Tensile Test Dr. Ken Lulay EGR270 Materials Laboratory Spring 2014

Overview Tensile testing review Tensile testing review Test procedure Test procedure Materials to be tested Materials to be tested

Tensile Testing Uniaxial test (load in one direction) Uniaxial test (load in one direction) Record force (  =F/A 0 ) and strain Record force (  =F/A 0 ) and strain Important mechanical properties 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 %RA) Ductility (%EL and %RA)

Test Standard ASTM E8 – Standard Test Methods of Tension Testing of Metallic Materials ASTM E8 – Standard Test Methods of Tension Testing of Metallic Materials Gage length > 4D (uniform stress) Gage length > 4D (uniform stress) Grips should be free to rotate Grips should be free to rotate uses spherical bearing to allow rotation uses spherical bearing to allow rotation creates a 2-force member (axial load) creates a 2-force member (axial load) Temperature between 50 and 100°F Temperature between 50 and 100°F

Procedure Mark, measure and record: Mark, measure and record: gage length (close to 2 inches) gage length (close to 2 inches) diameter diameter Load into test frame (SATEC) Load into test frame (SATEC) Apply load, record force and strain Apply load, record force and strain After fracture, measure and record: After fracture, measure and record: final gage length final gage length diameter in necked region diameter in necked region

Materials to be Tested 2024-T351 aluminum alloy 2024-T351 aluminum alloy AISI 1045HR (hot rolled) AISI 1045HR (hot rolled) UHMW-PE (polyethylene) UHMW-PE (polyethylene) Acrylic Acrylic Already tested: 1018CF, 1045CF, 4140CF Already tested: 1018CF, 1045CF, 4140CF

Aluminum Alloys Designation of wrought aluminum alloys (by the Aluminum Association) – the first digit of the four digit scheme indicates primary alloying elements: Designation of wrought aluminum alloys (by the Aluminum Association) – the first digit of the four digit scheme indicates primary alloying elements:

Heat Treatable Wrought aluminum alloys 2xxx – copper 2xxx – copper 4xxx – silicon 4xxx – silicon 6xxx – magnesium and silicon 6xxx – magnesium and silicon 7xxx – zinc 7xxx – zinc 8xxx – other elements 8xxx – other elements

Non-Heat Treatable wrought aluminum alloys 1xxx – commercially pure aluminum 1xxx – commercially pure aluminum 3xxx – manganese 3xxx – manganese 5xxx – magnesium 5xxx – magnesium

Cast aluminum alloys 1xx.x – 99.00% pure aluminum 1xx.x – 99.00% pure aluminum 2xx.x – copper 2xx.x – copper 3xx.x – silicon with copper and/or magnesium 3xx.x – silicon with copper and/or magnesium 4xx.x – silicon 4xx.x – silicon 5xx.x – magnesium 5xx.x – magnesium 7xx.x – zinc 7xx.x – zinc 8xx.x – tin 8xx.x – tin 9xx.x – other elements 9xx.x – other elements

Temper Designation F: As fabricated F: As fabricated O: Annealed O: Annealed W: Solution heat-treated. W: Solution heat-treated. H: Strain hardened. H: Strain hardened. T: Thermally treated. T: Thermally treated.

T1 – Cooled from hot working temperature and naturally aged T1 – Cooled from hot working temperature and naturally aged T2 – Cooled from hot working temperature, cold worked, naturally aged T2 – Cooled from hot working temperature, cold worked, naturally aged T3 – Solution heat treated, cold worked, naturally aged T3 – Solution heat treated, cold worked, naturally aged T4 – Solution HT, naturally aged T4 – Solution HT, naturally aged T5 – Cooled from elevated temperature and artificially aged T5 – Cooled from elevated temperature and artificially aged T6 – Solution HT, artificially aged. T6 – Solution HT, artificially aged. T7 – Solution heat treated and overaged or stabilized (corrosion resistance). T7 – Solution heat treated and overaged or stabilized (corrosion resistance).

2024-T351 2xxx = copper main alloy element 2xxx = copper main alloy element 2024: 4.4%Cu, 1.5%Mg, 0.6%Mn 2024: 4.4%Cu, 1.5%Mg, 0.6%Mn T: Thermally treated T: Thermally treated T3: sol’n HT, cold worked, nat. aged T3: sol’n HT, cold worked, nat. aged T351: sol’n HT, cold worked for stress relief, natural aged. T351: sol’n HT, cold worked for stress relief, natural aged.

UHMW-PE Ultra-High Molecular Weight, Polyethylene Ultra-High Molecular Weight, Polyethylene Ultra-High Molecular Weight? Ultra-High Molecular Weight? Thermoplastic Thermoplastic Thermoplastics are strain rate sensitive Thermoplastics are strain rate sensitive Stiffness Stiffness Strength Strength Thermoplastics are temperature sensitive Thermoplastics are temperature sensitive

Acrylic (Polymethylacrylate)

Any questions Any questions Tensile testing? Tensile testing? Stress-strain curves? Stress-strain curves? What we are doing today? What we are doing today? What is required? What is required?