# A Nonintrusive Distributed Reduced Order Modeling Framework for nonlinear structural mechanics -- application to elastoviscoplastic computations

## TL;DR

This paper introduces a nonintrusive, distributed reduced order modeling framework for nonlinear structural mechanics, enabling efficient large-scale elastoviscoplastic simulations by leveraging existing commercial software and parallel computing.

## Contribution

It presents a novel nonintrusive framework that constructs reduced order models from commercial software data, compatible with different codes, and demonstrates significant computational speedups.

## Key findings

- Framework handles large-scale elastoviscoplastic simulations efficiently.
- Achieved a speedup from 9.5 days to 6.5 hours in a high-pressure blade model.
- Compatible with commercial finite element software like Zset and Ansys Mechanical.

## Abstract

In this work, we propose a framework that constructs reduced order models for nonlinear structural mechanics in a nonintrusive fashion, and can handle large scale simulations. We identify three steps that are carried out separately in time, and possibly on different devices: (i) the production of high-fidelity solutions by a commercial software, (ii) the offline stage of the model reduction and (iii) the online stage where the reduced order model is exploited. The nonintrusivity assumes that only the displacement field solution is known, and relies on operations on simulation data during the offline phase by using an in-house code. The compatibility with a new commercial code only needs the implementation of a routine converting the mesh and result format into our in-house data format. The nonintrusive capabilities of the framework are demonstrated on numerical experiments using commercial versions of the finite element softwares Zset and Ansys Mechanical. The nonlinear constitutive equations are evaluated by using the same external plugins as for Zset or Ansys Mechanical. The large scale simulations are handled using domain decomposition and parallel computing with distributed memory. The features and performances of the framework are evaluated on two numerical applications involving elastoviscoplastic materials: the second one involves a model of high-pressure blade, where the framework is used to extrapolate cyclic loadings in 6.5 hours, whereas the reference high-fidelity computation would take 9.5 days.