Alexandria UniversityFaculty of Engineering

Application of Line Heating Method In Shipbuilding Industry

1

”تطبيق طريقة التسخين الخطى فى صناعة بناء السفن “

9-Apri-2009

Submitted by

Engr. Kamal Hassan Kamal Mohamed

Supervisors

Prof. Dr. Ahmed El-BadanProf. Dr. Ahmed Mohamed Rashwan

Naval Architecture & Marine Engineering DepartmentFaculty of EngineeringAlexandria University

Submitted: April 2009

THESIS OUTLINES1. INTRODUCTION

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2. AIM OF THE STUDY

3. THE PRINCIPLES OF HEATING OF METALS

4. PARAMETERS AFFECTING PERMANENT DEFORMATIONS

5. LINE HEATING FORMING PROCEDURES

6. EXPERIMENTS VERIFICATION

7. CONCLUSION

8. RECOMMENDATIONS FOR FUTURE WORK

9-Apri-2009

1. INTRODUCTION

1. Quicker and more accurate than methods using heavy machinery.

2. Build much more complicated shapes with only minor investment in new equipment.

3

Line Heating Advantages:Line Heating

Press

Roller

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2. AIM OF THE STUDY

To build a scientific practical guide informing flat plates to certain shapesby Line Heating Method.

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3. THE PRINCIPLES OF HEATING OF METALS

Phenomenon of Heating of Metals

Fig. 3.2: Schematic diagram showing

basics of creating permanent deformation

from heating

Fig. 3.1: Schematic representation of permanent

deformation due to single heating line.

The compressive plastic strain is the main source for the body permanent deformation and residual stresses.

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These simple examples suggest the following:1. The shrinkage is important to form a spherical shape which has

curvatures in two directions.2. The bending angle is necessary to create cylindrical shape which has

unidirectional curvature.

Line Heating Idea

Fig. 3.3: Forming of cylinder shape Fig. 3.4: Forming of shallow spherical shell shape

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4. PARAMETERS AFFECTING PERMANENT DEFORMATIONS Maximum Heating Surface Temperature

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Fig. 4.1: Bending angle as a function of heat input power [10]

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Effective Heat Input Power

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Plate Thickness and Heating Torch Travel Speed

Torch Tip-Plate Separation

Fig. 4.2: Torch tip-plate separation detail 99-Apri-2009

Fig. 4.3: Bending angle obtained with no

initial stress (0 N/mm2) [4]

Fig. 4.4: Bending angle obtained with

initial stress (-80 N/mm2) [4]

Fig. 4.5: Bending angle obtained with

initial stress (-160 N/mm2) [4]

Initial Stress

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Cooling Method

Fig. 4.6: Cooling on the heated side of steel plate.

Fig. 4.7: Cooling on the back side

of steel plate

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5. LINE HEATING FORMING PROCEDURES

Fig. 5.1: Usual Different Forms of Curved Plates in Ship Structure

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a) Single Curvature Shape

Constant Curvature Shape in Transverse Direction without Twist

Fig. 5.2: Constant Curvature Shape in the

Transverse Direction without Twist

Fig. 5.3: Heating Application Sequence

Constant Curvature Shape in the Transverse

Direction without Twist139-Apri-2009

Constant Curvature Shape in Transverse Direction with Twist

Fig. 5.4: Constant curvature shape in

the transverse direction with twist

Fig. 5.5: Heating application sequence

for constant curvature shape in the

transverse direction with twist149-Apri-2009

Variable Curvature Shape in Transverse Direction

Fig. 5.6: Variable curvature shape in the transverse direction

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b) Double Curvature Shape in the Same Direction of thePlate Surface – Longitudinal Concave Curvature Shape(Pillow Shape)

Fig. 5.27: Longitudinal concave

curvature shape (Pillow Shape)

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Longitudinal Concave Curvature Shape without Twist

Stage 1 Stage 2

22

22

2

Tradrad

T

Trad

T

rad

hy

hWNOHL

hy

hWNOHL

R

WNOHL

22

22

481.0

4

481.0

4

LTT

TL

LT

TL

hL

hhLNOHT

hL

hhLNOHT

(Eq. 4.1)(Eq. 4.3)

