Analysis Of Tall Buildings Research Articles

Analytical, semi-analytical and numerical solutions for global stability analysis in buildings: Double-Beam Systems Timoshenko

In this article, two analytical solutions, one semi-analytical solution, and one numerical solution are proposed to calculate the global critical buckling load of buildings employing a continuum model parallel coupling two Timoshenko beams. The parallel coupling of two Timoshenko beams represents the four types of building behavior: global bending, global shear, local bending, and local shear, the latter of which has been widely ignored in the literature. The model is associated with one translational kinematic field and two rotational fields. The equilibrium equations, constitutive laws, and boundary conditions are derived using a variational approach by applying Hamilton’s principle to the relevant Lagrangian function. Specifically, to solve the classical problem of buildings with uniform properties along their height, the first analytical solution proposes exact closed-form equations for a vertical load applied at the top and a closed-form analytical solution based on the decomposition of two subsystems for a polynomial vertical load uniformly applied along the height of the beam. Meanwhile, the semi-analytical solution exactly solves the differential equation associated with a polynomial vertical load profile and is based on coefficient iteration, converging with only two or three iterations. To address the challenge of buildings with variable properties along their height, the combined application of the continuous method and the transfer matrix method allows us to propose an efficient numerical method leading to a 6 × 6 transfer matrix, constant regardless of the number of discretizations and derived analytically, which results in a computational advantage by drastically reducing computational costs. The numerical results are encouraging and show good agreement with the results of the finite element method, suggesting that the proposed method can be used for engineering purposes in both the preliminary and final phases of the structural analysis of tall buildings.

Practical solutions for global buckling analysis in tall buildings: classic sandwich continuous model

Static stability analysis of global buckling and critical load ratio calculation are among the fundamental and most important parameters for structural analysis and design in numerous engineering applications across various fields. Particularly in the field of structural engineering, the critical load ratio is a parameter that determines the overall performance of tall buildings; however, due to the complexity of coupled differential equations with variable coefficients associated with different classical continuous models, its analysis has not been widespread, and only specific cases have been solved. This article utilizes the classic sandwich beam, widely studied in the literature, to propose an analytical solution and a generalized numerical solution to address the elastic buckling problem with applications in tall building stability analysis. The analytical solutions are applicable to uniform structures and consider point, uniform, and variable compression loads along their length that can be expressed through polynomial functions. The generalized numerical solution addresses the general case of structures with uniform or variable properties. Numerical applications and parametric analyses show excellent agreement between the results of the proposed methods and those of one-dimensional finite element methods. The influences of key parameters on the behavior of the eigenvalue associated with global buckling analysis are analyzed, and graphs and tables are proposed for direct practical application by engineers. Due to their mathematical formulation and excellent precision in results, the proposed methods can be safely used in the preliminary and final analysis of tall buildings and can be easily adapted to other engineering fields.

Analysis of Tall Building by using Different Dimensions Under Wind Load Effects

Abstract: The expense of land is increasing day by day because of rapid increase in the population whereas vegetation is diminishing, due to diminished vegetation contamination is expanded. In this Research paper, we analyze the various types of the dimensions of the building considering them side ratios too and the effect of windward forces on the building in mainly X and Z direction. This paper is about the study of four-building models as Dimensions (30m*30m), (40m*25m), (55m*20m), (80m*15m) having their horizontal Aspect ratios viz. 1, 1.6, 2.75 & 5.33 at an angle of 0 degrees. The height of the building is 90m. Therefore, the research is proceeding to balance out the structure from an increasingly affordable perspective. To find out the best performance and economical for the lateral wind-force resisting system of different models of 25 storey buildings are modelled in STAAD-PRO, assuming the site location as AGRA (Uttar Pradesh), India. For the different structural systems that are compared for minimum and maximum storey displacement, storey drift. The structural system used is prototype. The axial force, shear force, moment, and reactions at various windward sides are used to compare the best performance of the structure. Above all, wind forces in x- direction shows the adequate displacement and drift values when compared to z- direction but from the economic point of view Model-2 gives the satisfactory result from all the above.

Linear Analysis of Tall Buildings and Tension Cracking of Shear Walls

Linear Analysis of Tall Buildings and Tension Cracking of Shear Walls

Analytical and numerical solution of generalized static analysis of tall buildings: double-beam systems Timoshenko

Analytical and numerical solution of generalized static analysis of tall buildings: double-beam systems Timoshenko

Partitioning of wind pressure coefficients on a tall building under interference effect: A cluster analysis approach

This study proposed a cluster analysis-based approach for partitioning wind pressure on tall buildings in densely-packed areas, considering interference effects. By utilizing a modified GK cluster algorithm and leveraging the coordinate positions of pressure taps along with their corresponding wind pressure coefficients (WPC), the study aimed to distinguish different parts of the building surface exhibiting varying wind load characteristics. The adoption of cluster validation indices (CVIs) allowed for the determination of the optimal number of clusters, enhancing the accuracy and reliability of the partitioning process. The resulting clusters effectively captured the distribution of wind pressure, providing valuable insights for wind-resistant design considerations. Overall, the proposed approach demonstrates promising potential in facilitating the design and analysis of tall buildings subjected to complex wind loads in urban environments.

