Stress-Strain Apparatus without Sensors • AP-8221A

This compact Stress-Strain Apparatus shows the stress and strain during the entire process of stretching and breaking a material. It offers a scaled-down version of traditionally expensive engineering devices, allowing students to explore all the same physics concepts without the high cost of a materials testing machine.

Since the Stress-Strain Apparatus shows the entire stress versus strain curve, it is possible to measure a wide range of material properties including:

• Young’s Modulus
• Yield strength
• Tensile strength
• Ductility 
• Toughness

Students can also compare the different curve shapes produced by various materials. 

PASCO Capstone software allows students to determine Young’s Modulus by measuring the slope of the initial straight line (the elastic region) and to determine the toughness by integrating under the curve.

How It Works

Tension is applied to the sample by turning the knob by hand until the sample breaks. The force used to stretch the sample is measured using a Force Sensor connected to a ScienceWorkshop or PASPORT Interface. A metal lever provides a five-to-one mechanical advantage, increasing the maximum force that the sensor can read to 250 N.

The stress is calculated using Capstone by taking the force over the cross-sectional area. No adjustment is made for any change in the cross-sectional area during stretching.

The change in length of the sample is measured using a Rotary Motion Sensor. The resolution is 0.007 mm. The strain is calculated using Capstone by dividing the change in length by the original length.

What's Included

• 1x Stress/Strain Apparatus