Analysis of the Quasi-Static and Dynamic Fracture of the Silica Refractory Using the Mesoscale Discrete Element Modelling

Abstract

Computer modelling is a key tool in the optimisation and development of ceramic refractories utilised as insulation in high-temperature industrial furnaces and reactors. The paper is devoted to the mesoscale computer modelling of silica refractories using the method of homogeneously deformable discrete elements. Approaches to determine the local mechanical properties of the constituents from the global experimental failure parameters and respective crack trajectories are considered. Simulations of the uniaxial compressive and tensile failure in a wide range of quasi-static and dynamic loading rates (102 s−1) are performed. The upper limit of the dynamic loading rates corresponds to the most severe loading rates during the scrap loading on the refractory lining. The dependence of the strength, fracture energy, and brittleness at failure on the loading rate is analysed. The model illustrates that an increase in the loading rate is accompanied by a significant change in the mechanical response of the refractory, including a decrease in the brittleness at failure, a more dispersed failure process, and a higher fraction of the large grain failure. The variation of the grain–matrix interface’s strength has a higher impact on the static compressive than on the static tensile properties of the material, while the material’s dynamic tensile properties are more sensitive to the interface strength than the dynamic compressive properties.

Design, Manufacturing and Properties of Refractory Materials

“…Grigoriev et al [6] presented computer modeling of 96% SiO 2 refractories (for coke ovens, heat exchangers of blast furnaces, and glass-making furnaces) using the method of homogeneously deformable discrete elements to simulate the uniaxial compressive and tensile failure in a wide range of quasi-static and dynamic loading rates. Also, crack patterns were presented for real and model materials.…”

Лагранжев Формализм Для Анализа Акустических Свойств Двухфазных Композитных Материалов С Дефектными Межфазными Границами

“…В лагранжиане (4) в выражении для плотности полной потенциальной энергии перейдем от эффективных характеристик к истинным, учитывая (10) и (11):…”

“…Для такой среды строится система определяющих соотношений с учетом условий для напряжений и деформаций на внутренних границах раздела (интерфейсах). В общем случае такая система уравнений решается численно, а усреднение получаемых результатов для представительных мезообъемов позволяет оценивать эффективные свойства композита [7][8][9][10][11][12][13]. Несмотря на хорошо известные преимущества (возможность явного учета микроструктуры и особых свойств интерфейсов), непосредственная компьютерная гомогенизация является вычислительно крайне затратной процедурой вследствие необходимости проведения многопараметрического исследования для определения однозначного соответствия внутренней структуры и макроскопических свойств материала.…”

A multilevel model for description of thermomechanical fracture of refractory linings of high-temperature equipment

“…The condition for the transition from meso-to macro-fracture is determined by the mechanism of mesocrack merging (through matrix and interfaces or through large reinforcing grains). The numerical study of the formation of a cracked structure done by Grigoriev et al (2021) and experimental data have shown that the main path of crack propagation in refractories is along the interfaces between large grains and the matrix, or through the matrix. It is obvious that large grains in most cases are insurmountable obstacles in the path of a crack, which is consistent with the results done by Romanov & Vladimirov (1992) and Gutkin et al (2007).…”