z:i~a ~ 1a o s' :ngineering studies o
TRANSCRIPT
· - -- --.-- -. - ------ .
z:i~A ~ 1A o s-S' :NGINEERING STUDIES
o :TURAL RESEARCH SERIES NO. 55
Copy l----
J" -.,~ ~EFFECT OF ~EARING PRESSURE ON.
l.!!ATlC STRENGTH OF ~VETED JOINTS. ·~-Y·r:Rii-t=1Z. ~R/V;;;.-rbD + GOL TED STRUCTL(K/lL ~o/rvE
By
--~ and 1Mi---____ . >.~_.UNSE
UNIVERSITY OF ILLINOIS
URBANA, ILLINOIS
THE EFFECT OF BEARING PRESSURE ON THE STATIC
STRENGTH OF RIVETED JOINTS
by
R. C. Bergendoff'
and
Wo H~ Mmse
A Progress Report of an Investigation Conducted by
THE UNIVERSITY OF ILLINOIS ENGINEERING EXPERIMENT STATION
in cooperation with
The Research Council on Riveted and Bolted structural Joints~
The Illinois Division of Highways9
and
Bureau of Public Roads
PROJECT I
University of Illinois Urbana 9 Illinois
Jl.Ule9 195.3
T}~ EFFECT OF BEARING PRESSURE ON THE STATIC
STRENGTH OF RIVETED JOINTS
CONTENTS
I. INTRODTIC TI ON
1 Object and Scope of Investigation
2 Acknowledgements
II. SPECIMENS AND TESTS
3 Descriptions of Specimens
4 Properties of Plate Materials
5 Method of Testing
III. RESULTS OF TESTS
6 Tension Tests
7 Compression Tests
8 stress~lip Relations
IVo DISCUSSION OF TEST RESULTS
9 Difference in Efficiencies of Specimens from Two Fabricators
10 Effect of Geometry of Specimens
11 Effect of Bearing Pressure on Strength of Riveted Joints in Tension
12 Effect of Bearing Pressure on Strength of Riveted Joint,s in Compression
Vo SUMMARY
13 Results of Tests
14 Conclusions
VI. BIBLIOGRAPHY
Page
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9
II
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19
20
LIST OF TABLES
Table
10 Dimensions of 5l=Series Static Test Specimens
20 Summary of Mechanical Properties of Plate Naterial CQ
Tension Specimens
.3 Q Summary of Hechanical Properties of Plate Material -Compression Specimens
40 Summary of Test Results ~ Tension Specimens
50 Symmary of Test Results .., Compression Specimens
21
22
2.3
24 ... 25
26
LIsrr OF FIGURES
Fig. NOa
10 Details of 51=Series Static Test Specimens
la Tension Specimens
Ib Compression Specimens
20 600~000 Ib .. Testing IV18chine
3. 300,000 Ib., Testing Nacbine
40 Tension Specimen ~Qth Slip Gage.s
5~ Compression Specimen with Slip Gages;
6 0 Location of Fractures, Specimens 51=1
7. Location of Fractures 9 Specimens 51=2
80 Location of Fractl1res 9 Specimens 51=3
90 Location "...,p vJ. Fractures 9 Specimens 51=4
10 0 Location of Fract.ures 9 Specimens 51=5
11. Location of Fra~turesSl Specimens 51~
12. Location of Fractures 9 Specimens 50=X6
13. Location of FractUJ':'8['; 9 Spec;imens 5~X7
14 .. L-ocation of Failures~ Specimens 51=79 8 9 9
15. Location of Failures, Specimens 51-=10 9 119 12
160 Stress-Slip Curves ,." lor Specimens 51=19 29 39 and 4
170 stress=-Slip C-t.U"ves for Specimens 51=6 9 7 and 5D=X6 9 rI
18. stress-Slip CUT.'Ves for Specim.ens 51=7 thru 51=12
19. Variation of Effi~iency of 51coS.eries Tension Specimens
200 Bearing Ratio VSo Relative Gage
210 Variation of Efficienc.y wi.th Bearing B.atio
220 Variation of Effioiency 'With Relative Gage
LIST OF FIGURES (Continued)
230 Variation of Ultimate Net Section stress with Bearing Ratio
240 Variation of Net Section Efficiency with Bearing Ratio
250 Variatio~ of Gross Section Yield and Ultimate Compressive stress with Bearing~hear stress Ratio
260 Variation of Yield Point Efficiency 11ith Bearing=Shear stress Ratio, Compression Tests
27 0 Variation of TIl tiruate Strength-Yield Strength Ratio with Bearing~hear stress Ratio 9 Compression Tests
THE EFFECT OF BEARING PRESSURE eN THE ST [!oTIC ST}ENGTH
OF RIVETED JOINTS
10 INTRODUCTION
10 Object and Scope of Investigation
The purpose of this investigation is to study the effect of bearing
pressure on the static strength of riveted joints. Although presen.t American
specifications limit the ratio of bearing stress to tensile stress, the value
of the limit is not the same in all specifications. The AISC specifications,
with a base tensile stress of 20,000 psi, while permitting a ratio of 260
for rivets in double shear 9 limits the ratio to 1.6 for rivets in single
shearo Both the AREA and the AASHO specifications, based on an 18,000 psi
tensile stress, limit the bearing-tension stress ratio to 1.5 for rivets in
either single or double shear.
To determine the effect of bearing pressure on the static strength
of riveted joints9 the Project I Committee of the Research Council on TIiveted
and Bolted Joints planned several experimental programso Previously reported
tests of this project include a series of exploratory tests in which such
variables as rivet grip, plate thickness, and transverse rivet spacing were
studiEd under both static and fatigue loadings~l)* a program of static ten-
sion tests of double strap butt-type joints designed to fail in the inner
plate~2) and a program of static tension tests of double strap butt-type
joints designed to fail in the outer Platesi3)
The purpose of the tests reported herein "las to obtain further
* The !1U.Bbers in parentheses refer to the Bibliography li::ltings.
