A Cohesive Element Framework for Dynamic Ice-Structure Interaction Problems: Part III—Case Studies

2010 ◽  
Author(s):  
Ibrahim Konuk ◽  
Shenkai Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Case Studies ◽  
General Framework ◽  
Element Model ◽  
Cohesive Element ◽  
Structure Interaction

The general framework for a cohesive finite element model for the analysis of ice-structure interaction problems incorporating plasticity and fracture was presented at OMAE 2009 as Parts I & II. This third paper presents the application of the framework to various ice-structure interaction problems. It investigates the important aspects of these scenarios and reveals their characteristics which may play a major role in the design of structures. The investigations include the geometry, size and velocity effects as well as the influence of the structure stiffness. The paper also studies the effects of ice characteristics, and interaction speeds.

A FINITE ELEMENT MODEL FOR COMPRESSIVE ICE LOADS BASED ON A MOHR-COULOMB MATERIAL AND THE NODE SPLITTING TECHNIQUE

2021 ◽  
pp. 1-33
Author(s):  
Hauke Herrnring ◽  
Søren Ehlers
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Material Behavior ◽  
Double Pendulum ◽  
Strain Rates ◽  
Splitting Technique ◽  
Structure Interaction ◽  
Node Splitting ◽  
Brittle Mode

Abstract This paper presents a finite element model for the simulation of ice-structure interaction problems, which are dominated by crushing. The failure mode of ice depends significantly on the strain rate. At low strain rates the ice behaves ductile, whereas at high strain rates ice reacts in brittle mode. This paper focuses on the brittle mode, which is the dominating mode for ship-ice interactions. A multitude of numerical approaches for the simulation of ice can be found in the literature. Nevertheless, the literature approaches do not seem suitable for the simulation of continuous ice-structure interaction processes at low and high confinement ratios in brittle mode. Therefore, this paper seeks to simulate the ice-structure interaction with the finite element method (FEM). The objective of the here introduced Mohr-Coulomb Nodal Split (MCNS) model is to represent the essential material behavior of ice in an efficient formulation. To preserve mass and energy as much as possible, the node splitting technique is applied, instead of the frequently used element erosion technique. The intention of the presented model is not to reproduce individual cracks with high accuracy, because this is not possible with a reasonable element size, due to the large number of crack fronts forming during the ice-structure interaction process. To validate the findings of the model, the simulated maximum ice forces and contact pressures are compared with ice-extrusion and double pendulum tests. During validation, the MCNS model shows a very good agreement with these experimental values.

Hydroelastic Modal Analysis of the Perforated Cylindrical Shell in SMART

2011 ◽  
Author(s):  
Youngin Choi ◽  
Seungho Lim ◽  
Kyoung-Su Park ◽  
No-Cheol Park ◽  
Young-Pil Park ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Steam Generators ◽  
Structure Interaction ◽  
The Finite Element Model ◽  
Reactor Internals

The System-integrated Modular Advanced ReacTor (SMART) developed by KAERI includes components like a core, steam generators, coolant pumps, and a pressurizer inside the reactor vessel. Though the integrated structure improves the safety of the reactor, it can be excited by an earthquake and pump pulsations. It is important to identify dynamic characteristics of the reactor internals considering fluid-structure interaction caused by inner coolant for preventing damage from the excitations. Thus, the finite element model is constructed to identify dynamic characteristics and natural frequencies and mode shapes are extracted from this finite element model.

Long-Span Reinforced Steel Box Culverts

1998 ◽  
Vol 1624 (1) ◽  
pp. 184-195 ◽  
Author(s):  
Thomas C. McCavour ◽  
Peter M. Byrne ◽  
Timothy D. Morrison
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Plate Thickness ◽  
Metal Structure ◽  
Element Model ◽  
Structure Interaction ◽  
Long Span ◽  
Box Culverts ◽  
Reinforced Steel ◽  
Soil Metal