Free vibration analysis of tall buildings using a generalized continuous model: simplified approach to soil-structure interaction

Currently, due to the simplifications imposed on continuous models, there is an absence of a generalized approximate solution to investigate all possible dynamic behaviors of a tall building. In an attempt to address this deficiency, this paper proposes a new generalized continuous model and its solution methods to generalize all types of behavior that may be encountered in structural systems and tall buildings. The continuous model results from a composite beam that serially couples the classical sandwich beam and a pure shear beam. Unlike existing continuous models, the serial coupling, inclusion of new kinematic fields, and inclusion of rotational inertia allow for the resolution of complex interaction among different types of bending and shear behaviors. Specifically, it is shown how local shear behavior simultaneously interacts with global bending behavior, global shear, and local bending. Two solutions to the dynamic problem are presented: a closed-form analytical solution method for structures with uniformity along their height, and a numerical method that combines the advantages of the continuous method and the transfer matrix method to resolve structural and geometric variability in height. The transfer matrix is analytically solved by maintaining a fixed 6 × 6 matrix range that is independent of the number of levels of the structure, drastically reducing computational cost by eliminating the classical need to calculate the inverse of the zero matrix. Numerical applications investigate the effect of rotational inertia and local shear on the accuracy of the proposed results compared to results from the finite element method. To this end, a parametric analysis of 1560 different cases covering a wide range of typical behaviors in individual structural systems and tall buildings is conducted. The results exhibit promising accuracy, showing that the qualities of the proposed continuous model significantly improve precision compared to classical continuous models and therefore justify its practical application by academics and practicing engineers. Furthermore, the proposed mathematical approach is easily applicable in various domains of composite materials engineering.

Static, Dynamic and Stability Analysis of Tall Buildings by the Transfer Matrix Method Using Replacement Timoshenko Beam

Static, Dynamic and Stability Analysis of Tall Buildings by the Transfer Matrix Method Using Replacement Timoshenko Beam

Reducing the cost of calculations for stability analysis of tall buildings using a new approach

Reducing the cost of calculations for stability analysis of tall buildings using a new approach

A modal conditional mean spectrum for nonlinear structural response time-history analysis of tall buildings to consider higher mode effects

A modal conditional mean spectrum for nonlinear structural response time-history analysis of tall buildings to consider higher mode effects

Review of Wind-Induced Effects Estimation through Nonlinear Analysis of Tall Buildings, High-Rise Structures, Flexible Bridges and Transmission Lines

The nonlinear effects exhibited by structures under the action of wind loads have gradually stepped into the vision of wind-resistant researchers. By summarizing the prominent wind-induced nonlinear problems of four types of wind-sensitive structures, namely tall buildings, high-rise structures, flexible bridges, and transmission lines, the occurrence mechanism of their nonlinear effects is revealed, providing cutting-edge research progress in theoretical studies, experimental methods and vibration control. Aerodynamic admittance provides insights into the aerodynamic nonlinearity (AN) between the wind pressure spectrum and wind speed spectrum of tall building surfaces. The equivalent nonlinear equation method is used to solve nonlinear vibration equations with generalized van-der-Pol-type aerodynamic damping terms. The elastic–plastic finite element method and multiscale modeling method are widely employed to analyze the effects of geometric nonlinearity (GN) and material nonlinearity (MN) at local nodes on the wind-induced response of latticed tall structures. The AN in blunt sections of bridges arises from the amplitude dependence of the aerodynamic derivative and the higher-order term of the self-excited force. Volterra series aerodynamic models are more suitable for the nonlinear aerodynamic modeling of bridges than the polynomial models studied more in the past. The improved Lindstedt–Poincare perturbation method, which considers the strong GN in the response of ice-covered transmission lines, offers high accuracy. The complex numerical calculations and nonlinear analyses involved in wind-induced nonlinear effects continue to consume significant computational resources and time, especially for complex wind field conditions and flexible and variable structural forms. It is necessary to further develop analytical, modeling and identification tools to facilitate the modeling of nonlinear features in the future.

