A new numerical approach for determination of the Lemaitre’s ductile damage parameter in bulk metal forming processes

Experimental Tooling for Contact Stress Measurement in Bulk Metal Forming Processes Knowledge of contact stresses in metal forming operations is essential not only for optimal die design, but also for theoretical and numerical analysis of the metal forming processes. Determination of contact stresses can be performed theoretically and experimentally. This paper presents a tool construction with built-in pin-load cells for experimental determination of contact stresses and friction coefficient at upsetting of prismatic specimen with cylindrical dies. This construction allows measurement of contact stresses in any point of the contact surface of specimen, due to adjustable location of pin-load cells. The adjustments are performed by turning cylindrical dies around its own axis in combination with the change of axial position of the specimen. Experimental determination of contact stresses in upsetting of Ck35 prismatic specimens using cylindrical tools was performed at the Laboratory for technology of plasticity, FTN Novi Sad.

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Ductile damage prediction in sheet and bulk metal forming

Comptes Rendus Mécanique ◽

10.1016/j.crme.2015.11.006 ◽

2016 ◽

Vol 344 (4-5) ◽

pp. 296-318 ◽

Cited By ~ 12

Author(s):

Houssem Badreddine ◽

Carl Labergère ◽

Khemais Saanouni

Keyword(s):

Metal Forming ◽

Ductile Damage ◽

Bulk Metal ◽

Damage Prediction ◽

Bulk Metal Forming

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Determination of Flow Curves for Bulk Metal Forming

Materials Testing for the Metal Forming Industry ◽

10.1007/978-3-642-50241-5_2 ◽

1989 ◽

pp. 10-85

Author(s):

Klaus Pöhlandt

Keyword(s):

Metal Forming ◽

Flow Curves ◽

Bulk Metal ◽

Bulk Metal Forming

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Trockenumformung strukturierter Halbzeuge aus 16MnCr5 und 42CrMo4*/Dry forming of surface structured workpiece made of 16MnCr5 and 42CrMo4 - Determination of friction shear stress by means of a pin-on-cCylinder Tribometer

wt Werkstattstechnik online ◽

10.37544/1436-4980-2016-10-38 ◽

2016 ◽

Vol 106 (10) ◽

pp. 712-718

Author(s):

R. Hild ◽

D. Trauth ◽

P. Mattfeld ◽

S. Bastürk ◽

T. Brögelmann ◽

...

Keyword(s):

Shear Stress ◽

Metal Forming ◽

Shear Stresses ◽

Bulk Metal ◽

Bulk Metal Forming ◽

Dry Forming ◽

Tool Coatings ◽

Green Factory

Der Einsatz von Schmierstoffen gestattet bisher die Umformung von Massivbauteilen. In der „Green Factory“ wird auf die Verwendung dieser Schmierstoffe verzichtet. Daraus resultieren unbekannte Anforderungen an das trockene Tribosystem. Selbstschmierende Werkzeugbeschichtung und strukturierte Halbzeuge ermöglichen das trockene Tribosystem und reduzieren die Reibschubspannung. Der Fachbeitrag zeigt die Auswirkungen von Oberflächenstrukturen auf Halbzeugen auf die Reibschubspannung.   Solid and liquid lubricants enable bulk metal forming processes. In the “Green Factory”, the application of lubricants is to be avoided. The absence of lubricants results in unknown demands on a dry tribosystem. Possible enablers of the dry tribosystem are self-lubricating tool coatings and structured workpieces that lower the friction shear stresses. This contribution shows how the workpiece structuring influences the friction shear stress.

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