Standard Test Method for Determination of Viscoelastic Properties of Elastomers using the Micro-Tribometer

DIN 53 513

Summary of Test Method:

This test method determines the viscoelastic properties of elastomers when exposed to forced vibration at non-resonant frequencies. A sinusoidal force of a given frequency and amplitude is applied to the test specimen while recording the applied force and the displacement required to achieve that force. The applied force, frequency of oscillation, test temperature, and test duration can be varied.

In the UMT the specimen is held on a stationary table while the z-carriage applies the force through a friction/load sensor. An encoder on the z-carriage is used to measure real-time displacement. Using the Viewer program to analyze the data, the Static Modulus, Complex Normal Modulus, Complex Compression or Shear Modulus, and loss Factor are calculated.

UMT Hardware Configuration:

· 4” Mounting Block – PN M30C116

· Model DFM-0.5 Dual Friction/Load Sensor

- range 5 to 500 grams

· Specimen

- length 10mm, diameter 10mm

· Stationary Specimen Table

· Optional Additional Sensors

- mod. TMR-150 Temperature Measurement & Recording

- mod. RTD Temperature Sensor

UMT Software Test Setup:

UMT Options File:

Load the options file that contains settings for the 500 gram force/load sensor.

Test Sequence:

The Test Sequence should consist of 2 sheets.

Sheet 1 is for settling time for the normal load and temperature.

Carriage - applies a Constant Force of 30 g for a 6 second Duration.

Spindle – Velocity is 0 revs/min.

Slider – is idle.

Sheet 2 is for the actual dynamic test.

Carriage - applies a Sinusoidal Force (Fz) by Time with a Mean force of 25 g,

a Magnitude of 25 g, and a frequency of 2 Hz for a 16 second Duration.

Spindle – Velocity is 0 revs/min.

Slider – is idle.

Data Collection:

The following should be checked under DataFile:

Fz – Normal Force

T – Time

SZ – Analog Carriage Position (Used to determine displacement))

Te – Temperature (Optional)

Report:

Use the Viewer program to plot the test results and to calculate the Static Modulus, Complex Normal Modulus, Complex Compression or Shear Modulus, and Loss Factor.

Select the parameters to be displayed (Fz and SZ) by checking the appropriate box under Parameters on the Viewer screen. Use the right-hand mouse button to place the yellow and green markers to encompass at least one complete cycle of either Fz or SZ.

Click on the Elastomer Graph button on the tool bar, and the following screen will appear.

The force-displacement plot is displayed. Select the Test Type (Compression or Shear). Select the Specimen Shape (Cylindrical or Square). Select the Number of Samples (usually 1 for compression and 2 for shear). Enter the sample dimensions, and click on the Calculate button. The following results will be automatically calculated and appear in the right-hand column.

Area (mm²)

Force Fa (N)

Displacement or Deflection SA (mm)

Stress (MPa)

Area of Ellipse (N x mm)

Static Modulus (MPa)

Corrected Static Modulus (MPa)

Corrected Complex Normal Modulus (MPa)

Complex Compression Modulus or Complex Shear Modulus (MPa)

Loss Factor

Click on the Printer button on the Tool Bar to print the plot and the calculation results.