The elasto-plastic deformation of a supported short cylindrical shell of mild steel under internal pressure

AbstractStrain localization in mild steel submitted to a sequential loading paths is investigated at macroscopic, mesoscopic and microscopic scales. The experimental results demonstrate that the morphology of the localization and the nominal load-displacement curves depend on the microstructural anisotropy. A crystalline model using a finite element code is proposed. The anisotropy is described by a hardening matrix whose terms correspond to dislocation-dislocation interactions and depend on the evolution of the dislocation densities on the activated slip systems during the sequential tests. The strain localization predicted by this model fits with the experimental observation and allows us to assume that localization is correlated to the saturation on the activated slip systems.

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Elastic-plastic response of a sandwich cylinder subjected to internal pressure

Journal of Strain Analysis ◽

10.1243/03093247v064273 ◽

1971 ◽

Vol 6 (4) ◽

pp. 273-278 ◽

Cited By ~ 2

Author(s):

H F Muensterer ◽

F P J Rimrott

Keyword(s):

Mild Steel ◽

Internal Pressure ◽

Plastic Flow ◽

Plastic Response ◽

Concentric Cylinders ◽

Initial Stage ◽

Sandwich Type ◽

Plastic Zones ◽

Thin Walled ◽

Von Mises

The propagation of plastic zones in a thin-walled sandwich-type cylinder has been analysed theoretically. Boundary conditions are clamped-clamped at both ends, i.e. no rotation is permitted. The material was assumed to behave isotropically and to obey the yieid criterion of Huber-Hencky-von Mises. Deformation was computed on the assumption that the vector of rate of strain was normal to the plastic-interaction curve. The predicted result was verified experimentally. Four specimens were built by lamination of a hexcell core between two concentric cylinders. In the two mild-steel specimens, the initial stage of plastic flow conformed well with the prediction. This proved that plastic flow is not initiated at the mid-position between the end constraints. In two aluminium specimens, this phenomenon of incipient plastic flow could not be observed owing to the absence of a pronounced yield point. The overall agreement was, however, satisfactory.

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Strain Growth in a Finite-Length Cylindrical Shell Under Internal Pressure Pulse

Journal of Pressure Vessel Technology ◽

10.1115/1.4035696 ◽

2017 ◽

Vol 139 (2) ◽

Cited By ~ 3

Author(s):

Qi Dong ◽

Q. M. Li ◽

Jinyang Zheng

Keyword(s):

Cylindrical Shell ◽

Boundary Conditions ◽

Internal Pressure ◽

Finite Length ◽

Pressure Pulse ◽

Elastic Response ◽

Local Dynamic ◽

Growth Phenomenon ◽

Modal Coupling ◽

Elastic Responses

Strain growth is a phenomenon observed in the elastic response of containment vessels subjected to internal blast loading. The local dynamic response of a containment vessel may become larger in a later stage than its response in the earlier stage. In order to understand the possible mechanisms of the strain growth phenomenon in a cylindrical vessel, dynamic elastic responses of a finite-length cylindrical shell with different boundary conditions subjected to internal pressure pulse are studied by finite-element simulation using LS-DYNA. It is found that the strain growth in a finite-length cylindrical shell with sliding–sliding boundary conditions is caused by nonlinear modal coupling. Strain growth in a finite-length cylindrical shell with free–free or simply supported boundary conditions is primarily caused by the linear modal superposition, possibly enhanced by the nonlinear modal coupling. The understanding of these strain growth mechanisms can guide the design of cylindrical containment vessels.

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