دانلود مقاله مدلسازی و بررسی هیسترزیس رفتار دینامیکی خمشی دیوار برشي

دانلود مقاله مدلسازی و بررسی هیسترزیس رفتار دینامیکی خمشی دیوار برشي

Hysteretic modelling of x-braced shear walls*
Natividad Pastor, Antonio Rodrı´guez-Ferran*
Laboratori de Ca`lcul Nume`ric (LaCa`N), Departament de Matema`tica Aplicada III, E.T.S. d’Enginyers de
Camins, Canals i Ports de Barcelona, Universitat Polite`cnica de Catalunya, Edifici C2, Campus Nord UPC,
Jordi Girona 1-3, E-08034 Barcelona, Spain
Received 16 September 2004; received in revised form 23 May 2005; accepted 6 June 2005
Available online 1 September 2005

Abstract
We present a differentialmodel of the hysteretic behavior of unsheathed x-braced frames. Themodel includes all the relevant aspects (perfect or hardening plasticity of diagonal straps under tension, buckling of diagonal straps under compression). The frame is treated as a single-degree-of-freedom system, and the hystereticmodel is written as a small systemof ordinary differential equations. In spite of this simplifiedmodelling approach, the proposed model captures the key features of hysteretic cycles of x-braced frames (extreme pinching and slackness) and can be used to obtain the q-factor for simplified seismic design based on the reduction of elastic spectra. The model also allows to couple several x-braced frames to obtain the response ofmore complex structures such as complete fac¸ades. In fact, the agreement with a more sophisticated approach, such as a finite elementmodel of the frame, is excellent, but the computational cost is considerably lower.This point is illustrated by various numerical examples. q 2005 Elsevier Ltd. All rights reserved.
Keywords: Hysteresis; Shear walls; x-Bracing; Cold-formed steel structures; Seismic design; q-Factor

منبع : Sciencedirect Springer

دانلود مقاله تجزیه و تحلیل دیوار برشی با دهانه (باز) با استفاده از عناصر فوق العاده

Analysis of shear wall with openings using super elements
H.-S. Kim , D.-G. Lee

Department of Architectural Engineering Sungkyunkwan University, Chun-chun-dong, Jang-an-gu, Suwon, 440-746, South Korea
Received 17 April 2002. Revised 29 January 2003. Accepted 3 February 2003. Available online 20 March 2003.

Abstract

The box system that consists of reinforced concrete walls and slabs is adopted for many high-rise apartment buildings recently constructed. In an apartment building, shear walls may have one or more openings for functional reasons. Some researches on the analysis of shear wall with openings were performed, but some restrictions prevent those research results from being applied to the practical analysis and design procedure. It is necessary to use fine mesh finite element models for an accurate analysis of a box system structure with openings. But it would take a significant amount of computational time and memory if the entire building structure were subdivided into a finer mesh. An efficient analysis method that can be used regardless of the number, size and location of openings is proposed in this study. The analysis method uses super elements developed using the matrix condensation technique. Static and dynamic analyses of example structures having various types of openings were performed to verify the efficiency and accuracy of the proposed method. The analyses of example structures demonstrated that the proposed method can be used for the analysis of a shear wall structure with openings. Outstanding accuracy in analysis could be achieved with drastically reduced computational time and memory.