Voxel-based finite element modelling of wood elements based on spatial density and geometry data using computed tomography

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jens U. Hartig ◽  
André Bieberle ◽  
Chris Engmann ◽  
Peer Haller
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Strain Distribution ◽  
Finite Element Modelling ◽  
Element Model ◽  
Spatial Density ◽  
Stress And Strain ◽  
Element Modelling ◽  
Stress And Strain Distribution ◽  
The Finite Element Model

Abstract In this paper, voxel-based finite element modelling based on spatial geometry and density data is applied to simulate the detailed stress and strain distribution in a large wood element. As example, a moulded wooden tube with a length of 3 m and a diameter of 0.3 m is examined. Gamma-ray computed tomography is used to obtain both, its actual geometric shape and spatial density distribution. Correlation functions (R2 ≈ 0.6) between density and elastic material properties are experimentally determined and serve as link for defining the non-uniform distribution of the material properties in the finite element model. Considering the geometric imperfections and spatial variation of the material properties, a detailed analysis of the stress and strain distribution of a wood element is performed. Additionally, a non-destructive axial compression test is applied on the wooden tube to analyse the load-bearing behaviour. By means of digital image correlation, the deformation of the surface is obtained, which also serves for validation of the finite element model in terms of strain distributions.

scholarly journals The elasto-mechanical behaviour of Douglas fir, its sensitivity to tree-specific properties, wind and snow loads, and implications for stability – a simulation study

2019 ◽  
Vol 48 (No. 2) ◽  
pp. 49-69 ◽  
Author(s):  
D. Gaffrey ◽  
O. Kniemeyer
Keyword(s):  
Mechanical Behaviour ◽  
Material Properties ◽  
Strain Distribution ◽  
Element Model ◽  
Douglas Fir ◽  
Stress And Strain ◽  
Gravitational Forces ◽  
Applied Forces ◽  
D Model ◽  
Stress And Strain Distribution

A full 3-D model was developed to simulate the elasto-mechanical behaviour of trees subjected to wind and gravitational forces with the aim of estimating the stress and strain distribution at the surface of the stem. The model was adapted to geometry and material properties of a 64-year old Douglas fir tree. The results are comparable, on the whole, with those of a finite element model of this tree. Original stem and crown data, as well as the applied forces, were modified manifold in order to study their importance on the change in fibre stress and thus, on the safety reserve against stem breakage.

A critical review on the three-dimensional finite element modelling of the compression therapy for chronic venous insufficiency

2019 ◽  
Vol 233 (11) ◽  
pp. 1089-1099 ◽  
Author(s):  
Yongtao Lu ◽  
Zhuoyue Yang ◽  
Yongxuan Wang
Keyword(s):  
Finite Element ◽  
Chronic Venous Insufficiency ◽  
Finite Element Modelling ◽  
Venous Insufficiency ◽  
Computational Modelling ◽  
Compression Therapy ◽  
Element Model ◽  
Material Models ◽  
Element Modelling ◽  
The Finite Element Model

Compression therapy is an adjuvant physical intervention providing the benefits of calibrated compression and controlled stretch and consequently is increasingly applied for the treatment of chronic venous insufficiency. However, the mechanism of the compression therapy for chronic venous insufficiency is still unclear. To elaborate the mechanism of compression therapy, in recent years, the computational modelling technique, especially the finite element modelling method, has been widely used. However, there are still many unclear issues regarding the finite element modelling of compression therapy, for example, the selection of appropriate material models, the validation of the finite element predictions, the post-processing of the results. To shed light on these unclear issues, this study provides a state-of-the-art review on the application of finite element modelling technique in the compression therapy for chronic venous insufficiency. The aims of the present study are as follows: (1) to provide guidance on the application of the finite element technique in healthcare and relevant fields, (2) to enhance the understanding of the mechanism of compression therapy and (3) to foster the collaborations among different disciplines. To achieve these aims, the following parts are reviewed: (1) the background on chronic venous insufficiency and the computational modelling approach, (2) the acquisition of medical images and the procedure for generating the finite element model, (3) the definition of material models in the finite element model, (4) the methods for validating the finite element predictions, (5) the post-processing of the finite element results and (6) future challenges in the finite element modelling of compression therapy.

