scholarly journals Seismic Analysis of the Bell Tower of the Church of St. Francis of Assisi on Kaptol in Zagreb by Combined Finite-Discrete Element Method

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 373
Author(s):  
Ivan Balić ◽  
Hrvoje Smoljanović ◽  
Boris Trogrlić ◽  
Ante Munjiza
Keyword(s):  
Numerical Model ◽  
Discrete Element Method ◽  
Seismic Analysis ◽  
Discrete Element ◽  
Masonry Building ◽  
Bell Tower ◽  
The Church ◽  
Good Agreement ◽  
Element Method ◽  
Francis Of Assisi

The paper presents a failure analysis of the bell tower of the church of St. Francis of Assisi on Kaptol in Zagreb subjected to seismic activity using the finite-discrete element method—FDEM. The bell tower is a masonry building, and throughout history it has undergone multiple damages and reconstructions. It was significantly damaged during the earthquake in Zagreb which occurred on 22 March 2020 with a magnitude of 5.5. The analysis was performed on a simplified FDEM 2D numerical model which corresponds to the structure in its current pre-disaster state and the structure after the proposed post-disaster reconstruction. The obtained results showed a good agreement of the crack pattern in the numerical model and the cracks that occurred due to these earthquakes. In addition, the conclusions based on the conducted analysis can provide a better insight into the behaviour and serve as guidelines to engineers for the design of such and similar structures.

Simulation for Silos Discharge with 2D DEM

2011 ◽  
Vol 236-238 ◽  
pp. 2721-2724
Author(s):  
Shou Yi Bi ◽  
Xing Pei Liang
Keyword(s):  
Numerical Model ◽  
Discrete Element Method ◽  
Static Pressure ◽  
Lateral Pressure ◽  
Dynamic Pressure ◽  
Discrete Element ◽  
Particle Flow ◽  
Static Equilibrium State ◽  
Good Agreement ◽  
Element Method

In this paper, using the discrete element method (PFC2D)particle flow procedure to establish a model of cylindrical silo, in the warehouse filled with particles within the reach of static equilibrium state, then the record of its wall static lateral pressure measurement value, while monitoring the measured dynamic wall pressure during the silo discharging. It was shown that the static pressure as well as the dynamic pressure simulated with the numerical model is in good agreement with the experimental results. So the discrete element method can give a new way to study dynamic question of silos.

Numerical Modelling of Masonry Dams Using the Discrete Element Method

2016 ◽  
pp. 171-199
Author(s):  
Eduardo Martins Bretas
Keyword(s):  
Numerical Modelling ◽  
Discrete Element Method ◽  
Seismic Analysis ◽  
Failure Mechanisms ◽  
Discrete Element ◽  
Structural Safety ◽  
Structural Behaviour ◽  
History Of ◽  
Numerical Tool ◽  
Element Method

This work concerns the numerical modelling of masonry dams using the Discrete Element Method. It begins with a review of the history of masonry dams and their behaviour. A numerical tool based on the Discrete Element Method developed specifically for the structural assessment of masonry dams is then presented. The mechanical calculations performed by the tool are discussed in detail, together with the approach used for the modelling of passive anchors and the modules for seismic analysis and hydromechanical analysis. Structural and hydraulic analyses of a diverse set of existing masonry dams conducted using the tool are then presented. The Discrete Element Method is shown to be capable of reproducing the structural behaviour of masonry dams and identifying their likely failure mechanisms as required for structural safety evaluations.

scholarly journals Resolved CFD-DEM simulation of blood flow with a reduced-order RBC model

2021 ◽  
Author(s):  
Achuth Nair Balachandran Nair ◽  
Stefan Pirker ◽  
Mahdi Saeedipour
Keyword(s):  
Blood Flow ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Computational Method ◽  
Dem Simulation ◽  
Reduced Order ◽  
Wide Range ◽  
Channel Constriction ◽  
Good Agreement ◽  
Element Method

AbstractMathematical modeling of the blood flow with a resolved description of biological cells mechanics such as red blood cell (RBC) has been a challenge in the past decades as it involves physical complexities and demands high computational costs. In the present study, we propose an approach for efficient simulation of blood flow with several suspended RBCs. In this approach, we employ our previously proposed reduced-order model for deformable particles (Nair et al. in Comput Part Mech 7:593–601, 2020) to mimic the mechanical behavior of an individual RBC as a cluster of overlapping spheres interconnected by flexible mathematical bonds. This discrete element method-based model is then coupled with a fluid flow solver using the immersed boundary method with continuous forcing in the context of computational fluid dynamics-discrete element method (CFD-DEM) coupling. The present computational method is tested with a couple of validation cases in which the single RBC dynamics, as well as the blood flow with several RBCs, were tested in comparison with existing literature date. First, the RBC deformation index in shear flow at different shear rates is studied with a good accuracy. Then, the blood flow in micro-tubes of different diameters and hematocrits was simulated. The key characteristics of blood flow such as cell-free layer (CFL) thickness, Fahraeus effect and the relative apparent viscosity are used as the validation metrics. The proposed approach can predict the formation of the migration of RBC toward the tube center-line and the CFL thickness in good agreement with previous measurement and simulations. Furthermore, the model is employed to study the CFL enhancement for plasma separation based on channel constriction. The simulation results compute the CFL thickness downstream of the channel constriction in good agreement with the experiments in a wide range of flow rates and constriction lengths. The original contribution of this study lies in proposing an efficient resolved CFD-DEM simulation method for blood flows with many RBCs which can be employed for numerical investigation of bio-microfluidic applications.

