ASTM F1455-92(2007)
(Guide)Standard Guide for Selection of Structural Details for Ship Construction
Standard Guide for Selection of Structural Details for Ship Construction
ABSTRACT
This guide provides a recommended list of selected ship structure details for use in ship construction. Structural details which have failed in service and are not recommended for use in ship construction are included as well. This guide is intended to convey the lessons learned on different configurations of ship structure details, not the dimensions, thickness, or construction methods which would result from structural calculations. Details are shown for the ten families of structural details, which are: beam brackets, clearance cut-outs, gunwale connections, miscellaneous cut-outs, non-tight collars, panel stiffeners, stanchion ends, stiffener ends, tight collars, and tripping brackets. Evaluation of details is based on in-service experience as described in "Design Guide for Structural Details". Data for over 400 details is summarized and rated by observed relative successful performance. Each of the ten families of details includes configurations with no signs of failures. The details without failures within each family group are shown in descending order of numbers observed. Those details with failures are shown in ascending order of failures (percentages are indicated for each). Thus the first detail shown in each family group has the best observed service performance and is most highly recommended while the last has the highest failure rate and therefore least desirable. The details provide guidance in the selection of structural detail configurations in future design and repair of such details.
SCOPE
1.1 This guide provides a recommended list of selected ship structure details for use in ship construction.
1.2 Structural details which have failed in service and are not recommended for use in ship construction are included as well.
1.3 This guide is intended to convey the lessons learned on different configurations of ship structure details, not the dimensions, thickness, or construction methods which would result from structural calculations.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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An American National Standard
Designation:F1455–92 (Reapproved 2007)
Standard Guide for
Selection of Structural Details for Ship Construction
This standard is issued under the fixed designation F1455; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The principal aim of this guide is to depict recommended practices related to the design of ship
structural 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 hull girder.
3) Thetrendtowarddecreasingshiphullscantlings(thatis,increasingaveragehullstresses)hasthe
potential of increasing the damage to details.
4) Researchers have largely neglected the analysis of structural details at least in part because the
configuration and purpose of these details vary greatly and are not commonly described or discussed
in the literature.
Due to lack of analytical and experimental effort devoted to structural details, their determination
has been left up to draftsmen and designers, with very little engineering input.
2,3
In two comprehensive reviews of the performance of structural details, 86 ships were surveyed.
These included naval and commercial ship types. The commercial ships included both U.S. and
foreign built. The vessels ranged from 428 to 847 feet in length, from 18,000 to 90,000 tons in
displacement, and from five to twenty-six years in age. The details obtained were grouped into 12
typicalfamilies.KnifeEdgeCrossings(FamilyNo.6)andStructuralDeckCutoutDetails(FamilyNo.
9) are shown but not covered in detail in this guide. The remaining ten detail families were further
categorized into 53 groups comprising a total of 611 detail configurations. A number of these
configurations are very similar to others in detail geometry and such duplicates have been excluded
from this guide.Anumber of others were eliminated because of relatively infrequent observed use.As
a result, a total of 414 details are included herein. However, all 611 details can be found in “Structural
Details,” if desired.
In total, 607,584 details were observed with a total of 6,856 failures. Failures were attributed to one
or a combination of five categories: design, fabrication, welding, maintenance, and operation (see 4.1
through 4.1.5). This extensive, well documented research, together with engineering judgement,
provides the principal support for this guide.
1. Scope 1.2 Structural details which have failed in service and are
not recommended for use in ship construction are included as
1.1 This guide provides a recommended list of selected ship
well.
structure details for use in ship construction.
1.3 This guide is intended to convey the lessons learned on
different configurations of ship structure details, not the dimen-
sions, thickness, or construction methods which would result
This practice is under the jurisdiction of ASTM Committee F25 on Ships and
from structural calculations.
Marine Technology and is the direct responsibility of Subcommittee F25.01 on
Structures.
Current edition approved May 1, 2007. Published June 2007. Originally 2. Terminology
approved in 1992. Last previous edition approved in 2001 as F1455 - 92(2001).
2.1 Definitions of Terms Specific to This Standard:
DOI: 10.1520/F1455-92R07.
2.1.1 Terms:
Jordan, C. R., and Cochran, C. S., “In-service Performance of Structural
Details,” SSC-272, Ship Structure Committee Report, March 1977, available
through the National Technical Information Service, Springfield, VA 22161.
Jordan, C. R., and Knight, L. T., “Further Survey of In-service Performance of
Structural Details,” SSC-294, Ship Structure Committee Report, May 1979, avail- Jordan, C. R., and Krumpen, P., Jr., “Structural Details,” American Welding
able through the National Technical Information Service, Springfield, VA 22161. Society Welding Journal, Vol 63, No. 1, January 1984.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F1455–92 (2007)
2.1.2 beam bracket—a bracket at the end of framing or
stiffening members that is used for increased strength, conti-
nuity and end constraint.
