FRAMING-TO-SHEATHING CONNECTION
TESTS IN SUPPORT OF NEESWOOD PROJECT
Charles Ekiert*, State University of New York at University at Buffalo
And
Jamie Hong*, University of California, Irvine
Network of Earthquake Engineering Simulation
Host Institution: State University of New York at University at Buffalo
Faculty Advisor: Dr. André Filiatrault*
Abstract
In the United States today woodframe structures make up almost eighty percent of low-rise
buildings, however they are very under researched. The purpose of the NEESWood project is to
safely increase the height of woodframed buildings by developing a new seismic design
philosophy in order to make mid-rise woodframe buildings possible in high seismic regions. In
order to develop a new seismic design philosophy, an 1800 square foot townhouse is being tested
on the two twin shake tables of the UB-NEES equipment site and modeled using computer
programs such as CASHEW and SAWS (Folz and Filiatrault 2000, 2001). The main input into
these computer software are nail parameters from monotonic and cyclic tests of frame-tosheathing connections.
In order to support the modeling of the test structure, fifty-two monotonic and cyclic tests were
conducted on 2 by 4 and 2 by 6 wood studs and 7/16” Oriented Strand Board positioned parallel
to grain and perpendicular to grain. These connection types were tested with 8d common nails
using the CUREE-Caltech protocol (Krawinkler et al. 2000). The monotonic tests were done to
find the reference displacement for the cyclic testing. The data retrieved from the cyclic testing
was used to plot force-displacement graphs. The force-displacement graphs show hysteretic
behavior. Analysis of the hysteretic loops of each test led to an average set of hysteretic
parameters to be used as the input to the computer modeling software.
Introduction
In the United States today woodframe buildings are built only up to approximately four stories in
seismic areas mostly because of the lack of research preformed on the effect of earthquakes on
larger and taller wood buildings. While woodframe construction is more economical than
buildings made with other materials, the lack of data for seismic response on wood buildings
prevents mid-rise and high-rise wood buildings from being built. The purpose of the
NEESWood Projet: Development of a Performance-Based Seismic Design Philosophy for MidRise Woodframe Construction is to safely increase the height of woodframed buildings by
developing a new seismic performance-based design philosophy in order to make mid-rise
woodframe buildings possible in high seismic regions. In the first year, a Benchmark shake table
test of a typical wood house in a high seismic region is to be tested at the State University of
New York at University at Buffalo to develop a performance-based seismic design, PBSD,
philosophy. Once this philosophy is developed, societal impacts will be investigated and the
philosophy will be implemented to design a five to seven story apartment building. This
apartment building will be constructed and tested on the E-Defense, Miki, shake table in Japan.
The first stage of the NEESWood project is the Benchmark Shake Table Testing of Full-Scale
Two-Story Townhouse Woodframe Building, in which an 1800 square foot, two-story
townhouse is tested on two three-dimensional shake tables moving simultaneously. These shake
tables are located at the Structural Earthquake Engineering Simulation Laboratory, SEESL, at
SUNY Buffalo. The test is the largest full scale wood structure to be tested on a tri-axial shake
table in the U.S. and therefore the results will be a benchmark for not only current performance
of timber structures but also for nonlinear models for seismic analysis of woodframe structures
(van de Lindt, John W. 2006). The benchmark testing consists of five phases:
 Phase 1 – series of tests on only the woodframe and sheathing of the building;
 Phase 2 – series of tests on the woodframe with four pre-fabricated walls incorporating
viscous dampers
 Phase 3 - series of tests on the woodframe with gypsum wallboard on the interior side of
the structural walls only
 Phase 4 – series of tests on the woodframe with gypsum wallboard on all walls, structural
and nonstructural
 Phase 5 – series of tests on the woodframe, gypsum wall board, and stucco on the exterior
of the house.
The results of the framing-to-sheathing connection tests described in this paper are to be used for
the modeling of the Benchmark test of the NEESWood Project. The purpose of the nail
connection strength test is to derive hysteretic behavior through monotonic and cyclic testing in
order to obtain hysteretic nail parameters needed to model the townhouse used in the Benchmark
test.
Background
The objective of the framing-to-sheathing connection tests is to find the parameters of the nails
used in the townhouse from data obtained by monotonic and cyclic testing. Under monotonic
loading the load-deformation curve of dowel type connectors, such as nails, in a wood shear wall
is non-linear. Under cyclic loading, those dowel type connectors produce hysteresis loops with
strength and stiffness weakening progressively. (Dolan and Madsen 1992). Through testing of
several specimens, a specific hysteresis model is found which can emulate the response of the
nail connections during general cyclic loading.