A comprehensive investigation of soil–metal structure interaction for long-span deep-corrugated reinforced steel box culverts was carried out in a project sponsored by the National Research Council of Canada in 1996. Two 12-m span box culverts were erected at a Dorchester, New Brunswick, test site using two backfill densities, one structural steel plate thickness, and a minimum cover of 300 mm. These structures are the largest steel box culverts erected to date. One structure was reinforced using continuous deep-corrugated crown stiffeners, and the other was intermittently reinforced using composite concrete metal-encased stiffeners. Strain and deflection of the structure were monitored in response to static axle loads positioned at six locations on the test surface. A finite element model was then used in numerical simulations of the soil–metal structure system. The measured culvert response was then compared with results from the finite element model. A nonlinear soil-structure interaction program (NLSSIP) was used to analyze the two long-span box culverts. NLSSIP was developed specifically for long-span soil–metal culverts and has been used for structures with and without stiffeners. The box culvert test provided a definitive relationship between soil stiffness and metal structure stiffness. The test was the first that evaluated intermittently reinforced composite concrete metal-encased stiffeners relative to conventional continuous reinforcement. The performance of the two types of stiffeners is evaluated and recommendations are made for future design and installation of long-span deep-corrugated steel box culverts.

scholarly journals Effect of Long-Term Soil Deformations on RC Structures Including Soil-Structure Interaction

2020 ◽  
Vol 6 (12) ◽  
pp. 2290-2311
Author(s):  
Kamel Bezih ◽  
Alaa Chateauneuf ◽  
Rafik Demagh
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Soil Structure ◽  
Element Model ◽  
Soil Structure Interaction ◽  
Structural Safety ◽  
Soil Behavior ◽  
Rc Structures ◽  
Structure Interaction

Lifetime service of Reinforced Concrete (RC) structures is of major interest. It depends on the action of the superstructure and the response of soil contact at the same time. Therefore, it is necessary to consider the soil-structure interaction in the safety analysis of the RC structures to ensure reliable and economical design. In this paper, a finite element model of soil-structure interaction is developed. This model addresses the effect of long-term soil deformations on the structural safety of RC structures. It is also applied to real RC structures where soil-structure interaction is considered in the function of time. The modeling of the mechanical analysis of the soil-structure system is implemented as a one-dimensional model of a spring element to simulate a real case of RC continuous beams. The finite element method is used in this model to address the nonlinear time behavior of the soil and to calculate the consolidation settlement at the support-sections and the bending moment of RC structures girders. Numerical simulation tests with different loading services were performed on three types of soft soils with several compressibility parameters. This is done for homogeneous and heterogeneous soils. The finite element model of soil-structure interaction provides a practical approach to show and to quantify; (1) the importance of the variability of the compressibility parameters, and (2) the heterogeneity soil behavior in the safety RC structures assessment. It also shows a significant impact of soil-structure interaction, especially with nonlinear soil behavior versus the time on the design rules of redundant RC structures. Doi: 10.28991/cej-2020-03091618 Full Text: PDF

A Finite Element Model for Compressive Ice Loads Based on a Mohr-Coulomb Material and the Node Splitting Technique

2021 ◽  
Author(s):  
Hauke Herrnring ◽  
Sören Ehlers
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Material Behavior ◽  
Fe Method ◽  
Splitting Technique ◽  
Structure Interaction ◽  
Node Splitting ◽  
Element Erosion ◽  
Brittle Mode

Abstract This paper presents a finite element model for the simulation of ice-structure interaction problems, which are dominated by crushing at low and medium confinement ratios. The failure mode of ice depends significantly on the strain rate. At very low impact velocities the ice behaves ductile, whereas at high velocities the ice reacts in brittle mode. This paper focuses on the brittle mode, which is the dominating mode for ship-ice interactions. A multitude of numerical approaches for the simulation of ice can be found in the literature. Nevertheless, the literature approaches do not seem suitable for the simulation of continuous ice-structure interaction processes at low and medium confinement ratios in brittle mode. Therefore, this paper seeks to simulate the ice-structure interaction with the FE method. To preserve mass and energy as much as possible, the node splitting technique is applied, instead of the often used element erosion technique. The intention of the presented model is not to reproduce individual cracks with high accuracy, because this is not possible with a reasonable element size, due to the large number of crack fronts forming during the ice-structure interaction process. The objective of the here introduced Mohr-Coulomb Nodal Split (MCNS) model is to represent the essential material behavior of ice in a efficient formulation. To validate the findings of the model, the simulated maximum ice forces and contact pressures are compared with experiments.

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