2.1.2.1 Discussion—see Fig. 1.
2.1.3 clearance cut-outs—a hole or opening in a pierced
member to allow passage of a piercing member.
2.1.3.1 Discussion—see Fig. 2.
2.1.4 gunwale connection—the connection of the sheer FIG. 2 Clearance Cut-outs (Family No. 8)
strake to the stringer strake of the uppermost deck of the hull.
2.1.4.1 Discussion—see Fig. 3.
2.1.5 knife edge crossing—the projected point intersection
of members (plate members, stiffeners or bulkheads) on
opposite sides of an intervening plate member.An undesirable
condition to be avoided.
2.1.5.1 Discussion—Included for information only, see 3.1.
2.1.5.2 Discussion—see Fig. 4.
2.1.6 miscellaneous cut-out—small holes or openings of a
FIG. 3 Gunwale Connections (Family No. 5)
variety of sizes and shapes used for access, drainage, ease of
fabrication, stress relief, and so forth.
2.1.6.1 Discussion—see Fig. 5.
2.1.7 non-tight collar—a fitting at the cut-outs in way of the
intersection of two continuous members that provides lateral
support for the piercing member which does not fully fill the
cut-out area of the pierced member. May be a lug.
2.1.7.1 Discussion—see Fig. 6.
2.1.8 panel stiffeners—intercostal, non-load-carrying mem-
FIG. 4 Knife Edge Crossing (Family No. 6)
bers used to reduce the size of plate panels.
2.1.8.1 Discussion—see Fig. 7.
2.1.9 stanchion ends—structuralfittingsattheends(topand
bottom) of a stanchion to transfer loads from the supported
member to the supporting member.
2.1.9.1 Discussion—see Fig. 8.
2.1.10 stiffener ends—the configuration of the end of an
unbracketed, non-continuous stiffener.
FIG. 5 Miscellaneous Cut-outs (Family No. 7)
2.1.10.1 Discussion—see Fig. 9.
2.1.11 structural deck cuts—allow passage through decks
for access, tank cleaning, piping, cable, and so forth.
2.1.11.1 Discussion—Included for information only, see
3.1.
2.1.11.2 Discussion—see Fig. 10.
2.1.12 tight collar—aspernon-tightcollarbutthecut-outin
the pierced member is fully filled and is air-, oil-, or watertight
as required. Tight collars may be lapped or flush fitted.
2.1.12.1 Discussion—see Fig. 11.
2.1.13 tripping bracket—a bracket or chock that provides
FIG. 6 Non-Tight Collars (Family No. 3)
lateral support to framing and stiffening members. Support
may be provided to either the web or the flange, or to both.
2.2 Symbols:Symbols:
2.1.13.1 Discussion—see Fig. 12.
2.2.1 Symbols are as indicated in Fig. 13. The detail
identification symbol (Fig. 13, 1-J-1 for example) is the same
as that assigned in the original research reports and is retained
throughout for all details for ease in referring back to the
reports if desired.
3. Summary of Guide
3.1 In this guide, details are shown for the ten families of
structural details identified above and as shown in Fig. 1–3,
5–9, 11 and 12. Knife Edge Crossings, Fig. 4, are not discussed
FIG. 1 Beam Brackets (Family No. 1) further in this guide since none were observed in the research
F1455–92 (2007)
FIG. 7 Panel Stiffeners (Family No. 12)
FIG. 12 Tripping Brackets (Family No. 2)
and rated in the figures by observed relative successful
performance. Each of the ten families of details include
configurations with no signs of failures. The details without
FIG. 8 Stanchion Ends (Family No. 10)
failures within each family group are shown in descending
order of numbers observed. Those details with failures are
shown in ascending order of failures (percentage are indicated
for each). Thus the first detail shown in each family group has
the best observed service performance and is most highly
recommended while the last has the highest failure rate and
therefore least desirable.
3.3 These details, rated as indicated above, provide guid-
anceintheselectionofstructuraldetailconfigurationsinfuture
design and repair of such details.
FIG. 9 Stiffener Ends (Family No. 11)
4. Failure Causes
4.1 Failures in the details shown in Figs. 14-28 were
attributed to either one or a combination of five categories:
design, fabrication, welding, maintenance, and operation.
4.1.1 Design:
4.1.1.1 Design failures generally resulted from the omission
of engineering principles and resulted in a buckled plate or
flange; the formation of a crack in a plate, flange or web; or the
rupture of the bulkhead, deck or shell. Each of the families,
with the exception of tight collars, had detail failures attributed
to design.
FIG. 10 Structural Deck Cuts (Family No. 9)
4.1.1.2 Failures directly related to design in structural de-
tails and supporting members were the result of being sized
without adequate consideration of applied forces and resulting
deflections.
