SAMB - Computer system of static analysis
of shear wall structures in tall buildings
In Poznań University of Technology a computer system of static
analysis of shear wall structures in tall buildings has been elaborated.
Using the system it is possible to carry out the analysis of stresses as well
as displacements of wide class of shear wall structures in multistorey
buildings subjected to complex loads.
Methods of analysis of shear wall structures in tall buildings, currently used in designing
practice, are characterised by introduction of considerable simplifications with reference to the
structure model and loads description as well as the method of solving the problem. Therefore,
the obtained values of displacements and stresses in the structure elements are considerably
approximate.
At the Institute of Structure Engineering of Poznań University of Technology in the team
supervised by prof. Kazimierz Wrześniowski there has been elaborated a computer system for the
strength analysis of shear wall structures in tall buildings in order to make a more precise analysis
of the complex structures possible. Originally, the system was used on ICL 1900 and Odra 1300
computers. Now it is possible to take advantage of the system making use of computers
compatible with IBM PC with medium size operating memory and DOS standard operating
system as well as Windows 3.1, Windows 95 and Windows NT environments.
Making use of the system it is possible to analyse structures the plan of which includes
walls and connecting beams arbitrarily located in the plan (Fig.1). The structures under
consideration can be exposed to horizontal loads (distributed arbitrarily along the building height
or applied on its top), vertical loads (arbitrarily located in the plan and arbitrarily changeable along
the height) and non-uniform settlement of foundations. The analysed structure , after its
description using a three-dimensional continuous model, is analysed without introducing
additional simplyfying assumptions. Input data of the SAMB (Static Analysis of Multistorey
Buildings) system include the information about arrangement of walls and connecting beams,
geometry and strength features which can be read from drawings of the building as well as data
describing loads. On the basis of the data determined in this way the system generates systems of
differential equations describing behaviour of the structure. Due to the consistent separation of
these systems it is possible to analyse the structure using a small operating memory field. Owing
to replacement of numerical integration by the integration according to formulas introduced
analytically and the best use of memory on magnetic discs, short computation times have been
obtained.
The results of the system constitute shearing forces and bending moments in connecting
beams, displacements of selected points of the building and values of normal, shear and principal
stresses at characteristic points of the structure. Internal forces in shear walls can be printed
optionally. All these groups of results are calculated for each load scheme and for described set
of extremes. The results are printed for arbitrary structure ordinates determined in the data. The
elaboration of the macro-command of operating system, the data number being its only
parameter, makes use of the system really simple. Using the system allows for the extensive
analysis of the structure in a short period of time. The above-described version of the SAMB
system, has been elaborated in the eighties, partly within the grant No 05.12 coordinated by the
Institute of Fundamental Technological Research of the Polish Academy of Sciences in Warsaw.
Since then many calculations concerning buildings being designed and erected or the existing ones
being modernised, have been made in Wielkopolska, Śląsk and Zielona Góra.
The system is being improved and developed continuously. In the past few years it has
been completed by new graphic pre- and postprocessors and a new subsystem of data
transmission to speed up computations.
The research has been focused currently on the development of the analysis taking into
account a non-linear model of the structure material.
Fig.1 Three-dimensional shear wall structure in tall building:
1 - 3-D shear wall, 2 - band of connecting beams, 3 - trace of floor slabs