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Analytical determination of form friction factor
Gattas, M and Abel, J F 'Three dimensional linear dynamic analysis of buildings with 32bit virtual-memory minicomputers' Comput. Struct. Vo117, No 1, (1983) pp 9 7 - 1 0 4 This paper focuses on computer-aided analysis of three dimensional buildings with 32-bit, virtual memory minicomputers. Various floor, inertial, geometry, stiffness and displacement models of 3D buildings are discussed with respect to implications for computational efficiency. From this discussion a model for 3D buildings is selected for use with virtual memory minicomputers. This paper also covers the use of symbolic manipulation, dynamic allocation of memory and matrix storage and manipulation to achieve computational efficiency. Examples with computational statistics illustrate the ideas presented. Ellingwood, B, Leyendecker, E V and Yao, T P 'Probability of failure from abnormal load' J. Struct. Division ASCE, Vo1109, No 4 (April 1983) pp 8 7 5 - 8 8 9 Abnormal loads, which usually are not considered in structural design because of their low probability of occurrence, may initiate a catastrophic failure if they occur. A case study shows that the probability of structural failure due to a gas explosion in a residential compartment may exceed probabilities associated with unfavourable combination of ordinary design loads. The paper studies the need for specific provision in design standards to mitigate the effects of abnormal loads. Hrabok, M M and Hrudey, T M 'Finite element analysis in design of floor systems' ]. 5truct. Division ASCE, Vo1109, No 4 (April 1983) pp 9 0 9 - 9 2 5 An analysis is presented of the factors that have contributed to the finite element method not being used as a design office tool for the elastic analysis of floor systems. Suggestions are made which attempt to make the finite element method more attractive for this purpose. A computer program incorporating some of these features is described and its use is demonstrated in the analysis of an example problem. The relative merits of the finite element method to more traditional techniques are considered.
studied, and a connection model is proposed. The model is used to demonstrate the nature of the nonlinear behaviour of bolted connections, including coupling effects between moment and axial force. Using double angle connections, the applicability of the model to the analysis of plane frames, including the problem of predicting the behaviour of a specific connection is examined. Numerical examples demonstrate the effectiveness of the model. Kanok-Nukulchai, W, Lee, S and Karasudhi, P 'A versatile finite strip model for three dimensional tall building analysis' Eorthquake Eng. Struct. Dyn. J. Vol 11 (MarchApril 1983) pp 149--166 This study attempts to show the inadequacy of thin beam eigenfunctions commonly used to represent displacement profiles of tall buildings in finite strip analysis. The present models fail to reflect the correct building behaviour when storey-shear distortion may be significant. A new set of strip functions that is free of this shortcoming is proposed. A polynomial series is specially constructed and shown to be effective for all building types. Several tall building examples are tested and the results are found to be very good, in both static and free vibration analysis. Justo, J L and Saura J 'Three dimensional analysis of Infiernillo dam during construction and filling of the reservoir' Int. J. Numer. end Anal. Methods in Geomechanlcs Vol 7 (1983) pp 2 2 5 243 A 3D finite element program has been prepared to study the behaviour of Infiernillo dam during construction and filling of the reservoir. A linear stress-strain behaviour of materials has been assumed. The parameters are deduced from the movements measured during construction, checked with the results of the odeometer tests at the laboratory. Collapse of the upstream shell is introduced into the calculation in a simple way from the settlement observed upon flooding under constant stress at the odeometer. A good agreement is found between measured and calculated movements.
Wales, M W and Rossow, E C 'Coupled moment-axial force behaviour in bolted joints'/. Struct. Division ASCE, Vol 109, No 4 (May 1983) pp 1250-1266
Roberts, E H and Yam, L C P 'Some recent methods for the design of steel, reinforced concrete, and composite steel-concrete columns in the U.K.' Am. Concr. Inst. J. Vol 80, No 2 (March-April 1983) pp 1 3 9 - 1 4 9
The sources of nonlinearities in the behaviour of bolted steel connections are briefly
A new British standard for steelwork is being drafted, incorporating much of the
v o l u m e 15 n u m b e r 5 s e p t e m b e r 1 9 8 3
research done since the issue of the present British standard in 1969. The variable stiffness method, the latest available method for column design in rigid jointed steel frames, is described in detail. Application of this method in the design of reinforced concrete columns is then discussed. Various methods are progressively given, covering the design of short and slender pin-ended composite steel-concrete columns when subjected to axial load only and to uniaxial and biaxial bending. Simplified design methods are described for the last two cases. Fardis, M N, Alibe, B and Tassoulas, J L 'Monotonic and cyclic constitutive law for concrete' ]. Eng. Mech. Division ASCE, Vo1109, No 2 (April 1983) pp 5 1 6 - 5 3 6
A simple time-dependent, mathematical model is proposed for the monotonic and cyclic behaviour of concrete under multiaxial stress conditions. An essential feature of the model is a bounding surface in stress space. Strain increments are considered completely plastic. The plastic modulus for calculation of these strain components is a function of: • •