4.1.1.3 In the beam bracket configurations of family no. 1
(Fig. 14), 20 % of the surveyed failures attributed to design
were caused by instability of the plate bracket edge or by
instability of the plate bracket panel. This elastic instability,
which resulted from loads that produce critical compressive or
FIG. 11 Tight Collars (Family No. 4)
shear stresses, or both, in unsupported panels of plating, can be
eliminated when properly considered in the design process.
and fortunately so. This detail represents very undesirable
4.1.1.4 The failures of beam brackets by cracking occurred
structural conditions and is to be avoided. Structural Deck
predominately where face plates had been sniped, at the
Cuts, Fig. 10, are not discussed in this guide since this detail
welded connections, at the ends of the brackets, at cutouts in
must be considered in relation to the size of the opening and its
the brackets, and where the brackets were not properly backed
proximity to primary structures.
up at hatch ends. The sniping of face plates on brackets
3.2 Evaluation of details shown in Figs. 14-28 is based on
prevents good transition of stress flow, creates hard spots and
in-service experience as described in “Design Guide for
produces fatigue cracks due to the normally cyclic stresses of
Structural Details”. Data for over 400 details is summarized
these members. Care must be taken to ensure proper transition
with the addition of chocks, back-up structure, reinforcement
of hole cuts, and the elimination of notches.
Jordan, C. R., and Krumpin, R. P., Jr., “Design Guide for Structural Details,”
4.1.1.5 To reduce the potential for lamellar tearings and
SSC 331, Ship Structure Committee Report , August 1990, available through the
National Technical Information Service, Springfield, VA 22161. fatigue cracks in decks, bulkheads, and beams, transition
F1455–92 (2007)
FIG. 13 Symbols
brackets should be made continuous through the plating or 6) Properly reinforce cuts in highly stressed areas.
supported by stiffeners rigid enough to transmit the loads. 7) Locate cuts on or as near the neutral axis as possible in
4.1.1.6 The greater number of failures in the tripping beam structures.
bracket configurations of family no. 2 (Fig. 18), occurred at 8) Avoid cuts at the head or heel of a stanchion.
hatch side girders, particularly in containerships.This will be a 9) Plug or reinforce structural erection cuts when located in
continuing problem unless the brackets are designed to carry highly stressed areas.
the large lateral loads due to rolling when containers are 4.1.1.10 The most damaging crack observed during the
stacked two to four high on the hatches. The brackets must, in survey was in the upper box girder of a containership. This
turn, be supported by properly designed backing structure to structure is part of the longitudinal strength structure of the
transmit the loads to the basic ship structure. ship in addition to being subjected to high local stresses due to
4.1.1.7 Tripping brackets supported by panels of plating can the container loading in the upper deck. Openings in this
be potential problems depending on the plate thickness. Brack- structure must be located, reinforced, and analyzed for second-
ets landing on thick plating in relationship to its own thickness ary bending stresses caused by high shear loads.
may either buckle in the panel of the bracket, produce fatigue 4.1.1.11 The clearance cutouts of family no. 8 (Fig. 20) are
cracks along the toe of the weld, or cause lamellar tearing in basically non-tight collars without the addition of the collar
the supporting plate. Brackets landing on plating with a plate. Suggestions made for non-tight collars and miscella-
thickness equal to, or less than its own thickness, may cause neous cutouts are applicable for this family.
either fatigue cracks to develop or buckling of an unsupported 4.1.1.12 Well rounded corners with radii equivalent to 25 %
panel of plating. ofthewidthperpendiculartotheprimarystressflowsshouldbe
4.1.1.8 The non-tight collar configurations of family no. 3 used. Special reinforcements in the form of tougher or higher
(Fig. 21) experienced only a few failures. There are consider- strength steel, inserts, coamings, and combinations of the
ations,however,thatmustbeusedbythedesignertoensurethe above should be used where fatigue and high stresses are a
continuation of this trend.The cutouts should be provided with problem.
smoothwellroundedradiitoreducestressrisers.Wherecollars 4.1.1.13 In general, failures in stanchion ends, family no. 10
are cut in high stress areas, suitable replacement material (Fig. 25), were cracks which developed in or at the connection
should be provided to eliminate the overstressing of the to the attachment structure. The addition of tension brackets,
adjacent web plating. These considerations should reduce the shear chocks, and the elimination of snipes would reduce the
incidents of plate buckling, fatigue cracking, and stress corro- incidents of structural failure. All stanchion end connections
sion observed in this family. should be capable of carrying the full load of the stanchion in
4.1.1.9 For detail family no. 7, miscellaneous cutouts, (Fig. tension or compression. Stanchions used for container stands
24), the reasons for failure were as varied as the types of or to support such structure as deckhouses on the upper deck
cutouts. Potential problems can be eliminated by the designer should be attached to the deck with long tapered
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