The nail parameters found from this nail connection tests will be used to obtain a computer
model of each shear wall in the townhouse structure for the Benchmark Test using a computer
program called Cyclic Analysis of Shear Walls, CASHEW. CASHEW uses the shear modulus
of the sheathing panels and the data from cyclic testing of the fastener connection tests to predict
the load-displacement response and energy dissipation characteristics under cyclic loading of
woodframe shear walls (Folz and Filiatrault 2000). In CASHEW, each connector is represented
by a non-linear spring which has the hysteretic properties of the connector. By modeling each
connector with a spring, the hysteretic response of the entire shear wall can be obtained.
After each wall is modeled, the earthquake response of the townhouse is predicted using another
computer program called Seismic Analysis of Woodframe Structures, SAWS. SAWS models
each shear wall as a non-linear spring, much like in CASHEW. SAWS then collapses the 3-D
building into a 2-D model giving zero-height to all of the shear walls (Folz and Filiatrault 2001).
This earthquake response can then be compared to the actual data from the shake table test of the
townhouse.
Previous Studies
Previous studies have been conducted on the seismic analysis of woodframe structures. One
project of significance is the CUREE-Caltech Woodframe Project: Earthquake Hazard
Mitigation of Woodrame Construction. Within this project sheathing to wood connection tests
were made. Task 1.4.8.1, “Nail, Wood Screw, and Staple Fastener Connections” through the
CUREE-Caltech Woodframe Project is similar to our study (Fonseca et al. 2002). In the
CUREE-Caltech study thirteen different connectors were used; including nails, wood screws and
staples; and several different types of sheathing were used. In the connection tests described in
this paper, four different specimens were used with only one type of connector. Our connection
setup was not tested specifically in the CUREE-Caltech study.
Materials Used and Material Properties
Materials used in this test are the same materials used in the NEESWood Benchmark testing
townhouse. The wood members are 2 by 4 and 2 by 6 Hem Fir, the sheathing panels are Oriented
Strand Board, and the nails are 8d common nails. Two connection types are tested in both
parallel to grain and perpendicular to grain loading directions, as shown in the Test Matrix in
Table 1.
Table 1 Test Matrix
Test
No.
Sheathing
1
7/16" OSB
2
7/16" OSB
3
7/16" OSB
4
7/16" OSB
Wood
Member
2” x 4” Hem
Fir
2” x 4” Hem
Fir
2” x 6” Hem
Fir
2” x 6” Hem
Fir
Fastener Type
8d Common
Nails
8d Common
Nails
8d Common
Nails
8d Common
Nails
Loading
Direction
No. of
Specimens
Perpendicular
13
Parallel
13
Perpendicular
13
Parallel
13
All wood members are Hem Fir and were bought dry with a moisture content of less than 19
percent. Two sizes of wood are used in this test, 2 by 4 and 2 by 6. The 2 by 4 wood members
have a standard dressed size of 1 ½ inches by 3 ½ inches and has an area of 5.25 square inches.
The 2 by 6 wood members have a standard dressed size of 1 ½ inches by 5 ½ inches and has an
area of 8.25 square inches.
The sheathing panels used in this test are Oriented Strand Board with a 7/16 thickness. Oriented
Strand Board is a sheathing panel made from reconstituted wood strands. The wood strands are
compressed and attached together with phenolic resin.
All fasteners used in our tests are nails, which are dowel-type fasteners. All nails are common
nails with a pennyweight of 8d. Then nail length and nail diameter of 8d common nails are 2 ½
inches and 0.113 inches, respectively. Common nails have a larger diameter and larger
allowable load than box nails, therefore common nails are less likely to bend when driven
manually.
Types of Failures
There are seven ways a connection can fail called yield modes. The modes, Im, Is, II, IIIm, IIIs,
and IV are shown in Figure 1. In our tests the OSB sheathing was considered the side member
and the wood studs were considered the main member. Mode Im and Is are yield modes when the
nail yields on the main or the side member respectively. Mode II does not occur in nails, but
occurs in other connection types such as bolts. Mode IIIm and IIIs occur when the connection
yields at one point on the main member or the side member respectively. The last yield mode is
Mode IV where the connector yields by bending at two points making an S shape.
Figure 1: Connection Yield Modes
(from NDS 2005 American Paper
and Association inc.)