distance of the stress point from the bounding surface maximum strain experienced by the material
This functional dependence of the plastic modulus and the fact that the bounding surface shrinks as the maximum strain increases allow realistic modelling of the nonlinear unloading and reloading behaviour of concrete. Haque, M I and Mahmood, K 'Analytical determination of form friction factor' ]. Hydraul. Div/s/on ASCE, Vol 109, No 4 (April 1983) pp 5 9 0 - 6 1 0 The form friction factors for an idealized series of 2D bedforms simulating a train of ripples or dunes in alluvial channels is obtained analytically by integrating the pressure along the bedform profiles. The pressure distribution along the bedform is determined by analysing the incompressible, rotational inviscid flow over a theoretical ripple profile with the help of the finite element method. A family of curves representing the relationship between form friction factor and relative depth with different bedform steepness ratios are numerically obtained. The comparison with observed data shows a fair agreement. Collated by S Sutharshana
301
studied, and a connection model is proposed. The model is used to demonstrate the nature of the nonlinear behaviour of bolted connections, including coupling effects between moment and axial force. Using double angle connections, the applicability of the model to the analysis of plane frames, including the problem of predicting the behaviour of a specific connection is examined. Numerical examples demonstrate the effectiveness of the model. Kanok-Nukulchai, W, Lee, S and Karasudhi, P 'A versatile finite strip model for three dimensional tall building analysis' Eorthquake Eng. Struct. Dyn. J. Vol 11 (MarchApril 1983) pp 149--166 This study attempts to show the inadequacy of thin beam eigenfunctions commonly used to represent displacement profiles of tall buildings in finite strip analysis. The present models fail to reflect the correct building behaviour when storey-shear distortion may be significant. A new set of strip functions that is free of this shortcoming is proposed. A polynomial series is specially constructed and shown to be effective for all building types. Several tall building examples are tested and the results are found to be very good, in both static and free vibration analysis. Justo, J L and Saura J 'Three dimensional analysis of Infiernillo dam during construction and filling of the reservoir' Int. J. Numer. end Anal. Methods in Geomechanlcs Vol 7 (1983) pp 2 2 5 243 A 3D finite element program has been prepared to study the behaviour of Infiernillo dam during construction and filling of the reservoir. A linear stress-strain behaviour of materials has been assumed. The parameters are deduced from the movements measured during construction, checked with the results of the odeometer tests at the laboratory. Collapse of the upstream shell is introduced into the calculation in a simple way from the settlement observed upon flooding under constant stress at the odeometer. A good agreement is found between measured and calculated movements.
Wales, M W and Rossow, E C 'Coupled moment-axial force behaviour in bolted joints'/. Struct. Division ASCE, Vol 109, No 4 (May 1983) pp 1250-1266
Roberts, E H and Yam, L C P 'Some recent methods for the design of steel, reinforced concrete, and composite steel-concrete columns in the U.K.' Am. Concr. Inst. J. Vol 80, No 2 (March-April 1983) pp 1 3 9 - 1 4 9
The sources of nonlinearities in the behaviour of bolted steel connections are briefly
A new British standard for steelwork is being drafted, incorporating much of the
v o l u m e 15 n u m b e r 5 s e p t e m b e r 1 9 8 3
research done since the issue of the present British standard in 1969. The variable stiffness method, the latest available method for column design in rigid jointed steel frames, is described in detail. Application of this method in the design of reinforced concrete columns is then discussed. Various methods are progressively given, covering the design of short and slender pin-ended composite steel-concrete columns when subjected to axial load only and to uniaxial and biaxial bending. Simplified design methods are described for the last two cases. Fardis, M N, Alibe, B and Tassoulas, J L 'Monotonic and cyclic constitutive law for concrete' ]. Eng. Mech. Division ASCE, Vo1109, No 2 (April 1983) pp 5 1 6 - 5 3 6
A simple time-dependent, mathematical model is proposed for the monotonic and cyclic behaviour of concrete under multiaxial stress conditions. An essential feature of the model is a bounding surface in stress space. Strain increments are considered completely plastic. The plastic modulus for calculation of these strain components is a function of: • •
distance of the stress point from the bounding surface maximum strain experienced by the material
This functional dependence of the plastic modulus and the fact that the bounding surface shrinks as the maximum strain increases allow realistic modelling of the nonlinear unloading and reloading behaviour of concrete. Haque, M I and Mahmood, K 'Analytical determination of form friction factor' ]. Hydraul. Div/s/on ASCE, Vol 109, No 4 (April 1983) pp 5 9 0 - 6 1 0 The form friction factors for an idealized series of 2D bedforms simulating a train of ripples or dunes in alluvial channels is obtained analytically by integrating the pressure along the bedform profiles. The pressure distribution along the bedform is determined by analysing the incompressible, rotational inviscid flow over a theoretical ripple profile with the help of the finite element method. A family of curves representing the relationship between form friction factor and relative depth with different bedform steepness ratios are numerically obtained. The comparison with observed data shows a fair agreement. Collated by S Sutharshana
301