2025-07-24 –, Main Room 1 (Main stage)
This talk will present the latest developments in JuLDPM.jl, a Julia package for the Lattice Discrete Particle Model (LDPM), in the context of mechanics of porous media. The talk will first present the main features of the LDPM approach, highlighting several computational advantages in the description of discontinuities and localized phenomena. Three applications will be presented, with emphasis on the computational advantages granted by Julia in performing large-scale simulations.
Lattice models simulate the behavior of solid media by means of a dense network of 1D elements, connected on a structured or unstructured set of nodes. These approaches originate from the work of Navier and Cauchy on the central force approach as the framework for the theory of elasticity (1827). In the early 1940s, Hrennikoff proposed the so-called framework method, in which the mechanical behavior of continuous media is discretized by means of a network of 1D bars. This work constitutes the basis for the variety of lattice modeling approaches derived decades later. Among these, the Lattice Discrete Particle Model (LDPM) emerged as one of the most accurate methodologies to solve elasticity and fracture problems for engineering mechanics applications, such as cementitious composites and granular assemblies. The main feature of LDPM that sets it apart from other available lattice modeling techniques is that the mesoscale features of the materials are directly represented by randomly placing poly-sized spheres in the computational domain. The spheres, which idealize inclusions such as aggregate particles in concrete, are sized according to the physical length scales governing the fracture processes (e.g, the granulometric curve in a concrete mix). The lattice elements are constructed by means of a Delaunay tessellation constructed on the sphere centroids, while their inertial properties are derived from a dual tessellation that was specifically designed to represent potential crack paths in the domain based on the internal structure of the material.
This talk will be delivered as a cohesive sequence of three lightning talks, and will feature three speakers, discussing three significant advancements in LDPM recently developed by our research team : (1) a stochastic LDPM approach for simulation of fracture in porous cementitious composites, (2) an extension of the classical lattice model to encompass dual tessellations for the simulation of erosion in flood protection system infrastructure, (3) recent development and implementation of a novel reduced-order modeling technique for LDPM based on a Proper Orthogonal Decomposition. Emphasis will be given to the description of several numerical techniques implemented in JuLDPM, such as automatic differentiation and graph coloring techniques, multithreading (via Threads.jl), as well as ongoing research for deployment of the package on HPC clusters.
Dr. Alessandro Fascetti received his bachelor and master degrees in Civil Engineering from the Sapienza University of Rome. He obtained his Ph.D. from the same institution in 2016. He then joined the Multiscale Computational Mechanics Laboratory (MCML) in the Civil and Environmental Engineering Department of Vanderbilt University as a Postdoctoral Research Fellow. After 2 years as a Lecturer for the School of Engineering at The University of Waikato, he joined the Department of Civil and Environmental Engineering at the University of Pittsburgh in 2021. Dr. Fascetti conducts research on digital twin modeling of horizontal and vertical infrastructure for large-scale resilience assessment and maintenance optimization. His work focuses on failure mechanics as well as durability aspects, combining multiscale numerical simulations with in-situ and remote sensing techniques for the real-time assessment of complex interconnected infrastructure systems. He has been a contributor of the Julia ecosystem for almost a decade.