Stochastic seismic response of multiply-supported secondary systems in flexible-base structures

Dey, Aparna; Gupta, Vinay K.

doi:10.1002/(sici)1096-9845(199904)28:4<351::aid-eqe821>3.0.co;2-s

Cited by 20 publications

(6 citation statements)

References 19 publications

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“…Partial pragmatic remedies to these issues may include selective neutralisation of the receptor titratable groups and/or use of continuum models to correct the ∆<V elec_Lig > term for long-range electrostatics [113,123,124,263,279,283,285]. On the other hand, several studies yielded operational LIE models without reported ad hoc adjustment of the system charges [106,107,[286][287][288]. When neutralising the net charge of the system by adding counterions to the simulation zone, the calculated interaction energies were found to converge more slowly than when adjusting the charge state of the receptor [123].…”

Section: The Lie Approach: Methods and Applicationsmentioning

confidence: 99%

Towards Predictive Ligand Design With Free-Energy Based Computational Methods?

Foloppe¹,

Hubbard²

2006

CMC

199

188

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The accurate prediction of ligand-biopolymer binding affinities is of general interest to medicinal chemistry, as well as to the broader field of molecular recognition. The ability to predict computationally the thermodynamics of these molecular recognition processes has been relatively weak until recently, however, continued developments on several fronts are extending the scope of applicability of these methods. The rapid growth in the number of protein-ligand structures has initially led to the development of a range of empirical scoring functions based on relatively simple descriptions of intermolecular interactions. These methods have had some success in ranking binding affinities when tuned to particular protein systems or in rather qualitative estimates of molecular fit in fast docking calculations. However, they are too unreliable for more detailed, quantitative, assessment and comparison of binding affinities. Physics-based free energy calculations are in principle more general and have the potential to be significantly more accurate. These approaches have seen steady development over many years and rely on carefully calibrated molecular energy functions (force-fields), simulations of the systems with explicit solvent, and the coming-of-age of continuum solvation models. In addition to the initially developped Free Energy Perturbation (FEP) and Thermodynamic Integration (TI) methods, new approaches include the Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) and the Linear Interaction Energy (LIE) approaches. This review concentrates on MM-PBSA and LIE, and their variants. The routine application of these calculations is becoming possible because of enhanced computational hardware and the development of a range of computational chemistry tools. This review addresses: i) the basic principles behind free energy calculations ii) recent methodological advances iii) comparisons of predicted and experimentally determined affinities iv) the uncertainties and limitations of both the computational and experimental data v) areas where progress can be made vi) the practicality of applying the methods at the different stages of the drug discovery and optimization process.

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Section: The Lie Approach: Methods and Applicationsmentioning

confidence: 99%

Towards Predictive Ligand Design With Free-Energy Based Computational Methods?

Foloppe¹,

Hubbard²

2006

CMC

199

188

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“…In terms of influence factors considered, the studies by Dey and Gupta [50,51] made a significant leap to introduce soil-structure interaction (SSI) effect in the analysis of multiplyattached secondary structures. In their studies, both fixed and flexible-base primary structures were assumed to behave linearly.…”

Section: mentioning

confidence: 99%

Review of Approaches for Analysing Secondary Structures in Earthquakes and Evaluation of Floor Response Spectrum Approach

Lim

Chouw

2015

International Journal of Protective Structures

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Secondary structures are the members that are not part of the primary load-bearing components in a structural system. Although not intended to bear loads, secondary structures could be subjected to earthquake loading that may lead to failures. Damage to secondary structures could pose significant threats to life safety, prevent buildings from functioning and result in major economic loss. During past decades, a considerable amount of research efforts has been dedicated to develop rational approaches for seismic analysis of secondary structures. This paper aimed to assess these developments to today's knowledge as a reference for more accurate design. The review began with a brief description of the response characteristics of secondary structure under seismic loading, especially focusing on the factors that influence the responses. An appraisal of current numerical and experimental analysis methods of secondary structure is presented. Results from experimental work are used to validate the reliability of floor response spectrum and current design provision. Finally, an outlook of future possible research direction for more realistic design of secondary structures is given.

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“…(15) and (16) h o ðxÞ with hydrodynamic forces P n i¼1 ðk si þ ixc si Þu si ðxÞ and ground acceleration € Z g ðxÞ are established using impedance functions, base shear and base moment equations of the aqueduct structure. According to Dey and Gupta (1999), if the foundation is assumed to be massless, then base shear V s ðxÞ and base moment M s ðxÞ can be expressed in terms of foundation displacements relative to the soil medium using the impedance functions. …”

Section: Frequency Domain Analysismentioning

confidence: 99%

Seismic response of an elevated aqueduct considering hydrodynamic and soil-structure interactions

Valeti

Ray-Chaudhuri

Raychowdhury

2016

Int J Adv Struct Eng

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In conventional design of an elevated aqueduct, apart from considering the weight of water inside the channels, hydrodynamic forces are generally neglected. In a few special cases involving high seismic zones, hydrodynamic forces have been modeled considering equivalent lumped-mass type idealization or other models. For support conditions, either the base is considered as fixed or in a few cases, equivalent spring-dashpot system is considered. However, during an intense seismic event, nonlinear soilstructure interactions (SSI) may alter the response of the aqueduct significantly. This paper investigates the effect of hydrodynamic forces and SSI on seismic response of a representative elevated aqueduct model. Different modeling concepts of SSI has been adopted and the responses are compared. Frequency domain stochastic response analysis as well as time-history analysis with a series of ground motions of varying hazard levels have been performed. Demand parameters such as base shear and drift ratio are studied for varying heights of water in channels and different site conditions. From the frequency domain analysis, the effect of convective masses is found to be significant. From the time history analysis, the overall effect of increase in height of water is found to be negligible for nonlinear base case unlike the fixed and elastic base cases. For the nonlinear base condition, the base shear demand is found to decrease and the drift ratio is found to increase when compared to the results of linear base condition. The results of this study provide a better understanding of seismic behavior of an elevated aqueduct under various modeling assumptions and input excitations.

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Stochastic seismic response of multiply-supported secondary systems in flexible-base structures

Cited by 20 publications

References 19 publications

Towards Predictive Ligand Design With Free-Energy Based Computational Methods?

Towards Predictive Ligand Design With Free-Energy Based Computational Methods?

Review of Approaches for Analysing Secondary Structures in Earthquakes and Evaluation of Floor Response Spectrum Approach

Seismic response of an elevated aqueduct considering hydrodynamic and soil-structure interactions

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