FOCUS ON PRODUCTIVITY
Advanced methodology for rapid fracture resistance characterisation in thin AHSS sheets and high-strength aluminium alloys based on the Essential Work of Fracture ( EWF ).
Our main goal has been to respond to challenges faced by the sheet metal industry when manufacturing high-performance metal parts using new high-strength materials
forming industry , FormPanet has developed and optimised a set of advanced testing methodologies for more accurate metals characterisation , non-destructive in-process measurements and modelling approaches .
The innovative methods propose solutions which solve relevant industrial problems in sheet metal forming . These range from edge-cracking , hydrogen embrittlement , formabilityrelated cracks or non-expected part performance . These challenges lead to productivity losses or inaccurate quality .
Materials characterisation and modelling
The research , concluded in January 2022 , focused on delivering techniques optimising the development of sheet materials and improving the forming processes of highstrength sheet metals , as well as improving the manufacturing process of complex parts with high-strength sheet metals for lightweight solutions .
The novel methodologies , to be launched to the market as services of a commercial entity to be created this year , range from advanced metal characterisation methodologies , nondestructive in-process measurements to modelling approaches ( aimed at ensuring zerodefects production and the optimisation of sheet material development , production and performance ).
For sheet metal characterisation , leading research centres and universities developed advanced tests to evaluate edge-cracking and stretch-frangibility and to determine the fatigue resistance and fracture toughness in thin and thick metal sheets . Micro tensile tests were developed to assess basic tensile properties such as yield stress ; ultimate tensile strength ; total elongation ; area reduction and uniform elongation . Other methodologies developed include forming limit assessments and the evaluation of delayed hydrogen embrittlement .
At the same time , novel modelling approaches , to be used in the design process of components , have been developed . Modelling advances included : -
HELIOS 4 HOT PROBE equipment for an on-line diffusible H measurement on sheet metal parts .
■ A model to predict damage initiation and damage evolution .
■ Optimisation of a novel direct method to characterise the constitutive stressstrain relation from initial yielding to final fracture .
■ A direct method to characterise the post necking plasticity for sheet metals .
■ A new user interface module to streamline a routine for calibrating experimental data to material and fracture models .
■ A Finite Element Model able to predict the hydrogen concentration distribution into structural components made in Advanced High-Strength Steel ( AHSS ).
“ These methodologies have proved to be effective in improving sheet metal part performance prediction and reducing production losses caused by unexpected fractures in serial production . This is a great advantage compared to testing methods currently available in the market ,” said David Frómeta , a researcher at Eurecat Metallic and Ceramic Materials Unit .
Finally , novel non-destructive techniques have been studied for quality control and material integrity . These include :
■ In-process check systems for monitoring both the process and the product quality .
■ An alternative method for the prediction of wear based on piezo sensors .
■ Deep-drawing measurements .
■ Equipment to perform industrial on-line diffusible hydrogen measurements on sheet metal parts .
■ Technology based on advanced thermography for in-situ detection of defects .
Micro-mechanical characterisation technique for the assessment of material properties when an insufficient volume of the material is available .
ISMR March 2022 | sheetmetalplus . com | 23