Structural Design and Response in Collision and Grounding

More documents

Recommendations

Info

develop the details of the design, and to insure that thearrangement satisfies IMO regulations and the structuraldesign satisfies ABS classification requirements. A 60000dwt double hull tanker and a 283000 dwt double tankerwere also developed in accordance with the InterimGuidelines [3]. Results for the baseline 150000 dwtdouble-hull tanker are presented in this paper.5.3.1 Struck ShipThe 150000 dwt Baseline Tanker design shown in Figure19 is the primary struck ship used for the initial modeltesting. Tables 2 and 3 list principal characteristics andstructural data for this design.Table 4 lists the input data for each test matrix. Thefirst test matrix considers damage for a series of strikelocations on the web at the center of each cargo tank. Thisrepresents a large global variation in strike location. Thesecond test matrix considers damage for a series of strikelocations on either side of the web at the center of themidship cargo tank. This represents a relatively smalllocal variation in location on and between webs. Thethird test matrix considers damage for a series of collisionangles with a strike location on the web at the center ofthe midship cargo tank.Deadweight, tonnes 150,000Length L, m 264.00Breadth B, m 48.00Depth D, m 24.00Draft T, m 16.80Double Bottom Ht hDB, m 2.32Double Hull Width W, m 2.00Displacement, tonnes 178,8675.3.2 Model Test MatricesThree scenario test matrices were used in the initial study.All matrices use the Baseline Tanker as the struck shipand a 150000 dwt bulk carrier as the striking ship.Principal characteristics for the striking ship are listed inTable 4 and the resulting vertical alignment of the twoships is shown in Figure 20. Since the focus of the initialtests is on penetration damage, zero struck ship speed isused in all cases. Scenarios for the test matrices aredescribed in Table 5.Table 3. Baseline TankerShip150,000 dwtdouble hull tankerWeb Frame Spacing L s , m 3.30Deck 47.32SmearedThicknesst h , mmInner Bottom 26.92Bottom 28.29Stringers 3 ´ 15.34SmearedThicknesst v , mmSide Shell 21.92Inner Skin 22.94Bulkhead 22.28Figure 19 - Baseline Tanker Design [3]Table 2. Baseline Tanker Principal CharacteristicsWeb Upper 12.00Thicknesst w , mm Lower 18.00Table 4. Striking Ship Principal Characteristics12
Ship Type150,000 dwtbulk carrierLength L, m 274.00Breadth B, m 47.00Depth D, m 21.60Bow Height H, m 26.00Draft T, m 15.96Struck Ship Speed (knt)Striking Ship Speed (knt)Collision Angle (deg)Strike Location (m fwd MS)5.3.3 Model ResultsDisplacement, tonnes 174,850Half Entrance Angle, α 38°Representative model results for struck ship penetrationare shown in Figures 22-27. The figures show transversepenetration into the struck ship as a function of theparticular variables in each matrix. The results showgood agreement between the models. DAMAGEgenerally predicts the lowest penetration, andALPS/SCOL generally predicts the highest.Figures 22 and 23 (Matrix 1) show the effect of theexternal dynamics. More energy is absorbed in strikesaround midship. SIMCOL shows a larger variation inpenetration as a function of global strike location than theother models, particularly at low energy. SIMCOL’scoupled dynamics predict larger changes in the relativemotions at the strike point of the two ships as the strikelocation moves away from midship. This results in morelongitudinal damage and less penetration. ALPS/SCOLshows a similar, but lesser trend. This has the greatesteffect on shell and web deformation, and is most evidentin the lower energy case, Figure 22.Matrix 1 0 3,4,5,6,7 90 -62.5,29.5,3.5,36.5,69.5,102.5Matrix 2 0 3,4,5,6,7 90 1.85,2.675,3.5,4.325,5.15Matrix 3 0 3,4,5,6,7 45,60,75,105,120,1353.5pen [m]Matrix 1: pen(x) Vb=3 knt43210-100 -50 0 50 100 150x [m fwd MS]DTUSIMCOL2.11DAMAGEALPS/SCOLFigure 22 – Matrix 1 Low Energy CollisionMatrix 1: pen(x) Vb=7 knt150,000 dwtDouble HullTanker150,000 dwtBulk Carrierpen [m]10864DTUSIMCOL2.11DAMAGE2ALPS/SCOL0-100 -50 0 50 100 150x [m fwd MS]Figure 21 - Collision Strike Vertical AlignmentFigure 23 – Matrix 1 High Energy CollisionTable 5 - Test Matrices13
Page 1 and 2: Brown, A.J., Tikka, K., Daidola, J.
Page 3 and 4: 3 PROBABILISTIC FRAMEWORKFigure 2 i
Page 5 and 6: 4.2.2 Method by Wang [15]Dr. Wang d
Page 7 and 8: damage results. Surprisingly, the t
Page 9 and 10: ybeginning of time step nStriking S
Page 11: location, COG, and detailed structu
Page 16 and 17: 6.2 DATA FOR MODEL VALIDATIONThe se
Page 18 and 19: Force (N)8.00E+087.00E+086.00E+085.
Page 20 and 21: Figure 37 - Macro flow diagram for
Page 22 and 23: enhance resistance to collision. Th
Page 24 and 25: Figure 42 - Load versus lateral ind
Page 26 and 27: Accidental Grounding and Collision

Structural Design and Response in Collision and Grounding

Create successful ePaper yourself

Delete template?

Save as template?