Evaluating material failure of AHSS using acoustic emission analysis

authored by
Eugen Stockburger, Hendrik Vogt, Hendrik Wester, Sven Hübner, Bernd Arno Behrens
Abstract

Driven by high energy prices and strict legal requirements on CO2 emissions, high-strength sheet steel materials are increasingly gaining importance in the automotive industry regarding electric vehicles and their battery range. Simulation-based design of forming processes can contribute to exploiting their high potential for lightweight design. However, previous studies show that numerical simulation with conventional forming limit curves does not always provide adequate prediction quality. Failure models that take the stress state into account represent an alternative prediction method for the shear-dominated failure, that frequently occur in high-strength steels during forming. The failure behaviour of the sheet materials can be determined by different specimen geometries for a wide range of stress states and by using an optical measurement system to record the local strain on the surface of the specimen at the location of failure. However, for many high-strength steels, critical damage or failure initiation already occurs inside the specimen. Therefore, a method is needed that allows detection of failure initiation at an early stage before the crack becomes visible on the surface of the specimen. One possible method is the use of acoustic emission analysis. By coupling it with an imaging technique, the critical strains leading to failure initiation inside the specimen can be determined. In the presented paper, butterfly tests are performed for a wide range of stress states and measured with an optical as well as an acoustical measurement system. The tests are analysed regarding the failure initiation using a mechanical, optical as well as acoustical evaluation method and compared with each other.

Organisation(s)
Institute of Metal Forming and Metal Forming Machines
Type
Conference contribution
Pages
379-386
No. of pages
8
Publication date
2023
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Materials Science(all)
Electronic version(s)
https://doi.org/10.21741/9781644902417-47 (Access: Open)
 

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