The unconfined compression test is by far the most popular mechanical testing configuration to measure the mechanical properties of cylindrical samples. This undergraduate biomechanics class laboratory module consists of assessing mechanical properties of both rubber and hydrogel samples. Throughout this laboratory, each team will: prepare the rubber and hydrogel samples; test sample in unconfined compression with various stain rates; obtain the rubber and hydrogel samples’ stiffness and Young’s modulus for various strain rates considering the sample geometry; discuss the effect of stain rate on the Young’s modulus; conclude with the effect of strain rate on Young’s modulus for materials with elastic vs. non-elastic behavior.
Includes syllabus (instructor’s editable version) and turn-key sample preparation kit (e.g. rubber sheet, agar powder, 8-mm punches, metal rod) allowing about 10 repetitions (team of 2-5 students).
Requires Mach-1 tester (MA001 or higher), a uniaxial load cell (MA296 or MA297), a flat indenter (MA262 or MA263), testing chamber (small MA740 and large MA626).
- Deemed an excellent educational tool for students
- Includes a syllabus with clear learning goals, detailed procedure for sample preparation, mechanical testing and data analysis, descriptive video capsule and wrap-up questions.
- Learning Goal – Become familiar with the safe operation of a mechanical tester
- Learning Goal – Learn how to prepare disk-shaped samples
- Learning Goal – Measure the stiffness and Young’s modulus of disk-shaped samples
- Learning Goal – Understand the effect of stain rate on the measured Young’s modulus
- Learning Goal – Understand how the structure and composition of materials determine their mechanical behavior
