Summaries of ASTM standards

• 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.

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

Figure 1: Universal Testing Machine (UTM)

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

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 specimen into the test fixture as shown in the equipment and apparatus section.

4. Attach the deflection transducer.

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

• 3-point or 4-point bend test

Figure 3: 3-Point Bend Test

Figure 4: 4-Point Bend 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

• 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:

    • 
    • 
    • 

• Test at least 5 specimens

• UTM

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

• Tensile Test

• Equipment required:

  • Special Alignment Jig as shown in the figure below.

• Apparatus will be a compression test fixture

• Condition specimens

• Apply strain gages/extensometers to both faces of the specimen

• Monitor test temperature using thermocouples.

• 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.

• https://www.youtube.com/watch?v=qfHoq9w3glE

This video is a good example of this test being carried out.

• Failure modes:

  • Record them by giving a code as shown 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*

• Test at least five specimens per test condition

• Same as ASTM D3039 standard along with the following:

• Same as ASTM D3039

• Same as ASTM D3039 as well as:

  • This test will have normal strain instrumentation in both the longitudinal and transverse directions. It will also have a continuous/nearly continuous force normal strain data recording. 

• Tensile Test

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

•   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.

• Apart from the testing apparatus, the only equipment needed is a conditioning room/desiccators

• The following is a picture of the testing apparatus:

• Hehe…remember this…yeah it still makes no sense :C

• Pendulum testing apparatus

• These are the only values needed to be reported (they don’t seem like they’re calculations)

  • Average peel/stripping strength.

  • Max and Min strength values of the series.

  • Type of failure.

• Will conform to the following geometry:

  

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

• No equipment listed, just apparatus:

  • The machine will have a capacity of no less than 6810kg in compression and shall be fitted with a shearing tool containing a self-aligning seat to ensure uniform lateral distribution of the load.

  • It will be able to maintain a uniform rate of loading so the load may be applied with a continuous motion. The apparatus is pictured below:

• At least 20 specimens should be tested, they will represent at least four different joints.

• We will have to prep the test joints:

  • They will be hard maple blocks, having a minimum specific gravity of 0.65 based on oven-dry weight and volume shall be selected. Below is a picture of the test joints and how they should be cut?

• I don’t really get how to explain this one to be honest help :C

• Calculations:

  • Shear stress at failure.

  • Max and min shear stress at failure and percentages of wood failure.

  • The standard deviation of all individual test values.

  • Average shear stress at failure and the average percentage of wood failure.

• Use these if you can:

• Test 10 test specimens for each adhesive

• Equipment:

  • Desiccators

  • Conditioning chambers

• Apparatus:

  • Use a pendulum-type impact machine (pictured below).

• Use a jig to hold the specimen as shown below.

• Use a vise/bolts to hold the jig rigid.

• Put the specimen in the jig in the vise of the machine so the specimen butts squarely against the end of the jig.

• Rest the impact head against the specimen and adjust the jig so the head fits squarely against the impact face.

• Raise the impact head and release the safety catch.

• We will then note the impact energy absorbed.

• A pendulum will fall and hit our specimen and test the adhesive strength

• Joules of energy absorbed in producing failure of the specimen

• Percentages of cohesion, adhesion, and contact failure. This will be based on visual inspection. 

• Calculation:

  • Impact strength of the specimen over the bonded area. 

*the calculations will be available in the confluence page*

• Substrates—Fiber reinforced plastic (FRP) as specified, with metal composition (heat treat, temper, and condition) and roughness as specified when bonding FRP to metal. (I don’t know what this means)

• Cut fiber-reinforced plastic parts into flat coupons 1 by 4 in. (25.4 by 100 mm) at a nominal thickness of 0.1 in. (2.5 mm). In the case of FRP-to-metal bonding, use metal with a nominal thickness of 0.06 in. (1.5 mm). It is recommended that a diamond tip water-cooled saw blade be used, or a cutting method capable of producing sharp cut edges.

• Joint Geometry—Control joint geometry by appropriate fixturing, using glass beads or other suitable means to control a 0.03-in. (0.76-mm) adhesive bondline thickness. Use the minimum number of glass beads in the glue line needed to hold bondline thickness. Fixturing pressure is allowed. Lap shear overlap will be 1 by 1 in. (25.4 by 25.4 mm) See Figure 1 below.

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

• No equipment is outlined, only an apparatus which is said to most likely just be a simple tensile tester like pictured below

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

• Prep the surface of the FRP as recommended by the adhesive manufacturer. If there is no recommendation, prep the surface as outlined in practice D2093. 

• 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.

• The initial grip separation is 75mm, with a minimum of 25.4mm of each sample end held in the test grips.

• The load rate is 13mm/min. 

• This load rate is said to be an important difference compared to other standards. 

• Tensile test.

• Complete identification of the adhesive tested, this includes the type and manufacturers code number. 

• Complete identification of the substrates used. This includes the type of resin and fiber orientation as well as the method of surface prep prior to bonding.

• Cure schedule time and temperature for bonding sample. 

• Individual peak load values, and averages by maximum and minimum values.

• Test temperature and conditions.

• Type of failure whether it be fiber tear, cohesive, adhesive.