Inelastic Behaviour of Structures under Variable Loads

This collection of papers is a state of the art presentation of theories and methods related to the problem of the behaviour of mechanical structures under variable loads beyond their elastic limit In particular, the problems of shakedown, ratchetting, transient and asymptotic cyclic states are addressed. The volume is composed of four chapters devoted to material modelling for cyclic loading conditions; general theory of accommodated states of structures; effects of changes of the geometry on the inelastic structural response; and numerical techniques with applications to particular engineering problems. It was aimed to provide a unified approach in order to understand both inelastic material and structural response under variable loading conditions. The attempt to extend the classical shakedown theory of Melan and Koiter to geometrically non-linear problems is presented in several papers. The industrial application of cyclic plasticity to the analysis and the design of pressure bellows, compensators, turbine disks, or flange connections under thermal and pressure cycles illustrates the great potential of the numerical techniques developed for this purpose using mostly min-max approaches. The treatment of railway problems and the analysis and optimisation of pavements are further examples of important areas of applications. Emphasis was laid on approaches that take into account the fact that loading histories are often not precisely known Therefore, the center of interest lies in other than step by step calculation methods.

Table of Contents:
The Modified multisurface hardening model and its application to cyclic loading problems.- Structures consisting of two-phase materials under thermomechanical loads.- Shakedown for systems of kinematic hardening materials.- Related mathematical models for solids and structures deformation and failure processes under repeated loading.- Nonlinear behaviour of low-plastic structures.- Elastic-viscoplastic solids subjected to thermal and loading cycles.- Some basic elements of the shakedown theory.- A variational deduction of upper and lower bound shakedown theorems by Markov’s and Hill’s principles over a cycle.- Influence of cyclic creep on the upper bound to shakedown inelastic deflections.- On shakedown theorems in the presence of Signorini conditions and friction.- On theorems of adaptation of elastic-plastic structures.- Extremum problems in shakedown theory.- Geometric effects on shakedown and ratchetting of axisymetric cylindrical shells subjected to variable thermal loading.- Shakedown of shells undergoing moderate rotations.- Limit, shakedown, post-yield and inadaptation analyses of discrete plastic structures.- Constitutive model and incremental shakedown analysis in finite elastoplasticity.- Case studies on the influence of geometric effects on the shakedown of structures.- Discussion of the chaotic behaviour of an elastic-plastic structure.- Inadaptation mechanisms in bellows subject to sustained pressure and cyclic axial loadings in terms of finite deformations.- Min-max approach to shakedown and limit load analysis for elastic perfectly plastic and kinematic hardening materials.- An indirect incremental method for a shakedown analysis based on the min-max approach.- Slackened systems under variable loads.- Plastic analysis and design of skeletalstructures accounting for their sensitivity to ratchetting.- Shakedown of rail corrugations.- Steady cyclic state of a structure: methods of its direct determination.- An improved boundary element analysis for the bending of a thin plate with a crack.- Stability of pavement structures under long term repeated loading.