Finite Element Modelling Of Compartment Fire Using ABAQUS

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Mariyana A. A. K. ◽  
A. S. M. Abdul Awal ◽  
Mahmood Md. Tahir
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Elevated Temperature ◽  
Finite Element Model ◽  
Finite Element Modelling ◽  
Fire Test ◽  
Element Model ◽  
Compartment Fire ◽  
Element Modelling ◽  
The Finite Element Model

This paper presents finite element modelling (FEM) of a reinforced concrete (RC) frame subjected to elevated temperature. The work presented is part of the UK-India Education and Research Initiative (UKIERI) project. In this project, an experimental test of sub-assemblage frame with elevated temperature has been performed at Indian Institute of Technology (IIT) Roorkee, India. The finite element model using ABAQUS software has been used to validate the increased in temperature distribution on reinforced concrete frame exposed to fire. The idea of this study is to design a compartment fire, and determination of emissivity value at different height. And composition of hot gases was calculated. Gas temperatures used was based on the average temperature-curve obtained in the fire test. The validity of the finite element model was established by comparing the predicted values from the FEM with test data direct from fire test results. The results obtained indicate that suggested FEM analysis procedure is capable of modelling temperature in compartment fires.  

scholarly journals Thermal Cracks Development Study in Newly Built Reinforced Concrete Residences

2021 ◽  
Vol 1203 (2) ◽  
pp. 022036
Author(s):  
Hymabaccus El Fez Hashmi ◽  
Seeboo Asish
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Element Model ◽  
Crack Development ◽  
Element Modelling ◽  
Thermal Cracks ◽  
Physical Conditions ◽  
Concrete Blocks ◽  
Recorded Data ◽  
The Finite Element Model

Abstract Concrete blocks and concrete assemblies are affected by natural physical conditions, which impacts on the durability and service life of the structures. In this paper, site data was gathered, which was used to perform a numerical and a finite element modelling to investigate the impacts of several conditions on thermal cracking in a structure. The field recorded data was used for the numerical modelling, using MATLAB software, and the finite element modelling, using ANSYS Mechanical software. It was observed that among the conditions considered, the wall ratio in the structure and formation of microcracks have significant impacts, while the age of the structure, the compressive strength of the concrete have minimal impacts, as the shifting in the curve is small. Finally, a probabilistic crack development model was made to study the potential crack development in the finite element model, which was seen to tally with observed site data, demonstrating the potential of predicting cracks development.

Study on Stress and Strain of Anchorage Using Finite Element Method

2013 ◽  
Vol 325-326 ◽  
pp. 1314-1317
Author(s):  
Cong Sheng Chen ◽  
Ping He ◽  
Cheng Yong Wang ◽  
Xue Hui Chen ◽  
Lei Huang ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Distribution ◽  
Maximum Stress ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Integrated Modeling ◽  
Stress And Strain ◽  
Steel Strand ◽  
Prestressed State ◽  
Stress And Strain Distribution

Three-dimensional integrated modeling method and the numerical simulation of elastoplastic finite element are adopted in the paper. The mechanical response of the five holes anchorage is analyzed in certain prestressed state. The stress and strain distribution information of the anchor ring, clip and steel strand is obtained respectively, and the structure safety is discussed by investigating on the maximum stress and strain.

Numerical Study of the Effect of Geometry and Boundary Conditions on the Collapse Behaviour of Stocky Stiffened Panels

2012 ◽  
Vol 154 (A2) ◽  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

Impact Analysis of an Oxygen Mask Locking Panel of Aircraft Using Finite Element Modelling

2014 ◽  
Vol 657 ◽  
pp. 735-739 ◽  
Author(s):  
Emilian Ionut Croitoru ◽  
Gheorghe Oancea
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Impact Analysis ◽  
Element Model ◽  
Composite Panel ◽  
Cad Model ◽  
Stress Variation ◽  
Element Modelling ◽  
Oxygen Mask ◽  
The Impact

This paper presents a method of finite element modelling used for the impact analysis of a composite panel. In this research, the composite panel consists of an oxygen mask locking panel of an aircraft. This panel is loaded with one concentrated abuse loading and three uniform distributed abuse loading cases and the stress variation within the composite panel for each load case is determined. In order to assess the impact analysis on the oxygen mask panel of the aircraft, a finite element model is created using Patran as the main application for pre/post-processing and Nastran as the main processor. The paper also presents a comparison between results obtained using the same finite element modelling of the composite panel CAD model of the panel with four load cases with different material types. The results are used to determine the most capable material stresswise.

Parametric Studies of Retinal Strain Distribution due to Repair Stent Using Finite Element Modelling

2016 ◽  
Author(s):  
Razvan Rusovici ◽  
Dennis Dalli ◽  
Kunal Mitra ◽  
Michael Grace ◽  
Gary Ganiban ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Distribution ◽  
Finite Element Modelling ◽  
Element Modelling ◽  
Parametric Studies
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