An Operator Inference Oriented Approach for Mechanical Systems

Model-order reduction techniques allow the construction of low-dimensional surrogate models that can accelerate engineering design processes. Often, these techniques are intrusive, meaning that they require direct access to underlying high-fidelity models. Accessing these models is laborious or may not even be possible in some cases. Therefore, there is an interest in developing non-intrusive model reduction techniques to construct low-dimensional models directly from simulated or experimental data. In this work, we focus on a recent data-driven methodology, namely operator inference, that aims at inferring the reduced operators using only trajectories of high-fidelity models. We present an extension of operator inference for mechanical systems, preserving the second-order structure. We also study a particular case in which complete information about the external forces is available. In this formulation, the reduced operators having certain properties inspired by the original system matrices are enforced by adding constraints to the optimization problem. We illustrate the presented methodology using three numerical examples

Innovative transport technologies as a basis of cities’ and regions’ progressive development

The article raises modern Russian cities’ vital problems which are associated with the traffic situation – problems of ecology, safety, economy, lack of mobility. The author reviews the possibility of solving these problems by means of introducing wire transport into modern life. The aim of the research is to investigate the factor influence of new transport technologies on the future of cities, regions and their population. The article deals with the aspects of possible influence of wire transport SkyWay on the functioning of cities and regions, it provides a comparison with the existing urban and intercity kinds of transport, future changes are forecast. Using the example of the city of Samara, the author shows all aspects of the positive effects of transport innovations on the life of the city and its citizens, as a complement to the existing transport systems

Innovative transport technologies as a basis of cities’ and regions’ progressive development

The article raises modern Russian cities’ vital problems which are associated with the traffic situation – problems of ecology, safety, economy, lack of mobility. The author reviews the possibility of solving these problems by means of introducing wire transport into modern life. The aim of the research is to investigate the factor influence of new transport technologies on the future of cities, regions and their population. The article deals with the aspects of possible influence of wire transport SkyWay on the functioning of cities and regions, it provides a comparison with the existing urban and intercity kinds of transport, future changes are forecast. Using the example of the city of Samara, the author shows all aspects of the positive effects of transport innovations on the life of the city and its citizens, as a complement to the existing transport systems

Evolution Strategies in the Multipoint Connections Routing

Routing of multipoint connections plays an important role in final cost and quality of a found connection. New algorithms with better results are still searched. In this paper, a possibility of using the evolution strategies (ES) for routing is presented. Quality of found connection is evaluated from the view of final cost and time spent on a searching procedure. First, parametrical analysis of results of the ES are discussed and compared with the Prim’s algorithm, which was chosen as a representative of the deterministic routing algorithms. Second, ways for improving the ES are suggested and implemented. The obtained results are reviewed. The main improvements are specified and discussed in conclusion

A new approach to the design of preschool institutions

The paper considers a new approach to the design of preschool institutions, taking into account the psychology of children's perception. The basic principles of creating the environment, motivating children to study, developing their mental, creative and physical abilities were identified. Buildings of preschool institutions are seen as means of the world perception and social adaptation of children. The child perceives the world through visual, tactile and other sensations. All factors of changing world should be reflected in the architectural style of a building. The paper defines principles of designing preschool institutions based on numerous studies of architects and psychologists: it is proposed to create projects for children, which will function as “giant space for games” with an open plan, and child-sized friendly corners as well. It is necessary to provide visual variety of forms, to use playful elements as a part of the façade, to convert the walking paths into the playground, and also to use the ecological approach in the design

Inelastic Behavior of Polyoxymethylene for Wide Strain Rate and Temperature Ranges: Constitutive Modeling and Identification

The aim of this paper is to present experimental data and the constitutive model for the inelastic behavior of polyoxymethylene in wide strain rate and temperature ranges. To capture the non-linearity of the stress responses for both loading and unloading regimes, the composite model of inelastic deformation is utilized and further developed. The equivalent inelastic strain rate is described by the Prandtl–Eyring law, while the temperature dependence is characterized by the modified Arrhenius-type law. Generalized equivalent stress and the flow rule are formulated to capture pressure sensitivity, transverse strain and volumetric strain responses. The results obtained by the constitutive law are compared with experimental data for stress vs. axial strain from standard tension tests as well as with axial and transverse strains measured by digital image correlation. The developed composite model is able to capture the non-linearity of stress–strain curves for complex loading paths within the small strain regime. For higher strains, apart from geometrically non-linear theory, evolution laws for the volume fraction of the constituents should be modified and calibrated. For the small strain regime, the inelastic dilatation is negligible. For higher axial strain values, a decrease in Poisson’s ratio under tension and increase in it under compression are observed. The Drucker–Prager-type equivalent stress and the developed flow rule provide a better description of both the transverse and volumetric strains than that of the classical von Mises–Odqvist flow rules