ABS 75-1995 Safehull System for Tankers Guide on Improvement for Structural Connections and Sample Structural Details - Service Experience and Modifications - for Tankers《油轮修改及运行经验.pdf

1、ABS TITLE GISCSSDSEMT 95 065LL02 DOL0793 9T5 FOUNDED :862 - AMERICAN BUREAU OF SHIPPING such as locations at the bracket toes, cut-outs, terminations of heavily loaded members, the connection of flexible elements with much stiffer members, the ends of unbalanced structural members, just to name a fe

2、w. For ship structures designed with relatively low working stresses and high safety margins, the 1 ABS T%TL,E GISCSSDSEMT 95 Ob5LL02 0030777 5YO detrimental effects of such stress concentrations may not be readily apparent. On the other hand, for structures designed with relatively high working str

3、esses and low safety margins, damaging effects of such stress concentrations could appear sooner than the anticipated period of time. Appropriate stress concentration factors (SCFs) obtained from either experimental data or structural analyses are required to evaluate the design of structural detail

4、s. 2.3 Weld Effects and Fatigue Strength Another important factor to be considered is the effects of welding on the properties of material (heating effects) and on structural continuity (profile of the weld deposit and under- cuts). This factor which highly depends on the welding methods, processes

5、and workmanship is vital for assessing the fatigue strength of the joint. To date, the welding effects on the fatigue strength are primarily determined by experimental data presented in the form of S-N curves and characteristics of the test specimens, as shown in the Appendix 52AA of the Rules. 3.0

6、CONSIDERATIONS FOR DESIGN OF STRUCTURAL DETAILS In light of the discussions given in Y2A5.4, it is apparent that the necessary criterion for the design of structural details is simply to offer a well balanced joint which is compatible with the anticipated working stresses. To this end, the solution

7、is to be tailored to a specific location of a specific design. In addition, there is no unique solution to the problem. Many alternatives may exist. The designerdbuilders would have to exercise their judgment based on their fabrication facilities, techniques and experience. The information offered b

8、elow is provided for reference. 3.1 Structural Configuration and Arrangement of Brackets When selecting the structural configurations and sizing the brackets connecting primary supporting members, due consideration is to be given to the bad transmission and the 2 AR5 TITLE GISCSSDSEMT 95 Ob51102 OOL

9、0798 487 W 3.2 relative stiffnesses of the members to be connected. A smooth pattern of load transmission is essential. The connecting bracket is to be of sufficient size to withstand the highly concentrated loads and to shift the critical spots (bracket toes) to the lower stressed regions. An appro

10、priate stiffening system is also required for large brackets to prevent local structure instability and tripping. Sample illustrations are shown in Fig. 1 and Fig. 2 for damages experienced in existing tankers with recornmended modfications. Installation of Brackets and Collar Plate To prevent local

11、 distortions and to minimize the magnifying effects of structural notches, consideration is to be given to additional brackets and collar plates (or lugs) at the criitical joints and cut-outs, respectively. Sample illustrations are shown in Fig. 3 for local damages recorded and the recommended modif

12、ications. Alternatively, different stiffening systems may be considered to minimize the critical spots in highly stressed regions. For example, utilization of the horizontal stiffeners with appropriate tripping brackets for floors in the double bottom, instead of vertical stiffeners would eliminate

13、the critical spots at the face bar toes on the flange of longitudinal as shown in Fig. 342. 3.3 Softening Hard Spots To minimize the stress concentration at hard spots, such as bracket toes, tapered face plate, and welded connections of the face plate of transverses and bulkhead plating, the welded

14、joints may be softened by providing a large radius at bracket toes or a cope hole with proper reinforcement of the surrounding panel to prevent local instability. Some sample illustrations are shown in Fig. 4. To minimize the detrimental effects of knuckles in structural elements, sample illustratio

15、ns are shown in Fig. 5. 3 ABS TITLE GISCSSDSEMT 95 = Ob51102 0010799 313 3.4 Improvement of Fatigue Strength At crkal structural joints, the fatigue strength can be improved, as discussed in the previous paragraphs, by reducing the magnitudes of nominal stresses (working stresses) andor minimizing t

