451 Study on Elastic-plastic Deformation of Thin Cylindrical Shell Subjected to Horizontal and Vertical Excitations Simultaneously

2005 ◽  
Vol 2005 (0) ◽  
pp. _451-1_-_451-6_
Author(s):  
Toshiyuki Tachibana ◽  
Katsuhisa Fujita ◽  
Tomohiro Ito
Keyword(s):  
Plastic Deformation ◽  
Cylindrical Shell ◽  
Thin Cylindrical Shell ◽  
Elastic Plastic ◽  
Vertical Excitations

A Parametric Study of Elastic-Plastic-Creep Buckling of a Thin Cylindrical Shell

1974 ◽  
Vol 96 (3) ◽  
pp. 155-161 ◽  
Author(s):  
I. Berman ◽  
J. M. Chern ◽  
G. D. Gupta
Keyword(s):  
Cylindrical Shell ◽  
External Pressure ◽  
Buckling Load ◽  
Sustained Load ◽  
Thin Cylindrical Shell ◽  
Elastic Plastic ◽  
Creep Buckling ◽  
Explicit Reference ◽  
Class 1 ◽  
Plastic Creep

The elastic-plastic-creep buckling of a long thin cylindrical shell with initial out-of-roundness subjected to uniform external pressure is herein studied. The work is carried out by means of an economical computer program which consistently accounts for the effects of load changes and plastic strains and which has a calculation procedure based on direct integration. The ratio of the sustained load to the initial buckling load is discovered to be a parameter which relates the sustained load to the buckling time without explicit reference to the geometric parameters for the conditions considered. Other results are uncovered concerning the effect of: the shape of the imperfection, the temperature variations and the choice of creep relations on initial buckling load and buckling time. Alternatives to the expensive and time consuming calculations to meet the requirements of the time factor of safety on Code Case 1331 of the ASME Boiler and Pressure Vessel Code for Class 1 nuclear components are explored. Recommendations are made.

scholarly journals Multi-parameter actuation of a neutrally stable shell: a flexible gear-less motor

2017 ◽  
Vol 473 (2204) ◽  
pp. 20170364 ◽  
Author(s):  
W. Hamouche ◽  
C. Maurini ◽  
S. Vidoli ◽  
A. Vincenti
Keyword(s):  
Plastic Deformation ◽  
Cylindrical Shell ◽  
Principal Curvature ◽  
Experimental Testing ◽  
Fibre Composite ◽  
Piezoelectric Actuators ◽  
Piezoelectric Actuation ◽  
Thin Cylindrical Shell ◽  
Actual Structure ◽  
Morphing Structure

We have designed and tested experimentally a morphing structure consisting of a neutrally stable thin cylindrical shell driven by a multi-parameter piezoelectric actuation. The shell is obtained by plastically deforming an initially flat copper disc, so as to induce large isotropic and almost uniform inelastic curvatures. Following the plastic deformation, in a perfectly isotropic system, the shell is theoretically neutrally stable, having a continuous set of stable cylindrical shapes corresponding to the rotation of the axis of maximal curvature. Small imperfections render the actual structure bistable, giving preferred orientations. A three-parameter piezoelectric actuation, exerted through micro-fibre-composite actuators, allows us to add a small perturbation to the plastic inelastic curvature and to control the direction of maximal curvature. This actuation law is designed through a geometrical analogy based on a fully nonlinear inextensible uniform-curvature shell model. We report on the fabrication, identification and experimental testing of a prototype and demonstrate the effectiveness of the piezoelectric actuators in controlling its shape. The resulting motion is an apparent rotation of the shell, controlled by the voltages as in a ‘gear-less motor’, which is, in reality, a precession of the axis of principal curvature.

Effects of Material Parameter Variability on Buckling and Creep Fatigue Interaction at Elevated Temperature

1976 ◽  
Vol 98 (1) ◽  
pp. 75-80 ◽  
Author(s):  
I. Berman ◽  
A. C. Gangadharan ◽  
G. H. Jaisingh ◽  
G. D. Gupta
Keyword(s):  
Cylindrical Shell ◽  
Fatigue Damage ◽  
Initial Imperfection ◽  
External Pressure ◽  
304 Stainless Steel ◽  
Thin Cylindrical Shell ◽  
Elastic Plastic ◽  
Creep Buckling ◽  
Creep Fatigue ◽  
Type 304

The effects of variation of elastic-plastic and creep properties of type 304 stainless steel on solutions of two specific inelastic problems are studied in this paper. The problems considered are: 1 – elastic-plastic-creep buckling of a thin cylindrical shell with initial imperfection and sustained external pressure at high temperature; and 2 – creep and fatigue damage in a thin cylindrical shell subjected to cyclic thermal load and constant internal pressure. Some conclusions are drawn as to the relative importance of variations of different material parameters on initial buckling load, creep buckling time and creep and fatigue damage factors.

Elasto-plastic state of curve beam system subjected to complex loading

1996 ◽  
Vol 18 (4) ◽  
pp. 14-22
Author(s):  
Vu Khac Bay
Keyword(s):  
Cylindrical Shell ◽  
Solution Method ◽  
Complex Loading ◽  
Numerical Results ◽  
Elastic Solution ◽  
Plastic State ◽  
Curve Beam ◽  
Elastic State ◽  
Elastic Plastic ◽  
Beam System

Investigation of the elastic state of curve beam system had been considered in [3]. In this paper the elastic-plastic state of curve beam system in the form of cylindrical shell is analyzed by the elastic solution method. Numerical results of the problem and conclusion are given.

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