1. Tensile Test Post-Laboratory Dr. Ken Lulay EGR270 Spring 2009

2. Tensile Testing Uniaxial test Record force (  =F/A 0 ) and strain Important mechanical properties Yield strength (  ys or  yp ) Yield strength (  ys or  yp ) Tensile strength (  UT ) Tensile strength (  UT ) Modulus of Elasticity (E) Modulus of Elasticity (E) Ductility (%EL and %AR) Ductility (%EL and %AR)

3. Materials Tested 2024-T351 aluminum alloy AISI 1045 hot rolled steel UHMW-PE (polyethylene) Acrylic AISI 1045 CF, 1018CF and 4140CF provided

6. Unload/reload “Blips” are due to changes in load rate (many polymers are very rate sensitive) Necking extends

7. Extensometer removed, Cross-heads stopped Unload/reload Load rate increased

8. Young’s modulus of steel: 30Mpsi, of aluminum alloys: 10Mpsi Density of aluminum is about 1/3 that of steel

9. Tensile Strength Fracture Stress

10. Conclusions Stress-strain data was recorded for five materials Basic mechanical properties were determined Did mechanical properties meet or exceed specifications?

11. Recommendations Additional testing could include: Hardness Hardness Charpy impact toughness Charpy impact toughness Chemical composition Chemical composition

12. QUESTIONS?