A new technique for the production of glass foams was developed, based on alkali activation and gel casting. The alkali activation of soda-lime waste glass powders allowed for the obtainment of well dispersed concentrated suspensions, undergoing gelification by treatment at low temperature (75 degrees C). An extensive direct foaming was achieved by mechanical stirring of partially gelified suspensions, comprising also a surfactant. The suspensions were carefully studied in terms of rheological behavior, so that the final microstructure (total amount of porosity, cell size) can be directly correlated with the degree of gelification. \ud
A sintering treatment, at 700-800 degrees C, was finally applied to stabilize the foams, in terms of leaching of alkaline ions. Considering the high overall porosity (88-93%), the newly obtained foams exhibited a remarkable compressive strength, in the range of 1.7-4.8 MPa
State-based peridynamics is a non-local reformulation of solid mechanics that replaces the force density of the divergence of stress with an integral of the action of force states on bonds local to a given position, which precludes differentiation with the aim to model strong discontinuities effortlessly. A popular implementation is a meshfree formulation where the integral is discretized by quadrature points, which results in a series of unknowns at the points under the strong-form collocation framework. In this work, the meshfree discretization of state-based peridynamics under the correspondence principle is examined and compared to traditional meshfree methods based on the classical local formulation of solid mechanics. It is first shown that the way in which the peridynamic formulation approximates differentiation can be unified with the implicit gradient approximation, and this is termed the reproducing kernel peridynamic approximation. This allows the construction of non-local deformation gradients with arbitrary-order accuracy, as well as non-local approximations of higher-order derivatives. A high-order accurate non-local divergence of stress is then proposed to replace the force density in the original state-based peridynamics, in order to obtain global arbitrary-order accuracy in the numerical solution. These two operators used in conjunction with one another is termed the reproducing kernel peridynamic method. The strong-form collocation version of the method is tested against benchmark solutions to examine and verify the highorder accuracy and convergence properties of the method. The method is shown to exhibit superconvergent behavior in the nodal collocation setting.
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