Uniaxial Tests
For test data for a specimen undergoing a uniaxial test consider the following figure:
1. Initial configuration
2. Loaded configuration
3. Stress
4. Strain
In a uniaxial test, the specimen is slowly loaded or pulled in one direction, say the x-direction. No other loads or constraints are applied to the specimen.
For a nearly incompressible hyperelastic material, the stretch ratios are given by:
where 
For test data enter engineering stress as:
Enter engineering strain as:
