The Experts below are selected from a list of 11727 Experts worldwide ranked by ideXlab platform

Ropyak, Liubomyr Y. - One of the best experts on this subject based on the ideXlab platform.

  • Analytical model of oil pipeline overground transitions, laid in mountain areas
    'EDP Sciences', 2019
    Co-Authors: Velychkovych, Andriy S., Andrusyak Andriy, Pryhorovska, Tetiana O., Ropyak, Liubomyr Y.
    Abstract:

    International audienceAbnormal climate changes cause adverse physical and geographical processes (erosion of soils, waterlogging, flooding, etc.) over the world. This situation stipulates study on effect of soil foundation malleability on pipeline transition strength because of its important diagnostic value.The article develops an engineering approach for stress–strain state estimation of oil pipeline overground transitions, laid in mountainous areas. A Mathematical Statement was made and analytical solutions of the boundary-value problem were described, which take into account overland transition contact with soil foundation. In order to carry out the force analysis, a tubular rod simulated the oil pipeline contacting with the soil foundation on the adjacent to the overground transition section according to the Fuss-Winkler hypothesis. The overground transition was schematised with a thin-walled shell at the final stage of the assessment of strength. The maximum axial stresses were determined for overground transition operation, considering transition’s two-dimensional thermoelastic state. The final assessment of the strength was carried out according to the energy criterion. The proposed method for the overground transition simulation makes possible considering the soil foundation property effects on the behavior of the oil pipeline transition and presents the results in the form of concise analytical expressions convenient for engineering practice. The conducted researches showed the effect of significant redistribution of loading in the oil pipeline overground transition caused by changes of soil foundation stiffness. Also, the boundary effect of perturbation of the stressed state in adjacent underground sections was found. It was determined the zone sizes the boundary effect has significant manifestations. The boundary state of the pipeline is most often achieved in its lower fibers at a short distance from the edge of the underground section. The obtained results of researches were tested on real constructions of overground transitions of oil pipeline laid in mountainous areas

Liubomyr Y. Ropyak - One of the best experts on this subject based on the ideXlab platform.

  • Analytical model of oil pipeline overground transitions, laid in mountain areas
    'EDP Sciences', 2019
    Co-Authors: Andriy S. Velychkovych, Andriy V. Andrusyak, Tetiana O. Pryhorovska, Liubomyr Y. Ropyak
    Abstract:

    Abnormal climate changes cause adverse physical and geographical processes (erosion of soils, waterlogging, flooding, etc.) over the world. This situation stipulates study on effect of soil foundation malleability on pipeline transition strength because of its important diagnostic value. The article develops an engineering approach for stress–strain state estimation of oil pipeline overground transitions, laid in mountainous areas. A Mathematical Statement was made and analytical solutions of the boundary-value problem were described, which take into account overland transition contact with soil foundation. In order to carry out the force analysis, a tubular rod simulated the oil pipeline contacting with the soil foundation on the adjacent to the overground transition section according to the Fuss-Winkler hypothesis. The overground transition was schematised with a thin-walled shell at the final stage of the assessment of strength. The maximum axial stresses were determined for overground transition operation, considering transition’s two-dimensional thermoelastic state. The final assessment of the strength was carried out according to the energy criterion. The proposed method for the overground transition simulation makes possible considering the soil foundation property effects on the behavior of the oil pipeline transition and presents the results in the form of concise analytical expressions convenient for engineering practice. The conducted researches showed the effect of significant redistribution of loading in the oil pipeline overground transition caused by changes of soil foundation stiffness. Also, the boundary effect of perturbation of the stressed state in adjacent underground sections was found. It was determined the zone sizes the boundary effect has significant manifestations. The boundary state of the pipeline is most often achieved in its lower fibers at a short distance from the edge of the underground section. The obtained results of researches were tested on real constructions of overground transitions of oil pipeline laid in mountainous areas

Maksim Iurlov - One of the best experts on this subject based on the ideXlab platform.

  • algorithm for solving problems related to the natural vibrations of electro viscoelastic structures with shunt circuits using ansys data
    International Journal of Smart and Nano Materials, 2019
    Co-Authors: Nataliia Iurlova, Natalia Sevodina, Dmitrii Oshmarin, Maksim Iurlov
    Abstract:

    ABSTRACTAn algorithm for numerical realisation of a Mathematical Statement of the natural vibrations problem for electro-viscoelastic bodies with passive external electric circuits (i.e. shunting circuits) with an arbitrary configuration using the finite element method is proposed in the present paper. The proposed algorithm allows considering the viscoelastic properties of materials using the model of linear hereditary viscoelasticity with complex dynamic moduli and is used to solve 3D solid structure problems that are compatible for ANSYS package element types. This technique implies the usage of the global assembled matrices of stiffness and mass, formed in the ANSYS package. The basis of the algorithm is a novel approach that allows performing decomposition of the global assembled stiffness matrix formed in the ANSYS software package into constituents that are needed for calculation of the natural vibration frequencies of the objects under study. These matrix components are used in the program that wa...

  • Algorithm for solving problems related to the natural vibrations of electro-viscoelastic structures with shunt circuits using ANSYS data
    Taylor & Francis Group, 2019
    Co-Authors: Nataliia Iurlova, Natalia Sevodina, Dmitrii Oshmarin, Maksim Iurlov
    Abstract:

    An algorithm for numerical realisation of a Mathematical Statement of the natural vibrations problem for electro-viscoelastic bodies with passive external electric circuits (i.e. shunting circuits) with an arbitrary configuration using the finite element method is proposed in the present paper. The proposed algorithm allows considering the viscoelastic properties of materials using the model of linear hereditary viscoelasticity with complex dynamic moduli and is used to solve 3D solid structure problems that are compatible for ANSYS package element types. This technique implies the usage of the global assembled matrices of stiffness and mass, formed in the ANSYS package. The basis of the algorithm is a novel approach that allows performing decomposition of the global assembled stiffness matrix formed in the ANSYS software package into constituents that are needed for calculation of the natural vibration frequencies of the objects under study. These matrix components are used in the program that was written in FORTRAN (Formula Translation) language. This problem could be efficiently applied for analysis of the dynamic processes in smart systems based on piezoelectric materials and could also form a basis for the development of numerical finite element algorithms for optimization of the dissipative characteristics of electromechanical systems with shunted piezoelectric elements

Juan Pablo Mejía-ramos - One of the best experts on this subject based on the ideXlab platform.

Alan H Morris - One of the best experts on this subject based on the ideXlab platform.

  • a frame based representation for a bedside ventilator weaning protocol
    Journal of Biomedical Informatics, 2008
    Co-Authors: Dean K Sorenson, Colin K Grissom, L Carpenter, A Austin, Katherine A Sward, L Napoli, Homer R Warner, Alan H Morris
    Abstract:

    We describe the use of a frame-based knowledge representation to construct an adequately-explicit bedside clinical decision support application for ventilator weaning. The application consists of a data entry form, a knowledge base, an inference engine, and a patient database. The knowledge base contains database queries, a data dictionary, and decision frames. A frame consists of a title, a list of findings necessary to make a decision or carry out an action, and a logic or Mathematical Statement to determine its output. Frames for knowledge representation are advantageous because they can be created, visualized, and conceptualized as self-contained entities that correspond to accepted medical constructs. They facilitate knowledge engineering and provide understandable explanations of protocol outputs for clinicians. Our frames are elements of a hierarchical decision process. In addition to running diagnostic and therapeutic logic, frames can run database queries, make changes to the user interface, and modify computer variables.