2
information concerning the effect of high rivet bearing pressures on the
strength and behavior of double strap butt tYF€ joints tested in stetic
tension and compression at room temperature~ and to answer the questions
1-Thich have developed from the data of the previous testso
3
2& Acknowledgements
The experimental investigation described in this !eport is a part
of the l.Jork covered by a cooperative agreement between the Etgineering Ex-
periment Station of the University of Illinois and~ the Illin:ds Division of
P~ghways, the Bureau of Fublie Roads 9 and the Research Council on Riveted and
Bolted Structural Joints. This work is a part of the structural research pro-
gram of the Department of Civil Engineering under the general lirection of
N. Mo Newmark, Research Professor of structural Engineeringo i='he work was
performed by R. Co Bergendoff; Research Assistant in Civil Engi1eering, under
the immediate supervision of Wo Ho Munse9 Research Associate Prcfessor of
Civil Engineering, W. S. Beam, Research Assistant in Civil Engineering,
assisted in the performance of the tests and in the preparation of this
report 0
The specimens and scope of the program were planned by the froject
I Committee of the Research Council on Riveted and Bolted structural Jointso
This committee is concerned '-lith the effect of bearing pressure on the f:tatic
and fatigue strength of riveted jointso The members of the Project I Cmn-
mittee are:
Jonathan Jones~ Chairman Bethelehm Steel Company
Raymond Archibald Bureau of Fublic Roads
Frank Baron Northwestern University
Co Neufeld Canadian Pacific Railroad
11. H. Ivlunse University of Illinois
No No Newmark University of Illinois
To Co Shedd University of Illinois
Wo Mo Wilson University of Illinois
Lo To Wyly Purdue University
4
II. SPEC INENS .AND TESTS
~ Description of Specimens
The tests of sixty-six riveted specimens 'Were included in this in=
vestigatioD; forty-eight were double strap butt type joints tested in tension
and eighteen were double strap butt type joints tested in compressiono The
tension specimens consisted of eight joint designso Each design was furnished
in triplicate by two fabricators, hereafter designated as fabricator A and
fabricator B. The compression specimens9 six designs, were obtained in tripli
cate from fabricator B. The details and dimensions of the joints are given in
Table 1 and Fig. 1.
The tension specimens were of rectangular rivet pattern with the
edge distance one half the interior spacingo End distances caried from 1=5/8
to .3-1/4 ino as required by the AISC nSpecifications for the Design9 Fabric..
cation and Erection of Structural Steel Bui1dingsll9 Section 2.3fo
The bearing ratio, the ratio of bearing stress to tensile stress for
the tension specimens and the ratio of bearing stress to shear stress for the
compression specimens9 varied from 1.45 to 2074 for the tension specimens and
from 1088 to 4071 for the compression specimenso To provide this variation,
the tension specimen 1Iddths varied from 8t'22 to 15072 ino The tension speci.".
men center plate thicknesses varied from 7/16 to 13/16 ino for the specimens
failing in the center plate 0 The side plate thicknesses were 1/4 and 3/16 ino
for the specimens f ailing in the side plate 0 The change in bearing pressUre
for the compression specimens was made by varying the failure plate thickness
from 3/16 to 5/8 ine
The methods of fabrication Qy the two fabricators differed onlY
slightlyQ Both fabricators specified hot manufactured and pneumatic driven
rivets and finished plate edgeso Fabricator A specified 1/4 ino subpuncbing
5
and reaming as the method of hole preparation while fabricator B subpunched
the holes 3/16 ino and reamedo
Rivet sizes of 3/4 and 1 ino i-Jere included in these specimens so
that the effect of rivet size on static strength under high bearing pressure
could be studied alsoo
l. 0 Properties of Plate l1aterials
The specimens were fabricated from plates specified to be ASTN ...4..=7
structural grade steelo Laboratory tests of standard flat coupons cut from
the parent plates of the specimen material were made to determine the mech
anical properties of the steel in tension.. A minimum of two coupons were
tested from coupon material provided in th each set of specimens"
The dimensions of the tension coupons and details of the testing
procedure conformed with ASTM Designation E8-52 for "Tension Testing of
Metallic Naterials n • The coupons had an overall length of 20 in .. with a
centered gage length of 8 in .. and a standard gage-section ~ddth of 1-1/2 ino
The coupons were tested in a 120,000 lbo Baldwin-Southwark hydraulic universal
testing machineo
The tension coupon test results~ summarized in Tables 2 and 3, list
average values for yield point, ultimate strength, percent reduction of area,
and percent elongation in 8 in. The properties of the coupons for each
parent plate thickness are reasonably consistant~ though the material for
51-lA and 51-4A failed to meet ASTH requirements for yield point.. The
deviation, however, was small.
Compression coupons were cut from the coupon plate material sup
plied with the compression specimens~ Three coupons of square cross-section
were tested for each specimen designo The size of the coupons was governed
6
by the tb-i ckness of the materiale The sides of the square cross-sect.ior.\ were
equal to the plate thickness It Tl-:e length vlas three times this dimensiono
These coupons were tested in a 120,000 lb. Baldwin-Southwark hydraulic uni
vers21 testing machine to deterrrane yield point only. The results of these
tests are included in Table 30
5'0 ~!lethod of Testing
The testing proced1.u:-e was kept as uniform and consister.:.t as poss
ible throughout the entire programe
End plates \.-Jere butt :.jelded to the ends of the tension specimens"
Centric loading was assured by careful al~gnment of the specimen and these
end plateso This assembly ~{as then bolted to the pull heads i-[bieh had been
placed in the 600,000 lb~ rtieble screw type testing machine shown in Figo 20
Before the bolts in the pttil heads were tightened, a small load was applied
to the specimen. S~nce a pin connection exists in each of the pull heads 9
any initial eccentricity is reduced upon the application of this small load o
The test load Has applied to the specimen at a rate of 0.05 in. per minuteo
The loading was continuous throughout the test.
