Timber Frame Tension Joinery - Timber Frame Engineering Council

More documents

Recommendations

Info

Figure 4-3 Shear Test Fixture restraint within the mortise and tenon connection and to determine relationships between the shear span and the shear capacity of the peg. When actual mortise and tenon connections are loaded to failure, the observed shear spans have been in the range of 1D or less (where D is the peg diameter). These shear spans were observed by removing the peg from the failed connection and measuring the length of the region with fibers disturbed by bending. Hence, it is necessary to understand how the shear spans affect the strength of the peg. The pegs were tested using shear spans of 1/4D, 1/2D and 1D. The load rate for the shear tests was 0.024 inches per minute in order to conform to ASTM D143-94 (ASTM, 1995a). This load produced a test duration between six and ten minutes in all but a few cases. In these cases, the ultimate load was reached in just under six minutes and was probably due to abnormally weak pegs. 4.4 Dowel Bearing Test Procedure The dowel bearing tests determine the compressive strength of the material surrounding the dowel. For a wood peg the dowel bearing yield strength of the material is 33
affected by the deformation in the peg as well as in the base material. It is important to test the dowel bearing strengths with pegs of different materials and at different orientations relative to the base material. This test was based on ASTM D5652-95 (ASTM, 1995b) which stated that the maximum load should be achieved in approximately ten minutes, but in no less time than five minutes. The base material testing blocks were cut from the 8x8 timbers using a chainsaw and an industrial bandsaw. The minimum dimensions for each block were 4D x 4D x 2D. Two of the blocks were then clamped together (end-to-end) and a hand-powered brace and auger bit were used to drill a hole to create a half-round hole or trough in the edge of each sample (see Figure 4-4). Note, in this figure the peg is loaded in the tangential orientation. Similar data were taken for the dowel bearing tests as for previously described tests. Pegs were measured in the same way that they were measured for bending and shear tests. The base material was measured for its trough length and the number of rings per inch. When each test was completed, a 3” sample was removed from the peg and a 2”x2”x1” Figure 4-4 Standard Dowel Bearing Test 34
Page 1 and 2: TIMBER FRAME TENSION JOINERY Richar
Page 3 and 4: Acknowledgments Acknowledgments go
Page 5 and 6: 5.4 Dowel Bearing Test Results.....
Page 7 and 8: List of Figures Page Figure 1-1 Typ
Page 9 and 10: List of Appendices Page Appendix A
Page 11 and 12: elasto-plastic behavior an ideal yi
Page 13 and 14: normal distribution orthotropic mat
Page 15 and 16: xiii
Page 17 and 18: Tie Beam Figure 1-2 American Timber
Page 19 and 20: 2. Timber Framing Background 2.1 Hi
Page 21 and 22: territories. Using the new construc
Page 23 and 24: Although timber framing is still a
Page 25 and 26: 3. European Yield Model and Propose
Page 27 and 28: strength, then the dowel could bend
Page 29 and 30: P III s = k3 ⋅D⋅ts ⋅F ( 2 + R
Page 31 and 32: The areas under the shear diagram c
Page 33 and 34: and F es = 1728 psi) (see Sections
Page 35 and 36: Figure 3-7 Combined Shear - Bending
Page 37 and 38: 3.5 Additional Yield Model Equation
Page 39 and 40: need to know the required load and
Page 41 and 42: Using the equivalent bolt diameter,
Page 43 and 44: 4. Peg Testing Procedures and Analy
Page 45 and 46: dowel diameter and the intercept of
Page 47: were taken for two orientations (e.
Page 51 and 52: Figure 4-6 Orientation of Prelimina
Page 53 and 54: The main purpose of the full-size t
Page 55 and 56: 5. Test Results 5.1 Introduction Th
Page 57 and 58: Table 5-1 Bending Test Correlation
Page 59 and 60: Table 5-4 Bending Yield Strength Re
Page 61 and 62: 5.3 Shear Test Results 181 shear te
Page 63 and 64: 0.90 0.90 Specific Gravity 0.80 0.7
Page 65 and 66: Yield Stress τ (psi.) 3/4" Red Oak
Page 67 and 68: 5.4 Dowel Bearing Test Results The
Page 69 and 70: obtained from shear tests at variou
Page 71 and 72: To obtain allowable stress design v
Page 73 and 74: l e l v Figure 6-1 Full-size Test D
Page 75 and 76: each mode in the general yield mode
Page 77 and 78: 7. Conclusions and Recommendations
Page 79 and 80: Appendix A Derivation of Dowel Rota
Page 81 and 82: Appendix C NDS Yield Mode II, Alter
Page 83 and 84: Appendix D NDS Mode III s , Alterna
Page 86 and 87: Appendix E Standard Test Setup for
Page 88 and 89: Appendix G Bending Test Data Summar
Page 90 and 91: Summary of Bending Tests: Last Revi
Page 92 and 93: Appendix H Shear Test Data Summary
Page 94 and 95: Summary of 1-1/4" Red Oak Shear Tes
Page 96 and 97: Summary of 1" White Oak Shear Tests
Page 98 and 99:
Appendix I Dowel Bearing Data Summa
Page 100 and 101:
Bibliography Abe M., and Kawaguchi,
Page 102:
Soltis, L. A.; Karnasudirdja, S.; L
show all

Timber Frame Tension Joinery - Timber Frame Engineering Council

Create successful ePaper yourself

Delete template?

Save as template?