A novel generalized sandwich-type replacement beam for static analysis of tall buildings: Inclusion of local shear deformation of walls

As the length of the shear walls increases, local shear deformation leads to increased error when using classical continuum models for static structural analysis of tall buildings. In this paper, a novel continuous beam of the generalized sandwich type is proposed for the structural analysis of tall buildings that have shear walls of significant length as lateral bracing systems. The proposed continuous beam includes in its formulation an additional kinematic field of rotation due to the local shear deformation of the walls and results from the series coupling of a classic sandwich beam and a shear beam. The equilibrium equations, the constitutive laws, and the boundary conditions of the continuous model are obtained with a variational approach using the Hamilton principle on the relevant Lagrange function. A system of three coupled differential equations leading to sixth-order differential equation and six boundary conditions are obtained. Two closed-form analytical methods are proposed for uniform-height tall buildings. For the case of buildings with variable properties along their height, a numerical method of the modified transfer matrix type is proposed, which is directly derived from the analytical method and avoids the need to calculate the inverse of the classical zero transfer matrix method. The numerical results show the validation of the continuous model and the proposed solution methods. In addition, a parametric analysis of 352 buildings was performed to demonstrate the superiority of the continuous model and the proposed solution methods.

A Novel Generalized Sandwich Beam for Global Stability Analysis of Tall Buildings with Shear Walls Using a Modified Transfer Matrix Method

This research presents the study of the global buckling analysis of tall buildings with shear walls of significant length, where it is not possible to neglect the stiffness due to local shear. In order to correctly idealize the tall building, this research proposes a novel generalized sandwich beam replacement resulting from the generalization of the classical sandwich beam by including an additional mechanism due to the consideration of the local shear stiffness. The association of mechanisms of model shows that the proposed beam results from the series coupling of the classic sandwich beam and the local shear beam. Four characteristic stiffnesses and three kinematic fields associated with the model are considered. The differential equations and boundary conditions governing equilibrium are obtained by applying a variational approach using Hamilton’s principle to the relevant Lagrangian function. A modified transfer matrix method is proposed that diagonalizes the inverse of the zero transfer matrix and reduces the computational cost to solve the equilibrium equations numerically. The modified transfer matrix method allows the analysis to be generalized to buildings with uniform and non-uniform properties along their height considering a constant or variable compressive load along the height of the building. A parametric analysis is presented to evaluate the importance of the inclusion of the local shear mechanism of the shear walls. The results of the numerical examples are encouraging and show that at a reduced computational cost, the presented numerical procedure can greatly help engineers in the preliminary and final structural analysis of tall buildings.

Seismic Analysis of Tall Buildings Connected with Sky Bridge

Seismic Analysis of Tall Buildings Connected with Sky Bridge

Hybrid AI-Bayesian-based demand models and fragility estimates for tall buildings against multi-hazard of earthquakes and winds

The uncertainty coming from various sources will have a considerable influence on the credibility of the structural performance evaluation of tall buildings. This paper proposes a hybrid AI-Bayesian-based methodology for fragility estimates of tall buildings subjected to simultaneous earthquake and wind events that is feasible to incorporate into both the epistemic and aleatory uncertainties. The main contributions and concept of this proposed methodology include (1) The Back Propagation (BP) Artificial Neural Network (ANN) technique is applied to train a surrogate model to replace finite element (FE) analysis of tall buildings under concurrent seismic and wind excitations, which can highly reduce computing time of nonlinear dynamic analyses and is beneficial for quantifying the aleatory uncertainty with material properties and structural characteristics. (2) A physics-based demand model is developed for fragility estimates, and the Bayesian statistics method is utilized to obtain the posterior probability distributions of the unknown parameters in the demand model, which is beneficial for quantifying the epistemic uncertainty in the fragility estimates. Finally, this proposed method is implemented in a representative composite tall building. The application highlights the importance of incorporating both the epistemic and aleatory uncertainties into the fragility estimates of tall buildings under multiple hazards. This AI-Bayesian-based method provides great help for quantifying various uncertainties and improving resilience assessment reliability of tall buildings under multiple hazards.

Coupled dynamic analysis of tall buildings isolated with friction pendulum bearings under three-dimensional wind loads

Coupled dynamic analysis of tall buildings isolated with friction pendulum bearings under three-dimensional wind loads

Analysis of Tall Building by Various Types of Structural Forms under Earthquake Analysis

Abstract: In the current world scenario, high-rise buildings are favoured due to the rapid rise in land values, land shortages, and to conserve land in rural areas for agricultural use. The construction of high-rise buildings primarily depends on wind and seismic loads. The performance of buildings depends on the structural configuration. The structural system of a high-rise building is designed to work with vertical gravity loads and mainly with lateral loads caused by wind and seismic activity. The structural system consists only of elements designed to transfer loads, all other elements that are not involved in the transfer of loads are called non-structural element. The research assist the analysis of G+16 Storey level with various mode of structural form used in tall building construction. The G+16 Tall building is modelled on CSI ETBAS for Zone 4 under seismic analysis by Response spectrum analysis. The various types of struural form used in the model 1 to model 6. The structural form consists of 1) Moment resisting frame 2) Building with Braced Frame Structure 3) Building with Hull-Core (Tube-in-Tube Structure) 4) Building with Shear Wall 5) Building with Composite 6) Building with Outrigger Structure. The research concluded that the model cases no 3 is optimised under the G+16 Storey building. Other than model 2, 4, 1 & 6 recommended for optimised case in descending order