For the compression tests a loading block was clamped on the end
of those thin side or center plates which needed stiffening to prevent local
hu.ckling 0 The specimens '.;e:re then tested in the 300,000 Riehle screw type
testing machine shov.Jr.] in Ylg. 3. The ultimate strength of several specimens
exceeded the capacity of tr~s mac~ine and were tested in a 3,0009 000 Ibo
S.outhHark-Emery hydrau~ic ~,8chine. The load for the compression tests was
applied at a rate of 0.05 in. per minute and the machine was stopped mome~t
arily 2t each load increment to permit the taking of slip gage readingso
Slip bet1.Jeen the center and side plates at the first transverse rOvl
7
of rivets of each tension specimen was measured by means of mechanical dial
gageso Readings were taken at equal load increments until the load was just
short of its maximum valueo The gages were attached to the center plates of
the tension members by means of a lug soldered to the edge of the plateo The
plunger of the gage rested on the machined head of a bolt in the horizontal
shelf of a U-shaped yoke attached to the side plates by pointed screwse This
arrangement is shown in Figo 40
The slip measurements on the compression specimens were obtained Qy
mechanical dial gages mounted on Y-shaped brackets positioned by pointed
screws and held in place ty a spring arrangemento The gage plunger rested
on a pin driven through the center plate midway between the rivets at the
center rOWe Small slots were cut in the side plate to allow movement of
the pin. This dial arrangement and the loading blocks for the compression
tests are shown in Fig. 50
8
III RESu~TS OF TESTS
~ Tension Tests
The tension test results are tabulated in Table 4 0 The data pre-
sented includes values of ultimate strengthg ultimate plate tensile 9 rivet
shearing, and bearing stresses~ the tension-bearing area ratio~ reduction
of area of the net section~ and values of theoretical and test efficiencieso
In accordance with the general policy of the Research COUl1cil, the
net areas were computed on the basis of the actual hole size and the measured
dimensions of the specimense Reduction of area was obtained by measurement
of the reduced section after failuree Theoretical efficiencies were computed
from the ratio of net area to gross area and by the relative gage met.hod
proposed recently~4) The test efficiency is a ratio of the maximum test load
to the coupon strength times the gross area of the specimeno
Specimen failures were predo~nently plate tensile failures al-
though four specimens failed by rivet shear~ seven failed by a combination
of rivet shear and plate tension, and three specimens failed qy tearing of
the side plates at the rivets accompanied by bending of the plates over the
rivet headso The failure section of each of the tension specimens is shown
in Figso 6 through 130
Eighteen of the forty-eight tension specimens had ultimate strengths
based on the net section of less than 60 9 000 psi, the stresses ranged from
50,670 to 70,700 psi. Three of these eighteen were the joints which failed
by tearing and bending of the plates, three were shear failures and nine were
fabricated from the materials having the lowest coupon strengthso
Reduction of area of the coupons ranged from 28 to 52 percent~ the
average about 48 percent; the reduction of area of the specimens ranged from
15 to 35 percent, the average about 23 percento
~ Compression Tests
The results of the compression tests are tabulated in Table 50
Included in the data are values of ultimate plate compressive stress, rivet
shear stress, and bearing stress, the ratio of rivet bearing to shear stress9
and the yield strengthe
Failure occured by buckling of either the center or sia8 plates in
fourteen of the eighteen tests, by rivet shear in one case at a ve~y high load
relative to the load on duplicate specimens. ~~ximum deflection allowed qy
the specimen dimensions forced the termination of testing of the remaining
three specimens although the maximum load carrying capacity had not been
reached 0 The specimens at failure are shovm in Figs. 14 and 15; a close-up
o£ a typical failure is given on the right for each specimen designe Several
of the specimens were loaded until rivet shear took place after initial fail-
ure had occured by buckling.
8. stress-Slip Relations
Slip measurements were made on each tension specimen at the first
transverse row of rivets and at the center row of rivets of the compression
specimens. The stress-slip diagrams of Figs. 16, 17, and l8 s are plotted
from average values of the slip readings at the two edges of the tension
specimens and of the slip readings on opposite sides of the compression
speClmenso
The difference in the two measurements of slip was generally quite
small in the early stages of the tests although the difference was about 0 0 05
in. at maximum load for most specimens and as high as 0010 inQ in several caseso
It should be noted that these "slip" curves do not represent mere~
10
the slip between the side and center plates of the jointo Elastic and plastic
deformations of the plates and distortions of the rivets are also inherent in
the measurementso
The agreement of the stress-slip curves for duplicate joints of the
same tension specimen, (Figso 16 and 17) is slightly better for the specimens
from fabricator A than for those from fabricator B although the curves for
the specimens from fabricator B are nearly always above those of the specimens
from fabricator A. In genera1 9 the curves are typical for riveted tension
joints and the agreement among the curves is reasonably goode
The stress-slip curves for the compression specimens are given in
Figo 18. The agreement for duplicates of the specimens failing in the center
plate (upper diagrams) is very good except for specimen 5l-9~3 which has a
considerably higher stress at slip than its duplicateso The agreement among
the curves for the side-plate-failure specimens (lower dia~ams) is good for
the first slip stress although the spread becomes large near failureo
11
~ Differences in Efficiencies of Specimens from rwo Fabricators
The efficiency of each specimen tested is plotted in Fig. 19. The
open bars represent the specimens from fabricator B and the shaded bars, the
specimens from fabricator Ao
The maximum spread in efficiencies of duplicate specimens of fab
ricator A is 10.0 percent and the average spread, 501 percent. The maximum
spread in efficiencies of duplicate specimens of fabricator B is 10.4 per
cent and the average spread is 6e2 percento Considering duplicate specimens
without regard to fabricator 9 the maximum difference of efficiency is 14.3
percent and the average difference 902 percento
10. Effect of Geometry of Specimens
In order that a particular variable in the design of a joint may be
studied, it is desirable that all other variables be held constant as the
element being studies is variedQ Unfortunately~ in riveted joints, it is
usually impossible to isolate the element to be studied or to vary it along
with some other element or elements whose effects have been, or can be de
termined. Such is the case in a study of bearing pressure. The controlling
variables in such a study are plate width and thickness, and rivet size,
length, and number. From these variables arise the additional factors of gage,
pitch, number of longitudinal lines of rivets, and number of transverse rows
of rivets.
In the present program, these variables have been reduced to plate
width and thickness, rivet size, length, and number, gage, and number of
transverse rows of rivetso The thickness of the plate has been found to have
no effect on joint efficiency while the ratio of gage (a measure of plate
12
width) to rivet size has been found to affect joint efficiency; the efficiency
rises ~rlth increasing values of this ratio up to about 5e25~4) Therefore,
plate w~dth, rivet size, and gage can be grouped together to shoy theif effect
on static strength. The remaining two elements, number of rivets and number
of rows, can be reduced to just the latter upon consideration of the fact
that the number of rivets depends not only on the number of transverse rows
but also on the number of longitudinal lines. The number of longitudinal
lines has been found to have no effect~4) The important variables, then,
appear to be the ratio of gage to rivet hole diameter, (hereafter called
relative gage or G/D), bearing ratio, and the number of transverse rows.
Figure 20 is a plot showing the relationship of these three vari-
ablesQ This plot, assuming the rivet diameter equals the hole diameter,
shows that for any given rivet pattern the bearing ratio varies linearly
~th G/D but that the linear variation is different for each rivet pattern.
Variations for rectangular patterns with different numbers of rows are
noted; non-rectangular patterns will vary in the same general manner.
Present specifications express the efficiency of rectangular pattern
joints by the ratio of net section to gross section, or, the quantity G;D •
Schutz(4) found that the efficiency of a joint is a function of the qU8ntity
G/D. Then, since the bearing ratio is a function of G/D, efficiency may be
some function of bearing ratio.
Schutz(4) found that the value of G/D, above which no increase in
efficiency is realized, is approximately 5.25, his tests being made at bear-
ing ratios less than 2.0. He reasoned also that there is no effect of bear~
ing pressure of values of bearing ratio less than 2.0.
13
Figure 20 indicates that a difference in spacing, (G/D)9 is poss-
ible at any bearing ratioo However, to obtain SUCh-8 difference it would be
necessary to add additional rows of rivets. Tests have not been run at b~gh
bearing ratios with la~ge spacing differences nor have many tests been con~ JI.'
ducted on one row joints in which the variation of the relative gage can be
held to a minimum as the bearing ratio is varied.
