The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

Lyube D Ivanov - One of the best experts on this subject based on the ideXlab platform.

  • hull girder Elastic Section Modulus as a representative of hull girder geometric properties in probabilistic analyses
    Ship Technology Research, 2012
    Co-Authors: Lyube D Ivanov
    Abstract:

    AbstractThe input data for the time variant reliability calculation of the hull girder contain uncertainties. The level of uncertainty of the calculated hull girder probability of failure depends on the accuracy in the probabilistic presentation of all parameters, including hull girder geometric properties. In the paper, all hull girder geometric properties used in calculation of its bending, shear and torsion stresses are presented by their annual probabilistic distributions and probabilistic distributions for any given time period. A proposal is made for simplifying the calculations using the probabilistic distribution of the hull girder Elastic Section Modulus (deck) as a representative of the probabilistic distributions of all other hull girder geometric properties. The example given is for a bulk carrier.

Julio C.r. Cyrino - One of the best experts on this subject based on the ideXlab platform.

  • Structural Reliability Applications in Design and Maintenance Planning of Ships Subjected to Fatigue and Corrosion
    Volume 2: Structures Safety and Reliability, 2012
    Co-Authors: Marcos Corrêa Câmara, Julio C.r. Cyrino
    Abstract:

    This paper presents structural reliability applications in design and maintenance planning for ships hull structures. For the assessment of structural strength, the model developed consists in an ultimate limit-state of hull-girder considering degradation by corrosion based in a statistical investigation of time-variant hull girder strength made by ABS (American Bureau of Shipping) on 2007. The time dependent reliability index obtained with the minimum Elastic Section Modulus required by the rules of the classification society American Bureau of shipping (ABS), of two ship designs are compared against the results obtained from the target reliability index based design. The target reliability index assessment for corroded hulls is also showed. The monte-carlo simulation reliability method is used to calculate the time-dependent reliability of the primary hull structure.Two approaches of fatigue and corrosion-enhanced fatigue time dependent reliability are developed. A long term stress range applied to a detail is fitted to a weibull distribution based in a known design life. A utilization factor is introduced in order to consider the fraction of time at sea. A risk-based inspection planning is discussed for commercial and naval vessels Both S-N curve and fracture mechanics based reliability methods are used and the results are compared. An example of reliability updating after a inspection result is showed.Copyright © 2012 by ASME

Abdolhossein Baghlani - One of the best experts on this subject based on the ideXlab platform.

  • Numerical damage evaluation assessment of blast loaded steel columns with similar Section properties
    Structures, 2019
    Co-Authors: Mohammad Momeni, Mohammad Ali Hadianfard, Chiara Bedon, Abdolhossein Baghlani
    Abstract:

    Abstract In the last years, the increase of blast and terroristic attacks in the vicinity of critical structures and facilities highlighted the importance of appropriate simulation and design methods for blast loaded structures. Within a building exposed to blast, columns act as key components, being asked to sustain ordinary gravity and wind loads, but also possible additional exceptional loads like earthquakes or explosions. In this paper, the dynamic behavior of steel columns under blast pressures is numerically investigated. Careful consideration is spent – based on validated Finite Element (FE) models – for the blast performance of steel columns with different cross-Sectional shapes but similar mechanical properties (i.e., total area, moment of inertia and Elastic Section Modulus). Explicit FE analyses are carried out on a wide set of configurations, including variations in (a) cross-Section properties, (b) boundary conditions and (c) explosions features. In doing so, the accuracy and reliability of different FE models (i.e., based on solid, shell and beam elements) are also investigated, both in terms of global/local results and computational cost of the dynamic simulations. As key damage parameters due to blast, the maximum displacement and the residual load carrying capacity of the examined columns are examined. The collected parametric results show that the cross-Sectional shape only slightly affects the global dynamic behavior of steel columns, especially in terms of residual capacity. Moreover, compared to computationally expensive full solid models, the reliability and accuracy of geometrically simplified shell and beam is discussed, with respect to the observed responses and intrinsic computational efficiency.

Farhad Keshavarzi - One of the best experts on this subject based on the ideXlab platform.

  • Numerical Evaluation of Through Plate Beam to Box Column Connection
    Structures Congress 2008, 2008
    Co-Authors: Farhad Keshavarzi, Rasoul Mirghaderi, Ali Imanpour, Bardia Khafaf
    Abstract:

    Box column is used as one of the most desirable Sections between the designers in Iran and most Asian countries .this Section as column has considerable benefits such as high biaxial bending strength and higher plastic to Elastic Section Modulus ratio which is an effective factor for force controlled components .In typical beam to column connection for this type of column Section , one need to provide horizontal continuity plates in box Section which is challenge in construction phase and there is no chance to provide them in hot rolled box Section . This paper elucidates the seismic behavior of through-plates moment connections to box columns for use in steel moment resisting frames. This connection has lot of economical benefits such as no need to horizontal continuity plates and satisfying the weak beam-strong column criteria in the connection region .they might serve as panel zone plates as well. According to high shear demand in panel zone of beam to column joint one should use the doublers plates in order to decrease the shear demand in this sensitive part of structure but this plates have no possibility to mobilize the load transfer mechanism in column web and transfer them to column flanges. Finite element analysis was conducted to elucidate the seismic behavior of this connection; the results of finite element analysis established the effectiveness of the through plate in mitigating local stress concentrations and forming the plastic hinge zone in the beam away from the beam to column interface. The moment rotation hystersis graphs from sub-assemblage show a desirable seismic performance of this connection .the seismic behavior of this connection also has been investigated in diamond box columns.

  • Experimental Evaluation of Beam to Diamond Box Column Connection with Through Plate in Moment Frames
    AIP Conference Proceedings, 2008
    Co-Authors: Farhad Keshavarzi, Rasoul Mirghaderi, Shahabeddin Torabian, Ali Imanpour
    Abstract:

    Moment resisting frames with built up Section have very enhanced features due to high bending stiffness and strength characteristics in two principal axes and access to column faces for beam to column easy connections. But due to proper transfer of beam stresses to column faces there were always some specific controvertibly issues that how to make the load transfer through and in plane manner in order to mobilize the forces in column faces. Using diamond column instead of box column provide possibility to mobilize the load transfer mechanism in column faces. This Section as a column has considerable benefit such as high plastic to Elastic Section Modulus ratio which is an effective factor for force controlled components. Typical connection has no chance to be applied with diamond column.This paper elucidates the seismic behavior of through‐plates moment connections to diamond box columns for use in steel moment resisting frames. This connection has a lot of economical benefits such as no need to horizonta...

Marcos Corrêa Câmara - One of the best experts on this subject based on the ideXlab platform.

  • Structural Reliability Applications in Design and Maintenance Planning of Ships Subjected to Fatigue and Corrosion
    Volume 2: Structures Safety and Reliability, 2012
    Co-Authors: Marcos Corrêa Câmara, Julio C.r. Cyrino
    Abstract:

    This paper presents structural reliability applications in design and maintenance planning for ships hull structures. For the assessment of structural strength, the model developed consists in an ultimate limit-state of hull-girder considering degradation by corrosion based in a statistical investigation of time-variant hull girder strength made by ABS (American Bureau of Shipping) on 2007. The time dependent reliability index obtained with the minimum Elastic Section Modulus required by the rules of the classification society American Bureau of shipping (ABS), of two ship designs are compared against the results obtained from the target reliability index based design. The target reliability index assessment for corroded hulls is also showed. The monte-carlo simulation reliability method is used to calculate the time-dependent reliability of the primary hull structure.Two approaches of fatigue and corrosion-enhanced fatigue time dependent reliability are developed. A long term stress range applied to a detail is fitted to a weibull distribution based in a known design life. A utilization factor is introduced in order to consider the fraction of time at sea. A risk-based inspection planning is discussed for commercial and naval vessels Both S-N curve and fracture mechanics based reliability methods are used and the results are compared. An example of reliability updating after a inspection result is showed.Copyright © 2012 by ASME