Search results for " P-Delta effect."

Optimal design of steel frames accounting for buckling

2013

A formulation of a special design problem devoted to elastic perfectly plastic steel frame structures subjected to different combinations of static and dynamic loads is presented. In particular, a minimum volume design problem formulation is presented and the structure is designed to be able to elastically behave for the assigned fixed loads, to elastically shakedown in presence of serviceability load conditions and to prevent the instantaneous collapse for suitably chosen combinations of fixed and ultimate seismic loadings as well as of fixed and wind actions. The actions that the structure must suffer are evaluated by making reference to the actual Italian seismic code. The dynamic respon…

P-Delta effect in structural optimization

2010

The present paper is devoted to the optimal design of structures constituted by elastic perfectly plastic material. In particular, reference will be made to the minimum volume design of multi-storey steel frames taking into account the P-Delta effect. For the sake of generality, the structure is thought as discretized into compatible finite elements and subjected to fixed and quasi-statically acting (wind) loads as well as to dynamic (seismic) loads. The effects of the dynamic actions are studied by utilizing a classical modal technique. The relevant optimal design problem is formulated on the grounds of a statical approach and different resistance limits are considered: in particular, it i…

Discrete variable design of frames subjected to seismic actions accounting for element slenderness

2015

An optimal design problem formulation of elastic plastic frames under different combinations of fixed and seismic loads is presented. The optimal structure must behave elastically for the fixed loads, shakedown for serviceability conditions and prevent instantaneous collapse for fixed and high seismic loads. P-Delta effects and element buckling are considered. An appropriate modal technique is utilized. The design variables can have components in a continuous field or, alternatively, in chosen discrete sets or, yet, both kind of variables can be present. The design problem is formulated on the ground of a statical approach. The applications are related to steel frames.

Analysis and design of elastic plastic structures subjected to dynamic loads

In the last decades, the concept of “optimization” has reached considerable value in many different fields of scientific research and, in particular, it has assumed great importance in the field of structural mechanics. The present study describes and shows the scientific path followed in the three years of doctoral studies. The state of the art concerning the optimization of elastic plastic structures subjected to quasi-static loads was already well established at the beginning of the Ph.D. course. Actually, it was already faced the study of structures subjected to quasi-static cyclic loads able to ensure different structural behaviors in relation to different intensity levels of the appli…