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L. Flavio Campanile

Publications and source records attributed to L. Flavio Campanile.

2 recordsLinked to original sources

An AI-Assisted Design Method for Topology Optimization Without Pre-Optimized Training Data

Topology optimization is widely used by engineers during the initial product development process to get a first possible geometry design. The state-of-the-art is the iterative calculation, which requires both time and computational power. Some newly developed methods use artificial intelligence to accelerate the topology optimization. These require conventionally pre-optimized data and therefore are dependent on the quality and number of available data. This paper proposes an AI-assisted design method for topology optimization, which does not require pre-optimized data. The designs are provided by an artificial neural network, the predictor, on the basis of boundary conditions and degree of filling (the volume percentage filled by material) as input data. In the training phase, geometries generated on the basis of random input data are evaluated with respect to given criteria. The results of those evaluations flow into an objective function which is minimized by adapting the predictor's parameters. After the training is completed, the presented AI-assisted design procedure supplies geometries which are similar to the ones generated by conventional topology optimizers, but requires a small fraction of the computational effort required by those algorithms. We anticipate our paper to be a starting point for AI-based methods that requires data, that is hard to compute or not available.

cs.LG↗

Vibration Reduction by Stiffness Modulation -- a Theoretical Study

Semi-active vibration reduction techniques are defined as techniques in which controlled actions do not operate directly on the system's degrees of freedom (as in the case of active vibration control) but on the system's parameters, i.e., mass, damping, or stiffness. Cyclic variations in the stiffness of a structural system have been addressed in several previous studies as an effective semi-active vibration reduction method. The proposed applications of this idea, denoted here as stiffness modulation, range from stepwise stiffness variations on a simple spring-mass system to continuous stiffness changes on rotor blades under aerodynamic loads. Semi-active systems are generally claimed to be energetically passive. However, changes in stiffness directly affect the elastic potential energy of the system and require external work under given conditions. In most cases, such injection or extraction of energy (performed by the device in charge of the stiffness variation and denoted as the pseudo-active effect) usually coexists with the semi-active effect, which operates by redistributing the potential energy within the system in such a way that it can be dissipated more efficiently. This work focuses on the discrimination between these two effects, which is absent in previous literature. A first study on their dependence on the process parameters of stiffness modulation is presented here, with emphasis on the spatial distribution of the stiffness changes. It is shown that localized changes tend to result in a larger semi-active share of vibration attenuation, whereas a spatially homogeneous stiffness modulation only generates a pseudo-active effect.

math.DS↗