MATSPIF-ID

Identification of material parameters by Single Point Incremental Forming process.

 

Industry relies on simulations to avoid trials and errors in the development of new products and to enhance product quality. FiniteElement (FE) simulation is now a usual tool to answer industrial need, however a bottle neck is often the lack of accurate materialdata. Material data base are generally incomplete and often confidential. The production community waits from academic word to be inventive to solve this data problem. Indeed multi-scale simulations offer solution claiming that, once microstructure is identified,one does not need multiple tests to feed phenomenological models. In fact, it shifts the problem to microstructure identification and it brings CPU problems as FE² methods are very greedy. The classical approach relies on multiple types of tests: bulge, bi-axial,cyclic shear, Marciniak or Nakazyma for Forming Limit Diagram, cup drawing, hole expansion # to investigate the stress and strain states and identify constitutive laws such as anisotropic elasto visvo plastic law coupled with damage. Multiple difficulties arises:these tests require sample cutting in addition to the technician time, one lab does not gather the required equipment which means delayscoordination# This project aims to identify all the material data by the use of a single equipment: a Single Point IncrementalForming platform. The number of tests must be optimized: a minimal number of shapes to provide data allowing to accurately get a single material parameter set. It needs a careful computation of the sensitivity matrix to generate accurate data, to avoid local minimum ofthe functional expressing the difference between simulations and experiments. Both force and displacement fields must be involved in this functional. To validate the development, the project will be focused on a high strength steel with damage problems and on a titanium alloy with anisotropy and strain rate sensitivity issues.