The questions, then, raised by Fig. 20 are (1) what are the effects
of G/n and B on one, two, and possibly, three row joints? and (2) can these
effects!be separated or expressed in terms of one of the variables? The
bearing pressure of joints with more rows than three will not be high enough
to be of consequence without very wide rivet spacing.
The results of the tests in this series cannot satisfactorily
answer these questions for the geometry of the series is such that the pro=
tion of the graph that is covered is very linuted. The effect of G/D may
be a very critical factor in these tests and, consequently, cover any effects
of bearing pressure. This may not be the case in other portions of the graph.
~ Effect of Bearing Pressure on strength of Riveted Joints in Tension
A direct comparison of the bearing ratio with the joint efficiency
for the 51-series of tension tests, Fig. 21, suggests a relationship although
it 16 not olearly defined. Such a plot, however, may not provide a true com~
parison of the two row joints with the one row joints because of the differ
ence in the relation of B to a(D as indioated b.1 Fig. 20.
A oomparison of effioienoy with GID for these teste, Fig. 22, pro-
duces a more definite trend. The test results fall along a ourve which is
of the same shape as that proposed by Schutz (4) and lie very close to his
"punched hole curve". However, the hole preparation of the 51-series is
such that it would generallY be considered equivalent to drilled holeso It
should be noted that the efficiencies can be expressed as a function of G/D
without regard to bearing pressure in nearly all of the region covered by these
tests 0 Apparently 9 the effect of bearing pressure 9 if any9 is either over~
sh~dowed by the effect of G/D or covered by experimental scattero
The average efficiencies deviate froD the puncb£d=hole curve of Figo
22 in three cases. The first is by the three specimens qy fabricator A at the
relative gage of 3~56. These specimens9 5D-X79 had a bearing ratio of 20740
The efficiencies of these three specimens are 10 percent under the duplicates
supplied by fabricator Eo This difference might be explained in part by a
difference in the bending properties of the plate materialo Bend t~sts were
run on coupons cut from the specimens after failureo Quanitatively~ the re=
sults of these tests have little meaning for no criterion for bending proper=
ties is recognized by ASTM for material less than 1/4 ino in tbicknesso How
ever 9 a difference in results from this method of measuring ductility did
exist 0 The material from the low efficiency specimens showed less ductility
than the otherso Neither hardness tests on the rivet and plate material of
the two groups nor thorough inspection of the specimens produced any addition
al significant information which wOD~d explain the difference in efficiencies~
Eowever 9 other factors 9 such as driving conditions and fabrication procedures,
may also effect the joint action observed and be responsible for the resul~
ing decrease in efficien~o
The specimens of the second group deviating from the general curve 9
specimens 51~49 had a relative gage of 3e71 and a bearing ratio of 10450 These
three specimens, prepared by fabricator B9 failed qy rivet shear. To determine
a difference in the rivet material, Rockwell hardness tests were made on the
rivet shanks 9 rivet stock not being available for more complete informationo
15
The rivets 1·.rr-ach sheared had a b.o.u-'c~~'Jes8 cf 7705, Rock~.Je11 B~ and the others
a hardness of 84, Rocki,.Jell Bo ~-n'}ile tras variation does not 3ppear to be
large enough, in itself, to explain the shear failure~ it d06£ suggest the
reascn for the differences in failure typeso
The tlnrd group deviating from the curve had the largest relative
g2ge~ specimens 51-60 The agreement among thes2 six sp8c~~ens is excellent
but the group as a irJhole deviates 11 p2rCel1-c. from the pilllched-hole efficiency
curve., The effect of r.cigh bearing, in this case 20099 on the joint efficiency
in this region of high relative gage, 4093, may begin to be important. Up
t.o this point, high bearing (maximurn. 2.,74) in these tests, has had little
effect upon efficiencyo The deviation at this point may indicate the !Thigh
bearing effect zone l! • Ho-vrever, the reported tests are too fEW in number to
verify any such theory concerning this regiono
Since the designer may be more concerned with net sEction stress
thaD efficiencY1 Figo 23 is presented to give the variation of ultimate net
section stress "Ii th the bearing ratio" The same trend is exhibited in tills
graph as was found in the 50-series of tests: the ultimate net section stress
decreases somewhat with bearing ratioo
In Fig., 24 the net section efficiency is compared with the bearing
retio and reduces the test points of Fig. 23 to a common basis by taking
into aCcolh~t the strength of the plate materialo In Figo 2ly , as in Fig. 239
the strength of the net section decreases slightly witn an increase in the
bearing ratio o
12~ Effect oi' Bearing Fressure on strength of ill. veted Joints in Compression
The limiting value of the besring-shear stress ratio allowed by the
f ... ISC specifications is 2.66; the limit allowed b">J the lhttEA specifications is 2.0.
16
This ratio '\.Jas varied from 1888 to 4.71 for the compression specimens in the
51-series of tests.
The variation of yield and ultimate compressive stress on the gross
section with the bearing-shear stress ratio is given in Fig. 25~ The yield
point of the joints is unaffected by the bearing-shear ratio and the curves
for center-and-side-plate-critical specimens nearly coincidee At ultimate
load, though, the curves do not coincide and they do indicate an effect of
the bearing-shear ratio. The side-plate-critical curve drops lower than the
center-plate-critical curve. This is not unexpected because of the side plate
restraint in the center-plate-critical joints. Both curves indicate an effect
of the high bearing since the gross section stress decreases as the bearing~
shear ratio increases. However, this might be expected since the specimens
with the higher bearing ratios have thinner plates and as a result are sub
ject to buckling at a l01ver level of stress &
The compressive stress at yield is expressed in a slightly differ
ent way in Fig. 26. In this figure the yield point efficiency, load at
yield divided by the computed yield loa~is plotted against the bearing=
shear ratio. The lower set of curves is based on the gross section and in~
dicates a yield point efficiency of about 60 to 70 percent. The test results
~~11 in a fairly ~de scatter band and consequently it cannot be said that
the average curves indicate a trend o
Since the net section may be related to the yield load of compression
specimens, the upper curves of Fig& 26 are plotted on the basis of the net
section. It should be noted that no specimen reached its full yield strength.
