GENERATION, MECHANICAL AND STATISTICAL ANALYSIS, AND FEM SIMULATION OF FRACTURE OF REPEATABLE RANDOM ROUGH SURFACES

Natural weathering and wear of structural materials in service nearly always generate surface roughness, and follow the Central Limit Theorem prediction for surface topology. This study couples experimental and statistical theory, and FEM to extend knowledge of life of materials from initial service surface conditions through surface damage accumulation. Statistical moments and other parameters were correlated with fracture locations probability (H/N), versus auto correlation length, and depth. As the surface grows to a full Gaussian, H/N increases its dependence on profile’s Average and RMS Roughness, and derived parameters. This dependence shows an asymptotic limit behavior that approaches agreeably Griffith’s crack criterion, though with multiple pit locations. Importantly, a Transitional Region was observed, below which the probable location of fracture is uncorrelated to the parameters studied. This is because introduced roughness is insufficient to compete with impurities, internal and external manufacturing flaws, and scratches, due to handling and machining, on the samples.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical and Nuclear Engineering

Year dc:date.available

2012

Author dc:creator

• Medina, Hector

Contributors dc:contributor

• Brian Hinderliter

• random
• roughness
• fracture
• PMMA
• surface
• mechanical
• statistics
• Engineering

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/355

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1354