16、he stress concentrations. In addition, it may also be advisable to consider the following improvements on the fatigue strength: 1) Utilizing better contour shapes for cut-outs, such as the cope holes shown in Fig. 6. 2) Having bracket toe and the surrounding weld deposit ground smooth with an approp

17、riate radius as shown in Fig. 7. 4.0 SAMPLE STR UCTURAL DETAIL S These examples are divided into the following five groups: Figure 1 - Examples for Bracket Enlargement a) Connection of Bottom Girder and Vertical Web b) Bottom Girder End Bracket c) Bottom Transverse End Bracket d) Reinforcement at Co

18、nnection of Bottom Girder and Oil Tight Bulkhead Figure 2 - Examples for Bracket Modification a) Connection of Centerline Girder and Oil Tight Transverse Bulkhead b) Connection of Horizontal Girder and Side Longitudinal c) Longitudinal End Bracket Figure 3 - Examples for Additional Brackets and Coll

19、ar Plate a) Connection of Bottom Girder and Swash Bulkhead b) Tripping Bracket on Transverse Web c) Connection of Longitudinal to Floor in Double Bottom d) Connection of Longitudinal to Transverse Web Figure 4 - Examples for Hard Spot Effects a) Tapered Face Plate of Horizontal Girder b) Connection

20、of Transverse Face Plate and Bulkhead Plating c) Bracket Toe on Bottom Transverse d) Bracket Toe on Longitudinal e) Sniped Tripping Bracket on Horizontal Girder Figure 5 - Examples for Knuckle Effects 4 Modification II! ! i Existing Figure l(a) Connection of Bottom Girder and Vertical Web 5 ABS TITL

21、E GISCSSDSEMT 95 Ob5LL02 OOLOBOL BTL I Modification I& WAY Existing /- Figure l(b) Bottom Girder End Bracket 6 ARS TITLE GISCSSDSEMT 95 m Ob5LL02 OOLO802 738 Modification PENETRATION SERTED PLATE ITH INCREASED THICKNESS * LUGS Existing - .- LONGITUD I NAL BULKHEAD II Figure l(c) Bottom Transverse En

22、d Bracket 7 ABS TITLE GISCSSDSEMT 95 Ob51102 0010803 674 = Modification Existing Figure l(d) Reinforcement at Connection of Bottom Girder and Oil tight Bulkhead 8 ABS TITLE GISCSSDSEMT 95 m Ob51102 0010804 500 H Modification Existing 0.T. BULKHEAD BOTTOM TRANSVERSE I - , FRACTURE y BOTOM SHELL FRACT

23、URE 7 VIWA-A Figure 2(a) Connection of Centerline Girder and Oil tight Trans Bulkhead 9 ABS TITLE GISCSSDSEMT 95 m Ob5LL02 OOL0805 447 m Modification Existing TRANSVERSE BULKHEAD FRACTURE - f SIDE SHELL Figure 2(b) Connection of Horizontal Girder and Side Longitudinal 10 ABS TITLE GISCSSDSEMT 95 Ob5

24、1102 OOL080b 383 Modification Existing t I Figure 2(c) Longitudinal End Bracket 11 ABX TITLE GISCSSDSEMT 95 = Ob51102 0010807 21T Modification Existing I il Figure 3(a) Connection of Bottom Girder and Swash Bulkhead 12 ABS TITLE GISCSSDSEMT 95 m Ob51102 OOLOBOB 156 = Modification el - TRANS. CUTOUT

25、il I /I Figure 3(b) Tripping Bracket on Trans. Web 13 ABS TITLE GISCSSDSEMT 95 = Ob51102 0010809 O92 W Modification ect Existing f“ -7 VIEWA-A Figure 3(c) Connection of Longitudinal to Floor in D.B. 14 ABS TITLE GISCSSDSEMT 75 m OIALLOZ OOLOBLO 804 m Modification Existing VICW A -A t a+- I Figure 3(

26、d) Connection of Longitudinal to Trans. Web 15 ABS TITLE GISCSSDSEMT 75 Ob51102 00108LL 740 H Modification - I irr Figure 4(a) Tapered Face Existing i 1 Plate of Horizontal Girder 16 Modification Existing LONGITUCINAL BULKHE D Figure 4(b) Connection of Transverse Face Plate and Bhd Plating 17 ABS TI

27、TLE GISCSSDSEMT 95 m Ob5LL02 OOLOBL3 513 m Modification Existing BOlTOM TRANSVERSE Figure 4(c) Bracket Toe on Bottom Transverse 18 AS TITLE GISCSSDSEMT 95 ObSLL02 OOLOBL4 45T H Modification Existing Figure 4(d) Bracket Toe on Longitudinal 19 ABS TITLE GISCSSDSEMT 95 9 Ob51102 OOLOB1S 39b Modificatio

28、n Existing Figure 4(e) Sniped Tripping Bracket on Horizontal Girder 20 ABS TITLE GISCSSDSEMT 95 = 0652202 OOLDBLb 222 9 Modification * i-? VIE& A-A H IS Existing i i 5 Figure 5 Examples for Knuckle Effects 21 ABS TITLE GISCSSDSEMT 95 m Ob51102 DOL0817 Lb9 m Gpe hole ground back I Il t- * 1 Figure 6

29、Improved Cope Hole Details 22 ABS TITLE GISCSSDSEMT 95 m 0651102 0010818 OT5 W i Ground back welds 2 75m Longitudinal Figure 7 Improved Brackets Toes 23 ABS TITLE GISCSSDSEMT 95 m Ob5LL02 OOLOBL T3L m 1995 TECHNICAL PUBLICATION ORDER FORM AMERICAN BUREAU OF SHIPPING &AFFILIATED COMPANIES Corporate P

30、ublications Dept.: Two World Trade Center, 106th Floor New York, NY USA 10048 Tel: (21 2) 839-501 6 FAX: (21 2) 839-5208 MERICAN BUREN OF 8WFfiN AFFiLINED CYPhNIES I I I = 1995 Publication Price (US. $) includes shipping and handling -All local taxes to be paid by the purchaser Quantity Price $600 R

31、ef# Book, Rule Change Notice (RCN), corrigenda, addendum O0 RECORD of ABS (annual) 1995 edition (contains only I I I I vessels classed by ABS or with an ABS assigned loadline) I Rules for Building and Classing: notices and updates I $200 2 Steel Vessels 1995 = Complete set of rules including all I I

32、 1- $21 O 2CD CD-ROM version of Steel Vessels (annual) 1995 edition I (includes Ref. #IO) $50 3 Aluminum Vessels (1 975), RCN-3 &4 I 1- I $75 4 Steel Vessels for Service on and Intracoastal I Waterways (1 995) I $75 5 Steel Vessels Under 67 Meters (200 Feet) in Length I I (1983), RCN 1-10, 8A $1 O0

33、6 Mobile Offshore Drillina Units (1 995) I i I $50 6U 1995 Modu UDdate I - $75 7 Underwater Vehicles, Systems, and Hyperbaric Facilities I I I $50 9 Bulk Carriers for Service on the Great Lakes (I 978), I RCN-1 I I- (1 990), RCN 1 $50 1 0 Steel Baraes (1 991), RCN-1-4 i corr #1, also available on l

34、CD-ROM $75 1 1 Steel Floatina Drvdocks (1 977) $50 12 Reinforced Plastic Vessels (1978), RCN 1 & 2 - $50 28 Steel Vessels for Service in Southeast Asia (1982), RCN $75 29 Offshore Installations (1 983) 1-9, 7A Rules for: - $75 13 Certification of Carao Containers (1987) $75 14 Nondestructive Inspect

35、ion of Hull Welds (1986) Requirements for: lakes Vessels (1991) Gear on Merchant Vessels (1 975) $50 25 Certification of Self-Unloading Carao Gear on Great $25 26 Certification of the Construction and Survey of Carao $50 27 ADDroved Weldinq Consumables (1 995) $25 31 Notes on Heavv Fuel Oil (1984) $

36、50 36 List of TvDe Amroved EauiDment (1 995) Preliminary Rules for: Hotel Baraes (1 9891, RCN-1 (1978), RCN 1 $50 48 Building and Classing Accommodation Baraes and $25 15 Burnina Crude Oil and Slops in Main and Auxiliary Boilers Quantity Price Ref# Book, Rule Change Notice (RCN), corrigenda, addendu

