Portal frame

About: Portal frame is a research topic. Over the lifetime, 1778 publications have been published within this topic receiving 7210 citations.

Damage Detection in Steel Framed Structures by Vibration Measurement Approach

Abstract: This papa reports the application of a proposed method combiig Sensitivity .%I@ and MAUCOhfAC Analysis in damage detection for a steel portal frame. Experimental work has been carried out for the veritication of this method. Before and after the structure was damaged, altogether 6 sets of vibrational data were measured under 2 different joint conditions (Rigid and Pinned) and 2 different damage locations (Beam-Column and Column-Base connections). The results show that if the most sensitive correlated mode pairs selected from the sensitivity study are used in the MACICOMAC analysis, the COMAC values Vs. Node Number graph can give a more reliable indication of the location of damage. NOMENCLATURE

Short‐Term Behavior of Pultruded Fiber‐Reinforced Plastic Frame

Abstract: Results of an experimental and analytical investigation of the behavior of a pultruded fiber‐reinforced plastic (FRF) portal frame subjected to short‐term static loads are presented. A 6 ft high by 9 ft wide (1.83m×2.74m) plane portal frame was designed and constructed of glass/vinylester pultruded FRP thin‐walled sections. Data obtained from short‐term load tests on the frame are presented. Failure of the beam‐to‐column connections and compression flange buckling of the girder are discussed. An analytical investigation was performed to predict the nonlinear response of the frame. The numerical model includes the effects of axial, shear, and flexural deformation of the pultruded numbers, flexibility of the beam‐to‐column connections, and the postbuckling of the frame girder. An expression for the nonlinear rotational stiffness of the pultruded beam‐to‐column connection is presented. The experimental data, obtained from the full‐size test, are compared with the analytical model.

Integrated design of controlled linear structural systems

Abstract: This paper addresses the integrated design of civil engineering structures with control systems. Simultaneous optimization of such controlled structures is considered, showing that new alternative solutions can be achieved through integrated design. A procedure for design of controlled structural systems is developed using a two-stage approach: (1) a design of an optimal control system using a linear quadratic regulator algorithm; and (2) a redesign using an optimization procedure to match the performance of the controlled system obtained in (1). A linear single degree of freedom steel portal frame and a linear nine degree of freedom shear-type structure are used as examples to illustrate the feasibility of the proposed approach that reduces the structural weight of buildings by incorporating active or passive control elements while preserving the performance objectives.

Advanced Analysis of Imperfect Portal Frames with Semirigid Base Connections

Abstract: A robust finite element procedure for large deflection and inelastic analysis of imperfect steel frames with semirigid base is proposed and the nonlinear behavior of semirigid frames with various modes of initial imperfection is studied. Special consideration to the method of simulating the frame initial imperfections is given. The refined plastic hinge method is used for modeling of the section plastification and both the notional force and the initially imperfect geometry of the frames obtained by an eigenvalue buckling analysis are used for modeling the geometrical imperfections. The difference between the notional force and the eigenbuckling mode models and of semirigid base connections are studied. From the examples reported in this paper, the effective length is not required to be assumed and the advanced analysis is noted to be applicable to practical design of this type of steel frames.