Structural analysis of non-prismatic beams: Critical issues, accurate stress recovery, and analytical definition of the Finite Element (FE) stiffness matrix

AbstractStatic and kinematic matrix operator equations are revisited for one-, two-, and three-dimensional deformable bodies. In particular, the elastic problem is formulated in the details in the case of arches, cylinders, circular plates, thin domes, and, through an induction process, shells of revolution. It is emphasized how the static and kinematic matrix operators are one the adjoint of the other, and then demonstrated through the definition of stiffness matrix and the application of virtual work principle. From the matrix operator formulation it clearly emerges the identity of the usual Finite Element Method definition of elastic stiffness matrix and the classical definition of Ritz-Galerkin matrix.

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The Rise of Partnerships: From Local to Global

10.1093/oso/9780198782841.003.0001 ◽

2018 ◽

Author(s):

Barbara Gray ◽

Jill Purdy

Keyword(s):

Nongovernmental Organizations ◽

Public Services ◽

Civic Society ◽

Robust Solutions ◽

Essential Components ◽

Critical Issues ◽

Definition Of ◽

Societal Problems ◽

Shared Norms ◽

Multistakeholder Partnerships

Multistakeholder partnerships (MSPs) are formed to tackle knotty societal problems, promote innovation, provide public services, expand governance capabilities, set standards for a field, or resolve conflicts that impede progress on critical issues. Partnerships are viewed as collaboration among four types of stakeholders: businesses, governments, nongovernmental organizations (NGOs), and civic society. The objective of collaboration is to create a richer, more comprehensive appreciation of the iss/problem than any of the partners could construct alone by viewing it from the perspectives of all the stakeholders and designing robust solutions. Such partnerships are necessary because few organizations contain sufficient knowledge and resources to fully analyze issues and take action on them unilaterally. Five essential components of a rigorous definition of collaboration are presented: interdependence among partners, emergence of shared norms, wrestling with differences, respect for different competencies, and assuming joint responsibility for outcomes. Several examples of MSPs are provided.

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Shape Sensing of a Complex Aeronautical Structure with Inverse Finite Element Method

Sensors ◽

10.3390/s21041388 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1388

Author(s):

Daniele Oboe ◽

Luca Colombo ◽

Claudio Sbarufatti ◽

Marco Giglio

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Boundary Conditions ◽

Strain Field ◽

Element Analysis ◽

Inverse Finite Element Method ◽

Shape Sensing ◽

Definition Of ◽

High Level ◽

Element Method

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.

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Structural analysis of three-dimensional finite element model to design multifunction wheelchair for patients

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1137/1/012054 ◽

2021 ◽

Vol 1137 (1) ◽

pp. 012054

Author(s):

P. Keangin ◽

P. Chawengwanicha ◽

N. Wimala ◽

T. Nakbanpotkul

Keyword(s):

Finite Element ◽

Structural Analysis ◽

Finite Element Model ◽

Three Dimensional ◽

Element Model ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element

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Structural Analysis of Centrifugal Fan Impeller Using CATIA Software

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.809-810.859 ◽

2015 ◽

Vol 809-810 ◽

pp. 859-864

Author(s):

Dănuţ Zahariea

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Structural Analysis ◽

Design Methods ◽

Constant Thickness ◽

Blade Design ◽

Centrifugal Fan ◽

Element Analysis ◽

The Finite Element Analysis ◽

Modes Of Vibration

In this paper, the finite element analysis for stress/deformation/modes of vibration for the centrifugal fan impeller with constant thickness backward-curved blades using CATIA software will be presented. The principal steps of the finite element analysis procedure using CATIA/Generative Structural Analysis environment will be presented: creating the 3D model; configuring the mesh; applying the restraints; applying the loads; running the numerical static analysis and the numerical frequency analysis; interpreting the results and observing the modes of vibration correlating with the impeller mode shape. This procedure will be used for 4 different centrifugal fan impellers according with the 4 blade design methods and the results will be comparatively analyzed. For each design method, two materials will be used: steel with density of 7860 kg/m3 and aluminium with density of 2710 kg/m3. Two important results have been obtained after the structural analysis: under the working conditions considered for the analysis, all 4 blade design methods leads to impellers with very good mechanical behaviour; any frequency of the main modes of vibrations for all blade design methods and for both materials is not in phase with the impeller speed, thus the possibility of resonance being eliminated.

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