Each group will run one of the following two tests.
Parallel-to-Grain
- Draw two pencil marks (centered) 6 inches apart on a 2"x3"x8" specimen.
- Attach a 6" GL x 0.0001" mechanical extensometer through these pencil marks.
- Insert the specimen and extensometer in the Instron 4485 testing machine, with fixed-upper and spherical-lower bearing plates.
- Using a speed of 0.024 in/min (+/- 25%), record the deformation at 1000-lb increments.
- Stop the test once the maximum load is obtained.
- Determine the compression modulus and compressive strength. Compare these values to those given in the sample results.
- ASTM
D143 section 9 covers
this procedure in detail.
Perpendicular-to-Grain
- Insert a 2"x3"x6" specimen in the Instron 4469 testing machine, with fixed-upper and spherical-lower bearing plates.
- Use a 0.0001"x0.2" mechanical dial gage to determine the deformation.
- Using a speed of 0.012 in/min, record the load every 0.0025 inches.
- Stop the test once the maximum load is obtained or at 0.1 inches of deformation, whichever occurs first.
- Determine the compression modulus and compressive strength. Compare these values to those given in the sample results.
- ASTM
D143 section 12 covers
this procedure in detail.
For those groups running the
parallel-to-grain test, at what estimated load would your specimen buckle?
Summarize your results, as per your teachers'
instructions, and submit at the start of the next week's lab class.