Accession Number : AD0711949

Title :   THE EFFECT OF VARIATIONS IN THE CREEP EXPONENT n ON THE BUCKLING OF CIRCULAR CYLINDRICAL SHELLS IN AXIAL COMPRESSION,

Corporate Author : STANFORD UNIV CALIF DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s) : Honikman,Terence C. ; Hoff,Nicholas J.

Report Date : JUN 1970

Pagination or Media Count : 184

Abstract : The purpose of the investigation is to determine the effect of creep on the load carrying capability of axially symmetric circular cylinders when subjected to uniform axial compression. In particular, the effect of variation of the creep exponent in Odgvist's bi-axial creep law for creep, is investigated. The analysis of the problem is undertaken in the cases in which the creep exponent has the value one and five. Closed form analytical results are presented for the cases in which the creep exponent has the value one, three, and five. Two numerical procedures are developed. The first generates the governing equations of the creep problem symbolically, while the second solves these equations. Numerical results are presented for the cases in which the creep exponent has the value three, five, seven, and nine. The numerical results are compared with the analytical results. While the numerical programs offer a means of further extending the range of values of the creep exponent, this is carried out instead by two empirical methods, which are based on the numerical results already obtained. The case in which the creep exponent becomes unbounded is considered analytically. Dimensionless plots of radial displacement versus time are presented for each value of the creep exponent, and for a variety of values of initial imperfections in the shell wall. A simple graphical method is developed by which the plot for any given value of the initial imperfection may be obtained from another similar plot for which the value of the initial imperfection is smaller than the given value. (Author)

Descriptors :   (*SHELLS(STRUCTURAL FORMS), BUCKLING), (*BUCKLING, *CREEP), CYLINDRICAL BODIES, LOADS(FORCES), COMPRESSIVE PROPERTIES, CREEP STRENGTH, PLASTIC PROPERTIES, VISCOELASTICITY, YIELD POINT, COMPUTER PROGRAMS, STRAIN(MECHANICS), NUMERICAL METHODS AND PROCEDURES

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE