scholarly journals Automatic adaptive FE analysis of thin-walled structures using 3D solid elements

2008 ◽  
Vol 76 (2) ◽  
pp. 183-229 ◽  
Author(s):  
C. K. Lee ◽  
Q. X. Xu
Keyword(s):  
Fe Analysis ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
3D Solid

Fatigue Assessment of Large Thin-Walled Structures with Initial Distortions

2014 ◽  
Vol 891-892 ◽  
pp. 123-129 ◽  
Author(s):  
Ingrit Lillemäe ◽  
Heikki Remes ◽  
Jani Romanoff
Keyword(s):  
Fe Analysis ◽  
Stiffened Panel ◽  
Response Analysis ◽  
Geometrically Nonlinear ◽  
Global Response ◽  
Fatigue Assessment ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Actual Shape ◽  
Level Of Analysis

Due to economic reasons the industry is seeking new lightweight solutions for large steel structures. However, when moving from traditional steel plate thicknesses, i.e. 5 mm or larger, to thinner ones, the fatigue design becomes challenging due to larger initial distortions caused by welding. The fatigue assessment methods used for thicker welded structures are not fully validated for thinner ones. This paper deals with the fatigue assessment of large thin-walled structures starting from the global response analysis of a whole structure to the stiffened panel and finally welded joint. A modern cruise ship is used as an example case, where traditional superstructure deck plate thickness of 5 mm is replaced by 3 mm. The influence of initial distortion at different levels of structural analysis is studied using geometrically nonlinear finite element (FE) analysis. For the lowest level of analysis, i.e. small welded joint, the experiments have been carried out including geometry measurements and fatigue tests. It is shown that for a large thin-walled structure the global response analysis can be carried out with acceptable accuracy using ideally straight plates and geometrically linear FE analysis. For intermediate level of analysis, i.e. stiffened panel, the analysis can also be geometrically linear, but the actual shape of the plates influences the structural stresses near welds significantly. When analyzing small welded specimens to define experimental fatigue strength, both the actual shape and the geometrically nonlinear FE analysis are needed in order to capture the straightening effect and to obtain the correct structural stress.

scholarly journals Influence of Non-Structural Localized Inertia on Free Vibration Response of Thin-Walled Structures by Variable Kinematic Beam Formulations

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Alfonso Pagani ◽  
Francesco Zangallo ◽  
Erasmo Carrera
Keyword(s):  
Mass Matrix ◽  
Displacement Fields ◽  
Lagrange Polynomials ◽  
Thin Walled Structures ◽  
Solid Models ◽  
Torsional Coupling ◽  
Lagrange Expansion ◽  
Thin Walled ◽  
3D Solid ◽  
Beam Theories

Variable kinematic beam theories are used in this paper to carry out vibration analysis of isotropic thin-walled structures subjected to non-structural localized inertia. Arbitrarily enriched displacement fields for beams are hierarchically obtained by using the Carrera Unified Formulation (CUF). According to CUF, kinematic fields can be formulated either as truncated Taylor-like expansion series of the generalized unknowns or by using only pure translational variables by locally discretizing the beam cross-section through Lagrange polynomials. The resulting theories were, respectively, referred to as TE (Taylor Expansion) and LE (Lagrange Expansion) in recent works. If the finite element method is used, as in the case of the present work, stiffness and mass elemental matrices for both TE and LE beam models can be written in terms of the same fundamental nuclei. The fundamental nucleus of the mass matrix is opportunely modified in this paper in order to account for non-structural localized masses. Several beams are analysed and the results are compared to those from classical beam theories, 2D plate/shell, and 3D solid models from a commercial FEM code. The analyses demonstrate the ineffectiveness of classical theories in dealing with torsional, coupling, and local effects that may occur when localized inertia is considered. Thus the adoption of higher-order beam models is mandatory. The results highlight the efficiency of the proposed models and, in particular, the enhanced capabilities of LE modelling approach, which is able to reproduce solid-like analysis with very low computational costs.

Frame-Monolithic Technology of Construction of Low-Rise Buildings Made of Foam Gypsum and Steel Thin-Walled Structures

2018 ◽  
Vol 762 (8) ◽  
pp. 36-39 ◽  
Author(s):  
B.G. BULATOV ◽  
◽  
R.I. SHIGAPOV ◽  
M.A. IVLEV ◽  
I.V. NEDOSEKO ◽  
...  
Keyword(s):  
Thin Walled Structures ◽  
Thin Walled
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