Kiev Automobi l e -Highway Inst i tute, Kiev. T r a n s l a t e d f r o m P r i k l a d n a y a Mekhanika, Vol. 7, No. 8, pp. 77-82, August , 1971. Original a r t i c l e submi t ted May 12, 1970. 9 I974 Consultants Bureau, a division of Plenum Publishing Corporation, 227 g/est 17th Street, New York, N. Y. 10011. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission of the publisher. A copy of this article is available from the publisher for $15.00.