Subsoil movements due to boring of shallow tunnels with shield machines - application of finite elements in connection with a universally formulated material model

2009 ◽  
Vol 2 (4) ◽  
pp. 369-385 ◽  
Author(s):  
Christian Böttcher ◽  
Klaus Fabricius ◽  
Henning Kaufmann
Keyword(s):  
Finite Elements ◽  
Material Model ◽  
Shallow Tunnels

scholarly journals Applying Membrane Mode Enhanced Cohesive Zone Elements on Tailored Forming Components

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1333
Author(s):  
Felix Töller ◽  
Stefan Löhnert ◽  
Peter Wriggers
Keyword(s):  
Finite Elements ◽  
Cohesive Zone ◽  
Material Model ◽  
Bulk Metal ◽  
Novel Approach ◽  
Model Preparation ◽  
Cohesive Zone Elements ◽  
Tailored Forming

Forming of hybrid bulk metal components might include severe membrane mode deformation of the joining zone. This effect is not reflected by common Traction Separation Laws used within Cohesive Zone Elements that are usually applied for the simulation of joining zones. Thus, they cannot capture possible damage of the joining zone under these conditions. Membrane Mode Enhanced Cohesive Zone Elements fix this deficiency. This novel approach can be implemented in finite elements. It can be used within commercial codes where an implementation as a material model is beneficial as this simplifies model preparation with the existing GUIs. In this contribution, the implementation of Membrane Mode Enhanced Cohesive Zone Elements as a material model is presented within MSC Marc along with simulations showing the capabilities of this approach.

scholarly journals Influence of the cracking consideration in the displacements of a shallow tunnel lined in steel-reinforced concrete: numerical model

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Betina Mariano Jensen ◽  
Denise Bernaud ◽  
Américo Campos Filho
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Numerical Model ◽  
Finite Elements ◽  
Cross Section ◽  
Shallow Tunnel ◽  
Ansys Software ◽  
Concrete Cracking ◽  
Steel Reinforced Concrete ◽  
Shallow Tunnels

abstract: The study of shallow tunnels introduces different aspects when compared to deep tunnels analysis. Among these characteristics can be emphasized the non-uniform shape of the deformed cross-section and the impossibility of some simplifications such as the consideration of homogeneous stresses around the excavation. Since the tunnel lining is subject to combined bending and compression, shallow tunnels are more susceptible to the development of final tensile stresses (not founded in deep tunnels) and the consequent concrete cracking. This paper presents a numerical simulation in finite elements with the ANSYS software. The purpose of the study is to analyze the cracking influence in the displacements of shallow tunnels, treating the concrete behavior by three different models: elastic, viscoelastic and viscoelastic with cracking effects.

The Masonry Crack Propagation Simulation Based on LS-DYNA

2014 ◽  
Vol 1021 ◽  
pp. 105-110
Author(s):  
Ya Fei Lou ◽  
Bai Tao Sun ◽  
Xuan Zhang
Keyword(s):  
Finite Elements ◽  
Crack Propagation ◽  
Large Scale ◽  
Concrete Block ◽  
Material Model ◽  
Computer Hardware ◽  
Test Results ◽  
Finite Elements Analysis ◽  
Simulation Based ◽  
Masonry Material

Due to the development of the computer hardware and the difficulties in determining the constitutive relation, it is difficult to research the crack propagation of large-scale masonry with the finite elements analysis method. The paper analyses the single storey concrete block masonry experimental model with the software LS-DYNA, using winfrith concrete material model instead of masonry material. And the calculated results were compared with the test results. The comparison indicates that the crack propagation of masonry can be simulated better with winfrith material model, which can be used in the finite elements analysis of large-scale masonry.

Finite elements-boundary elements coupling for the movement modeling in two-dimensional structures

1992 ◽  
Vol 2 (11) ◽  
pp. 2035-2044 ◽  
Author(s):  
A. Nicolet ◽  
F. Delincé ◽  
A. Genon ◽  
W. Legros
Keyword(s):  
Finite Elements ◽  
Boundary Elements ◽  
Two Dimensional

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

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