This may be due to the fact that the slip measurements were taken between the
rivets in the middle rmv- where local yielding at the fasteners may be record
ed, rather than general yielding. ~uring testing9 dro~f~the-beam did not
17
occur to indicate yielding of the specimenso General yield was suggested on
some specimens by scaling of the ITill scale, sinular to Luder lines 9 usually
at a load of 20 to 30 kips above the yield load recorded by the slip dialso
The local yielding recorded may be the result of the high rivet bearing or
of yield of the rivet material in addition to the local yielding of the
plate material"
Figure 27 presents essentially the same ir£ormation as the upper
curves of Figo 25 but in a slightly different mannero Maximum load divided
by test yield load is plotted against the bearing-shear ratioo The curves
show an influence of high bearing, in much the same manner as Figo 25~ In
order to obtain the high bearing-shear ratios of this series 9 it 'was necessary
to vary the plate thickness" Since a thin plate is more susceptible to
buckling than a thick one, the decrease in strength with increasing bearing~
shear ratio suggested by these tests~ then~ is a result of the buckling
characteristics of the plates8
18
V SUHHARY
1..:b. Results of Tests
The significant results of the 51-series of tests may be summar~
ized as follows~
(1) Agreement among the three companion tension specimens from
one fabricator was only fair, the maximum spread in efficiency
was lO~4 percent and the average spread~ 602 percento The
agreement of efficiencies of tension specimens f rom the other
fabricator was somewhat better; the maximum spread was 10 0 1
percent and the average 501 percento !-faximum efficiency
spread for a set of six specimens9 however9 was 1403 percent
and the average spread~ 902 percento
(2) The joints from one fabricator did not have a constant differ~
ence in efficiency DQrwere the efficiencies of joints from
one fabricator consistently higher or lower than the dupli=
cates from the other fabricatoro
(3) The efficiencies showed fair agreement with the AREA effic=
iency curve and good agreement with Schutzus punched~hole
efficiency curve although the hole preparation would generally
be considered equivalent to drilled holeso
(4) The agreement of test data from duplicates of the compression
specimens is good in the region of major slip and 9 with two
exceptions~ at ultimate loado
(5) The ultimate strength on the gross section of the joints in
compression decreased with increasing bearing stress~shear
stress ratioso
19
(6) The gross sectio!"1 ::;:f the riveted joints in com.pression develcy=
ed only about 65 :;ercent of their base material yield strength
at the point of joint yielde
~ Conclusions
These conclusions are drawn from the 51~series of tests and from
the analysis of the data resulting therefromg
(1) Efficiencies of identical joints assembled by two fa.bricators
may differ by 10 to 15 percent 0
(2) The efficiency of a joint apparently varies with the relative
gage (gage divided by hole diameter)o
(3) Because of the interrelationship of the bearing ratio 9 the
number of rows of rivets in a joint, the rivet spacings and the hole dia~
meter~ it appears to be impossible to isolate an effect of bearing pressure
on the efficiency of a jointo ~Tb.ile such an effect may exist~ it is not
apparent in the region studied by these tests 9 bearing ratic between 1045
and 2074 and relative gage between 209 and 4e93o
(4) The ultimate stress on the net section a,nd the efficiency of
the net section decrease slight.ly with an increase in the bearing ratioo
(5) The yield strength on the gross section of riveted joints in
compression does not appear to be affected by a change of bearing stress=shear
stress ratio if the yield strength of the material is developed before the
member buckleso
20
VI BIBLIOGRAPHY
(1) "Tests of Riveted Joints with High Rivet Bearingrt 9 Progress Report by VI ~ Mo Wi1sor: and VI 0 He Munse ~ dated August 1948
(2) "The Effect of High Rivet Bearing on the Static Strength of Riveted Jointsn, by Wo Ko Becker 9 Go Ko Sinnamon and Wo Ho Munse 9 January 1951
(3) "The Effect of High Rivet Bearing on the Static Strength of Riveted Jointsn9 by J~ Me Massard 9 Go K~ Sinnamon and Wo Ho Munse9 January 1952
(4) fTThe Efficiency of Riveted struct.ural Jointsrt 9 Progress Report by .Fa We Schutz, Jre and N. M& Newmark 9 dated September 1952
21
TABLE I
DIMENSIONS OF 51-SERIES STATIC TEST SPECII,llENS
(See Figure 1)
Spec" Rivet Width Plate Dimensions, inc> No .. Dia. W Thickness
in. in. in" inner outer A B C D E
Tension
51..,,1 3/4 9.48 9/16 7/16 1.58 3016 2 3 1/2 1 5/8 51~2 3/4 10.34 1/2 3/8 1.72 3.45 2 2 1/2 1 3/4 51-3 3/4 11.50 7/16 5/16 1.92 3083 2 3 1/2 2
51-4 1 11084 13/16 9/16 1097 3095 2 1/2 4 2 51-5 1 13.44 11/16 1/2 2.24- 4.48 2 1/2 , 2 3/8 1+
51-6 1 15.72 9/16 7/16 2.62 5024 2 1/2 .I 2 7/8 LJ.-
50-x6 7/8 8.22 1 1/8 1/4 1Q37 2.74 2 1/2 2 1/4 50-v 7/8 10 0 02 1 1/8 3/16 1.67 3034 3 1/11- 2 1/4
ComEression
51-7 3/4 9.41 5/8 3/4 51-8 3/4 11076 1/2 3/4 51-9 3/4 8WF20 1/4 3/4
51-10 3/4 9.41 1 5/16 51-11 3/L~ 11076 1 1/4 51-l2 3/4 15.68 1 3/16
22
TABLE II
Sill·1HARY OF HECHANICAL PROPERTIES OF PLATE HATERIAL ..., TE.l\JSION SPEC I:MENS
* Coupons No. Yield Point Ultimate Elongation Reduction Avo stress, stress 9 in 8" of ltrea
psi psi percent percent
51-1 2 3rc;;OO 64540 30c>5 5202 1M 2 31980 63250 2ge3 1~601 lAB 2 32610 63750 2703 49,,9 lAC 2 31570 62940 2706 48,,8
51-2 3 L0170 67730 23.9 50.2 2AA 3 37440 64170 2409 4808 2AB 1 40460 64700 2506 4609 2AC 1 37500 62e:70 29 00 5104
51-.3 .3 39660 65540 2605 50,,4 3M 3 39390 67250 26QO 4601 3AB 1 38400 66240 2707 4608 <'")hr"l '"I .... n.,,""I"l LLdJ/("\ 'Y7 a 4608 ;;.i:iU ..L ;;O~'1U UVO{V .... [Q/
51-4 3 38100 67020 26.2 5102 4AA 2 31670 66760 2402 2709 4AB 2 31400 66660 2509 40e7 4AC 2 32030 66USO 2504 3708
51"",5 2 35/+40 66810 28 0 6 4902 5AA 2 38170 62140 2708 4608 5AB 1 32520 63400 2702 5Co6 5AC 1 3UOO 61780 2802 4707
51....6 2 37560 64070 3004 5103 6AA 2 33630 60460 27.1 4908 6AB 2 35980 63220 2502 4806 6AG 2 32080 61650 2803 5008
50-0x6 3 47120 64680 3004 4206 x6AA 2 43320 69620 270'3 4701 x6AB 2 40870 64.380 2603 4605 x6AC 1 40100 64660 27 0 0 4609
50=X1 2 46300 62150 2407 50 0 7 XlAA 2 47160 65530 3000 4502 XlAB 2 42560 64720 2907 4607 X7AC 2 43680 65110 2705 4504
* Coupon numbers followed qy letters indicate Fabricator A. .All other coupons are for specimens prepared by Fabricator Eo
23
TABLE III
.s.m~'1ARY OF 1'·lliCHANIC.AL PROPERTIES OF FLATE NA~'liAL
Coupon No. Averaged Yield feint Dltimate Elongation Reduction stress** stress in 8 11 of Area
