brittle fracture_Eddie.xlsx

brittle fracture_Eddie.xlsx - C) Environmental Effects...

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Part 1 Elastic Modulus 1) Mean of Elastic Modulus: We use “E(Pa) of Modulus Measurement” from raw data. Mean of Elastic Modulus= Ex) 59.798855366GPa= : Measurement value Literature Value of Elastic Modulus=65000000000 Pa With compare to Literature value, our measurement Elastic Modulus is about 8.002% lower than literature value. 2) Standard Deviation of Elastic Modulus: We use “E (Pa) of Modulus Measurement” from raw data. Standard Deviation of Elastic Modulus= Ex) 12.526333695GPa= 3) 95% confidence limits for our elastic modulus measurements: We use “E (Pa) of Modulus Measurement” from raw data. 95% confidence limits (upper)=Mean+(2*Standard deviation) Ex) 59.798855391GPa =62.213389947GPa+(2*12.526333695GPa) 95% confidence limits (lower)=Mean-(2*Standard deviation) Ex) 59.798855341GPa=62.213389947GPa-(2*12.526333695GPa) Part 2 Fracture Strength

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Unformatted text preview: C) Environmental Effects (Stress Corrosion Cracking) : We use “Force to fracture (Pa)” form raw data. 1) Calculate ( fail ) dry Ex) 33962354 N/= Calculate ( fail ) wet Ex) 29588017 N/= Compare ( fail ) dry vs. ( fail ) wet Average ( fail ) dry = 33493675 N/=33.493675MPa Average ( fail ) wet = 29416168 N/=29.416168MPa Difference = Average ( fail ) wet is 12.174% less than Average ( fail ) dry. 2) In the presence of water, cracks will continue to grow. This behavior can be exploited to study crack propagation under iso-thermal conditions. Water apparently acts as a catalyst for crack growth by reducing the surface energy of the glass. Griffith equation: Surface Energy at dry condition: =0.026226 Surface Energy at wet condition: Difference = Water reduces the surface energy by 24.1897%...
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This note was uploaded on 02/29/2012 for the course PHY 2218 taught by Professor Livingston during the Spring '12 term at University of Minnesota Crookston.

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brittle fracture_Eddie.xlsx - C) Environmental Effects...

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