caa a22 4500 467913900 CHVBK 20180406152856.0 cr unu---uuuuu 170328e20060601xx s 000 0 eng 10.1007/s10999-006-9018-7 doi (NATIONALLICENCE)springer-10.1007/s10999-006-9018-7 Some studies on wrinkling limit of commercially pure aluminium sheet metals of different grades when drawn through Conical and Tractrix dies [Elektronische Daten] [R. Narayanasamy, C. Loganathan] This paper deals with the wrinkling limit diagrams of annealed three different grades of commercially pure sheets namely ISS 19000, ISS 19600 and ISS 19660 having thickness of 2.00mm when deep drawing into cylindrical cups through Conical and Tractrix dies using a flat bottomed punch. It is well established that, the use of either a Conical die or a Tractrix die can enhance the limiting draw ratio compared with that obtainable in a conventional drawing operation. When a Conical or a Tractrix die is employed the need for a hold down or clamping ring is eliminated. However, this enhances the propensity of the blank to fail by wrinkling or buckling, particularly in the early stages of a drawing process in which thin sheet blanks are used. It is proved by these researchers and others that the onset of wrinkling takes place when the ratio of strain increments (dε r /dε θ ) or the ratio of strain (ε r /ε θ ) reaches a critical value during the drawing process. These values which could be determined experimentally over which the wrinkling takes place has been shown in the form of wrinkling limit diagrams for the above three different grades. An attempt is also made to develop the wrinkling theory that predicts the wrinkling based on results obtained in the form of wrinkling limit diagrams established for the above grades. Springer Science+Business Media, Inc., 2007 Wrinkling limit diagrams nationallicence Strain increments ratio nationallicence Strain ratio nationallicence Stress ratio nationallicence Conical die and Tractrix die nationallicence n av : Average strain hardening index value nationallicence n av : 0.25 (n 0+2n45+n 90) nationallicence k av : Average strength coefficient nationallicence k av : 0.25 (k 0+2k 45+k 90) nationallicence E av : Average young's modulus value nationallicence E av : 0.25 (E 0+2E 45+E 90) nationallicence R : Normal anisotropy (average plastic strain ratio) Plastic strain ratio is defined as width strain to thickness strain during the tensile test in the plastic region. In terms of expression it is defined as follows $$ {\hbox{plastic}}\ nationallicence \hbox{strain}}\ nationallicence \hbox{ratio}} = \varepsilon _w /\varepsilon _t $$ where ε w —true width strain and ε t —true thickness strain nationallicence R : 0.25 (R 0+2R 45+R 90) nationallicence (d σ /d ε )/ σ : Average normalized hardening rate obtained from the true stress-true strain data nationallicence x av : 0.25 (x 0+2x 45+x 90) nationallicence d σ /d ε : Average tangent modulus value obtained from the true stress-true strain data nationallicence x av : 0.25 (x 0+2x 45+x 90) nationallicence σ Y (average) : 0.25 (σ Y 0+2σ Y 45+σ Y 90) nationallicence σ U (average) : 0.25 (σ U 0+2σ U 45+σ U 90) nationallicence Δ R : Planar anisotropy nationallicence Δ R : 0.5 (R 0−2R 45+R 90) nationallicence Narayanasamy R. Department of production Engineering, National Institute of Technology, 620 015, Tiruchirappalli, Tamil Nadu, India aut Loganathan C. Department of Mechanical Engineering, Saranathan College of Engineering, Venkateshwara Nagar, 620 012, Tiruchirappalli, Tamil Nadu, India aut International Journal of Mechanics and Materials in Design Kluwer Academic Publishers 3/2(2006-06-01), 129-144 1569-1713 3:2<129 2006 3 10999 https://doi.org/10.1007/s10999-006-9018-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10999-006-9018-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Narayanasamy R. Department of production Engineering, National Institute of Technology, 620 015, Tiruchirappalli, Tamil Nadu, India aut NATIONALLICENCE 700 1- Loganathan C. Department of Mechanical Engineering, Saranathan College of Engineering, Venkateshwara Nagar, 620 012, Tiruchirappalli, Tamil Nadu, India aut NATIONALLICENCE 773 0- International Journal of Mechanics and Materials in Design Kluwer Academic Publishers 3/2(2006-06-01), 129-144 1569-1713 3:2<129 2006 3 10999 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer