Assumed Natural Strain NURBS-based solid-shell element for the analysis of large deformation elasto-plastic thin-shell structures

2015 ◽  
Vol 284 ◽  
pp. 861-880 ◽  
Author(s):  
J.F. Caseiro ◽  
R.A.F. Valente ◽  
A. Reali ◽  
J. Kiendl ◽  
F. Auricchio ◽  
...  
Keyword(s):  
Large Deformation ◽  
Thin Shell ◽  
Shell Element ◽  
Shell Structures ◽  
Solid Shell ◽  
Natural Strain ◽  
Assumed Natural Strain

Numerical Simulations of Dynamic Fracture in Thin Pipes

2009 ◽  
Author(s):  
Y. Shie
Keyword(s):  
Numerical Simulations ◽  
Large Deformation ◽  
Dynamic Fracture ◽  
Thin Shell ◽  
Large Scale ◽  
Shell Structures ◽  
Theory Approach ◽  
Continuum Approach ◽  
Ill Conditioning ◽  
High Flexibility

We present a meshless methodology for large scale computations of fractureing thin shell structures subjected to internal pressure loads. The contribution is the first step of an efficient numerical methodology for such kind of events. In this paper, numerical simulations of large deformation dynamic fracture in thin shell structures using 3-D meshfree methods is presented. Due to the smoothness of the meshfree shape functions, they are well suited to simulate large deformation of thin shell structures while avoiding ill-conditioning as well as stiffening in numerical computations. The 3D meshfree representation allows high flexibility since thin structures as well as thick structures can be studied by the same methodology. The meshfree approach makes the methodology more flexible and independent as compared to finite elements, i.e. there is no need for creation of mesh. Dynamic fracture is modeled by a simple criterion, i.e. removing connectivity between adjacent nodes once a fracture criterion is met. The main advantage of such a 3-D meshfree continuum approach is its simplicity in both formulation and implementation as compared to shell theory approach, or degenerated continuum approach. Moreover, it is believed that the accuracy of the computation may increase because of using 3-D exact formulation.

scholarly journals Exact geometry SaS solid-shell element for 3D stress analysis of FGM piezoelectric structures

2018 ◽  
Vol 5 (1) ◽  
pp. 116-135 ◽  
Author(s):  
G. M. Kulikov ◽  
S. V. Plotnikova
Keyword(s):  
Stress Analysis ◽  
Shell Element ◽  
Middle Surface ◽  
Functionally Graded ◽  
Superior Performance ◽  
Solid Shell ◽  
Lagrange Polynomials ◽  
Graded Material ◽  
Assumed Natural Strain ◽  
Shell Formulation

Abstract A hybrid-mixed functionally graded material (FGM) piezoelectric four-node solid-shell element through the sampling surfaces (SaS) method is proposed. The SaS formulation is based on choosing inside the shell N SaS parallel to the middle surface in order to introduce the displacements and electric potentials of these surfaces as fundamental shell unknowns. Such choice of unknowns with the use of Lagrange polynomials of degree N-1 in through-thickness interpolations of the displacements, strains, electric potential, electric field and material properties leads to a robust FGM piezoelectric shell formulation. The inner SaS are located at Chebyshev polynomial nodes that make it possible to minimize uniformly the error due to Lagrange interpolation. To implement the effective analytical integration throughout the element, the extended assumed natural strain (ANS) method is employed. As a result, the piezoelectric four-node solid-shell element exhibits a superior performance in the case of coarse meshes. To circumvent shear and membrane locking, the hybrid stress-strain solid-shell formulation via the Hu-Washizu variational principle is employed. The developed solid-shell element could be useful for the 3D stress analysis of FGMstructures because the SaS method allows obtaining the solutions with a prescribed accuracy, which asymptotically approach the exact solutions of electroelasticity as the number of SaS tends to infinity.

Solid Shell Element and its Application in Roll Forming Simulation

2007 ◽  
Vol 340-341 ◽  
pp. 347-352 ◽  
Author(s):  
Da Yong Li ◽  
Ying Bing Luo ◽  
Ying Hong Peng
Keyword(s):  
Degrees Of Freedom ◽  
Shell Element ◽  
Element Model ◽  
Roll Forming ◽  
Good Prospect ◽  
Solid Shell ◽  
Forming Process ◽  
Forming Simulation ◽  
Assumed Natural Strain ◽  
Roll Forming Process

Solid shell element models which possess only translational degrees of freedom and are applicable to thin structure analyses has drawn much attention in recent years and presented good prospect in sheet metal forming. In this study, a solid shell element model is introduced into the dynamic explicit elastic-plastic finite element method. The plane stress constitutive relation is assumed to relieve the thickness locking and the selected reduced integration method is used to overcome volumetric locking. The assumed natural strain method is adopted to resolve shear locking and trapezoidal locking problem. Two benchmark examples and a stage of roll forming process are calculated, and the calculating results are compared with those by solid element model, which demonstrates the effectiveness of the element.

Stress Resultant Analysis of Steel Penstocks Using a Flat Shell Element

2012 ◽  
Vol 170-173 ◽  
pp. 1887-1892
Author(s):  
Jing Min Liu ◽  
Lu Feng Yang ◽  
Jin Zhang ◽  
Wei Zhang
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Thin Shell ◽  
Shell Element ◽  
Shell Structures ◽  
Stress Resultant ◽  
Flat Shell ◽  
Flat Shell Element ◽  
Finite Element Procedure ◽  
Internal Forces

A finite element procedure of a four-node rectangular flat shell element (FSE) is programmed for structural analysis of steel penstocks. The influence of axial constraint and support settlement on the internal forces of the steel penstocks is investigated. It can be concluded that the FSE is suitable for thin shell structures of steel penstocks and can achieve satisfying accuracy. The axial constraint caused by rest piers would remarkably increase the axial internal forces along pipeline, while the influence of support settlement on the internal forces of the steel penstock is limited, and so is the increment.

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