Damage Detection in Tensegrity using Interacting Particle-Ensemble Kalman Filter

The 10th EWSHM, originally scheduled for the first week of July 2020, is planned to be held the first week of July 2022 in Palermo.International audienceTensegrity structures form a special class of truss with dedicated cables and bars, that take tension and compression, respectively. To ensure equilibrium, the tensegrity members are required to be prestressed. Over prolonged usage, the cables may lose their prestress while bars may buckle, affecting the structural stiffness as well as its dynamic properties. The stiffness of tensegrities also vary with the load even in the absence of damage. This can potentially mask the effect of damage leading to a false impression of tensegrity health. This poses a major challenge in tensegrity health monitoring especially when the load is stochastic and unknown. Present study develops a vibration based output-only time-domain approach for monitoring the health of any tensegrity in the presence of uncertainties due to ambient force and measurement noise. An Interacting Particle Ensemble Kalman Filter (IPEnKF) has been used that can efficiently monitor tensegrity health from contaminated response data. IPEnKF combines a bank of Ensemble Kalman Filters to estimate response states while running within a Particle Filter envelop that estimates a set of location based health parameters. Further to make damage detection cheaper, strain responses are used as measurements. The efficiency of the proposed methodology has been demonstrated using numerical experiments performed on a simplex tensegrity

Bioactive Silica Based Coatings on Stainless Steel Implants

In the field of body implants, surface plays an important role in the response of the tissue to the presence of foreign material. Surface modification by the application of coatings can be tailored to offer the best performance in service at the lowest cost. Coatings can improve the corrosion resistance limiting the diffusion of metal ions and products of corrosion in the body, along with enhancing the bioactivity of biocompatible metals by generating a natural union with the bone. The bioactivity can be achieved by adding bioactive particles to the coating than can react promoting new bone growth around the implant favoring its union with bone and muscle systems.In this chapter, the performance of silica based sol gel coatings with the addition of different bioactive particles (hydroxyapatite, wollastonite, glass or glass ceramic) applied onto stainless steel AISI316L is analyzed in terms of in vitro analysis (surface, electrochemical and bioactivity) and preliminary studies about in vivo behavior.Fil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Silvia M. Ceré. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin