Simulation of damage on laminates

An experimental study on controlled faulty perturbed flexible structures is developed using an active mass damper actuator, where the flexible structure is subject to external perturbation and sensor faults. To attenuate the disturbance effects on the flexible structure, we present three robust controllers: one is based on dynamics LMI control technique design, other is an improvement of the first one but adding a chattering term, and the last one is the second one but with the chattering gain adjusted dynamically. According to experiments, where a flexible two level building with active mass damper (by Quanser), external perturbation, and sensor faults, evidence that the proposed LMI controller with chattering term where its gain is dynamically adjusted presents the best closed-loop system behavior.Postprint (published version

Naturalness and theoretical constraints on the Higgs boson mass

Arbitrary regularization dependent parameters in Quantum Field Theory are usually fixed on symmetry or phenomenology grounds. We verify that the quadratically divergent behavior responsible for the lack of naturalness in the Standard Model (SM) is intrinsically arbitrary and regularization dependent. While quadratic divergences are welcome for instance in effective models of low energy QCD, they pose a problem in the SM treated as an effective theory in the Higgs sector. Being the very existence of quadratic divergences a matter of debate, a plausible scenario is to search for a symmetry requirement that could fix the arbitrary coefficient of the leading quadratic behavior to the Higgs boson mass to zero. We show that this is possible employing consistency of scale symmetry breaking by quantum corrections. Besides eliminating a fine-tuning problem and restoring validity of perturbation theory, this requirement allows to construct bounds for the Higgs boson mass in terms of $\delta m^2/m^2_H$ (where $m_H$ is the renormalized Higgs mass and $\delta m^2$ is the 1-loop Higgs mass correction). Whereas $\delta m^2/m^2_H<1$ (perturbative regime) in this scenario allows the Higgs boson mass around the current accepted value, the inclusion of the quadratic divergence demands $\delta m^2/m^2_H$ arbitrarily large to reach that experimental value.Comment: 6 pages, 4 figure

Simulation of damage on laminates

In this paper, we present a recently developed progressive damage model for composites (CPDM) that allows the switching between different damage modes during the numerical process to mimic real physical behaviour. The modelled damage modes are ranging from matrix cracking to fibre breakage or delamination. Moreover, the CPDM is flexible in the sense that provides the basic structure to include variations on the evolution of damage modes whenever appropriate by modifying basic second-order tensors. Ongoing work for potential linkage to the extended finite element method (XFEM) will be also shown

Simulation of damage on laminates

An experimental study on controlled faulty perturbed flexible structures is developed using an active mass damper actuator, where the flexible structure is subject to external perturbation and sensor faults. To attenuate the disturbance effects on the flexible structure, we present three robust controllers: one is based on dynamics LMI control technique design, other is an improvement of the first one but adding a chattering term, and the last one is the second one but with the chattering gain adjusted dynamically. According to experiments, where a flexible two level building with active mass damper (by Quanser), external perturbation, and sensor faults, evidence that the proposed LMI controller with chattering term where its gain is dynamically adjusted presents the best closed-loop system behavior