ASTM F1455-1992(2007) Standard Guide for Selection of Structural Details for Ship Construction《造船用结构部件选择的标准导则》.pdf

1、Designation: F 1455 92 (Reapproved 2007)An American National StandardStandard Guide forSelection of Structural Details for Ship Construction1This standard is issued under the fixed designation F 1455; the number immediately following the designation indicates the year oforiginal adoption or, in the

2、case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe principal aim of this guide is to depict recommended practices related to the desig

3、n of shipstructural details. The importance of structural details is clear:1) Their layout and fabrication represent a sizable fraction of hull construction costs.2) Details are often the source of cracks and other failures which, under certain circumstances,could lead to serious damage to the ship

4、hull girder.3) The trend toward decreasing ship hull scantlings (that is, increasing average hull stresses) has thepotential of increasing the damage to details.4) Researchers have largely neglected the analysis of structural details at least in part because theconfiguration and purpose of these det

5、ails vary greatly and are not commonly described or discussedin the literature.Due to lack of analytical and experimental effort devoted to structural details, their determinationhas been left up to draftsmen and designers, with very little engineering input.In two comprehensive reviews2,3of the per

6、formance of structural details, 86 ships were surveyed.These included naval and commercial ship types. The commercial ships included both U.S. andforeign built. The vessels ranged from 428 to 847 feet in length, from 18,000 to 90,000 tons indisplacement, and from five to twenty-six years in age. The

7、 details obtained were grouped into 12typical families. Knife Edge Crossings (Family No. 6) and Structural Deck Cutout Details (Family No.9) are shown but not covered in detail in this guide. The remaining ten detail families were furthercategorized into 53 groups comprising a total of 611 detail co

8、nfigurations. A number of theseconfigurations are very similar to others in detail geometry and such duplicates have been excludedfrom this guide. A number of others were eliminated because of relatively infrequent observed use. Asa result, a total of 414 details are included herein. However, all 61

9、1 details can be found in “StructuralDetails,”4if desired.In total, 607,584 details were observed with a total of 6,856 failures. Failures were attributed to oneor a combination of five categories: design, fabrication, welding, maintenance, and operation (see 4.1through 4.1.5). This extensive, well

10、documented research, together with engineering judgement,provides the principal support for this guide.1. Scope1.1 This guide provides a recommended list of selected shipstructure details for use in ship construction.1.2 Structural details which have failed in service and arenot recommended for use

11、in ship construction are included aswell.1.3 This guide is intended to convey the lessons learned ondifferent configurations of ship structure details, not the dimen-sions, thickness, or construction methods which would resultfrom structural calculations.42. Terminology2.1 Definitions of Terms Speci

12、fic to This Standard:2.1.1 Terms:1This practice is under the jurisdiction of ASTM Committee F25 on Ships andMarine Technology and is the direct responsibility of Subcommittee F25.01 onStructures.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1992. Last previous edit

13、ion approved in 2001 as F 1455 - 92(2001).2Jordan, C. R., and Cochran, C. S., “In-service Performance of StructuralDetails,” SSC-272, Ship Structure Committee Report, March 1977, availablethrough the National Technical Information Service, Springfield, VA 22161.3Jordan, C. R., and Knight, L. T., “Fu

14、rther Survey of In-service Performance ofStructural Details,” SSC-294, Ship Structure Committee Report, May 1979, avail-able through the National Technical Information Service, Springfield, VA 22161.4Jordan, C. R., and Krumpen, P., Jr., “Structural Details,” American WeldingSociety Welding Journal,

15、Vol 63, No. 1, January 1984.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.1.2 beam bracketa bracket at the end of framing orstiffening members that is used for increased strength, conti-nuity and end constraint.2.1.2.1 Discussion

16、see Fig. 1.2.1.3 clearance cut-outsa hole or opening in a piercedmember to allow passage of a piercing member.2.1.3.1 Discussionsee Fig. 2.2.1.4 gunwale connectionthe connection of the sheerstrake to the stringer strake of the uppermost deck of the hull.2.1.4.1 Discussionsee Fig. 3.2.1.5 knife edge

17、crossingthe projected point intersectionof members (plate members, stiffeners or bulkheads) onopposite sides of an intervening plate member. An undesirablecondition to be avoided.2.1.5.1 DiscussionIncluded for information only, see 3.1.2.1.5.2 Discussionsee Fig. 4.2.1.6 miscellaneous cut-outsmall ho

18、les or openings of avariety of sizes and shapes used for access, drainage, ease offabrication, stress relief, and so forth.2.1.6.1 Discussionsee Fig. 5.2.1.7 non-tight collara fitting at the cut-outs in way of theintersection of two continuous members that provides lateralsupport for the piercing me

19、mber which does not fully fill thecut-out area of the pierced member. May be a lug.2.1.7.1 Discussionsee Fig. 6.2.1.8 panel stiffenersintercostal, non-load-carrying mem-bers used to reduce the size of plate panels.2.1.8.1 Discussionsee Fig. 7.2.1.9 stanchion endsstructural fittings at the ends (top

20、andbottom) of a stanchion to transfer loads from the supportedmember to the supporting member.2.1.9.1 Discussionsee Fig. 8.2.1.10 stiffener endsthe configuration of the end of anunbracketed, non-continuous stiffener.2.1.10.1 Discussionsee Fig. 9.2.1.11 structural deck cutsallow passage through decks

21、for access, tank cleaning, piping, cable, and so forth.2.1.11.1 DiscussionIncluded for information only, see3.1.2.1.11.2 Discussionsee Fig. 10.2.1.12 tight collaras per non-tight collar but the cut-out inthe pierced member is fully filled and is air-, oil-, or watertightas required. Tight collars ma

22、y be lapped or flush fitted.2.1.12.1 Discussionsee Fig. 11.2.1.13 tripping bracketa bracket or chock that provideslateral support to framing and stiffening members. Supportmay be provided to either the web or the flange, or to both.2.1.13.1 Discussionsee Fig. 12.2.2 Symbols:Symbols:2.2.1 Symbols are

23、 as indicated in Fig. 13. The detailidentification symbol (Fig. 13, 1-J-1 for example) is the sameas that assigned in the original research reports and is retainedthroughout for all details for ease in referring back to thereports if desired.3. Summary of Guide3.1 In this guide, details are shown fo

24、r the ten families ofstructural details identified above and as shown in Fig. 13,59, 11 and 12. Knife Edge Crossings, Fig. 4, are not discussedfurther in this guide since none were observed in the researchFIG. 1 Beam Brackets (Family No. 1)FIG. 2 Clearance Cut-outs (Family No. 8)FIG. 3 Gunwale Conne

25、ctions (Family No. 5)FIG. 4 Knife Edge Crossing (Family No. 6)FIG. 5 Miscellaneous Cut-outs (Family No. 7)FIG. 6 Non-Tight Collars (Family No. 3)F 1455 92 (2007)2and fortunately so. This detail represents very undesirablestructural conditions and is to be avoided. Structural DeckCuts, Fig. 10, are n

26、ot discussed in this guide since this detailmust be considered in relation to the size of the opening and itsproximity to primary structures.3.2 Evaluation of details shown in Figs. 14-28 is based onin-service experience as described in “Design Guide forStructural Details”.5Data for over 400 details

27、 is summarizedand rated in the figures by observed relative successfulperformance. Each of the ten families of details includeconfigurations with no signs of failures. The details withoutfailures within each family group are shown in descendingorder of numbers observed. Those details with failures a

28、reshown in ascending order of failures (percentage are indicatedfor each). Thus the first detail shown in each family group hasthe best observed service performance and is most highlyrecommended while the last has the highest failure rate andtherefore least desirable.3.3 These details, rated as indi

29、cated above, provide guid-ance in the selection of structural detail configurations in futuredesign and repair of such details.4. Failure Causes4.1 Failures in the details shown in Figs. 14-28 wereattributed to either one or a combination of five categories:design, fabrication, welding, maintenance,

30、 and operation.4.1.1 Design:4.1.1.1 Design failures generally resulted from the omissionof engineering principles and resulted in a buckled plate orflange; the formation of a crack in a plate, flange or web; or therupture of the bulkhead, deck or shell. Each of the families,with the exception of tig

31、ht collars, had detail failures attributedto design.4.1.1.2 Failures directly related to design in structural de-tails and supporting members were the result of being sizedwithout adequate consideration of applied forces and resultingdeflections.4.1.1.3 In the beam bracket configurations of family n

32、o. 1(Fig. 14), 20 % of the surveyed failures attributed to designwere caused by instability of the plate bracket edge or byinstability of the plate bracket panel. This elastic instability,which resulted from loads that produce critical compressive orshear stresses, or both, in unsupported panels of

33、plating, can beeliminated when properly considered in the design process.4.1.1.4 The failures of beam brackets by cracking occurredpredominately where face plates had been sniped, at thewelded connections, at the ends of the brackets, at cutouts inthe brackets, and where the brackets were not proper

