Dynamic mechanical response of damaged alumina AD995. Issue 3 (March 2021)

• Record Type: Journal Article
• Authors: Koch, Brendan M.L.; Lo, Calvin; Li, Haoyang; Sano, Tomoko; Ligda, Jonathan; Hogan, James David
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 3(2021)
• Page Start: 2034
• Page End: 2048
• Publication Date: 2021-03
• Subjects: Ceramics -- Damage accumulation -- Thermal shock -- DIC -- Failure -- Compressive loading; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.10.020
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: This paper explores the compressive responses of alumina ceramics subjected to various levels of pre-damage via internal cracking. Pre-damage is achieved by subjecting the samples to thermal shock. Mechanical loading is performed using a load frame for quasi-static strain rates and a Kolsky bar for dynamic strain rates. Digital image correlation is used to obtain two-dimensional strains alongside independently measured applied stresses. Data acquisition used in this study allows for the calculation of apparent elastic moduli as a function of strain. This allows for the study of change in mechanical response with strain, strain-rate, and level of pre-damage. There is a complex interaction between pre-damage and compressive loading, leading to mechanical damage accumulation being divided into three stages rather than a single damage accumulation function. It was also found that shear modulus change was more indicative of physical failure phenomena during loading than Young's modulus or Poisson's ratio changes.