1,147 research outputs found
Adaptive multi-grid FE simulation on dynamic damage and seismic failure of concrete structures
This paper presents a new adaptive multi-grid method for analyses on damage and failure in concrete column under cyclic loading. Self-adaptation of the method can carry out automatically coupling analysis on the process of evolving damage to structural failure with dynamic grid-change due to damage, without user intervention in the computation. The theory of multi-grid FEM coupled evolving damage is developed on the basis of the improved variational principle to consider damage evolution, in which the elements in each sub-domain with different grid sizes are under the different state of damage. Then the multi-grid FEM method is provided with the theory and a 3D adaptive mesh refinement procedure. As a case study of the method, the process of evolving damage to failure of a concrete column under cyclic loading is simulated by using the developed method, and the simulated results fit well with the experimental data. The results show that, the developed method is reliable in simulation on evolving damage and failure in concrete column under dynamic seismic loading with lower cost and sufficient precision
Dynamic stress intensity factor of a finite crack based on a fractional differential model
Fractional differential constitutive models are introduced for transient problem of Mode III finite length crack in a viscoelastic medium. The basic equations which govern the deformation behavior are converted to fractional wave-like equations. Integral transform method reduces the problem to Fredholm integral equation of second kind. Dynamics stress intensity factors of Mode III finite crack based on fractional differential constitutive are obtained by numerical solution of Fredholm integral equation
Adaptive dynamic multi-grid method for simulation on seismic damage evolution of concrete column
A new adaptive dynamic multi-grid method is developed for simulation on evolving damage in concrete column under seismic loading. The method should possess adaptive capability in order to carry out automatically coupling analysis without user intervention in the computation. As a case study of the method, the process of evolving damage to failure of a concrete column under seismic loading is simulated, and the simulated results fit well with the experiment. It shows that, the developed method can be used to reveal the seismic failure mechanism of concrete structures by considering the dynamic coupling process from material damage in concrete of stress concentration zone to local failure in vulnerable component and eventually to structural failure with the adaptive capability as well as better computational efficiency
Properties of Heavy Higgs Bosons and Dark Matter under Current Experimental Limits in the NMSSM
Searches for new particles beyond the Standard Model (SM) are an important
task for the Large Hadron Collider (LHC). In this paper, we investigate the
properties of the heavy non-SM Higgs bosons in the -term extended
Next-to-Minimal Supersymmetric Standard Model (NMSSM). We scan the
parameter space of the NMSSM considering the basic constraints from Higgs
data, dark matter (DM) relic density, and LHC searches for sparticles. And we
also consider the constraints from the LZ2022 experiment and the muon anomaly
constraint at 2 level.
We find that the LZ2022 experiment has a strict constraint on the parameter
space of the NMSSM, and the limits from the DM-nucleon spin-independent
(SI) and spin-dependent (SD) cross-sections are complementary. Then we discuss
the exotic decay modes of heavy Higgs bosons decaying into SM-like Higgs boson.
We find that for doublet-dominated Higgs and , the main exotic decay
channels are , , and , and the branching ratio can reach to about
23, 10, 35 and 10 respectively. At the 13 TeV LHC, the
production cross-section of and
can reach to about pb and
pb, respectively
An Electronic Auction Scheme Based on Group Signatures and Partially Blind Signatures
AbstractA new electronic auction scheme is proposed based on group signatures and partially blind signatures. At the same security strengthen, an optimization was done on the processes of electronic auction scheme and the dependence on trusted third party was reduced, moreover, multiple goods is auctioned at the same time, therefore, this scheme suited to large-scale electronic auction. Furthermore, due to application of vickrey auctions, the principle of optimal allocation of goods is easily satisfied
The Phenomenological Research on Higgs and dark matter in the Next-to-Minimal Supersymmetric Standard Model
The -invariant next-to-minimal supersymmetric standard model (NMSSM) can
provide a candidate for dark matter (DM). It can also be used to explain the
hypothesis that the Higgs signal observed on the Large Hadron Collider (LHC)
comes from the contribution of the two lightest CP-even Higgs bosons, whose
masses are near 125 GeV. At present, XENON1T, LUX, and PandaX experiments have
imposed very strict restrictions on direct collision cross sections of {dark
matter}. In this paper, we consider a scenario that the observed Higgs signal
is the superposition of two mass-degenerate Higgs in the -invariant NMSSM
and scan the seven-dimension parameter space composing of via the Markov chain Monte Carlo (MCMC) method.
We find that the DM relic density, as well as the LHC searches for sparticles,
especially the DM direct detections, has provided a strong limit on the
parameter space. %Please check intended meaning has been retained. The allowed
parameter space is featured by a relatively small GeV and about
. In addition, the DM is Higgsino-dominated because of
. Moreover, the co-annihilation between
and must be taken into account to
obtain the reasonable DM relic density
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