34、ly backedup at hatch ends. The sniping of face plates on bracketsprevents good transition of stress flow, creates hard spots andproduces fatigue cracks due to the normally cyclic stresses ofthese members. Care must be taken to ensure proper transitionwith the addition of chocks, back-up structure, r

35、einforcementof hole cuts, and the elimination of notches.4.1.1.5 To reduce the potential for lamellar tearings andfatigue cracks in decks, bulkheads, and beams, transition5Jordan, C. R., and Krumpin, R. P., Jr., “Design Guide for Structural Details,”SSC 331, Ship Structure Committee Report , August

36、1990, available through theNational Technical Information Service, Springfield, VA 22161.FIG. 7 Panel Stiffeners (Family No. 12)FIG. 8 Stanchion Ends (Family No. 10)FIG. 9 Stiffener Ends (Family No. 11)FIG. 10 Structural Deck Cuts (Family No. 9)FIG. 11 Tight Collars (Family No. 4)FIG. 12 Tripping Br

37、ackets (Family No. 2)F 1455 92 (2007)3brackets should be made continuous through the plating orsupported by stiffeners rigid enough to transmit the loads.4.1.1.6 The greater number of failures in the trippingbracket configurations of family no. 2 (Fig. 18), occurred athatch side girders, particularl

38、y in containerships. This will be acontinuing problem unless the brackets are designed to carrythe large lateral loads due to rolling when containers arestacked two to four high on the hatches. The brackets must, inturn, be supported by properly designed backing structure totransmit the loads to the

39、 basic ship structure.4.1.1.7 Tripping brackets supported by panels of plating canbe potential problems depending on the plate thickness. Brack-ets landing on thick plating in relationship to its own thicknessmay either buckle in the panel of the bracket, produce fatiguecracks along the toe of the w

40、eld, or cause lamellar tearing inthe supporting plate. Brackets landing on plating with athickness equal to, or less than its own thickness, may causeeither fatigue cracks to develop or buckling of an unsupportedpanel of plating.4.1.1.8 The non-tight collar configurations of family no. 3(Fig. 21) ex

41、perienced only a few failures. There are consider-ations, however, that must be used by the designer to ensure thecontinuation of this trend. The cutouts should be provided withsmooth well rounded radii to reduce stress risers. Where collarsare cut in high stress areas, suitable replacement material

42、should be provided to eliminate the overstressing of theadjacent web plating. These considerations should reduce theincidents of plate buckling, fatigue cracking, and stress corro-sion observed in this family.4.1.1.9 For detail family no. 7, miscellaneous cutouts, (Fig.24), the reasons for failure w

43、ere as varied as the types ofcutouts. Potential problems can be eliminated by the designerif, during detail design, proper consideration is given to thefollowing:1) Use generous radii on all cuts.2) Use cuts of sufficient size to provide proper weldingclearances.3) Avoid locating holes in high tensi

44、le stress areas.4) Avoid square corners and sharp notches.5) Use adequate spacing between cuts.6) Properly reinforce cuts in highly stressed areas.7) Locate cuts on or as near the neutral axis as possible inbeam structures.8) Avoid cuts at the head or heel of a stanchion.9) Plug or reinforce structu

45、ral erection cuts when located inhighly stressed areas.4.1.1.10 The most damaging crack observed during thesurvey was in the upper box girder of a containership. Thisstructure is part of the longitudinal strength structure of theship in addition to being subjected to high local stresses due tothe co

46、ntainer loading in the upper deck. Openings in thisstructure must be located, reinforced, and analyzed for second-ary bending stresses caused by high shear loads.4.1.1.11 The clearance cutouts of family no. 8 (Fig. 20) arebasically non-tight collars without the addition of the collarplate. Suggestio

47、ns made for non-tight collars and miscella-neous cutouts are applicable for this family.4.1.1.12 Well rounded corners with radii equivalent to 25 %of the width perpendicular to the primary stress flows should beused. Special reinforcements in the form of tougher or higherstrength steel, inserts, coa

48、mings, and combinations of theabove should be used where fatigue and high stresses are aproblem.4.1.1.13 In general, failures in stanchion ends, family no. 10(Fig. 25), were cracks which developed in or at the connectionto the attachment structure. The addition of tension brackets,shear chocks, and

49、the elimination of snipes would reduce theincidents of structural failure. All stanchion end connectionsshould be capable of carrying the full load of the stanchion intension or compression. Stanchions used for container standsor to support such structure as deckhouses on the upper deckshould be attached to the deck with long tapered chocks toreduce stress flows from hull induced loads, and in no caseshould “V” notches be designed into such connections.4.1.1.14 The stiffener ends in family no. 11 (Fig. 27) withwebs or flanges sniped, or a combination of both