Methods
Testing apparatus
A testing apparatus was designed and constructed for both parallel and perpendicular to grain
testing as shown in Figure 2. The apparatus was designed so that the samples could be easily
placed and removed during the testing. The testing apparatus was constructed from ¼” A36
plate steel, 1 ¼” and ¾” cold rolled dowel steel. The apparatus was designed with three main
components, two which are used for testing samples parallel to grain (upper and lower main
connectors) and another piece that can be placed on the lower main connector piece to test
perpendicular to grain.
Figure 2: Test apparatuses parallel to grain (left) and perpendicular to grain (right)
In the design of this apparatus we also took into consideration the possibility of cupped samples
and slippage between the sample and apparatus. To handle the potential problem of cupping, we
allowed for a maximum width of 1 5/8”, if any samples were greater than a width of 1 5/8”
because of cupping they were discarded. In order to prevent the possibility of slippage, which
would cause false or inaccurate data, we placed the potentiometers in such a way that they were
connected to the samples themselves and not the apparatus. This would eliminate the possibility
of inaccurate data being collected.
When testing parallel to grain, the sample would be placed in the apparatus and bolted in place
using four ¾” pins, as shown in Figure 2. The reason we choose to use four bolts, two on the
upper and two on the lower parts of the sample, was to prevent the possibility of any rotation.
When testing perpendicular to grain, the connector piece would be placed over the lower main
connector and bolted into place using four ¾” pins, as shown in Figure 2. Spacers where also
used in order to keep the apparatus centered. The specimens were also bolted into place using
two bolts and spacers to keep the oriented strand board (OSB) centered, prevent rotation, and to
keep the OSB perpendicular to either the 2 by 4 or 2 by 6 specimens.
Specimens
In the construction of the structural walls in the NEESWood Townhouse, there are two types of
studs (2 by 6 and 2 by 4) and and one type of sheathing, OSB sheathing. The samples tested are 2
by 4 parallel to grain, 2 by 4 perpendicular to grain, 2 by 6 parallel to grain, and 2 by 6
perpendicular to grain.
For the 2 by 4 and 2 by 6 perpendicular to grain specimens we cut all the pieces which
comprised the sample using a table saw and compound miter saw. Both saws had stops on them
to ensure that each piece was exactly the same size. After manufacturing all the pieces we
constructed a jig in order to drill all the holes which will connect to the apparatus. Each
specimen was then nailed together using a Stanley Boshtich Framing nail gun. The nails used
were 8d common (2 ½ inches). To ensure the nails were set at the proper depth, the nail gun was
set to embed the nails either at the surface of the OSB or within 1/32 inch below the surface.
Each specimen had four 8d common nails in it, two on either side of the stud.
The 2 by 4 and 2 by 6 parallel to grain specimens were all cut and drilled following the above
stated procedure. Both specimens are nailed and glued at the lower connection to produce a
fixed end condition. The fixed end condition was obtained using four nails, two on either side
along with using Liquid Nails to adhere the OSB to the studding. For the 2 by 6 specimens the
OSB at the top part of the sample was nailed with four 8d common nails, two on either side,
However for the 2 by 4 specimens only two 8d common nails were used to attach the OSB to the
studding. The reason for this is to eliminate the possibility of splitting the stud.
Test Machine
The testing machine used for all of the monotonic and cyclic testing was manufactured in 1984
by MTS Systems Corporation. The testing machine consists of a load frame, a hydraulic collet
grip, and a micro console, shown in Figure 3. The model numbers of the load frame, hydraulic
collet grip and micro console are 309.40, 646.25A, and 458.10 respectively. The load frame has
a capacity of 110 kips and the hydraulic collet grip has a capacity of 55 kips, shown in Figure 4.
Figure 3: MTS micro console
Figure 4: MTS Hydraulic Collet Grip
Instrumentation
The load cell used in all tests was manufactured by Transducer Techniques as shown in Figure 5.
The model number on the load cell is SWO-10K and the capacity is 10 kips.
Figure 5: 10 Kip Load Cell
The displacement was measured using either ± 2 inch and/or ± 1 inch potentiometers. In the
monotonic testing of all parallel to grain and all cyclic testing two ± 2 inch potentiometers were
used as shown in Figure 6 (middle and left). In the testing of the monotonic testing of the
perpendicular to grain specimens two ± 1 inch and two ± 2 inch potentiometers were used as
shown in Figure 6 (right). The reason for the difference in the amount of potentiometers used in
either the monotonic or cyclic testing of the perpendicular to grain specimens is because of the
limited number of ± 2 inch potentiometers and the large displacement that was expected.
