An Inverse Analysis of the Erichsen Test Applied for the Automatic Identification of Sheet Materials Behavior

Adinel Gavrus; Mihaela Banu; Eric Ragneau; Catalina Maier

doi:10.4236/eng.2010.27062

Analysis of Metallic Materials Behavior during Severe Loadings Using a FE Modeling of the SHPB Test Based on a Numerical Calibration of Elastic Strains with Respect to the Raw Measurements and on the Inverse Analysis Principle

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.554-557.1133 ◽

2013 ◽

Vol 554-557 ◽

pp. 1133-1146 ◽

Cited By ~ 1

Author(s):

Adinel Gavrus ◽

Florina Bucur ◽

Adrian Rotariu ◽

Sorin Cănănău

Keyword(s):

Finite Element ◽

Inverse Analysis ◽

High Speed ◽

Constitutive Behavior ◽

Metallic Materials ◽

Strain And Strain Rate ◽

Analysis Strategy ◽

Shpb Test ◽

Materials Behavior ◽

Elastic Strains

The complex loading paths of non-conventional or rapid forging processes, especially as regards the important gradients of the plastic strain and strain rate characterizing the material deformation, require a reliable knowledge of the rheological constitutive equations. Some recent studies propose adequate phenomenological formulations taking into account the corresponding local physical mechanisms and the sensitivity of the true stress with respect to all mechanical variables. At the same time important scientific efforts have been focused in order to identify correctly all the constitutive law parameters, using adequate mechanical tests and robust numerical tools based generally on the inverse analysis principle. It is known that this new method requires building of a rigorous and adequate experimental space, using data obtained from loading conditions close to the industrial forming process. Then to explore high variations of plastic strain and strain rate, one of the most suitable tests are based on high speed hydraulically press and on the Split Hopkinson Pressure Bars test (SHPB). Consequently this paper propose to improve the experimental data accuracy obtained from the SHPB device by using finite element simulations of the entire high speed mechanical experiment together with the description of the inverse analysis strategy applied in order to analyze the thermo-mechanical constitutive behavior of metallic materials behavior and to identify the corresponding rheological parameters. The first part of this study will be dedicated to a short description of the experimental SHPB test analysis and to the analysis of the measurement data which can be used to describe the real mechanical loadings of the specimen. A new experimental calibration method of the acquisition signals, based on the finite element modeling of the elastic bars deformation during an impact without specimen, will be detailed. Using ABAQUS and CAST3M software, this method is validated from the comparison of the elastic strains variation obtained by the numerical simulations. In a second part will be detailed the inverse analysis strategy together with a real application concerning the rheological behavior of an aluminum alloy using a “dumbbell” specimen during a high speed upsetting test starting from a proposed constitutive relationship. Finally, special “cap” geometries of the material sample will be analyzed during a SHPB compression test in order to understand the feasibility of the proposed method to expand the material constitutive behavior identification to severe loadings. It is then shown the capacity to describe deformation path close to the rapid manufacturing processes and high speed machining.

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AA5083 Aluminium Alloy Constants Identification through Inverse Analysis of the Erichsen Test

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.271-272.208 ◽

2012 ◽

Vol 271-272 ◽

pp. 208-211 ◽

Cited By ~ 2

Author(s):

Giuliano Gillo

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Aluminium Alloy ◽

Inverse Analysis ◽

Sheet Material ◽

Experimental Tests ◽

Displacement Curve ◽

The Finite Element Method ◽

Inner Surface ◽

Erichsen Test

In this paper, considering an isotropic rheological law of the sheet material and the power law relationship between the stress and the plastic strain, the Erichsen test is used to identify the material constants of AA5083 aluminium alloy coupling experimental tests results with numerical ones obtained by using the finite element method. The function which is minimized by inverse analysis includes simultaneously the load-displacement curve of the punch, the normalized thickness measured at the bulge apex and the distance measured between the thinnest area of the metal sheet and the inner surface of the blankholder.

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An inverse analysis approach of the Erichsen test starting from a finite element model

International Journal of Material Forming ◽

10.1007/s12289-008-0058-4 ◽

2008 ◽

Vol 1 (S1) ◽

pp. 5-8 ◽

Cited By ~ 8

Author(s):

A. Gavrus ◽

M. Banu ◽

E. Ragneau ◽

C. Maier ◽

V. Oleksik

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Inverse Analysis ◽

Element Model ◽

Analysis Approach ◽

Erichsen Test

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Accuracy of Four Language Analysis Procedures Performed Automatically

American Journal of Speech-Language Pathology ◽

10.1044/1058-0360(2001/017) ◽

2001 ◽

Vol 10 (2) ◽

pp. 180-188 ◽

Cited By ~ 9

Author(s):

Steven H. Long ◽

Ron W. Channell

Keyword(s):

Automatic Identification ◽

Published Data ◽

Typically Developing ◽

Language Impaired ◽

Productivity Data ◽

Language Analysis ◽

Word Classes ◽

Human Coder ◽

Impaired Children ◽

Metalinguistic Skills

Most software for language analysis has relied on an interaction between the metalinguistic skills of a human coder and the calculating ability of the machine to produce reliable results. However, probabilistic parsing algorithms are now capable of highly accurate and completely automatic identification of grammatical word classes. The program Computerized Profiling combines a probabilistic parser with modules customized to produce four clinical grammatical analyses: MLU, LARSP, IPSyn, and DSS. The accuracy of these analyses was assessed on 69 language samples from typically developing, speech-impaired, and language-impaired children, 2 years 6 months to 7 years 10 months. Values obtained with human coding and by the software alone were compared. Results for all four analyses produced automatically were comparable to published data on the manual interrater reliability of these procedures. Clinical decisions based on cutoff scores and productivity data were little affected by the use of automatic rather than human-generated analyses. These findings bode well for future clinical and research use of automatic language analysis software.

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