Thermal Conductivity of Cement Concrete Using Discrete Element Method

2014 ◽  
Vol 1023 ◽  
pp. 32-35
Author(s):  
Wei Dong Liu
Keyword(s):  
Thermal Conductivity ◽  
Numerical Model ◽  
Discrete Element Method ◽  
Linear Thermal Expansion ◽  
Discrete Element ◽  
Constant Heat Flux ◽  
Test Method ◽  
Great Level ◽  
Cement Concrete ◽  
Element Method

Consideration on the traditional experiment was time-consuming and required a major investment in human and material resource, even leaded to a great level of error in the process of experiment. The new test method of thermal conductivity of cement concrete based on discrete element method was presented. The cylinder-shaped specimen was created via the mass graduation of the cement concrete, and make sure the numerical model was identical to the truth experiment. The thermal micro-properties composed of density,specific heat, coefficient of linear thermal expansion and thermal resistance were conducted. The applied constant heat flux and constant temperature as the boundaries were investigated via the herein developed model. The results testified that the virtual test data was nearly identical with the analytical values for both different boundaries, and it confirmed that the new numerical model using discrete element method is feasible and reliable. It also supplied a new method on thermal properties study.

scholarly journals Identification of numerical model parameters of tunnel lining in non-cohesive soil

2018 ◽  
Vol 67 (4) ◽  
pp. 41-58
Author(s):  
Paweł Szklennik
Keyword(s):  
Numerical Model ◽  
Discrete Element Method ◽  
Laboratory Tests ◽  
Cohesive Soil ◽  
Discrete Element ◽  
Tunnel Lining ◽  
Model Parameters ◽  
Soil Medium ◽  
Numeric Model ◽  
Element Method

The paper discusses identification of numeric model parameters of tunnel lining in a soil medium according to the discrete element method. An author’s program based on the discrete element method was used. Laboratory tests were conducted to determine the computer model parameters defining the lining and the soil medium. The numerical model was calibrated by comparing the lining deformations occurring in the laboratory test and in the numeric simulation. Tunnel lining displacement during laboratory tests was determined using digital photography. Keywords: civil engineering, discrete element method, cylindrical tunnel lining

Numerical Modelling of Ice Rubble Interactions Using Discrete Element Method

2021 ◽  
Author(s):  
Lei Liu ◽  
Eleanor Bailey ◽  
Rocky Taylor ◽  
Tony King
Keyword(s):  
Numerical Model ◽  
Discrete Element Method ◽  
Large Scale ◽  
Three Dimensional ◽  
Discrete Element ◽  
Test Results ◽  
Physical Test ◽  
Soil Response ◽  
Dem Model ◽  
Element Method

Abstract A three-dimensional, freeze-bonded, Discrete Element Method (DEM) numerical model has been developed to simulate various ice rubble/ridge interaction scenarios. The numerical model was validated against the physical tests conducted by C-CORE under the Pipeline Ice Risk Assessment and Mitigation (PIRAM) Joint Industry Project. Accurate representation of ice block geometries and sizes distributions was achieved using clumped particles, rather than the traditional DEM spheres. With the use of clumped ice blocks the numerical model was able to characterize the initial keel conditions (macro porosity and freeze bond contacts) and capture interlocking behavior between ice blocks. A DEM gravel seabed model was then introduced to the clumped ice block model to allow for better representation of soil response during the simulated experiments. The main features of these model developments are described in this paper, along with a comparison of simulated results and large scale physical test results. From this work it was concluded that: (1) clumped ice blocks give more representative ice block shapes for an ice keel than spherical ice blocks, which better capture ice block interactions and overall ridge keel properties and behavior; and (2) a DEM model of the seabed gravel provided a better representation of the seabed than was possible with a continuous stiffness plane, which had important implications for modelling the keel-seabed interactions. The development and inclusion of these two new model features were found to significantly improve the accuracy of the DEM model in reproducing physical test results, while still being sufficiently computationally efficient as to allow for simulation of interactions full-scale ice ridges.

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