Figure 6: Monotonic perpendicular to grain set up (Left), Monotonic and Cyclic parallel to
grain test setup (Middle), and Cyclic test setup perpendicular to grain (Right)
The data acquisition was done through two National Instruments PCI-6036E cards which
received data from the load cell and sent it to the software, Labview version 7.1, which is also
manufactured by National Instruments. The Labview software records the time, the
displacement from the test machine, the load from the load cell, and the displacements from each
of the potentiometers at a rate of 10 samples per second and 100 samples per second for the
monotonic and cyclic loading respectively.
Loading Protocol
The CUREE-Caltech loading protocol used in this connection strength test is based on tests done
by the Consortium of Universities for Research in Earthquake Engineering, CUREE, in the
CUREE-Caltech Woodframe Project (Krawinkler et al. 2000). In Task 1.4.8.1; Nail, Wood
Screw, and Staple Fastener Connections, the same monotonic and cyclic loading protocol were
used.
According to the protocol, the reference deformation, Δm, for the cyclic loading tests are
determined by conducting monotonic tests. The procedure in determining the reference
deformation is as follows:
 First find the maximum load applied to the specimen, Fmax, from the load-displacement
data given by each monotonic test.
 Next find the monotonic deformation capacity, Δm, by taking the displacement
corresponding to 80% of the Fmax.

Lastly a fraction of 0.6Δm is chosen as the reference deformation for the cyclic loading
tests.
Figure 7 shows the Δ, Fmax, and Δm on a load-displacement graph of monotonic testing was done
using the simplified loading history for basic cyclic load test from the CUREE-Caltech testing
protocol. The simplified loading history for basic cyclic load test is shown in Figure 8. In the
simplified loading history the reference deformation, Δ, is used as a reference point in increasing
the amplitude; each cycle has equal positive and negative amplitude; and several cycles of equal
amplitude are performed at each step (Krawinkler et al. 2000). The simplified loading history
starts with six cycles of 0.05Δ. The initial cycles are followed by seven primary cycles of
0.075Δ and 0.1Δ. Next the number of primary cycles is reduced to four of amplitude 0.2Δ and
0.3Δ. Finally the number of primary cycles is reduced to three cycles of amplitude 0.4Δ, 0.7Δ,
1.0Δ, and 2.0Δ.
Figure 7: General Monotonic Force-Displacement Response
Simplified Loading History for Basic Cyclic Load Test
4
3
% of Delta
2
1
0
-1
-2
-3
-4
Figure 8: CUREE-Caltech Cyclic Protocol
Connection Parameters
There are ten parameters used to fit hysteretic curves. These hysteretic model parameters
included in the CASHEW and SAWS programs are shown in Figure 9 and are as follows:
1. Fo – The load associated with the y-intercept of slope r1Ko
2. Δu – maximum displacement
3. Ko – initial stiffness
4. r1 – secondary stiffness divided by Ko
5. r2 – degradation stiffness divided by Ko
6. r3 – unloading stiffness divided by Ko
7. r4 – pinching stiffness divided by Ko
8. α – stiffness degradation factor
9. β – strength degradation factor
10. FI – The load associated with the y-intercept of slope r4Ko
400
(Δu, Fu)
Ko
r1Ko
300
Fo
r2Ko
200
r3Ko
Force (lbs)
100
FI
0
-0.8
-0.6
-0.4
-0.2
0
0.2
r4Ko
0.4
0.6
0.8
-100
-200
-300
-400
Displacement (in)
Figure 9: Hysteretic Model Parameters
The first five parameters are part of the monotonic envelope curve of the force displacement path.
While the last five parameters represent the hysteretic response of the connector due to a general
cyclic loading (Fonseca et al. 2002).
In these wood to sheathing connection tests, the envelope curve was fitted using an excel file
developed by Brian Folz. The parameters, Fo, Δu, Ko, r1, and r2 were found through this envelope
data fit along with the ultimate load, Fu, and the reference deformation, Δm. The data was first
graphed on excel and the parameters were found by simply changing numbers and visually
fitting the slopes, intercepts, and peak to the given hysteresis loop. Figure 10 shows an example
of the file. This process was repeated for both the positive and negative side and then averaged
to get the five parameters for each test. The file used the envelope curve formula below to find
the ultimate load and to fit the backbone curve to the force-displacement graph.
