and racing yacht production. RTM is assisted by vacuum applied to the stiff mould prior to injection, this is VARTM (ISSC, 2009).

Materials Options:Resins: Generally epoxy, polyester, vinylester and phenolic, although high temperature resins such as bismaleimides can be used at elevated process temperatures. Fibres: Any. Stitched materials work well in this process since the gaps allow rapid resin transport. Some specially developed fabrics can assist with resin flow. Cores: Not honeycombs, since cells would fill with resin, and pressures involved can crush some foams.

7 Main Steps of Composite Ship Building in Vietnam Shipyard (Nghị Tr. C., 2005)

Build female mould using composite materials

Prepare release agent (chất chống dính) for separating mould

Laminate gelcoat (lớp áo ngoài bề mặt) that is the first resin and defines the colour of the hull; then laminate the remaining layers

Build transverse and longitudinal stiffeners

Build transverse and longitudinal bulkhead using composite or other materials

Build deck and bridge (thượng tầng)

Make the connection of hull, deck and bridge

Screen shoot from http://www.corsaircatamarans.com/about.html

Application of Resin Infusion Techniques at Corsair Marine International in HCM City, Vietnam

4. Composite Technology in The Current Yacht Building Practice

17th International Ship and Offshore Structures Congress, August 2009

Materials Selection Criteria (Tiêu chí lựa chọn vật liệu) for building hull of yacht (ISSC, 2009)

Business Details and Materials Usage Amongst Industrial Organizations (ISSC, 2009)

Business Details and Materials Usage Amongst Industrial Organizations (ISSC, 2009) (Cont.)

Design Models and Production Methods used by Industrial Organizations (ISSC, 2009)

Design Models and Production Methods used by Industrial Organizations (ISSC, 2009) (Cont.)

5. Survey of MouldingRules for The Survey and Construction of Ship of Fiberglass Reinforced Plastics (ClassNK, 2010)

In this section, all Vietnamese notes I refer to TCVN 6282:2003 (VR, 2003) in surveying FRP yacht production.

Before moulding, considerating the below steps in Regulation 5.1.6 (ClassNK, 2010):

1- Environmental conditions of laminating shops (điều kiện môi trường phân xưởng dát), controlling system thereof and curing time of resins (thời gian xử lý nhựa)

2- Operation procedure (qui trình công nghệ) and scheduled operation process (quá trình công nghệ đã được lập trình)

3- Kinds (chủng loại), cutting methods, overlap of joints (phần phủ lên các mối nối), edge preparation (chuẩn bị mép) and number of plies of fiberglass reinforcements (số lượng lớp cốt sợi thủy tinh)

4- Kinds, amount, blending quatity at one time (lượng pha trộn trong một lần) and blending procedures of resins used (qui trình pha trộn nhựa được dùng)

Regulation 5.1.7 Enviromental Conditions of Laminating Shops (Rule of ClassNK, 2010) The temperature while laminating is to be kept suitable for the resins used (được giữ

thích hợp với nhựa được sử dụng) and not to be lower than 150 C. The humidity while laminating is preferable to be not lower than 60%, but not higher

than 80%. Dusts (bụi), rubbishes (vật vô dụng) and detrimental fumes (khói độc hại) in the

laminating shops are to cleared off as far as practicable.

Regulation 5.1.8 Gelcoats (Lớp nhựa phủ) (Rules of ClassNK, 2010) Gelcoat resins are to be coated (được bọc, bao phủ) or sprayed (được phun đều) The standard thickness of gelcoat film ( lớp nhựa phủ) is approximately 0.5 mm

Regulation 5.1.11 Cut Edges of Laminates (Mép cắt của lớp) (ClassNK, 2010) The cut edges of laminates, holes for bolts, etc. are to be thoroughly covered (che chắn

hoàn toàn) with resin so that the fiberglass reinforcements (cốt sợi thủy tinh) are not exposed.

Screen shoot source: http://www.youtube.com/watch?v=k1quabWb8vk&feature=player_embedded Horizon’s homepage < http://www.horizonpowercatamarans.com >

Regulation 5.1.12 Mould Releasing (Tháo khuôn) (ClassNK, 2010) Mould releasing operation is to be carefully carried out lest permanent deformations

and damages harmful to the hull laminates should be caused. After releasing, the hull laminates (các lớp thân tàu) are to be supported by an area as

wide as practicable so that they are subjected to a uniform load (tải phân bố đều).

Composite Hull Release applied SCRIMP technology in Horizon Shipyard

Hand lay-up method

Regulation 5.2.1 Seams of Fiberglass Reinforcements (Mối nối các cốt sợi thủy tinh) (ClassNK, 2010) Fiberglass reinforcements are to be arranged so as to have seams of reinforcements as

few as practicable. The overlap at seams is not to be less than 50mm (Phần cốt sợi thủy tinh phủ lên mối nối phải không nhỏ hơn 50mm). The centre lines of overlaps of two adjacent plies (đường tâm của 2 lớp cốt sợi kế tiếp) are not be less than 100mm apart from each (cách nhau ít nhất 100mm) so far as no obstruction exist for the work.

