Static and dynamic analysis of space frames with non‐linear flexible connections

Abstract

SUMMARYThis paper deals with the effect of non-linearly flexible hysteritic joints on the static and dynamic response of space frames. It is shown that a complementary energy approach based on a weak form of the compatibility condition as a whole of a frame member, and of the joint equilibrium conditions for the frame, is best suited for the analysis of flexibly jointed frames. The present methodology represents an extension of the authors' earlier workI4 on rigidly connected frames. In the present case also, an explicit expression for the tangent stiffness matrix is given when (i) each frame member, along with the flexible connections at its ends, is represented by a single finite element, (ii) each member can undergo arbitrarily large rigid rotations and only moderate relative rotations and (iii) the non-linear bending-stretching coupling is accounted for in each member. Several examples, with both quasi-static and dynamic loading, are included, to illustrate the accuracy and efficiency of the developed methodology.

Modal analysis of damaged structures by the modified finite element method

“…Results obtained were compared with known one and give accepted agreement, As mentioned in [5], the suggested method is also efficient, relatively simple and can easily be accepted by engineers in practice.…”

“…The frame structures with semi-rigid (or flexible) connection have been studied in series of papers by Lui and Chen [2][3][4], Shi and Atluri [5], Kawashima and Fujimoto [6). However, the methods proposed in their studies are limited either by the application for only some individual cases or by the difficulty for engineers in application.…”

Nonlinear dynamic analysis and natural frequencies of gabled frame having flexible restraints and connections

“…The impacts of non-linear flexible connections on static and dynamic responses of spatial frames were investigated by Shi and Atluri. They analyzed frames having semi-rigid connections by using geometric stiffness matrix of member with semi-rigid nodes (Shi and Atluri, 1989). A computational method was suggested for linear The and non-linear free vibration analysis of frames with flexible connections by Chan and Ho. connections were modeled with rotational springs and the stiffness matrix was introduced (Chan and Ho, 1994).…”

Comportamento Dinâmico de Estruturas Reticuladas com Juntas Semi-rígidas

“…Entretanto, a literatura sobre a análise dinâmica de estruturas semi-rígidas é limitada. Shi & Atluri (1989) e Chan & Ming Ho (1994) propuseram métodos para análise de vibrações livres de pórticos semi-rígidos, sem contudo explicitar os coeficientes das matrizes elementares envolvidas. Suarez et al (1996) estudaram o comportamento de estruturas reticuladas com conexões flexíveis, submetidas a excitações sísmicas, descrevendo o comportamento da junta em função de sua flexibilidade e de sua excentricidade.…”