Versions Compared

Version Old Version 15 New Version Current
Changes made by

Maciek Pajak (Deactivated)

Tommy Tran

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

...

...

...

...

...

...

Table of Contents

ASTM C393_Standard Test Method for Shear Strength

  • Specimen is rectangular in cross-section

    • Expand
    titleTest Specimen Sampling and Geometry
    Requirements

    • 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.

    Expand
    titleEquipment and Apparatus:

    • Apparatus: Universal Testing Machine (UTM) with a deflection transducer, as shown in the figure below.

    Image Removed

    Image Added

    Figure 1: Universal Testing Machine (UTM)

    Image Removed

    Figure 2: Deflection transducer setup in a 3-point bend test

    Expand
    titleProcedure:

    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.

    Variable

    Quantity

    Load rate

    6mm/min

    Failure occurence

    3-6 minutes

    Support bar separation

    150 mm

    Expand
    titleBasic Description:

    • 3-point or 4-point bend test

    Figure 3: 3-Point Bend Test

    Figure 4: 4-Point Bend Test

    Expand
    titleReported 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 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:

      • For 4-Point, Quarter-point loading:

      • For 4-Point (Third Point) Loading:

    ASTM D3039_Standard Test Methods for Tensile Properties

    Expand
    titleTest Specimen Sampling and GeometryRequirements

    • Test at least 5 specimens

    Expand
    titleEquipment and Apparatus:

    • Apparatus: Universal Testing Machine (UTM)

    Image Added

    Figure 1: Universal Testing Machine (UTM)

    Expand
    titleProcedure:

    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

    Variable

    Quantity

    Failure occurence

    1 to 10 min

    Head displacement

    2mm/min

    Expand
    titleBasic Description:

    • Tensile Test

    ...

     ASTM D3410_Standard Test Method for Compressive Properties of Polymer Matric Composite Materials

    Expand
    titleTest Specimen Requirements
    Image AddedImage Added

    • Test at least 5 specimens

    Expand
    titleEquipment and Apparatus:

    • Equipment required:

      • Special Alignment Jig as shown in the figure below.

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

    Expand
    titleProcedure:

    • Condition specimens

    • Apply strain gages/extensometers to both faces of the specimen(if we choose to).

    • Monitor test temperature using thermocouples (if we choose to).

    • If needed, move the testing machine crosshead to open the distance between the 2 housing blocks so both the upper and lower wedge rip assemblies may be accessed. 

    • Close the upper grips manually to check the specimens vertical displacement. Do it with the lower grips as well. The upper grips should be in full contact with the wedge when closed. Repeat if we need to. 

    • Attach strain transducers if they will be used. Then, attach the strain recording instrumentation to the strain gages or other transducers on the specimen. Then, remove any remaining preload and zero the transducer(s).

    • Apply the force to the fixture at the specified rate until failure while recording data.

    Variable

    Quantity

    Strain Rate

    0.01 min-1

    Crosshead Displacement

    1.5 mm/min

    Failure occurence

    1-10 min

    ...

    Expand
    titleReported during test:

    • 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. 

    Variable

    Symbol

    Compressive Stress/ Ultimate Compressive Stress

    F cu

    Compressive strain/ Ultimate Compression Strain

    Ɛi c

    Compressive Modulus of Elasticity

    E chord

    Compressive Poison’s ratio

    v c

    Transition Strain

    μ E

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

    ASTM D3518_Standard Test Method for In-Plane Shear Response of Polymer Matrix Composite Materials by Tensile Test

    Expand
    titleTest Specimen Sampling and GeometryRequirements

    • Test at least five specimens per test condition

    • Same as ASTM D3039 standard along with the following:

    ...

    Expand
    titleReported during test:

    Variable

    Symbol

    Max Shear Stress

    t12m

    Shear Stress

    t12i

    Shear Strain

    y12i

    Max Shear Strain

    y12m

    Shear Modulus of Elasticity

    G12chord

    Offset Shear Strength

    F12o

    *Again, all these formulas will be in the confluence page*

    ASTM D903_Standard Test Method for Peel or Stripping Strength of Adhesive Bonds

    Expand
    titleTest Specimen Sampling and Geometry

    •   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.

    ...

    ASTM D905_Standard Test Method for Strength Properties of Adhesive Bonds in Shear by Compression Loading (for adhesives on wood)

    Expand
    titleTest Specimen Sampling and Geometry:Requirements

    • Will conform to the following geometry:

    • At least 20 specimens shall be tested, representing at least four different joints

    ...

    ASTM D950_Standard Test Method for Impact Strength of Adhesive Bonds

    Expand
    titleTest Specimen Sampling and Geometry:Requirements

    • Use these dimensions if you can:

    • Test 10 test specimens for each adhesive

    ...

    ASTM D5868_Standard Test Method for Lap Shear Adhesion for Fiber Reinforced Plastic (FRP) Bonding

    Expand
    titleGeometry:Test Specimen Requirements

    • Prepare a minimum of 5 lap shear samples in each case and test.

    • See figure 1 below for the recommended geometry of the lap shear samples

    ...

    Expand
    titleProcedure:

    • Apply the adhesive in accordance with the adhesive suppliers recommendations. 

    • Adhesive Cure—Cure the adhesive at room temperature or elevated temperature using prescribed conditions determined by the adhesive supplier.

    • Condition the test specimens

    • Place specimens in UTM

    • Wait for failure

    Variable

    Quantity

    Grip Separation

    75mm

    load rate

    13mm/min

    ...