PeriFast/Corrosion: a 3D pseudo-spectral peridynamic Matlab code for corrosion

Abstract

We introduce PeriFast/Corrosion, a MATLAB code that uses the fast convolution-based method (FCBM) for peridynamic (PD) models of corrosion damage. The FCBM uses the convolutional structure of PD equations and employs the Fast Fourier transform (FFT) to achieve a computational complexity of 𝑂(𝑁𝑙𝑜𝑔𝑁). PeriFast/Corrosion has significantly lower memory allocation needs, 𝑂(𝑁), compared with, for example, the meshfree method with direct summation for PD models that requires 𝑂(𝑁2). The PD corrosion model and the fast convolution-based method are briefly reviewed and the detailed structure of the code is presented. The code efficiently solves 3D uniform corrosion (in copper) and pitting corrosion (in stainless steel) problems with multiple growing and merging pits, set in a complicated shape sample. Discussions on possible immediate extensions of the code to other corrosion damage problems are provided. PeriFast/Corrosion is a branch of PeriFast codes and is freely available on GitHub [1].

PeriFast/Dynamics: A MATLAB Code for Explicit Fast Convolution-based Peridynamic Analysis of Deformation and Fracture

“…In the current version of PeriFast/Dynamics, we use the naïve approach. The mirror-based fictitious nodes method (FNM) [24] is also compatible with FCBM and implemented in the /Corrosion branch of the PeriFast code [29].…”

“…These models work well in problems with precracks, but when applied to problems with no pre-cracks, a higher and higher effective strength is found if one uses smaller and smaller horizon sizes (for a discussion of how to select a "proper" horizon size please see [43], [44]). For quasi-brittle fracture problems in bodies without pre-cracks we recommend using (and implementing), for example, the two-parameter bond-failure model (see [29]). Such an extension is immediate by defining lambda in constitutive.m as a non-binary variable with a gradual transition from 1 to 0, capturing a softening behavior at the microscale.…”

“…PeriFast/Corrosion is one branch of the PeriFast suite of Matlab-based codes that implement the FCBM for PD models. The PeriFast/Corrosion branch solves corrosion damage problems (pitting corrosion, including with formation of lacy covers) and is described in [29]. By coupling the /Corrosion and /Dynamics code branches of PeriFast, one can solve, for example, stress-corrosion cracking problems like those in [5].…”

“…While not immediate, other interesting extensions may be possible: (1) fracture in heterogeneous materials (these could use the masking functions used in [29] to generate a polycrystalline microstructure); (2) impact and fragmentation (contact detection algorithms would be required for such models).…”