scholarly journals 3D mixed virtual element formulation for dynamic elasto-plastic analysis

2021 ◽  
Author(s):  
Mertcan Cihan ◽  
Blaž Hudobivnik ◽  
Fadi Aldakheel ◽  
Peter Wriggers
Keyword(s):  
Time Integration ◽  
Model Performance ◽  
Three Dimensions ◽  
Implicit Time ◽  
Integration Scheme ◽  
Element Formulation ◽  
Elasto Plasticity ◽  
Time Integration Scheme ◽  
Arbitrary Convex ◽  
Virtual Element

AbstractThe virtual element method (VEM) for dynamic analyses of nonlinear elasto-plastic problems undergoing large deformations is outlined within this work. VEM has been applied to various problems in engineering, considering elasto-plasticity, multiphysics, damage, elastodynamics, contact- and fracture mechanics. This work focuses on the extension of VEM formulations towards dynamic elasto-plastic applications. Hereby low-order ansatz functions are employed in three dimensions with elements having arbitrary convex or concave polygonal shapes. The formulations presented in this study are based on minimization of potential function for both the static as well as the dynamic behavior. Additionally, to overcome the volumetric locking phenomena due to elastic and plastic incompressibility conditions, a mixed formulation based on a Hu-Washizu functional is adopted. For the implicit time integration scheme, Newmark method is used. To show the model performance, various numerical examples in 3D are presented.

Numerical Analysis of Solute Segregation in Directional Solidification under Static Magnetic Field

2011 ◽  
Vol 312-315 ◽  
pp. 253-258 ◽  
Author(s):  
Sabrina Nouri ◽  
Mouhamed Benzeghiba ◽  
Ahmed Benzaoui
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Time Integration ◽  
Magnetic Field Effect ◽  
Computer Code ◽  
Thermosolutal Convection ◽  
Implicit Time ◽  
Integration Scheme ◽  
Dimensional Solution ◽  
Time Integration Scheme

This paper addresses the effect of thermosolutal convection in the formation of defects in directionally solidified alloys. The numerical model is based on a bi-dimensional solution consisting of an implicit time integration scheme to couple thermal and solutal fields, which is supported by a finite volume numerical modeling technique. In this article, the macrosegregation phenomenon under a static magnetic field effect is analyzed numerically by a computer code developed and validated with experimental data. The numerically obtained results have been widely discussed in dependence of the characteristic parameters of the studied problem.

Dynamics of Disconnected Risers Under Rigid and Compliant Hang-Off

1990 ◽  
Vol 112 (2) ◽  
pp. 106-114
Author(s):  
N. M. Patrikalakis ◽  
D. Y. Yoon
Keyword(s):  
Efficient Solution ◽  
Time Integration ◽  
Implicit Time ◽  
Integration Scheme ◽  
Nonuniform Grid ◽  
Implicit Time Integration ◽  
Time Integration Scheme ◽  
Type Response ◽  
Nonlinear Motions ◽  
Excitation Conditions

An efficient solution scheme to simulate the nonlinear motions of hanging risers based on an adaptive nonuniform grid finite difference method and an implicit time integration scheme is presented. Dynamic buckling-type response of hanging risers under rigid hang-off due to heave acceleration of the support platform in extreme excitation conditions is studied, and the important parameters affecting the response are identified. Significant reduction of motions and resulting stresses is obtained by employing compliant hang-off.

Studies on the Accuracy Stability and Efficiency of a New Time Integration Scheme for Ballast Modeling Using the Discrete Element Method

2014 ◽  
Author(s):  
G. F. Mathews ◽  
R. L. Mullen ◽  
D. C. Rizos
Keyword(s):  
Particle Interaction ◽  
Time Integration ◽  
Discrete Element ◽  
Critical Discussion ◽  
Implicit Time ◽  
Integration Scheme ◽  
Computationally Efficient ◽  
Time Step ◽  
Central Difference ◽  
Time Integration Scheme

This paper presents the development of a semi-implicit time integration scheme, originally developed for structural dynamics in the 1970’s, and its implementation for use in Discrete Element Methods (DEM) for rigid particle interaction, and interaction of elastic bodies that are modeled as a cluster of rigid interconnected particles. The method is developed in view of ballast modeling that accounts for the flexibility of aggregates and the arbitrary shape and size of granules. The proposed scheme does not require any matrix inversions and is expressed in an incremental form making it appropriate for non-linear problems. The proposed method focuses on improving the efficiency, stability and accuracy of the solutions, as compared to current practice. A critical discussion of the findings of the studies is presented. Extended verification and assessment studies demonstrate that the proposed algorithm is unconditionally stable and accurate even for large time step sizes. It is demonstrated that the proposed method is at least as computationally efficient as the Central Difference Method. Guidelines for the implementation of the method to ballast modeling are discussed.

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