scholarly journals Effects of Moisture Content and Grain Direction on the Elastic Properties of Beech Wood Based on Experiment and Finite Element Method

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 610
Author(s):  
Wei-Lian Fu ◽  
Hui-Yuan Guan ◽  
Sawata Kei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Content ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Beech Wood ◽  
Wood Products ◽  
Moisture Contents ◽  
Wide Range ◽  
Element Method

Beech wood (Fagus sylvatica L.) is used in a wide range of wood products. However, the influence of the wood’s moisture content on its mechanical functions will affect its structural strength. It would be complicated and time-consuming to experimentally measure wood’s mechanical functions under different moisture contents. Therefore, it is necessary to establish a prediction formula between the moisture content and elastic constants, and then verify whether its mechanical functions within a wide range of moisture content can be studied by using FEM (finite element method). In this study, which was based on experimentation, we studied the influence of a wide range of moisture contents and grain direction on the compressive yield strength, modulus of elasticity and shear modulus of beech wood. The relationship between the moisture content and elastic constants was established; the moisture sensitivities of different elastic parameters were obtained. Ultimately, compression curves under different moisture contents were plotted out, using both FEM and experimentation. According to the results, the interaction of moisture with the grain direction had a significant effect on the elastic constants of wood, with grain direction having a greater effect on the elastic properties than the moisture content. Moreover, the decay function can be used to fit these experimental results well. The elastic constants of beech wood responded differently to the moisture content, depending on whether it was in the longitude or transverse directions. Finally, this study proved the feasibility of using FEM to simulate wood’s compressive performance with a wide range of moisture contents.

scholarly journals Finite Element Analysis of Square Aquifers Containing Pumped Wells and Comparison with Finite Difference Method

1983 ◽  
Vol 14 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Tilahun Aberra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Difference ◽  
Discrete Time ◽  
Surface Element ◽  
Dimensionless Time ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Wide Range ◽  
Element Method

The numerical solution of the behaviour of discrete time steps in digital computer analysis of square aquifers containing pumped wells is examined by using the finite element method with a 4 node linear quadrilateral isoparametric surface element. A wide range of time steps are used in the computation. The calculations show that discrete time steps can cause errors and oscillations in the calculations particularly when wells start and stop pumping. Comparison with known results obtained by theoretical and finite difference procedures has been considered. The main objective of this paper is to demonstrate comparison of the finite element and finite difference simulation results over a regular linear 4 node quadrilateral mesh suitable to represent the two numerical schemes with a marked similarity. The dimensionless time drawdown results of the finite element method agreed well with the finite difference and analytical results for small time increment. However, for large time increments, there are from slight to significant oscillations in the results and notable discrepancies are observed in the solutions of the two numerical methods.

Comparing Computational and Experimental Failure of Composites Using XFEM

2016 ◽  
Author(s):  
Andrew W. Hulton ◽  
Paul V. Cavallaro
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Materials ◽  
Composite Structures ◽  
Experimental Testing ◽  
Composite Cylinder ◽  
Lateral Compression ◽  
Flat Plates ◽  
Wide Range ◽  
Element Method

Fiber reinforced polymer (FRP) composites have been used as a substitute for more conventional materials in a wide range of applications, including in the aerospace, defense, and auto industries. Due to the widespread availability of measurement techniques, experimental testing of composite materials has outpaced the computational modeling ability of such complicated materials. With advancements in computational physics-based modeling (PBM) such as the finite element method (FEM), strides can be made to reduce the efforts required in building and testing future composite structures. In this work, the extended finite element method (XFEM) is implemented to model fracture of composite materials under quasistatic loading. XFEM is applied to a three-dimensional (3D) computational model of a carbon fiber/epoxy composite cylinder, in half symmetry, that is subjected to lateral compression between two flat plates. Independent material properties are instituted for each composite layer, depending on individual layer orientation. The crack path produced by the analytical results is compared to experimental testing of lateral compression of a composite cylinder. Fracture site initiation and growth path are consistent in both the experimental and computational results.

scholarly journals Finite element method for stress and strain analysis of FGM hollow cylinder under effect of temperature profiles and inhomogeneity parameter

2021 ◽  
Vol 10 (1) ◽  
pp. 477-487
Author(s):  
Dinkar Sharma ◽  
Ramandeep Kaur ◽  
Munish Sandhir ◽  
Honey Sharma
Keyword(s):  
Differential Equation ◽  
Finite Element Method ◽  
Finite Element ◽  
Hollow Cylinder ◽  
Functionally Graded ◽  
Stress And Strain ◽  
Temperature Profiles ◽  
Wide Range ◽  
Inhomogeneity Parameter ◽  
Element Method