Contact Molding (Khuôn tiếp xúc ) applying hand lay – up (R&G, 2009)

Regulation 5.2.2 Degassing (khử khí) (ClassNK, 2010) In laminating, after having the fiberglass reinforcements thoroughly (careful)

impregnated with resin (được tẩm với nhựa), air bubbles in the resin are to be removed by degassing rollers (trục lăn khử khí) or rubber pallets (bàn xoa cao su). However, excessive squeezing of resin is not desirable (nhựa không nên bị ép quá đáng) and care is to be taken to keep the glass content proper.

Wet/Hand Lay-up MethodImage Source: http://www.netcomposites.com/education.asp?sequence=56

Regulation 5.2.3 Glass Content ( Hàm lượng thủy tinh) (ClassNK, 2010) In laminating, the standard glass content (ratio in weight) is approximately 30% in case of

chopped mats (tấm sợi băm) or approximately 50% in case of roving cloths (vải sợi thô) and laminating is to be carried out uniformly to avoid local excess or scarcity of resin (dát đều tránh thừa hoặc thiếu nhựa cục bộ).

The aggregated weight of roving cloths (trọng lượng chất độn của vải sợi thô) is to be 25% to 60% of the total weight of glass. Where, however, special fiberglass reinforcements are used, the weight is to be in accordance with the discretion of society (sự chấp nhận của Đăng kiểm).

Regulation 5.2.4 Laminating (dát) (ClassNK, 2010) Where the successive laminating is interrupted (quá trình dát bị gián đoạn) in such a case

of laminating thick shell plating, etc., non-paraffin resins are to be used for the first of any subsequent layers (nhựa không có parafin phải được dùng cho lớp thứ 1 của các lớp tiếp theo) of reinforcement to be laid in that area and care is to be taken not to leave over the excessive resin layer (thận trọng để không để lại lớp nhựa quá thừa)

Regulation 5.2.5 Laminating For Final Ply (dát lớp sau cùng) (ClassNK, 2010) As for laminating for the final ply, effective measures to cure the outer surface are to be

provided.

Spray lay-up Method

Regulation 5.3.2 Moulding of Primary Structural Members (Tạo hình các cơ cấu cơ bản) (ClassNk, 2010) Where the chopped mat parts (phần tấm sợi băm) of primary structural members of

hull are moulded by means of the spray lay-up method, the method is to be approved by the Society.

Image source: www.composites.ugent.be/home_made_composites/organizing_your_composite_workshop.html

Laminating using Spray lay-up method

Strength and Stiffness in Sandwich vs Solid (Larsson and Eliasson, 2000)

Sandwich Construction (Kết cấu nhiều lớp)Regulation 5.4.1 Cores (Lõi) (ClassNK, 2010) Where the cores which are composed of hard plastic foams (bọt nhựa cứng) are

temporarily set by nails (được đóng tạm bằng đinh), care to be taken to ensure that the cores are free from dent (bị dập), misalignment (bị lệch) and other defects due to nailing (Khuyết tật khác do đóng đinh). And, no penetrating clearance not less than 1mm is to be left between the cores (Giữa các lõi, khe hở không lớn hơn 1mm).

Where balsas are used for cores, care is to be taken to have the balsas thoroughly impregnated with resins (cẩn trọng để gỗ Balsa tẩm đều với nhựa). The clearance between the balsas is, as a rule, not to be more than 4mm.

Regulation 5.5.1 Bonding (Gắn) (ClassNK, 2010) Bonding is to be executed after making effective preparation such as sanding the surface

to be bonded (mặt để gắn phải được đánh cát) and thoroughly removing oils (khử dầu) and sanding dusts (bụi cát).

Bonding is to be executed paying careful attention not to cause spring back of fiberglass reinforcements (phải thận trọng để cốt sợi thủy tinh không bị nẩy ngược).

Bonding is to be carefully executed so as not to cause any deformation due to excessive exothermic effect (ảnh hưởng nhiệt).

Bonding is to be carefully carried out so as not to cause strength discontinuity at the joint (phải thận trọng để độ bền không bị gián đoạn ở các liên kết).

T-joints and L-joints are to be laminated at the site (phải được tạo hình ở hiện trường).

Regulation 5.5.2 Fastening (Ghép) (ClassNK, 2010) Where laminates are connected each other (các lớp liên kết với nhau) or where metallic

fittings are fastened to laminates (các chi tiết kim loại liên kết với các lớp), mechanical fastening may be applied. In this case, the fasteners such as bolts, rivets, screws, etc. are to be sea-water-corrosion –resistent metal or to be properly protected against corrosion.

Regulation 5.5.3 Bolts (bu lông) (ClassNK, 2010) The distance between the center of bolt hole and the edge of laminate (khoảng cách từ

tâm lỗ đặt bu lông đến mép của lớp) is not to be less than three times the diameter of the hole. The distance between the bolt holes (khoảng cách giữa các lỗ đặt bu lông) is not ot be less than three times diameter of the hole.

Where bolts are used, washers are to be used on the surface of laminate (đặt vành đệm lên mặt lớp).

