Period of vibrations of framed structures

AbstractThis paper describes a detailed numerical investigation into the inelastic displacement ratios of non-structural components mounted within multi-storey steel framed buildings and subjected to ground motions with forward-directivity features which are typical of near-fault events. The study is carried out using detailed multi-degree-of-freedom models of 54 primary steel buildings with different structural characteristics. In conjunction with this, 80 secondary non-structural elements are modelled as single-degree-of-freedom systems and placed at every floor within the primary framed structures, then subsequently analysed through extensive dynamic analysis. The influence of ground motions with forward-directivity effects on the mean response of the inelastic displacement ratios of non-structural components are compared to the results obtained from a reference set of strong-ground motion records representing far-field events. It is shown that the mean demand under near-fault records can be over twice as large as that due to far-fault counterparts, particularly for non-structural components with periods of vibration lower than the fundamental period of the primary building. Based on the results, a prediction model for estimating the inelastic displacement ratios of non-structural components is calibrated for far-field records and near-fault records with directivity features. The model is valid for a wide range of secondary non-structural periods and primary building fundamental periods, as well as for various levels of inelasticity induced within the secondary non-structural elements.

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Discussion of “Nonlinear Analysis of Elastic Framed Structures”

Journal of the Structural Division ◽

10.1061/jsdeag.0002229 ◽

1969 ◽

Vol 95 (3) ◽

pp. 517-523

Author(s):

H. S. Srinivas Prasad ◽

Semih S. Tezcan ◽

Bijay C. Mahapatra

Keyword(s):

Nonlinear Analysis ◽

Framed Structures

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Discussion of “Optimum Design of Framed Structures”

Journal of the Structural Division ◽

10.1061/jsdeag.0002364 ◽

1969 ◽

Vol 95 (9) ◽

pp. 1983-1989

Author(s):

Harold Switzky

Keyword(s):

Optimum Design ◽

Framed Structures

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Development of a divergent fluid wall damper for framed structures subjected to dynamic loads

Structural Control and Health Monitoring ◽

10.1002/stc.2108 ◽

2017 ◽

Vol 25 (3) ◽

pp. e2108

Author(s):

Soheil Nikpour ◽

Farzad Hejazi ◽

Mohd Saleh Jaafar

Keyword(s):

Dynamic Loads ◽

Framed Structures

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A bi-dissipative damage model for concrete

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952015000100006 ◽

2015 ◽

Vol 8 (1) ◽

pp. 49-65

Author(s):

J. J. C. Pituba ◽

W. M. Pereira Júnior

Keyword(s):

Reinforced Concrete ◽

Structural Engineering ◽

Damage Mechanics ◽

Damage Model ◽

Continuum Damage Mechanics ◽

Concrete Material ◽

Framed Structures ◽

Energy Equivalence ◽

Proposed Model ◽

Damage Processes

This work deals with an improvement of an anisotropic damage model in order to analyze reinforced concrete structures submitted to reversal loading. The original constitutive model is based on the fundamental hypothesis of energy equivalence between real and continuous media following the concepts of the Continuum Damage Mechanics. The concrete is assumed as an initial elastic isotropic medium presenting anisotropy, permanent strains and bimodularity induced by damage evolution. In order to take into account the bimodularity, two damage tensors governing the rigidity in tension or compression regimes are introduced. However, the original model is not capable to simulate the influence of the previous damage processes in compression regimes. In order to avoid this problem, some conditions are introduced to simulate the damage unilateral effect. It has noted that the damage model is agreement with to micromechanical theory conditions when dealing to unilateral effect in concrete material. Finally, the proposed model is applied in the analyses of reinforced concrete framed structures submitted to reversal loading. These numerical applications show the good performance of the model and its potentialities to simulate practical problems in structural engineering.

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