土木工程英文期刊及中文翻译

土木工程英文期刊以及中英文翻译

NONLINEAR FINITE ELEMENT ANALYSIS OF

REINFORCED CONCRETE TUBE IN TUBE OF TALL

BUILDINGS

1Abdul Kadir Marsono 1 and Lee Siong Wee 2 Associate Professor, Dept. Of Structure & Material, Faculty Of Civil Engineering,

Universiti Teknologi Malaysia.

2 Graduate Student, Faculty Of Civil Engineering, Universiti Teknologi Malaysia, 2004.

Abstract: The non-linear finite element analysis (NLFEA) has potential as a readily

usable and reliable means for analyzing of civil structures with the availability of

computer technology. The structural behaviors and mode of failure of reinforced concrete

tube in tube tall building via application of computer program namely COSMOS/M are

presented. Three dimensional quarter model was carried out and the method used for this

study is based on non-linearity of material. A substantial improvement in accuracy is

achieved by modifying a quarter model leading deformed shape of overall tube in tube

tall building to double curvature. The ultimate structural behaviors of reinforced concrete

tube in tube tall building were achieved by concrete failed in cracking and crushing. The

model presented in this paper put an additional recommendation to practicing engineers

in conducting NLFEA quarter model of tube in tube type of tall building structures.

INTRODUCTION

Tube in tube concept in tall building had led to significant improvement in structural efficiency to lateral resistance. In its basic form, the system comprising a central core surrounded by perimeter frames which consists of closed spaced perimeter column tied at each floor level by spandrel beams to form a tubular structure. Usually these buildings are symmetrical in plan, and their dominant structural action take place in the four orthogonal frames forming the perimeter tube and in the central core (Avigdor Rutenberg and Moshe Eisenberger, 1983). Under the lateral load, a frame tube acts like a cantilevered box beam to resist the overturning moment and the central core acting like second tube within the outside tube. In order to get the more accurate result of analysis, the central core may be designed not only for gravity loads but also to resist the lateral loads. The floor structure ties the exterior and interior tubes together to make then act as a single unit and their mode of interaction depending on the design of floor system. No torsion effect was considered in this study, thus the floor system is effectively pin jointed to allow horizontal forces transmission before primary vertical structural elements of the building.

Combining shear wall and frame structures has proven to provide an appropriate lateral stiffening of tall building. As the shear wall deflects, shear and moments are induced in connecting beam and slabs which later induced axial forces in walls. The perimeter frame and the central wall act as a composite structure and deformed as in Figure 1. The lateral force is mostly carried by the frame in the upper portion of the building and by the core in the lower portion. The deflected shape has a flexural profile in the lower part and shear profile in the upper part. The axial forces causing the wall to shed the frame near the base and the frames to restrain the wall at the top.

The main purpose of this study is to predict the ultimate failure behavior of overall reinforced concrete tube in tube tall building. Hence, non-linear analysis has to be carried out in this study for better understanding of failure mode. Non linear analysis is a modelling of structural behavior to the ultimate state while linear analysis is a conventional analysis that does not pretend to be accurate (Aldo Cauvia, 1990). A sysmetrical tube in tube reinforced

土木工程英文期刊以及中英文翻译

concrete tall building as shown in Figure 2, three dimensional (3D) quater model was implemented with finite element analysis method and take into account material non linearity.

( a ) ( c ) Figure 1 (a) Deform shape of frame; (b) Deform shape of shear wall;(c)Deformshapeofcombineframe+shearwall

METHOD OF ANALYSIS

Description of Model

The NLFEA model is a 16 stories reinforced concrete tube in tube tall building with typical storey height of 3.50m except ground floor is 6.0m heights. The full tube model is symmetrical in both axes in plan. The internal tube 7.50m x 7.50m is surrounded by perimeter frame tube 22.50m x 22.50m. All perimeter columns were arrange closely spaced at 4.5m center to center with the size of 0.90m x 0.90m from ground floor up to level 10 and 0.75m x 0.75m column after level 10. The spandrel beams are dimensioned 250mm thick and 750mm depth and tied to the perimeter column to form a perimeter tube. The thickness for slab is 175mm and presumed to act as a horizontal diaphragm to transfer the lateral load as well as vertical loads. The internal tube is formed by square perforated shear wall with the thickness of 350mm and the coupling beam is kept similar as thickness of the shear wall with the depth of 1000mm. COSMOS/M 2.0 (64K Version) finite element software is used to generate the model and perform subsequent non linear static analysis. For modelling idealization and domain discretization viability, only a modified quarter of tube in tube tall building is modelled in view of symmetrical and to cater limitation of COSMOS/M. After several attempts of NLFEA Run were performed out, the final model as indicated in Figure 2(b) was adopted as a final result in this study.

土木工程英文期刊以及中英文翻译

Proceedings of the 6th Asia-Pacific Structural Engineering and Construction Conference (APSEC 2006), 5 – 6 September 2006, Kuala Lumpur, Malaysia Frame system acting

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