Fig. 5.8: Heating application sequence for longitudinal concave

curvature without twist 179-Apri-2009

Longitudinal Concave Curvature Shape with Twist

Stage 1 Stage 2

22

1

22

1

1

2

Tradrad

T

Trad

T

rad

hy

hWNOHL

hy

hWNOHL

R

WNOHL

22

22

481.0

4

481.0

4

LTT

TL

LT

TL

hL

hhLNOHT

hL

hhLNOHT

(Eq. 4.2) (Eq. 4.3)

Fig. 5.9: Heating Application Sequence for longitudinal

concave curvature with twist 189-Apri-2009

c) Reverse Double Curvature Shape – Longitudinal convexcurvature Shape (Saddle Shape)

Fig. 5.10: Longitudinal convex curvature shape

Fig. 5.11: Line heating technique details for forming the longitudinal convex curvature shape (Saddle shape)

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Longitudinal Convex Curvature Shape without Twist

Stage 1

22

22

481.0

4

481.0

4

LLL

TL

LL

TL

hL

hhLNOHL

hL

hhLNOHL

(Eq. 4.1) (Eq. 4.4)

22

22

2

Tradrad

T

Trad

T

rad

hy

hWNOHL

hy

hWNOHL

R

WNOHL

Stage 2

Fig. 5.12: Heating sequence for longitudinal convex curvature shape without twist209-Apri-2009

Longitudinal Convex Curvature Shape with Twist

Stage 1

22

1

22

1

1

2

Tradrad

T

Trad

T

rad

hy

hWNOHL

hy

hWNOHL

R

WNOHL

22

22

481.0

4

481.0

4

LLL

TL

LL

TL

hL

hhLNOHL

hL

hhLNOHL

Stage 2

(Eq. 4.2)(Eq. 4.4)

Fig. 5.13: Heating sequence for longitudinal convex

curvature shape with twist219-Apri-2009

d) Double Curvature Shape due to Twist on the Plate Surface

Fig. 5.14: Twisted Curvature Shape

Fig. 5.15: Heating sequence for twisted curvature shape

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Line Heating Tools

Line Heating Workstation

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6. EXPERIMENTS VERIFICATION

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Modals Dimensions & Line Heating Conditions

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Experiments of Single Curvature Shape1. Constant Curvature Shape in Transverse Direction without Twist

(Expr.1) Plate Dims. 12X4060X1789 mm.

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Fig. 6.1: The result of Experiment No. 1279-Apri-2009

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2. Constant Curvature Shape in Transverse Direction with Twist (Expr.2) Plate Dims. 12X1500X900 mm.

9-Apri-2009

Fig. 6.2: The result of Experiment No. 2299-Apri-2009

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3. Variable Curvature Shape in Transverse Direction (Expr.3) Plate Dims.

10X3000X(820+720) mm.

9-Apri-2009

Fig. 6.3: The result of Experiment No. 3 Part (1) 319-Apri-2009

Fig. 6.4: The result of Experiment No. 3 Part (2)329-Apri-2009

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1. Longitudinal Concave Curvature Shape without Twist (Expr.4) Plate Dims. 10X1500X900 mm.

Experiments of Double Curvature Shape in the SameDirection of the Plate Surface (Pillow Shape)

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Fig. 6.5: The result of Experiment No. 4359-Apri-2009

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2. Longitudinal Concave Curvature Shape with Twist (Expr.5) Plate Dims. 12X1500X900 mm.

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Fig. 6.6: The result of Experiment No. 5389-Apri-2009

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Experiments of Reverse Double Curvature Shape (SaddleShape)

1. Longitudinal Convex Curvature Shape without Twist (Expr.6) Plate Dims. 10X1500X870 mm.

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Fig. 6.7: The result of Experiment No. 6419-Apri-2009

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2. Longitudinal Convex Curvature Shape with Twist (Expr.7) Plate Dims.

12X1500X900 mm.

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Fig. 6.8: The result of Experiment No. 7449-Apri-2009

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Experiments of Double Curvature Shape due to Twist on the Plate Surface (Expr.8) Plate Dims. 10X5343X2283 mm.

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Fig. 6.9: The result of Experiment No. 8469-Apri-2009

7. CONCLUSION

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8. RECOMMENDATIONS FOR FUTURE WORK

9-Apri-2009

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QUESTIONS

489-Apri-2009

499-Apri-2009

THANK YOU

509-Apri-2009