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ASTM Testing Standards

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title	Test Specimen Sampling and Geometry

Specimen has 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.

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title	Equipment and Apparatus:

Equipment: ball-interfaced and anvil interface micrometer, deflectometer, conditioning chamber, environmental test chamber are recommended but not required.
Apparatus: The machine will have a stationary and movable head, the machine should be able to indicate the total force being carried by the test specimen, it will either be a 3- or 4-point bend test. Below is what they used

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title	Equipment and Apparatus:

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title	Procedure:

Test at least five specimens.
Condition the specimen in a chamber if the test environment is not the same as a conditioned environment.
Measure the length, width and thickness at three places in the specimen.
Place the specimeninto the test fixture and align the fixture so the longitudinal axis of the specimen is perpendicular (within 1 degree) to the longitudinal axes of the loading bars, the bars must also be parallel (within 1 degree) to the plane of the specimen facings. Attach Measure the length, width and thickness at three places in the specimen.
Place the specimeninto the test fixture as shown in the equipment and apparatus section.
Attach the deflection transducer.
Apply a compressive force to the specimen until failure or until a deflection equal to the thickness is reached.
It was noted that the speed of testing should be around Speed of Testing = 6mm/min.
Failure should occur at 3-6 minutes.

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title	Reported during the test:

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 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:
  - Core Shear Ultimate Stress
  - Core Shear Yield Stress
  - Facing StressImage AddedImage Added
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- For 4-Point, Quarter-point loading:
  - Core Shear Ultimate Stress
  - Core Shear Yield Stress:
  - Facing Bending StressImage Added
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- For 4-Point (Third Point) Loading:
  - Core Shear Ultimate Stress
  - Core Shear Yield Stress:
  - Facing Bending Stress:

these calculations are in the confluence page

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title	Equipment and Apparatus:

Compression Testing Fixture(pictured below are schematics and the actual fixture)

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Apparatus:
- There will be a force indicator
- The machine will have two loading heads.

^^^I don’t exactly know what this means (interpret pls)

The drive mechanism will be able to give a controlled displacement rate with respect to the stationary head.
If the atmosphere conditions suck use a conditioning chamber and an environmental test chamber.
If the material is super stiff use an extensometer.

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