Inelastic Analysis of Structures under Variable Loads

The question whether a structure or a machine component can carry the applied loads, and with which margin of safety, or whether it will become unserviceable due to collapse or excessive inelastic deformations, has always been a major concern for civil and mechanical engineers. The development of methods to answer this technologically crucial question without analysing the evolution of the system under varying loads, has a long tradition that can be traced back even to the times of emerging mechanical sciences in the early 17th century. However, the scientific foundations of the theories underlying these methods, nowadays frequently called "direct", were established sporadically in the Thirties of the 20th century and systematically and rigorously in the Fifties. Further motivations for the development of direct analysis techniques in applied mechanics of solids and structures arise from the circumstance that in many engineering situations the external actions fluctuate according to time histories not a priori known except for some essential features, e. g. variation intervals. In such situations the critical events (or "limit states") to consider, besides plastic collapse, are incremental collapse (or "ratchetting") and alternating plastic yielding, namely lack of "shakedown". Non evolutionary, direct methods for ultimate limit state analysis of structures subjected to variably-repeated external actions are the objectives of most papers collected in this book, which also contains a few contributions on related topics.

An early upper bound method for shakedown of beams and structures. - Shakedown limits for a general yield condition: implementation and application for a von Mises yield condition. - Shakedown at finite elasto-plastic strains. - Shape optimization under shakedown constraints. - Numerical simulations of thermo-viscoplastic flow processes under cyclic dynamic loadings. - Subdomain bounding technique for shakedown analysis of structures. - Failure investigation of fiber-reinforced composite materials by shakedown analysis. - Analysis of masonry structures subject to variable loads: a numerical approach based on damage mechanics. - CYCLONE - system for structural adaptation and limit analysis. - Variational principles for shakedown analysis. - Shakedown of elastic-plastic structures with non linear kinematical hardening by the bipotential approach. - Shakedown and fatigue damage in metal matrix composites. - On shakedown of elastic plastic bodies with brittle damage. - Simplified methods for the steady state inelastic analysis of cyclically loaded structures. - Direct finite element kinematical approaches in limit and shakedown analysis of shells and elbows. - Shakedown and damage analysis applied to rocket engines. - Reliability analysis of elasto-plastic structures under variable loads. - Upper bounds on post-shakedown quantities in poroplasticity. - Fatigue behavior of fiber reinforced concrete: comparison between material and structural response. - Shakedown analysis by elastic simulation. - Application of the kinematic shakedown theorem to pavements design.