F  ( F0  K1)  1  exp(  K 0  / F1 F0 )
(Eq. 1)
The parameters FI, r3, and r4 were found manually through Microsoft excel. FI was found by
looking at the graph and finding the mean y-intercept of slope r4Ko. Slopes r3Ko and r4Ko were
found by connecting two points on excel to show the mean slope of the hysteresis loop.
Figure 10: Envelope Curve Excel File
The last two parameters α and β were estimated through the following process:
 First, Δmax is estimated by connecting the peaks of the two trailing cycles of the largest
primary cycle in the force-displacement graph and extending the maximum force to find
Δmax as the intersection of those two lines.
 β is estimated as

(Eq. 2)
  max
u
where Δu = is the maximum displacement found in the envelope curve.
 If β is less than 1, β is set at 1 and Δmax is equal to Δu
 Kp is then found by connecting the peak of the primary cycle to the intersection of the
unloading of the primary cycle and the reloading of the first trailing cycle. Kp is found by
calculating the slope of that line.
 α is then estimated using the following formula

  
K p  K o  0 
(Eq. 3)
  max 
where Ko= is the initial slope found from the envelope curve.
Results
Monotonic Testing
Figures 11 thru 14 show the results from the 2 by 6 and 2 by 4 perpendicular and parallel to grain
monotonic testing. It can be noticed that the results are consistent with one another.
Figure 11: 2” x 4” Monotonic loading Parallel to Grain
Figure 12: 2” x 4” Monotonic loading Perpendicular to Grain
Figure 13: 2” x 6” Monotonic loading Parallel to Grain
Figure 14: 2” x 6” Monotonic loading Perpendicular to Grain
Table 2 shows the Δ, Fmax, 0.8* Fmax and Δm. As shown in this chart the average values of the
Fmax are similar and the value of Δ ranges from 0.41 to 0.66.
Table 2: Results from Monotonic Testing
Sample
1
Fmax
(lbs/nail)
0.8*Fmax
(lbs/nail)
2” x 4” Perpendicular
Sample Sample
2
3
Average
Sample
1
2” x 6” Perpendicular
Sample Sample Sample
2
3
4
Average
294.19
285.19
305.25
294.88
238.72
278.24
330.81
283.43
282.80
235.35
228.15
244.20
235.90
190.98
222.60
264.65
226.75
226.24
Δm (inch)
0.72
0.91
0.66
0.76
0.35
0.77
0.79
0.78
0.68
Δ (inch)
0.43
0.54
0.40
0.46
0.21
0.46
0.47
0.47
0.41
Sample
1
Sample
2
2” x 4” Parallel
Sample Sample
3
4
Sample
5
217.13
278.78
363.16
238.34
173.71
223.02
290.53
Δm (inch)
0.18
1.11
Δ (inch)
0.11
0.67
Fmax
(lbs/nail)
0.8*Fmax
(lbs/nail)
Average
Sample
1
2” x 6” Parallel
Sample Sample Sample
2
3
4
343.63
288.21
281.68
218.66
342.33
274.43
279.27
190.67
274.90
230.57
225.34
174.93
273.86
219.54
223.42
1.08
1.35
1.27
1.00
1.26
0.82
1.17
1.15
1.10
0.65
0.81
0.76
0.60
0.76
0.49
0.70
0.69
0.66
Average
Table 3 shows the maximum loads, both the positive and negative values of the loads and
corresponding maximum positive and negative displacements at those loads.
Table 3: Maximum Loads and Displacements
Max Negative
Displacement at Max Positive
Test Specimen
Displacement at
Load
Max Negative Load
Load
Max Positive Load
(lbs)
(inch)
(lbs)
(inch)
2x4 Perpendicular to grain
-323.65
-0.47
312.32
0.54
2x6 Perpendicular to grain
-326.15
-0.44
324.07
0.46
2x4 Parallel to grain
-326.93
-0.52
292.79
0.55
2x6 Parallel to grain
-282.51
-0.45
276.07
0.40
Nail Parameters
Each of the ten nail parameters were derived for each cyclic test, using methods from above, and
then averaged for all parallel to grain and all perpendicular to grain. Finally all tests were
averaged for a single set of nail parameters to be used in the CASHEW and SAWS programs.
The mean nail parameters are shown in Table 4.