Regulation 5.5.4 Connection of Sandwich Laminates (Liên kết các lớp của kết cấu nhiều lớp) (ClassNK, 2010) Where bolts (bu-lông), screw (đinh vít), rivets (đinh tán), etc., are used, penetrating

sandwich laminates with cores of hard plastic foams (xuyên qua kết cấu nhiều lớp có lõi là bọt nhựa cứng), timbers (gỗ) or plywoods (ván ép, gỗ dán) well seasoned are to be inserted in such parts of the cores in advance (phải được đặt xen vào phần lõi đó từ trước).

Regulation 5.5.5 Watertight Construction (kết cấu kín nước) (ClassNK, 2010) Where mechanical fastening (ghép cơ khí) such as bolted joints (mối ghép bu lông), etc., is

used in way of a location where watertightness is required, suitable measures (biện pháp thích hợp) are to be provided to maintain watertightness (đảm bảo tính kín nước).

Regulation 5.6.1 T-joints (liên kết chữ T) (ClassNK, 2010)

The overlap width of T- joints of structural members are generally to be in accordance with Fig.5.1.

In T- Joints of members of sandwich construction, the aggregated thickness (chiều dày tổng cộng) of the inner laminate and the outer laminate of FRP may be used as the thickness (t) shown in Fig.5.1.

The form of laminating of T Joints is to be as shown in Fig.5.2 (a) and Fig. 5.2 (b).

(Khô

ng n

hỏ h

ơn 6

t ho

ặc 4

0mm

lấy

trị

số n

ào lớ

n hơ

n)

(Kích thước phần chồng của liên kết chữ T)

Overlap

(ClassNK, 2010)

(Bột nhựa mềm dát theo góc lượn)

Trường hợp tấm sợi băm và vải sợi thô được dùng để liên kết

(ClassNK, 2010)

Trường hợp dùng tấm sợi băm (tấm sợi vô hướng)

(Bột nhựa mềm dát theo góc lượn)

(ClassNK, 2010)

Regulation 5.6.1 T-joints (liên kết chữ T) (ClassNK, 2010)(Cont.) Where the members such as engin girders, bulkheads, etc., which are

subjected to considerably heavy load or vibration are connected, careful considerations are to be given in such a manner as to arrange structural members upon the laminates which are increased in thickness as shown in Fig.5.3 (a)

Where the members other than those specified in the preceding -4, that is, the members which are not deemed subjected to specially heavy load or vibration, are connected to the structural members, plastic foam or other similar materials are to be inserted between the member and the laminate as shown in Fig. 5.3 (b) or the corners are to be sufficiently laminated by filling with soft resin puttys (bột nhựa mềm) or other similar materials as shown in Fig.5.3 (c).

Trường hợp cơ cấu chịu tải trọng hoặc rung động như bệ máy, vách…

Trong chỗ liên kết với cơ cấu lớp vỏ được tăng chiều dày

(ClassNK, 2010)

Tấm trong

Tấm phủ

Dạng chuẩn của liên kết chữ T

Bọt nhựa được đặt giữa cơ cấu và các lớp

(ClassNK, 2010)

(ClassNK, 2010)

References

1. Trần Công Nghị. 2005. Thiết kế tàu cỡ nhỏ chạy nhanh (Small High-speed Craft Design). Vietnam National University Pulisher. HCMC. Vietnam

2. Nguyễn Văn Dán. 2003. Công nghệ vật liệu mới (Modern Material Technology). Vietnam National University Pulisher. HCMC. Vietnam

3. Lars Larsson and Rolf E Eliasson. 2000. Principle of Yacht Design. Adlard Coles Nautical. London. Great Britain

4. International Ship and Offshore Structures Congress (ISSC). 2009. Committee V8: Sailing yacht Design. Seoul. Korea. 433p - 492p

5. Jürgen Klimke and Daniel Rothmann. 06 July 2010. Carbon composite materials in modern yacht building, < http://www.reinforcedplastics.com/view/10751/carbon-composite-materials-in-modern-yacht-building/ >

6. American Bureau of Shipping (ABS). 2000. Guide for Building and Classing of Motor Pleasure Yachts. New York. USA

7. American Bureau of Shipping (ABS). 2006. Rules for Materials and Welding – Aluminium and Fiber Reinforced Plastics (FRP). New York. USA

8. ClassNK. 2010. Rules for Survey and Construction of Ship of Fiberglass. Tokyo. Japan9. Vietnam Register (VR). TCVN 6282: 2003 Qui Phạm Kiểm Tra và Chế Tạo Các Tàu Làm Bằng Chất Dẻo

Cốt Sợi Thủy Tinh (Rules for the Survey and Construction of Ships of Fiberglass Reinforced Plastics). Ha Noi. Vietnam

10. Daniel Gray, Suong V. Hoa and Stephen W. Tsai. 2003. Composite Meterials – Design and Application. CRC Press LLC. USA

11. R&G Faserverbundwerkstoffe. 2009. Composite Material Handbook, < http://download.r-g.de/handbuch_edition_06_09.pdf >

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