Evaluating the flow stress of aerospace alloys for tube hydroforming process by free expansion testing

Saboori, M.; Champliaud, Henri; Gholipour, Javad; Gakwaya, A.; Savoie, Jean; Wanjara, P.

doi:10.1007/s00170-014-5670-5

Cited by 26 publications

(28 citation statements)

References 20 publications

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“…The axial direction of the tube was defined as the 0°direction (RD direction) which is referring to the definition of direction for the rolled sheet, and the circumferential direction of the tube was defined as the 90°direction (TD direction). In order to measure the anisotropy coefficient of a seamless tube, the tube is often cut into halves and then is flattened to be a sheet sample whose anisotropy coefficients along different directions can be obtained easily [5]. However, the occurrence of work hardening during the tube-flattening process has an influence on the measurement of its anisotropy coefficient.…”

Section: Measurement Of Anisotropy Coefficientmentioning

confidence: 99%

“…In order to conduct a finite element analysis and obtain reasonable process parameters for the tube hydroforming process, the mechanical property and formability of the tubes must be tested and evaluated accurately [1]. The testing methods for the tubes mainly have uniaxial tension test [2], full-section tension test [3], ring hoop tension test [4], and tube hydro-bulging test [5]. Tubes used in the hydroforming process usually possess a large diameter, which makes the full-section tension test hard to conduct.…”

Section: Introductionmentioning

confidence: 99%

“…According to Eqs. (5) and (6), curvature radii along circumferential and axial directions can be determined, and then the stress components and the equivalent stress can be calculated using Eqs. (7), The actual internal pressure in experimental study was recorded and given in Table 3.…”

mentioning

confidence: 99%

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Determination of mechanical properties of anisotropic thin-walled tubes under three-dimensional stress state

Cui

Yuan

2016

Int J Adv Manuf Technol

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Tube hydro-bulging test is a specialized method to obtain the mechanical properties of tubes when they are deformed under bi-axial stress states. However, the normal stress cannot be ignored in double-sided tube hydroforming process. In order to investigate the mechanical properties of anisotropic thin-walled tubes under three-dimensional stress state, an analytical model for stress component calculation for fixed-end tube under internal and external pressures was proposed. Furthermore, the equivalent stress and the equivalent strain were derived using the Hill 1948 yield criterion through plastic increment theory. A thin-walled AA5052-O aluminum alloy tubes were bulged under different external pressures using a dedicated testing apparatus for double-sided tube hydrobulging tests. Then, hardening curves considering anisotropy were obtained for each external pressure condition, respectively. It is shown that the strain hardening exponent of AA5052 tube shows a slight increase with the increasing external pressure, and the external pressure of 85 MPa has little or no effects on the hardening behavior of tubes. Moreover, the anisotropy has a little effect on the strain hardening exponent, but has an obvious influence on the strength coefficient of the AA5052 tube. Therefore, for the measurement of the AA5052 tube's mechanical properties under three-dimensional stress state, the effect of external pressure can be ignored but the anisotropy of tubes must be considered.

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Section: Measurement Of Anisotropy Coefficientmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Determination of mechanical properties of anisotropic thin-walled tubes under three-dimensional stress state

Cui

Yuan

2016

Int J Adv Manuf Technol

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“…The sampling parameters (i.e., metamodel, order, point-selection, and number of simulation Table 1. Material properties of the tube (SS321) and the die (Saboori et al, 2014 points) related to this strategy were then selected as given Table 2. In particular, 10 sampling points for the internal pressure and end feed were selected for each iteration based on Doptimal design (LS-OPT user manual).…”

Section: Optimizationmentioning

confidence: 99%

“…The material properties of the 0.9 mm and 1.2 mm thick SS321 tubes were extracted from the free expansion tests. Saboori et al (2014) developed a semianalytical online approach that utilizes a 3-D automated deformation measurement system (Aramis † ) to measure the coordinates of the bulge profile, the maximum bulge height, and the associated tube thickness to extract the effective stresses and effective strains at different stages of the free expansion process. In this way, bi-axial stressÁstrain curves for tubular materials can be generated for THF applications.…”

Section: Introductionmentioning

confidence: 99%

Load path optimization in tube hydroforming

Mojarad¹,

Champliaud²,

Gholipour³

et al. 2015

Can. Aeronaut. Space J.

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Load path optimization in tube hydroformingMojarad, S.; Champliaud, H.; Gholipour, J.; Savoie, J.; Wanjara, P.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21276028&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21276028&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.5589/q15-003Canadian Aeronautics and Space Journal, 60, 3, pp. 82-89, 2015-03-02 Load path optimization in tube hydroforming S. Mojarad, H. Champliaud, J. Gholipour, J. Savoie, and P. WanjaraAbstract. The goal of this work was to identify the optimum combination of the main process parameters, i.e., the internal pressure and end feeding (load path), for tube hydroforming to minimize the thickness reduction, while satisfying the failure constraint defined by the forming limit diagram of the material. To perform process design optimization with minimum experimentation, the LS-OPT software was utilized in combination with a finite element model (FEM) that simulated a round to square tube hydroforming (THF) process for stainless steel 321 in LS-DYNA. The load path obtained through the optimization procedure was applied to the THF process and the tube expansion and the thickness results obtained from the FEM were compared with the experimental results in the critical regions of the hydroformed tube.Résumé. L'objectif de cette étude était de déterminer la combinaison optimale des principaux paramètres du procédé, c'est-à-dire la pression interne et la compression axi...

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Extension of flow stress–strain curves of aerospace alloys after necking

Saboori

Champliaud

Gholipour

et al. 2015

Int J Adv Manuf Technol

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To define accurately the expansion limits of aerospace materials, determination of the material behavior before and after the onset of necking, as well as the failure threshold are essential requirements. The plastic flow behavior before necking (pre-necking phase) has been fully identified by various mathematical models, such as Hollomon and Swift constitutive equations, but a criterion to satisfy the material behavior after necking (post-necking phase) is lacking. To obtain or calibrate accurately the damage constants in coupled and decoupled damage models, a precise stress-strain behavior after necking is required to reduce significantly the error in predicting fracture in metal forming processes. A tool was developed to determine the true stress-true strain curve for the post-necking regime of different aerospace alloys, such as inconel 718 (IN 718), stainless steel 321 (SS 321), and titanium (Ti6Al4V). Uniaxial tensile tests based on the ASTM E8M-11 standard were performed to determine the true stresstrue strain behavior before necking. Two different methods, a weighted average method and a new hardening function, were utilized to extend the true stress-true strain curve after necking. The two methods resulted in similar post-necking curves for the different materials, with consideration that the new hardening function could be used for more complicated hardening laws. The flow curves were employed in the simulation of the dome height test and then validated through experimentation. The simulation results were compared with the experimental data to verify the accuracy of the proposed methods in this work.

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Evaluating the flow stress of aerospace alloys for tube hydroforming process by free expansion testing

Cited by 26 publications

References 20 publications

Determination of mechanical properties of anisotropic thin-walled tubes under three-dimensional stress state

Determination of mechanical properties of anisotropic thin-walled tubes under three-dimensional stress state

Load path optimization in tube hydroforming

Extension of flow stress–strain curves of aerospace alloys after necking

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