GEORGII STEPANOVICH PISARENKO -SIXTIETH BIRTHDAY

On November 12, 1970, Doctor of Technical Sciences, P r o f e s s o r Georgi i Stepanovich P i sa renko , Academic ian and V i c e - P r e s i d e n t of the Academy of Sciences of the Ukrainian SSR and d i rec to r of the Ins t i -

tute of Strength P r o b l e m s of the Ukrainian Academy, ce lebra ted his sixt ieth bir thday and 35 y e a r s of scientif ic , pedagogical , and public ac - t ivi t ies . G. S. P i s a r enko is an eminent sc ien t i s t and an o rgan ize r of scient i f ic r e s e a r c h in the field of mechanics . He is the author of m o r e than 220 works including 23 monographs and textbooks.

G. S. P i s a r enko was the f i r s t to succeed in evolving a method for calculat ing the vibrat ions of e last ic s y s t e m s allowing for the nonlinear c h a r a c t e r of the re la t ion between energy dissipat ion and s t r e s s ampl i - tude, for which asymptot ic techniques of nonlinear mechanics a r e used. A g rea t deal of work was done in this field, yielding fundamental r e - sults which made it poss ib le to formula te genera l laws of energy d i s s i - pation in m a t e r i a l s and s t r u c t u r e s and to p ropose methods for taking into account energy diss ipat ion in the analysis of the vibrat ions of v a r i - our s y s t e m s .

G. S. P i sa renko has done much to init iate and develop radical ly new complex r e s e a r c h techniques for studying the s t rength of s in te red ma te r i a l s and const ruct ional e lements produced by powder meta l lu rgy p r o c e s s e s . This work was c a r r i e d out by P i sa renko and his students

in the per iod 1951-66 a t the Insti tute of Powder Metal lurgy and Special Alloys {now the Insti tute of Mate- r i a l s Science), Academy of Sciences of the Ukrainian SSR. In this p a r t i c u l a r field, P i s a r enko devised c e r - tain fundamental approaches to the development of the theory of s t rength of s in te red ma te r i a l s , which allow for the s t r u c t u r a l he terogenei ty of such m a t e r i a l s and a r e based on techniques of the theory of probabi l i ty and ma themat i ca l s t a t i s t i c s .

G. S. P i s a r e n k o has opened up a new a r e a of study, which has a t t r ac ted cons iderable attention both in the Soviet Union and abroad. Basical ly , work of this type cons is t s in conducting, under conditions c losely s imula t ing those encountered in actual s e rv ice , theore t ica l and exper imenta l invest igat ions of the effect of fo rms of force and t h e r m a l loading on the s t rength and ductility of ma te r i a l s , and a lso on the l oad -ca r ry ing capaci ty of the mos t typical h i g h l y - s t r e s s e d cons t ruc t ional e lements . This work, undertaken in r e sponse to demands of industry, has led to the adoption of a number of new ma te r i a l s , including those made by powder meta l lu rgy techniques.

G. S. P i s a r e n k o and his students have es tabl ished scientif ic pr inc ip les underlying the methods of high- and l o w - t e m p e r a t u r e tes t ing of m a t e r i a l s and pa r t s , and built many original , s o m e t i m e s unique, ins ta l la - tions for such tes t s . Using this equipment, s tudies have been made of the phys ieomechanica l p rope r t i e s of potential ly useful new m a t e r i a l s , including r e f r a c t o r y and heat insulating a l loys ; work is in p r o g r e s s on the s t rength c r i t e r i a of m a t e r i a l s under complex s t r e s s e d s ta te condit ions; invest igat ions have been made of the loss of l o a d - c a r r y i n g capaci ty exper ienced by machine components in a centr i fugal force field; r e - s e a r c h e s a r e being conducted into t h e behavior of m a t e r i a l s subjected to t h e r m a l cycling and pu l se - type loading, the m e c h a n i s m of rupture with var ious types of load or heat application, and other p r o b l e m s . The resu l t s obtained, which a r e often of fundamental s ignif icance, const i tute a m a j o r contribution to the development

T rans l a t ed f rom Poroshkovaya Metal lurgiya, No. 11 (95), pp. 105-106, November , 1970.

1971 Consultants Bureau, L a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00.

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of scientific principles of the mechanics of materials and the load-carrying capacity of parts operating under stressed conditions.

For a series of works containing results of researches, performed over a period of many years, into the high-temperature strength of materials, G. S. Pisarenko was awarded in 1969 the State Prize of the Ukrainian SSR.

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