Page Comparison

• Specimen is rectangular in cross-section

• Length x Width x Depth - 200 mm x 75 mm x Thickness of Sandwich Construction

• Make sure to test at least five specimens per test condition unless you are confident that the results obtained are valid through the use of fewer specimens.

1. Condition the specimen in a chamber if the test environment is not the same as a conditioned environment.

2. Measure the length, width and thickness at three places in the specimen.

3. Place the specimeninto the test fixture as shown in the equipment and apparatus section.

4. Attach the deflection transducer (if we choose to use one).

5. Apply a compressive force to the specimen until failure or until a deflection equal to the thickness is reached.

• Force versus crosshead displacement, force versus deflection data continuously, or at frequent intervals (around 2-3 recordings per second, with a target minimum of 100 recorded data points)

• If there are any initial failures, record force, displacement and mode of damage where the failure occurs. 

• Record mode, area and location of each failure. 

• Use the failure identification codes, shown in the figure below.

• Record the max force, failure force, head displacement and the deflection at the moment of ultimate failure. 

• For ultimate failure modes, record the mode, area and location of ultimate failure for each material. 

• Calculations:

  • For 3-Point Mid-Span Loading:

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  • For 4-Point, Quarter-point loading:

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  • For 4-Point (Third Point) Loading:

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1. Measure the specimen in 3 places and report average thickness and width as well as average area. 

2. Place the specimen into the grips of the testing machine

3. Apply the force until failure occurs

• Equipment required:

  • Special Alignment Jig as shown in the figure below.

• Apparatus will be a compression test fixture as shown in the figures below.

• Failure modes:

  • Record them by giving a code as shown in figure 9, below:

• There are a few unacceptable failure modes including end-crushing and euler buckling. 

*remember all these formulas will be in the astm document for finding the above values*

•   The above is the diagram of the geometry

• Test at least 10 test specimens for each adhesive.

• Discard specimens that give out-of-line test results due to obvious flaws and then retest.