psi psi percent percent
51-7 2 35680T 64400 29&,3 51.4 360900
51-8 2 40500T 68260 28.0 5201 42130C
51-9 2 45080T 60,310 27.,3 4900 43360C
51-10 2 470201 69850 24c7 50 0 5 49110C
51-11 2 43L,,90T 60050 32.4 47cl 43710C
51-12 2 45960T 63530 22e5 4ge3 L.,. 937 00
** T and C designate values obtained in tension and compression tests respecti vely.
TABLE IV
S~~y OF TEST RESULTS - TENSION SPECIMENS
Spec':= Bearing Test Red 0 Tensile Shear No e Ratio wad, of .Area stress stress
51001-1 2 :3 1A 2A :3A
51-~!-1 2 :3 1A 2A 3A
51-:3-1 2 3 1A 2A 3A
51-t~ .. 1 2 3 1A 2A 3A
1.56
1076
2001
1()45
kips percent psi psi
267.9 24500 244.6 228.8 248.9 238.9
279.2 28000 247c2 261.9 231.3 24108
266G6 26709 24402 229.0 242()6 251.0
443.2 2 3f?r1 e7 2 400002 457.2 42503 409.0
35el 29.9 27,,2 1909 1409 23.1
2909 28.4 26.5 19.2 20.1 24.4
2404 24 0 0 25.4 20.8 2006 2309
23.1 2705 2500
66480 60790 60540 57630 62540 60020
70150 71(60 62110 58110 66140 60450
67150 65980 60440 59170 62200 64360
62000 53850 55560 64940 60000 57360
53410 46210 46140 43160 46950 45060
52660 52810 46630 49400 43630 45610
50280 50530 46060 43190 45760 47340
47030 41140 42440 48510 1,,5130 43400
Bearing stress
psi
103870 95480 95030 90210 95430 94040
123720 123690 109180 116260 101530 1CXS130
131660 133390 121590 119180 125510 129680
89330 77770 80190 93710 86710 82810
Efficiency 9 percent AREA Schutz Test
7205
7408
7702
71e7
80.8 7604 70 0 0 69~7 6706 71.5 70.4
83.0 80fl5 79c5 70 0 1 78,,9 6808 7207
8409 78,,8 7907 7206 69()2 7209 7582
79.2 >68.2 >59~3 ~6102
7102 6508 6209
t2
TABLE IV (Continued)
SUMMARYaOF TEST RESULTS - TENSION SPECIMENS
c-.~ '"""=~
Spee() B38.ring Test R0d o Tensile Shear Bearing Efficiency~ pereent Noo Ratio; Load~ of Area stress Stress Stress AREA Schutz Tet;lt
kips percent psi psi psi
51co)=1 1071 46906 14~; 66510 49830 113610 7409 82~7 7509 I') 46101 ]1"08 65130 48920 111420 74Ct4 (;~
':1 .,/ 40905 1504 58000 43450 99(J]O 66 0 2 lA 40000 1803 58560 42440 100160 7106 ~~A 36908 1701 53980 39240 92330 65~5 311. 37600 230.3 54730 39890 93690 6700
51=6=1 2009 38607 2609 53830 41030 112380 7803 85~9 6602 2 38506 2003 53880 40910 112590 6603 3 38900 2107 53900 41270 1131,30 6603 lA 369d)3 2403 51550 39180 107550 66e4 2,A 37504 2603 52210 39830 109110 67/)4 3A 367~8 2305 51800 39020 108280 66Q9
5 ()o..x6coal 20c6 1 62350 48560 112520 63<1'5 7208 63~5 175~21
2 16'107 59680 46480 10774.0 60tJ8 3 168$°2 60210 46560 108400 6102 lA 178031 63680 49420 114820 ~6209 2A 184~2i tr!'I!!IIe!!= 65550 51060 118480 64'09 3A 189~1 67rbO 52410 121150 6604·
5D=x!=1 2074 1 6D~OO 494,0 146580 70 0 2 7803 70G6 178 0 41
2 1690°1 57680 46840 139820 66~9
3 169013 57910 46f?!10 138900 6609 lA 1380 93 5164.0 38500 123630 5701 2A 13705'" 52880 38110 12,3670 5801 3A 1.36o~r3 5084,0 37920 122380 5603
1\,) ~Ji\
1 Combined plate failure and rivet. shear .3 Failure by tearing of platA3
2 Rivet shear
TABLE V
SUMHARY OF RESULTS'"" COl1£JRESSION SPECIMENS
....... ~.I:) ... "V~. C-=.·~~·R-=><C.~ ___ ~~~~~~=~~~n.~~~-~.=-~=
Spec Q Bearing=Shear Test Maximum Compressi va Shear , Bearing NC!" R.stia Yield strength load stress* stress stress
Ibs" Ibs 0 psi psi psi
51~7~1 1088 160000 291600 49780 55010 104120 2 170000 301000 51390 56790 107580 3 170000 287000 49120 54150 102830
51~8~1 2036 170000 282750 47600 53350 127700 2 170000 290000 48890 54720 127890 3 170000 292600 49550 55210 128960
51~9~1 4071 150000 2154001 36630 40650 170920 ~ 150000 220000i 37410 41510 174550
170000 228000 38780 43020 180000
51-10~1 le88 160000 2859002 46390 53950 97520 2 190000 352000 55940 66420 11797'0 3 200000' 329000 54CJ70 62(J70 113100
51-=-11...,1 2036 160000 271100 43950 51150 11504,0 2 200000 343000 55650 64720 145520 3 170000 270000 43740 5094·0 1147~~O
51=12=1 3~14 170000 238600 38450 45020 134120 2 170000 225500 36650 42550 137800 3 180000 21+4000 38390 46040 135250
