Search results for "potential model"
showing 5 items of 5 documents
A new dynamic identification technique: application to the evaluation of the equivalent strut for infilled frames
2003
A new time domain identification technique for systems under Gaussian white noise input is presented, requiring for its application the measurement of the system response but no information about input intensity. The technique proposed is based on the statistic moment equations derived by using a special class of mathematical models named "potential models". These models allow one to determine fundamental properties of the response statistics, making it possible to identify stiffness and dissipation features of a structural system, and also to determine the excitation input. The technique proposed is here applied to the identification of the strut equivalent to the infill of a single story-…
Potential models for the simulation of methane adsorption on graphene: development and CCSD(T) benchmarks
2018
Different force fields for the graphene–CH4 system are proposed including pseudo-atom and full atomistic models. Furthermore, different charge schemes are tested to evaluate the electrostatic interaction for the CH4 dimer. The interaction parameters are optimized by fitting to interaction energies at the DFT level, which were themselves benchmarked against CCSD(T) calculations. The potentials obtained with both the pseudo-atom and full atomistic approaches describe accurately enough the average interaction in the methane dimer as well as in the graphene–methane system. Moreover, the atom–atom potentials also correctly provide the energies associated with different orientations of the molecu…
Identification of stiffness,dissipation and input parameters of randomly excited non-linear systems: Capability of restricted potential models (RPM)
2006
Abstract A dynamic identification technique in the time domain for time invariant systems under random external forces is presented. This technique is based on the use of the class of restricted potential models (RPM), which are characterized by a non-linear stiffness and a special form of damping, that is a product of the input power spectral density (PSD) matrix and the velocity gradient of a non-linear function of the total mechanical energy. By applying It o ^ stochastic differential calculus and by specific analytical manipulations, some algebraic equations, depending on the response statistics and on the mechanic parameters that characterize RPM, are obtained. These equations can be u…
LHCb pentaquarks in constituent quark models
2016
The recently discovered $P_c(4380)^+$ and $P_c(4450)^+$ states at LHCb have masses close to the $\bar D\Sigma_c^*$ and $\bar D^*\Sigma_c$ thresholds, respectively, which suggest that they may have significant meson-baryon molecular components. We analyze these states in the framework of a constituent quark model which has been applied to a wide range of hadronic observables, being the model parameters, therefore, completely constrained. The $P_c(4380)^+$ and $P_c(4450)^+$ are studied as molecular states composed by charmed baryons and open charm mesons. Several bound states with the proper binding energy are found in the $\bar D\Sigma_c^*$ and $\bar D^*\Sigma_c$ channels. We discuss the pos…
A Strategy for the Prediction of the Response of Hysteretic Systems: A Base for Capacity Assessment of Buildings under Seismic Load
2014
A statistical non linearization method is used to approximate systems modeled by the Bouc differential equa- tion and excited by a Gaussian white noise external load. To this aim restricted potential models (RPM) are used, which are suitable for an extended number of nonlinear problems as have been proved several times. Since the solution of RPM is known by the probabilistic point of view, all statistical characteristics can be derived at once with advantages by the computational point of view. Hence, this paper discusses the possibility to determine sets of parameters characterizing po- tential models that are valid for describing a hysteretic behavior. In this way the characterization of …