Load Duration and Seasoning Effects on Mortise & Tennon Joinery

More documents

Recommendations

Info

from the short-term eastern white pine joint tests. Base material was tested both parallel <strong>and</strong> perpendicular to grain.. In the next chapter, short-term tests of eastern white pine joints are described. These tests were performed to establish target strength values <strong>and</strong> detailing requirements for the joints used in the long-term study. Chapter 3 describes the method for determining the dowel bearing strength of wood with nonmetalic (in this case, wood) fasteners. The timedependent behavior of pegged mortise <strong>and</strong> tenon joints under long-term load is presented in Chapter 4, <strong>and</strong> Chapter 5 contains the results of failure testing of the specimens subjected to long-term load. Analysis of the test results, plus a summary <strong>and</strong> conclusions are presented in Chapter 6. 9
2. Joint Tests (Eastern White Pine) 2.1. Introduction Schmidt <strong>and</strong> Daniels (1999) reported joint detailing requirements along with tension test results for three different species of wood. The reported results were from full-scale tests on southern yellow pine, recycled Douglas fir <strong>and</strong> red oak joints. In a continuation of this work, tests of a similar nature were performed on eastern white pine joints. Detailing requirement are composed of end (l e ), edge (l v ) <strong>and</strong> spacing (l s ) distances. These distances are illustrated in Figure 2-1 below. l s l v e l Figure 2-1 Detailing Distances from Schmidt <strong>and</strong> Daniels (1999) Yielding of the peg is the preferred mode of joint failure. There are two primary reasons for this. First, peg yielding leads to a ductile failure of the joint under tension loading. The second reason is that the joint can be repaired by replacing the failed pegs with new ones. This mode of failure also helps to isolate the peg as the primary design criterion of the joint. Alternate joint failure modes include mortise splitting <strong>and</strong> tenon 10
Page 1 and 2: LOAD DURATION AND SEASONING EFFECTS
Page 3 and 4: Acknowledgments This report is base
Page 5 and 6: 5.5.1. Joint Properties ...........
Page 7 and 8: List of Tables Page Table 2-1 Easte
Page 9 and 10: ugged traditional style has helped
Page 11 and 12: 1.3. Literature Review Previous res
Page 13 and 14: However these failures were away fr
Page 15: 1.5. Overview Primary among the thr
Page 19 and 20: Figure 2-2 Short Term Test Set-up f
Page 21 and 22: Figure 2-3 Typical Mortise Member F
Page 23 and 24: offset horizontally a distance of 5
Page 25 and 26: 2.7. Dowel Bearing Strength Dowel b
Page 27 and 28: 2.8. Detailing Requirements (End/Ed
Page 29 and 30: Figure 2-9 Illustration of Peg Fail
Page 31 and 32: properties of a base material loade
Page 33 and 34: ut the load is applied through the
Page 35 and 36: Table 3-2 Spring Theory Summary Tes
Page 37 and 38: the stiffer of the two materials; r
Page 39 and 40: 4. Long Term Seasoning</str
Page 41 and 42: of the calibration markings were ob
Page 43 and 44: appropriate location for the center
Page 45 and 46: Table 4-1 Douglas Fir Long-Term Joi
Page 47 and 48: Normalized Douglas Fir 0.25 0.20 1.
Page 49 and 50: 4.2.3. Results and
Page 51 and 52: 4.3. Southern Yellow Pine Twenty-on
Page 53 and 54: Southern Yellow Pine 0.160 Deflecti
Page 55 and 56: Southern Yellow Pine Moisture Conte
Page 57 and 58: Normalized Southern Yellow Pine 0.0
Page 59 and 60: 2.0D end distance and</stro
Page 61 and 62: two pegs was active in carrying the
Page 63 and 64: Normalized White Oak 0.25 0.20 Defl
Page 65 and 66: White Oak 40 35 30 Moisture Content
Page 67 and 68:
loaded to 1000 lb which is 16% of t
Page 69 and 70:
with only one joint it is difficult
Page 71 and 72:
4.5.2. Moisture Content The eastern
Page 73 and 74:
Eastern White Pine 0.30 0.25 0.20 D
Page 75 and 76:
5. Failure Testing of Long Term Spe
Page 77 and 78:
earing test samples were oriented i
Page 79 and 80:
5.3.2. Material Properties (Dowel B
Page 81 and 82:
twelve joints had white oak pegs <s
Page 83 and 84:
the load-deflection plots shown in
Page 85 and 86:
6.2. Modification to minimum end <s
Page 87 and 88:
unloaded. Therefore, the Madison Cu
Page 89 and 90:
7. References AFPA, (1997). “Nati
Page 91 and 92:
Load-Deflection Pl
Page 93 and 94:
Dowel Bearing Test Results Test Num
Page 95 and 96:
Peg Specific Gravity and</s
Page 97 and 98:
Load-Deflection Pl
Page 99 and 100:
SYP 35 SYP 36 9000 4000 3760.44 800
Page 101 and 102:
Specific Gravity and</stron
Page 103 and 104:
Appendix C (white oak) 7.1.1. Joint
Page 105 and 106:
WO 27 WO 28 7000 6000 6474.64 9000
Page 107 and 108:
WO 43 WO 44 12000 10000 16000 14000
Page 109 and 110:
Page 111 and 112:
Appendix D (eastern white pine) oin
Page 113 and 114:
EWP 27 EWP 28 12000 8000 7579.80 10
Page 115 and 116:
EWP 43 EWP 44 9000 8000 7000 5000 4
Page 117 and 118:
show all

Load Duration and Seasoning Effects on Mortise & Tennon Joinery

Create successful ePaper yourself

Delete template?

Save as template?