Determination of fracture strength and fracture energy of (metallo-) ceramics by a wedge loading methodology and corresponding cohesive zone-based finite element analysis

Abstract

Determination of fracture strength and fracture energy of (metallo-) ceramics by a wedge loading methodology and corresponding cohesive zone-based finite element analysis Determination of fracture strength and fracture energy of (metallo-) ceramics by a wedge loading methodology and corresponding cohesive zone-based finite element analysis. Engineering Fracture Mechanics, 196, 56-70. https://doi. A B S T R A C TA wedge loaded testing methodology to determine the fracture energy and strength of (semi-) brittle (metallo-)ceramics is presented. The methodology combines a tailored specimen geometry and a comprehensive finite element analysis based on cohesive zone modelling. The use of a simulation-based approach to extract both fracture strength and energy from experimental data avoids the inherent inaccuracies found in closed-form expressions that rely on a priori assumptions about the deformation field. Results from wedge splitting tests on Ti 3 SiC 2 and Ti 2 AlC (MAX phase) materials are used to illustrate the procedure. The simulation-based approach is further validated by comparing the fracture strength and fracture energies predicted by the proposed method and those indicated by a conventional four-point bending fracture toughness test (ASTM standard). The new protocol offers the possibility to measure not only the fracture properties of brittle material in its pristine state but also in the healed state.

Full strength and toughness recovery after repeated cracking and healing in bone-like high temperature ceramics

“…Monitoring crack extension by acoustic emission. Acoustic emission was employed to monitor crack extension during the wedge splitting test 50 . Two microphones (type PICO S/N 4926 and 4928, nominal frequency 500 kHz) were mounted on the WST sample; see Fig.…”

Multiscale modeling of the effect of sub-ply voids on the failure of composite materials

“…However, microscale damage does not immediately translate into macroscopic failure. Indeed, as it is common in multiscale analysis of fracture, the onset of fracture at the microscale typically occurs during the early stages of the loading but can only be detected at the macroscale once sufficient damage has accumulated (see, e.g., Suiker and Turteltaub, 2007a;Suiker and Turteltaub, 2007b;Farle et al, 2018;Hille et al, 2011 for examples in distinct material systems). In the current Fig.…”

Uncertainty Quantification of the Lifetime of Self-Healing Thermal Barrier Coatings Based on Surrogate Modelling of Thermal Cyclic Fracture and Healing

“…Finite element simulations have been extensively used to study the influence of self-healing particles and other microstructural parameters on the TBC lifetime [7][8][9][10][11][12][13][14][15][16][17][18]. These numerical simulation techniques can in general capture the experimentally-observed damage process that occurs in metallo-ceramic material systems [19,20]. However, finite element methods are deterministic in nat-ure, neglecting the randomness in the output as a result of possible uncertainties in the inputs.…”