Assignment

1. Students will run the following experiments.
    

   • Data Sheet
      

2. Together, the entire section will test two plate-connector joints using the Instron 4485 and Bluehill software.

   specimen 1		specimen 2
   two 1"x2"x6" #2 top-choice pine blocks		two 1"x3"x6" #2 top-choice pine blocks
   two Simpson MP14 mending plates (1"x4" steel plate with 24 teeth)		two Simpson MP24 mending plates (2"x4" steel plate with 56 teeth)

Instructions:

• Attach a mending plate to either side of the wood blocks.
• Insert the specimen in the testing machine.  Use a speed of 0.035 in/min and a maximum displacement of 0.60".
• The load and deflection data will automatically be stored and analyzed.  Your GTA will explain how to retrieve the data.
• ASTM D1761 sections 31-40 cover this procedure in detail.

3. Each group will run one dowel bearing test using the Instron 5583 and Bluehill software.

   specimen 1		specimen 2
   load applied in transverse direction		load applied in axial direction
   2"x4" #2 pine block with 13/16" half-hole		2"x4" #2 pine block with 13/16" half-hole
   3/4"-diameter bolt		3/4"-diameter bolt

   Instructions:

   • The holes have been drilled 1/16" larger than the bolt diameter to mimic common construction practices.
   • Insert the specimen in the testing machine.  Use a speed of 0.04 in/min.  Stop the test when the maximum displacement is equal to one half the bolt diameter or after the maximum load has been reached.
   • The load and deflection data will automatically be stored and analyzed.  Your GTA will explain how to retrieve the data.
   • The yield point is determined by using a deformation offset equal to 5% of the bolt's diameter (see Figure 6 in ASTM D5764).  If the yield point cannot be identified, the maximum load shall be used as the yield load.
   • ASTM D5764 covers this procedure in detail.

4. Each group will run one fastener withdrawal test using the Tinius Olsen Super L.

    

   wood		nails		screws
   2"x4" #2 pine block		6d bright common (0.114"-dia. x 2.0")		#8 x 1.75" wood screw, flat Phillips (0.164"-dia.)
   		8d bright common (0.131"-dia. x 2.5")		#10 x 1.75" wood screw, flat Phillips (0.190"-dia.)
   		10d bright common (0.150"-dia. x 3.0")		#12 x 1.75" wood screw, flat Phillips (0.216"-dia.)
   		16d common (0.162"-dia. x 3.5")

   Instructions:

   • Choose one of the available fasteners and drive it 1" into the wood block.
   • Insert the specimen in the testing machine and determine the maximum load required to withdraw the fastener.
   • ASTM D1761 sections 1-12 cover this procedure in detail.

5. Each group will run one Janka hardness test using the Instron 4469.

    

   Material	Janka Side  Hardness (lb)	Reference Value (lb)
   2"x2" clear western red cedar		***
   2"x2" composite decking		***
   2"x2" poplar		600
   2"x2" douglas fir		660
   2"x2" southern yellow pine		690
   2"x2" red oak		1260

   Instructions:

   • Insert the specimen in the testing machine and determine the maximum load required to drive the Janka indenter to 0.222" at 0.25in/min.
   • ASTM D143 sections 1-12 cover this procedure in detail.

6. Together, the entire section will run a planar (rolling) shear test on plywood using the Instron 4469 and Bluehill software.

   • Setup notes from ASTM D2718, Method B (5-point flexure)
     • "width shall be at least 4.5 in. and no greater than 10 in."
     • "test span shall be at least 16 times the nominal specimen depth for the primary axis and 11 times the nominal specimen depth for the secondary strength axis"
       • specimen size:  0.5"-thick x 5.5"-wide x 20"-long (two 8" spans)
     • "a 0.05 in./min loading rate is recommended as an initial rate"
     • shear stress = 33 x ultimate load (lb) / (64 x width x thickness) (psi)
     • bending stress = 9 x ultimate load (lb) x span / (16 x width x thickness^2) (psi)
   • See Figure 30 in Beam Design Formulas - American Wood Council for a comparison of shear-force and bending-moment diagrams.

7. Summarize your results, as per your teachers' instructions, and submit at the start of the next lab class.

   • Sample Results