Numerical computations of spaghetti fracture

Abstract

Peridynamics offers decisive advantages for the simulation of dynamic fracture and is used here to investigate the fracture of long beams with the material properties of dry spaghetti. The aim of this work is to identify boundary conditions that reproduce the experimentally known fracture behavior while remaining simple to parameterize and suitable for future studies. Different loading concepts for bending the beam up to fracture are therefore compared, including a four-point bending setup and simplified end-loading approaches. The simulations show that the four-point bending test can reproduce the expected fracture patterns, but involves many sensitive parameters. End loading by force density reduces the geometric complexity of the setup, yet the fracture behavior remains strongly dependent on the selected parameters and is difficult to realize experimentally. The most suitable alternative is a velocity-controlled load at the beam ends. In combination with a slightly pre-bent beam, it yields fracture patterns with similarly few fragments as the four-point bending test, keeps the simulation time sufficiently low, and allows the required simulation time to be estimated in advance. Thus, the developed velocity boundary condition provides a relatively easy-to-apply basis for future peridynamic investigations of spaghetti fracture.