1 Deflection' fOl:.ced . termination of test.9 specimen still loading 2 Failure by rivet shear * ~ Compression stres~ based on gross area of membero
o +++~ f---------~ UJ
______ -4 __ ...L-
A A A B B A ~
w w
SPECIMENS 51-1 THRU 51-6 SPECIMENS 50-X6,X7
10. TENSION SPEC I MENS
w ~ I
,.------'---.., -
--1'IIt C\I = en
fC')f~
a:>
=
I I --IV
I t l_
N
I 1 --~
I -t'- I _ N ft)~ --IV
C\I
-~ ........ -1- - - - - _'to--...., -~-rt)-IV-+
I I --~ I _.-1 I j I -~
6" 911
SPECIMENS 51-7,8,9 SPECIMENS 51-10,; 1,12
lb. COMPRESSION SPECIMENS
FIG. I DETAILS OF 51 SERIES OF STATIC TEST SPECIMENS
FIG. 2 600000 lb. TESTING MACHINE
FIG. 3 3000001b. TESTING MACHINE
FIG. 4 SLIP GAGE ON TENSION SPECIMEN
FIG.5 SLIP GAGES AND LOADING BLOCKS ON COMPRESSION SPECIMENS
FIG. 6 LOCATION OF FRACTURES - SPECIMENS 51-1
-. 00
:'IG. 7 LOCATION OF FRACTURES - SPECIMENS 51-2
FIG. 8 LOCATION OF FRACTURES - SPECIMENS 51-3
FIG. 9 LOCATION OF FRACTURES - SPECIMENS 51- 4
FIG.IO LOCATION OF FRACTURES - SPECIMENS 51- 5
FIG.13 LOCATION OF FRACTURES - SPECIMENS 50-X7
'-
FIG.15 LOCATION OF FAILURES - SPECIMENS 51-10, 111
12
70
en ~ 60
z
en 50 ~ 0: ~ en 40 w -I en z 30 w ~
z 0
20 t= U 0.05
11
W (J)
~ 10 w z
0
70
(J) ~ 214 Z ~
en (J) w 0: ~ en w -I U5 Z w
30 ~
z 51-3 0 t=
20 u w 0.05" en
~ 10 w
z
0
FIG. 16 STRESS-SLIP CURVES FOR SPECIMENS 51-1,2,3,84
C/)
~ 6 z
0
0
~ 00 w a:: ~ C/)
w 4 ...J C/)
Z
0
W 30 ~
z o I- 2 u W C/)
IW Z
0
0
0
70
~ 6 z
~ 5 W a: ~ C/)
W ...J U5 Z
4
0
0
0
W 30 I-z o i= 2 (,) W C/)
~ W z·
0
0
/. ~
/ ~ ~ ~
J ~?
, 51-5
I
2ft. ~~.........:: ~
/f; ~ ~ ~
~ VI
r 50-X6
l----" ~l -----~2. ----- ~
~ -~ l..----"
'3
l,...---- ~ lA __ 2.
\ '3 JA-.-"""" - - .... A
~ .... 3A ~ ---- lA
~ ~ ~
~ P""
, 51-6
r 0.05
11
_2. \ _2
V-- -~ ;""-'3 ..............--"""'=
/ ~
,?>ft. 2~\ft.
~ v
~ 1 '/
50-X7
0.05"
O~I --~~--~--~----~--~----~--~--~----~--~----~--~
FIG. 17 STRESS-SLIP CURVES FOR SPECIMENS 51-6,7 a 50-X6,X7
-(/) ~
z
Cf) Cf) w a:: ..... Cf)
w
70
60
50
> 4 0 Cf) Cf) w a:: a.. ~ o u z o ~ u w Cf)
Cf) Cf)
o a:: (!)
30
20
10
0
/ /
'I'
r 51-7
~'Z. _?J ~
~ ~ 'Z. ~'?>
A ?J
~ v / / /' ~ r 51-8 V- 51-9
0.0511
~ ::1 1 1 1 I I I I I I I I I ... '?>
f= 50 Cf)
w > (/) 40 Cf)
w a:: ~ 30 o u z o 20 ~ u w Cf)
(f) 10 Cf)
o a:: <!> o
----- 'Z.
/ ~ :.------ \ ~
~
-------~ ~ 1,3
;; / ~ ~ ---~\ L
~ .---::.
~ P'
V r 51-10 51-1 r 'f 51-12
0.05"
FIG. 18 STRESS-SLIP CURVES FOR SPECIMENS 51-7 THRU 51-12
lZ.a Fabricator A
o Fabricator B
100
90
80 .-r _r--
r-~ -7 I--
~ 70 z w U
0:: 60 w Il.
Z 50 >-u z w 40 u ii: LL W 30
20
10
0
L 1/ r7 ~ 7 / ...- "7" r-- /V V tr V Ii"""' / / V /
V -/7 /V / V V V / V V ro- / 1--[( T -~
V /V V V ~ V / V V V / ~V //~ - _VV / /1/ 1/ 1/ V / 1/ ~ V v7 / // ...... -/// V vV V V V V / / ~ V V/ V V ~ // / /V / / ~~ V V V / j V V/ V V // / /V r-T
V ~ V / V ~ V / V /V' / V ~ /V / /V V ) V VV ~ / / / / // / / L // / // / V V VV V V V V V j ~ VV V V ~ /V' / /V / v V / V // / V V V j V/ V V VV / /V / / / ~ V VV V ~ V ~ / V ~~ V ~ ~ // / /V V V / V VV / V / / V / // / / V / V V Vv V V V' // / ~ vv
~ V ~ VV j /V / V / ~ V V V V // j VlV V VV' / V /
~ ~V V V V /V V V/ V V ~ j~ ~ /V / / V V
/V V V V /L / V VIV / / /V / / V / v VV V / V /V / V VV V V V // / /V V V V / V V/ V V / /V / V V/ V / ~ // / /V
~ / / / V VV V V V /V ~ V ~~ V V V/ V /V V / / V /1/ 1/ L / /L / / L / /1/ V /
V VV I V V V ~~ j ~ VV V / ~ //
/ /V V V V /V V V ~ ~~ V / / /V / / /
1/ V/ V / /V / / V ~ ~ VV / /V / V / /
1/ /i/ / ./ ~ /L' / / // / V/ / /V / V V V 1/ V/ ~ / V /V / /V ~ V V / vv / /V V /V / V VV / ~ /V V VV V / / VV ~ VV / // / V VV V / /V / /V ~ V / / VV Vv V // / V Vl/ V / V // / /1/ / / / --'----- __ L- lIk'" v: // / // /
51-1 51-2 51-3 51-4 51-5 51-6 50-X6 50-X7
FIG. 1~3 VARIATION OF EFFICIENCIES OF 51-SERIES TENSION SPECIMENS
8.n-----------r----------.--------~~----~--~------~--~--------~
7.0
" ~~ ~ .~ \ ·o~ y.\..~ ~ '\ "~ ,,0
<Q ,.0 -.;:
6.0 a:::: LLI t-L&J ::E <t 0 lIJ 5.0 ..J 0 ::a::
>-CD
C lIJ C
> 4.0 0 10'\ 'r.,r:, lIJ
~-;. \) \0"\ (!) ~o~ <t ot'tt (!) .. lIJ (!) <t 3.0 (!)
