Application of mean-force potential lattice element method to modeling complex structures

Abstract

Natural hazards such as windstorms, earthquakes, and floods cause damage and failure to both structural and non-structural elements, significantly impacting the functional integrity and overall performance of the building systems. The economic loss due to such events and the often tortuous path to recovery call for revisiting engineering approaches to resilience assessment through developing simulation methods that provide a balance between fidelity and efficiency, particularly if the post-event assessment is to be performed at a large scale, e.g., the scale of a community. In this paper, we develop a discrete simulation framework for modeling the response of structures as a middle-ground solution between overly simplistic multi-degree-of-freedom models on the one hand and intricate FE models on the other. The framework draws upon the Potential-of-Mean-Force (PMF) approach to Lattice Element Method (LEM) where the main idea is to discretize the system into a set of particles that interact with each other through prescribed interaction potentials. These potentials are calibrated beforehand at member scale, for different structural and non-structural components. Here we focus on providing the main elements and the steps necessary for adaptation to modeling structural components in linear regime and leave the extension to nonlinear regime and the modeling of damage for future developments. This includes calibration of the potentials for structural members of different types (1D vs. 2D) under different actions (axial, bending, in-plane and out-of-plane actions) through an energetic handshake between the lattice model and continuum theories, e.g., the Timoshenko beam theory and Kirchhoff–Love plate theory. We explore the utility of the proposed method through its application to simulation of a set of building systems with different levels of complexity and under various loading conditions.