Abstract Summary
Buildings subject to natural hazards should be considered as a system composed of structural elements and non-structural components. This is crucial for resilience assessments where the damage of both structural and nonstructural components can lead to loss of functionality and affect robustness. Most traditional modeling frameworks only account for the behavior of structural systems or use cascaded methods to study the behavior of nonstructural elements [1]. Here we discuss the simulation framework we are developing to simulate the entire building comprising both structural and nonstructural components. The framework is based on the potential of mean force approach to Lattice Element Method (LEM), used for modeling fracture in heterogeneous materials [2]. The discrete nature of LEM is particularly advantageous for damage and failure assessment as it does not suffer from the limitations of the classical continuum approaches in modeling discontinuity. We calibrate the parameters of interaction potential for one- and two-dimensional members. The computational tool is shown to be accurate and efficient for quasi static simulations. This is essential to make the simulation tool amenable to resilience assessments under natural hazards with dynamic nature such as earthquakes and hurricanes. To evaluate versatility of the proposed approach in simulating the dynamic response of the buildings, we leverage the fundamental of molecular dynamics within the PMF-based LEM framework. Analogous to static condensation in continuum mechanics, here, at every single time step, the mass-included degrees of freedom are updated and obtained through MD algorithm while the LEM formulation obtain the remaining degrees of freedom evoking theorem of minimum potential energy. In this presentation, we discuss the adaptation of MD to LEM formulation to account for dynamic effects. The promise of the dynamic extension of the PMF-based LEM is then evaluated through its application to free vibration analysis of the large-scale buildings. This is essential to make the simulation tool amenable to resilience assessments under natural hazards with dynamic nature such as earthquakes and hurricanes.