Variable Factors Affecting Progressive Destruction of Composite Steel Tall Building

In recent years, the presence of progressive collapse in tall buildings induced a catastrophic event which attracted the majority of the community’s attention. The purpose of this paper is to develop a 3D numerical analysis of tall building under column loss. A composite steel frame building with 25 stories with five spans in both directions is proposed. The building has 3 m story height and 8 m span in both directions. The building is designed through the commercial software SAP2000 software against wind loads based on Eurocode 1-2005. The focus here is to investigate various parametric studies under abrupt column loss of multi-story composite building. The effect of composite slab is considered with full composite action between beam and slab. The findings of a parametric formulation incorporating important parameters for the progressive collapse design technique are given and confirmed using nonlinear dynamic time history analyses. The assessment of results has been introduced based on deformation, axial force in columns, equivalent plastic strain, major moment and axial force in the considered beams above the column loss. Next, a probabilistic analysis has been performed to assess the behavior of composite steel buildings against column loss. The study investigates the critical column loss and pinpoints the location of the next critical column. The results show that the concrete grade, position of the removed column, beams cross-section, and place of bracings have a significant effect in the response of the building rather than the steel grade and bottom reinforcement density. The removal of exterior column has the significant increase of the axial force percentage by 111.4% for the corner column. The corner column removal gives the maximum equivalent plastic strain with a value of 0.00449. Furthermore, the results reveal the potential impact of uncertainty on the structural elements of the considered buildings through the progressive collapse analysis. The vertical displacement above the column is fitted with mean value of 0.0251387 m and with a coefficient of variation 0.01664.

Free Vibration and Frequency Calculation in Tall Buildings with Stepped Tube-in-Tube Systems

This study investigates the free vibration and frequency analysis of tall buildings with stepped cross-sections for stepped tube-in-tube structures. Dynamic equations were presented in accordance with the stepped structural system for free vibration and the differential equations were solved according to the application of boundary conditions and flexural and shear stiffness and stepped cross-section of different steps. The answer was converted to an 8x8 matrix and was obtained using the determinants of matrix and mathematical calculations of frequency. Nine mathematical computational models were designed for stepped tube-in-tube structures for a 50-story tube-in-tube building by increasing the height of the outer tube by 15 meters. Finally, the heights of the inner and outer tubes were equalized by increasing the height of the outer tube and then compared with the results of free vibration in the articles with the tube-in-tube structural system with equal height and characteristics. Using this method, the frequency of structures was calculated correctly and the obtained results from finite element analysis showed that this mathematical method accurately calculated the frequency. It was found that this method was accurate enough and the obtained computational error was very small. The results showed that the frequency decreases by adding to the outer tube and increasing its height.

Time-domain model for prediction of generalized 3DOF buffeting response of tall buildings using 2D aerodynamic sectional properties

A time-domain method to calculate the buffeting response of a rectangular tall building (AR of B/D = 1.5 and H/D = 6) in along-wind, across-wind and torsional degrees of freedom using 2D aerodynamic sectional properties is presented here. The aerodynamic sectional properties were identified first using wind tunnel section models. Aerodynamic damping, which is critical in wind-induced response analysis of tall buildings, was calculated using the identified aeroelastic derivatives (flutter derivatives) and validated by comparing with those extracted directly from the response measurements of aeroelastic models of the tall building. A good agreement between the numerically simulated responses and the experimental measurements of an aeroelastic model (1:175 scale) shows the capability of the proposed method in the prediction of generalized 3DOF buffeting response of tall buildings in a wide range of wind speeds. Furthermore, the response of a tall building with two other cross-sectional shapes, circular and elliptical, was calculated using the developed method and compared amongst the three cross-sectional shapes to study the effect of cross section on buffeting response. The relative dependency of buffeting response of a tall building along each of the 3DOF on cross section, wind speed as well as angle of attack was assessed. Finally, the effect of taper on tall building’s buffeting response was studied using the developed method which showed that taper could significantly reduce the wind-induced response of tall buildings. The time-domain method to assess wind loads and buffeting response of tall buildings based on experimentally or theoretically derived aerodynamic properties of two-dimensional sections, as presented here, provides a viable and perhaps the only alternative to methods based on aeroelastic model tests and CFD simulations.