Showing papers on "Shear wall published in 1969"

New Rectangular Finite Element for Shear Wall Analysis

Abstract: Most previously derived plane stress finite elements cannot be connected with line elements in bending. This difficulty is overcome by devising a new element which has rotational degrees of freedom at the node points. Application to analysis of simple shear wall problems with a single row of openings illustrates the method and comparison of results with other solutions demonstrates its validity. A study of the behavior of the new element in comparison with results for a more conventional element shows: (1) For the same number of elements, the accuracy of estimation of deflection is increased and (2) the ratio of length to breadth of the elements has a less significant effect on the results.

Analysis of Shear Walls with Openings

Abstract: Openings are often introduced into shear walls in multistoried buildings for either architectural or environmental reasons. These openings reduce the efficiency and change the deformation characteristics of the shear walls, depending on the distribution of the loads and the geometry of the walls with openings. Variations of the material properties also affect the stress distribution. The use of the finite-element method in analyzing these problems is found to be convenient and more accurate than conventional approximate methods. A model shear wall problem is selected and analyzed by the finite-element method and the results are presented. It was observed that local distortions occurred at the junctions of the lintel beams and the shear walls due to the bending moments, shear forces, and axial loads carried by the lintel beams. Because of these distortions, the bending moments on the lintel beams were found to be much less than the bending moments obtained from other approximate methods of analysis.

Torsion of Perforated Concrete Shafts

Abstract: A simple method of analysis is presented for torsionally loaded perforated shafts. This difficult topic is presented for the first time in a manner suitable for use in engineering offices. The internal forces, the twist and the period of the free torsional vibrations are found to depend on a single, dimensionless, parameter, which is denoted as torsional stiffness parameter of the shaft. The use of dimensionless coefficients makes it possible to find the general solution and to express it in explicit form. Moreover, it is recognized that there exists a complete mathematical analogy between the torsionally loaded shaft and the laterally loaded shear wall. This, it is expected, will simplify future research in the theory of building structures.

Reinforced concrete shear walls

Abstract: This paper describes the likely behaviour of shear walls of multistorey buildings when subjected to a seismic type of lateral loading, and in particular, to alternating plasticity. The problems associated with the analysis of cantilever shear walls and rigid jointed frames, when interacting with each other, are briefly discussed and some examples of the undesirable consequences of irrationally placed openings in shear walls are reviewed. The principles are postulated upon which the elastic performance of coupled shear walls can be approximated, also taking into account the effects of cracking in its components. The post-elastic behaviour, ultimate strength, and in particular the ductility requirements of the coupling system are examined. Features of the performance of reinforced concrete coupling beams, identified in a recent experimental study, are also presented.

Design of Connecting Beams in Coupled Shear Wall Structures

Abstract: CURVES ARE PRESENTED FOR THE DIRECT EVALUATION OF THE MAXIMUM SHEAR FORCE IN ANY CONNECTING BEAM OF A COUPLED SHEAR WALL SYSTEM. SUPPLEMENTARY TABLES YIELD THE ACTUAL POSITION OF THE MOST HIGHLY STRESSED BEAM. THE CURVES CAN DEAL WITH A SHEAR WALL WITH ONE ASYMMETRICAL BAND OR TWO SYMMETRICAL BANDS OF OPENINGS, SUBJECTED TO EITHER A UNIFORM OR TRIANGULARLY DISTRIBUTED LOAD. STEPPED VARIATIONS IN THE WALL THICKNESS MAY BE INCLUDED IN THE ANALYSIS. /AUTHOR/

A note on the earthquake performance of reinforced concrete shear walls

Abstract: A great many one and two story buildings as well as many buildings as tall as 10 stories or higher have cast in situ reinforced concrete walls designed to act as shear walls for resisting seismic forces. Allowable design stresses in reinforced concrete shear walls have been increased in recent years in many building codes, although in one major code they have been drastically reduced. Concurrently, modern architectural trends have often resulted in the reduction of certain reserve strength features neglected in seismic design such as "non-structural" panel walls of brick or of reinforced concrete since these elements are often replaced by glass or by insulated metal panels. This, in effect, results in greater applied seismic forces on the shear walls. The frequent elimination of deep spandrel beams in favor of thin slabs which may meet glass or metal walls also tends to increase stresses in the shear walls since the strength and stiffness of the spandrels were often neglected when interior shear walls existed. In summary, it has been the experience in the United States and in many other countries in the world that the effective factor of safety in reinforced concrete shear walled structures has often been substantially reduced for seismic loadings. In many cases, inadequate methods of analysis have neglected critical stresses at boundaries and openings.