lIJ > i= <t ..J lIJ 0::
2.0~--~_r--~--------~~--------_r----------r_--------_+--------~ c:
~I II
CI)
1.0~--------~---------+----------~--------~--------~--------~ E ::::J
'§I
~I I
05 1.0 1.5 2.0 2.5 3.0
RATIO OF BEARING STRESS TO TENSILE STRESS
FIG. 20 RELATIVE GAGE VS. BEARING RATIO
t-Z w 0
0:: W Q..
z
)-0 z w ~ LL LL W
80
75
70
65
60
55
50 1.0 1.2
o 0 u
• p
0 0 • 0
• ~ • • I (") (]
0 • . '
I 6- • • • I .8(5) 8
• 0 I • I
• I 0 • •
6. 8 I
6- I
..... I .. I .. I
Fob. A Fab.S
• 0 Plate Tensile Failure
• 0 Shear-Tension Failure
• A Rivet Shear Failure .. Tearir)g-Bearing Fail~!e 1.4 1.6 1.8 2.0 22 2.4 2.6 2.8 3.0
RATIO OF BlEARING STRESS TO TENSILE STRESS
FIG. 21 VARIATION OF EFFICIENCY WITH BEARING RATIO
--------------------------------------'----------------------------------------------------,
I-z w 0
a:: w a..
z
>-0 z w 0 lL lL W
90
85
80
75
70
65
60
55
50 2.0 225 2.5 2.75 3.0 325 3.5 3.75 4.0 4.25 4.5 4.75 5.0 5.25 55
RELATIVE (3AG€ t GAGE DIVIDED BY HOLE DIAMETER
FIG. 22 VAHIATION OF EFFICIENCY WITH RELATIVE GAGE
en ~
z
z 0 ~ u w en .-. w z
z 0
en en w et: .-. en
72
70
68
66
64
62
60
58
56
54
52
50 1.2 1.3 1.4
FIG. 23
0 Fab./\ Fab.B
• 0 Plate Tension Failure 0 Itt.. t;. Rivet Sheor Failure I
• 0 Shear~ Tension Failure I ..... Tearing- Bending Failure
0 0 • 0 • v •
0 • L"" r--- •
fl,,,C:> '/ r------, ...
~ "'" • ~ 0
---0
~
/ """ ~~ 8 0
• 0 0 - • ~-
~ 0 ~ ;'" - L---- • ~ ..........
"tal's 11"'1. •
• • ~ I"~ ~ 0
~ tal'~
'" ~ "'" "-b.
• D. ,- 0(3)
---• , ~
------------ '------ ---- -- -- - -- --
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.~~
RATIO OF BEARING STRESS TO TENSILE STRESS
VARIATION OF ULTIMATE NET SECTION STRESS WITH BEARING RATIO
.... Z l1J 0
0.: w 0..
Z
>-u z l1J 0 LL IL. W
.... l1J z
105
100
95
90
85
80
75 1.0 1.2 1.4
FIG. 24
0 Fab.A Fab.B • 0 Plate Tension Failure
0 • ~ 6 Rivet Shear Failure
10 • • 0 Shear-Tension Failure .. Tearing-Bending Failure b 0
• 0
~ 4. II • , -/ f'18 0
~~ -• I'"
"' ~ 8 - I"f' 0 6-
~ g Is 0
~ .- -/ ~ 7
~ ~
'/~
~ - ~{r Ie i - ~
I:!.. )(5J ---I:!..
------
1.6 1.8 2.0 22 2.4 2.6 2.8 3.0
RATIO OF BEARING STRESS TO TENSILE STRESS
VARIATION OF NET SECTION EFFICIENCY WITH BEARING RATIO
60
55 ~ .0-~ -- Ultimate stress -0--4-
50
45 z 0 .... 40 0 IJJ CJ)
35
~ t'...... - - Yield stress ---+ ~ ~
~ 4- ~ ----~(1~ -~. ~ ~ea -I---~tr ~ 1'% ~ca ~ rn, I
~) ~ ~
.6- ...0-
CJ) CJ) 0 a:: 30 (!)
z 0 25
.. 0+-• (2)~
r"'_ F==!'(3) 1- - ==1- ~~~e -- sIdE ~t~ rEilli af .... t tPlate 1--_ ... cr Icaf
f-- _
~ 1(2}
CJ) CJ) IJJ 20 a:: .... CJ)
15 I I
10
5 I
o 1.0 125 L5 1.75 2.0 2.25 2.5 2.75 3.0 3.25 3.5 3.75 4.0 4.25 4.5 4.75 5.0 525 5.5
RATIO OF BEARING STRESS TO TENSILE STRESS
FIG.25 VARIATION OF GROSS SECTION YIELD AND ULTIMATE COMPRESSIVE STRESS WITH BEARING RATIO'
0 ~ 0 ...J
0 0 ...J
lIJ ..J
>- lIJ
>= I-
0 ~ LLJ
0 I-~ ::J 0 a. ..J :e
0 0
1.00
0.95
0.95
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50 1.0
- - -L.-.---
1.25 1.5
\ \ ---- Based on Net Section
\ , Based on Gross Section I"
0-0-
\ \ \
\ \
1\ \
0(2) \ ..
"" -- --- I"-_ --0 ~ -~ ----'\ -0- ~
t--. ........
1""---- -- --........ -...... 1'-_ t\. 1' ...... -.. r-_
~ ......... - -...... --
-0- t----r---t'-, t- __ ..()
............... r---t----
V .......
~ --r---~ -0- ~ 'fical
~ ~ ~
-~.
0/ (2) 0
:00-(2)
-0-
I
1.75 2.0 2.25 2.5 2.75 3.0 3.25 3.5 3.75 4.0 4.25 4.5 4.75 5.0
RATIO OF BEARING STRESS TO SHEAR STRESS
FIG. 26 VARIATION OF YIELD POINT EFFICIENCY WITH BEARING-SHEAR STRESS RATIO, COMPRESSION TESTS
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0 1.0 1.25 1.5 1.75 2.0 2.25 2.5 2.75 3.0 3.25 3.5 3.75 4.0 4.25 4.5 4.75 5.0
RATIO OF BEARING STRESS TO SHEAR STRESS
FIG. 27
VA~IATION OF ULTIMATE STRENGTH-YIELD STRENGTH RATIO WITH BEAIRING-SHEAR STRESS RATIO, COMPRESSION TESTS