Table 4: Mean Nail Parameters
K0
(lbs/in)
F0 (lbs)
r1
mean of 2” x 4”
perpendicular
249.4
9555
0.018
mean of 2” x 4”
parallel
245
9614.286 0.022
mean of all
2” x 4”
247.2 9584.643 0.02
mean of 2” x 6”
perpendicular 243.75 7138.889 0.02
mean of 2” x 6”
parallel
223.393
7000
0.025
mean of all
2” x 6”
233.571 7069.444 0.022
mean of all
tests
240.386 8327.044 0.021
u (in)
r2
r3
r4
FI (lbs)
0.51405
0.024
0.447
0.006
24.29
0.45986
0.017
0.795
0.005 6.02857 0.126 1.005
0.48695
0.021
0.621
0.006 15.1593 0.194 1.003
0.52633
0.031
0.495
0.017 26.3689 0.232 1.001
0.43
0.017
0.717
0.005 21.6343 0.093 1.011
0.47817
0.024
0.606
0.011 24.0016 0.162 1.006
0.48256
0.022
0.613
0.008 19.5804 0.178 1.005
α
β
0.263 1.001
The mean force-displacement curve was derived for all 2 by 4 stud tests, all 2 by 6 stud tests, and
all tests. These mean force-displacement curves show a hysteric loop found from the nail
parameters and characteristics taken from each specific force-displacement curves for each
specific cyclic test. These average hysteresis loops are found in Figures 15 thru 17.
400
(Δu, Fu)
Ko
r1Ko
300
Fo
r2Ko
200
r3Ko
Force (lbs)
100
FI
0
-0.8
-0.6
-0.4
-0.2
0
0.2
r4Ko
0.4
0.6
0.8
-100
-200
-300
-400
Displacement (in)
Figure 15: Mean Force-Displacement Curve for 2 by 4 Studs
400
Ko
(Δu, Fu)
r1Ko
300
Fo
r2Ko
200
r3Ko
Force (lbs)
100
FI
0
-0.8
-0.6
-0.4
-0.2
0
0.2
r4Ko
0.4
0.6
-100
-200
-300
-400
Displacement (in)
Figure 16: Mean Force-Displacement Curve for 2 by 6 Studs
0.8
400
(Δu, Fu)
Ko
r1Ko
300
Fo
r2Ko
200
r3Ko
Force (lbs)
100
FI
0
-0.8
-0.6
-0.4
-0.2
0
0.2
r4Ko
0.4
0.6
0.8
-100
-200
-300
-400
Displacement (in)
Figure 17: Mean Force-Displacement Curve for All Tests
Discussion
The results of these monotonic and cyclic tests show that the behavior of the four different type
of test specimens are very similar. For example, for the monotonic tests the average maximum
load for monotonic testing in each type of specimen was within 5%, which is shown in Table 2.
The nail parameters which were found during the cyclic testing were also very comparable. For
example, the β values range from 1.001 to 1.011. Again the nail parameter results are shown in
Table 3.
During the cyclic testing, nail failure modes were almost all modes IIIm and IV, with the
exception of two cases of the nail shearing off due to nail fatigue. Nails in the parallel to grain
positions in both 2 by 4 and 2 by 6 failed with mode IIIm failures. Actual nails pulled from the
parallel of grain test specimens are shown in Figure 18. Nails in the perpendicular to grain
positions had mode IV failures. Actual nails taken from the testing of perpendicular to grain
specimens are shown in Figure 19. The modes IIIm and IV were normal however the nail
shearing was unexpected. Figure 20 shows an example of a sheared nail.
Figure 18: Mode IIIm nail failures from
parallel to grain testing directions
Figure 19: Mode IV nail failures from
perpendicular to grain testing directions
Figure 20: Shearing of nail due to nail fatigue
Conclusions
Monotonic and Cyclic tests were performed on framing to sheathing connections found in the
NEESWood townhouse. The findings are summarized below:




The nail parameters found for each type of connection were consistent
Test apparatus performed very well
The variation in the wood did not affect the results very much
Maximum load was very similar in each test
Appendix A
Shop Drawing of Testing Apparatus
References
van de Lindt, John W. (2006). NEESWood: Development of a Performance-Based Seismic
Design Philosophy for Mid-Rise Woodframe Constructio: Abstract.
http://www.engr.colostate.edu/NEESWood/NEES%20Abstract%20-%20van%20de%20Lindtupdated%20June%202006.pdf
American Forest and Paper Association (AF&PA). (2005a). National Design Specifications for
Wood Construction and Supplement. 2005 ed., AF&PA, Washington, DC.
Breyer, D., Frideley, K., Pollock, D., and Cobeen, K. (2003). Design of Wood Structures-ASD.
Fifth Edition. McGraw-Hill, New York, NY.
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