Abstract This study represents a numerical analysis of stress and strain in the functionally graded material (FGM) hollow cylinder subjected to two different temperature profiles and inhomogeneity parameter. The thermo-mechanical properties of a cylinder are assumed to vary continuously as power law function along the radial coordinate of a cylinder. Based on equilibrium equation, Hooke's law, stress-strain relationship in the cylinders, and other theories from mechanics second order differential equation is obtained that represents the thermoelastic field in hollow FGM cylinder. To find a numerical solution of governing differential equation, the finite element method (FEM) with standard discretization approach is used. The analysis of numerical results reveals that stress and strain in the FGM cylinder are significantly depend upon variation made in temperature profile and inhomogeneity parameter n. The results show good agreement with results available in the literature. It is shown that thermoelastic characteristics of the FGM cylinder are controlled by controlling the value of the above discussed parameters. Moreover, these results are very useful in various fields of engineering and science as FGM cylinders have a wide range of applications in these fields.

scholarly journals Stability Charts for Pseudostatic Stability Analysis of 3D Homogeneous Soil Slopes Using Strength Reduction Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Chaowei Sun ◽  
Junrui Chai ◽  
Bin Ma ◽  
Tao Luo ◽  
Ying Gao ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Slope Failure ◽  
Strength Reduction ◽  
Seismic Load ◽  
Wide Range ◽  
Soil Slopes ◽  
Homogeneous Soil ◽  
Element Method

This paper uses the modified strength reduction finite element method to propose stability charts for pseudostatic stability analysis of three-dimensional (3D) homogeneous soil slopes subjected to seismic excitation. These charts are developed in a wide range of input parameters for purely cohesive slopes and cohesive-frictional slopes, respectively. Effect of the horizontal seismic load is approximately considered using the quasistatic approach. The stability charts allow to determine the factor of safety without any iterative procedure and identify the corresponding critical slope failure mechanism. A slope example is employed to illustrate the application and reliability of these stability charts.

Development of software based on NX Open for assessing the reliability of REA designs

2018 ◽  
Author(s):  
С.А. Пименов ◽  
П.П. Зорков
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Methods ◽  
Statistical Modelling ◽  
Probabilistic Methods ◽  
The Finite Element Method ◽  
Random Loading ◽  
Random Load ◽  
Wide Range ◽  
Element Method

Рассматриваются основные алгоритмы и численные методы решения задач оценки надежности конструкций радиоэлектронной аппаратуры. Алгоритмы реализованы в виде расчетного программного обеспечения АРКОН для проведения оценки надежности конструкций в условиях случайного нагружения с применением численных методов: метода конечных элементов и метода статистического моделирования. The paper deals with the development of new software which allows us to use probabilistic methods for evaluating the reliability of CEA designs. The main algorithms and numerical methods for solving problems of reliability assessment of REA structures are considered. The reason for conducting the study was the presence of the lag in development of the program-technical complexes aimed at assessment of the strength reliability in relation to the tasks being solved. At the moment, analytical methods for estimating the probability of failure-free operation have been developed. Their implementation requires the existence of a law for the distribution of random load parameters and the system itself. This method is deprived of the method of statistical modelling with the calculation of stresses using the finite element method. The algorithms are implemented in the form of computational software for assessing the reliability of structures under random loading conditions. To implement this method, an open CAE was chosen — a system with the ability to program its own modules — the NX Open system. The developed software is displayed on the NX panel in the form of a special icon tray Reliability. The developed software is intended for analysis of the strength of reliability of CEA structures with random loading. The software does not have domestic or foreign alternatives. The main advantages are universality (the ability to perform calculations for a wide range of designs, taking into account the statistical nature of the initial data), the reliability of the estimated estimates, confirmed by the use of modern numerical methods: the finite element method and the statistical modelling method.

Fundamentals and Applications of the Finite-Element Method in Analyzing Structural and Nonstructural Marine Problems

1982 ◽  
Vol 19 (03) ◽  
pp. 272-292
Author(s):  
Donald Liu ◽  
Yung-Kuang Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Element Formulation ◽  
The Finite Element Method ◽  
Static And Dynamic Analysis ◽  
Marine Industry ◽  
Wide Range ◽  
Element Method

The finite-element method has become a popular and effective tool not only for structural analysis, but also for a wide range of physical problems which are of particular interest to the marine industry. A brief review of the finite-element formulation for structural and nonstructural problems is presented. Applications to marine structures, including static and dynamic analysis and fracture mechanics, are given. Nonstructural applications to heat transfer and ship hydrodynamic problems are also demonstrated. Recent developments in the coupled fluid-structural interaction problem using the boundary integral method, which is considered as an extension of the finite-element method, are also described.

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