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Elastic‐plastic transition is obtained in current literature with the help of a semi‐empirical yield condition like that of Tresca or Von Mises. The stresses are obtained from the elastic solution and then substituted in the yield condition to get the transition surface. The possibility of treating it as a transition or turning point phenomenon in finite deformation has not been explored. When the plastic state tends to set in, the stressstrain relations undergo a change. This should be reflected in our equations. The linear classical theory cannot do it. If we adopt the theory of finite deformation, the equations of equilibrium give rise to non‐linear differential equations whose turning points can give the elastic‐plastic transition. The asymptotic solution at these points then give the displacements and the stresses, and no semi‐empirical yield condition is necessary. The yield stress can be related to the elastic coefficients in the transition range through the tension‐stretch result in finite deformation. This method is applied to the plastic deformation of shells and tubes under pressure.

Hive einiger ad-hoc-Annahmen wie derjenigen der Inkompressibilitat und einer besonderen Form der FlieJbedingung hat T . Y . T h o m a s theoretische Ergebnisse uber den Zusammenbruch dicker Zylinder erhulten, die mit den experimentellen Ergebnissen von P . W. B r i d g m a n gut iibereinstimmen. Die von B . R . Seth und anderen aufgestellte Ubertragungstheorie liefert bereits diese und noch allgemeinere Ergebnisse, ohne irgendwelche Annahmen machen zu mussen. By making a number of ad-hoc assumptions like that of incompressibility and a particular form of the yield condition T . Y. T h o m a s has obtained theoretical results on the collapse of thick cylinders, which compare well with the experimental results of P . W. B r i d g m a n . The transition theory, developed by B . R. S e t h and others, readily gives all these and more general results without making any assumptiow. C n 0~0 1 4 b m pans ad-hoc-npennocHnoH KaH o HecxmaeMocTH EI 0~0608 4opMbi YCJIOBEI$I TeKy.recm nonyseabi. T. IO. T o Ma c o M TeopeTmecme ~C~O B E I H n n~ pacnana TOJICTHX U~~H H H P O B , Xopomo COBnaxamqtie c ~K C~~P E I M~H T~J I~H M M H p e a y n b~a~a~~ n. B. EpHxxMaHa. kl3 c03nam08 5. P. C B T O M H np. TeopHH nepexona, He HymRamqeZicsx B ~a~nx-nmBo npennocbinHax, BbiTeHamT rcpoMe sbrmenpw BeneHHbtX Cm6 6onee 061IIEIe pe3ynbTaTbI.