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In structural engineering verifications, the plastic capacity of steel members may be utilized for cross sections of class 1 and 2. In literature, algorithms for the primary torsional capacity considering different types of numerical procedures, such as finite element methods, have mainly been addressed. However, there is a lack of explicit illustration of algorithms for cross sections considering combined loading, i.e. procedures for bending and torsional analysis. This paper therefore presents an algorithm for the plastic analysis connected to a cross‐sectional finite element approach. The algorithm considers the description of bilinear material laws, accounting for ideal‐plastic behavior as well as effects of isotropic hardening. Cross sections are discretized by isoparametric two‐dimensional nine‐node elements with curvilinear boundaries, which allow describing any geometry with high accuracy. The study proves that the plastic algorithm combined with the isoparametric elements accurately represents the behavior of cross sections. In addition, precise cross‐sectional capacities of hot‐rolled U‐sections gained by the methodology, i.e. plastic torsional moments and plastic bending moments, are presented. In future research, this methodology will be combined with finite element formulations for beams. [ABSTRACT FROM AUTHOR]

Global structural analyses in civil engineering are usually performed considering linear‐elastic material behavior. However, for steel structures, a certain degree of plasticization depending on the member classification may be considered. Corresponding plastic analyses taking material nonlinearities into account are effectively realized using numerical methods. Frequently applied finite elements of two and three‐dimensional models evaluate the plasticity at defined nodes using a yield surface, i.e. by a yield condition, hardening rule, and flow rule. Corresponding calculations are connected to a large numerical as well as time‐consuming effort and they do not rely on the theoretical background of beam theory, to which the regulations of standards mainly correspond. For that reason, methods using beam elements (one‐dimensional) combined with cross‐sectional analyses are commonly applied for steel members in terms of plastic zones theories. In these approaches, plasticization is in general assessed by means of axial stress only. In this paper, more precise numerical representation of the combined stress states, i.e. axial and shear stresses, is presented and results of the proposed approach are validated and discussed. [ABSTRACT FROM AUTHOR]

In recent years, structural health monitoring (SHM) has become a widely used state-of-the-art method for analyzing and assessing the condition of civil infrastructure. SHM systems are characterized by a plethora of heterogeneous system components. For optimizing, documenting, and change tracking of SHM systems, information about SHM systems needs to be formally described on a sound basis. However, with current methods, such as ontologies, description languages or metamodels, only a small subset of information inherent to SHM systems, such as information about sensors, can formally be described. This paper presents a conceptual approach towards identifying and specifying monitoring-related information. Based on a summary review of SHM modeling approaches, metaization concepts to overcome the current limitations are discussed and a robust formalism to describe SHM systems mathematically is proposed. The review methodology is based on a three-pillar concept. First, regulations, standards, and guidelines related to SHM and, second, the current research landscape is examined to identify information required for describing SHM systems, and hierarchies of terms are proposed to categorize the findings. Third, metamodel architectures, such as SHM-related ontologies, BIM-based metamodels and description languages, are reviewed with respect to formally describe SHM systems. Being part of the third pillar, mathematical metamodeling approaches based on category theory, set theory and type theory are presented, capable to describe SHM system as well as approaches suitable to couple metamodels. As an outcome of this study, besides a comprehensive review of the above directions, a strategy towards developing a metaization concept is proposed to provide a robust formalism for SHM system descriptions, aiming to advance optimization, documentation, and change tracking of SHM systems. [ABSTRACT FROM AUTHOR]