37、m $25 $25 $25 $50 $25 $75 $25 $50 $25 $50 $25 $75 $75 $50 Guide for: 16 Construction of Shbboard Elevators (1 993) 17 Repair and Claddina of Shaffs (i 980), RCN 1 19 Underwater Inspection in Lieu of Drydocking Survey (1 986) 20 Lay-Up and for Reactivation of Laid-Up Shim (1 986) 21 Ships Burning Coa

38、l (1980) 22 Building and Classing Fire Fighting Vessels (1 981), RCN-I 24 Material Selection and Inspection of inert Gas S.vstems (I 980) 30 Ultrasonic Examination of Carbon Steel Forainac for Tail Shafts (1 983) 32 Bronze and Stainless Steel ProDeller Castinas (1 984) 33 Certification of Thrusters

39、and Dvnamic Positioning S.vstems (1 994) 35 Survey Based on Preventative Maintenance Techniques 37 Building and Classing Offshore Racina Yachts (1 994), RCN 1 39 The Certification of Offshore Moorina Chain (1 986) 42 Lay-Up and for Reactivation of Mobile Offshore Drilling & (1 986) 43 Classing Vesse

40、ls for Safety Standbv Service (I 986) 44 Certification of Cranes (l991), RCN-1 45 Certification of Container Securino Svstems (1 988) 55 Building and Classing Fishina Vessels (May 1989), RCN-1 56 The Use of Refrigerated (Low Pressure) Carbon Dioxide as a Fire Extinguishing Medium on Board Ship (1 98

41、9) 57 The Certification of Drillinq Systems (1990) 58 Application of Dynamic-Remonse-Based Intact Stabilitv Criteria for Column-Stabilized Mobile Offshore Drilling Units (1 990) 59 Preparing Fishing Vessels Stability Booklet (1 990) 60 Carao Vapor Emission Control Systems on Board Tank Vessels (1991

42、) 61 Building and Classing Hiah SDeed Craft, (1 990), Corr-1 , 62 Building and Classing Motor Pleasure Yachts, (1990), Corr-I, RCN-I 63 Building and Classing Facilities on Offshore Installations 64 Building and Classing Undersea Pipeline S-vstems and 66 Controlled Atmosphere Systems (1 992) 68 One M

43、an Bridpe ODerated (OMBO) Ships (1992) 69 Certification of Oil %ill Recovery EauiDment (1 993) 71 Building and Classing Oil Recoverv Vessels (1 993) 72 Dynamic Based Design and Evaluation of Bulk Carrier Structures (1 995) 73 Hull Condition Monitoring Systems (I 995) 74 Guide For Assessing Hull-Gird

44、er Residual Strength for Tankers 75 Guide On Improvement for Structural Connections and Sample Structural Details-Sewice Experience and Modification-for Tankers (1 995) RCN-1 (1 991) Risers (1991) 953 Please give complete shipping information on reverse side. ABS TITLE GISCSSDSEMT 95 = Ob51102 00108

45、20 753 1995 TECHNICAL PUBLICATION ORDER FORM Two World Trade Center, 106th Floor New York, NY USA 10048 Tel: (21 2) 839-501 6 FAX: (21 2) 839-5208 Corporate Publications Dept.: Please provide Company Date shipping address: Purchase order or reference number: If your company has an account with ABS g

46、ive number: Attention of Telephone We ship UPS. Please give street address. City, State, Zip codes Country If your company issues purchase orders enclose it with this form. No. UNLESS YOU HAVE ESTABLISHED AN ACCOUNT FOR MARITIME-RELATED SERVICES WITH ABS, PAYMENT MUST ACCOMPANY YOUR ORDER Furnish bi

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48、mpt use certificate with order. ABS BOOK ORDER SECTION TWO WORLD TRADE CENTER, 106TH FLOOR NEW YORK. NY 10048 You may charge your order to your VISA or MASTERCARD The New York Publications Department now accepts VISA and MasterCard payment for book orders. Speed the delivery of your books by using your credit card and faxing your order to fax # (21 2) 839-5208 Attn: Don Evans I I I I I I I l I I I I I I I I I I I I I I I l l I I I