Analytical, Numerical, and Experimental Studies of Effective Elastic Properties of Periodically Perforated Materials

1996 ◽  
Vol 118 (1) ◽  
pp. 43-48 ◽  
Author(s):  
S. A. Meguid ◽  
A. L. Kalamkarov ◽  
J. Yao ◽  
A. Zougas
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Experimental Studies ◽  
Perforated Plate ◽  
Element Model ◽  
Asymptotic Homogenization ◽  
Element Analysis ◽  
Effective Elastic Properties ◽  
Uniaxial Testing ◽  
Circular Holes

Comprehensive analytical, finite element analysis and experimental studies are made of the interaction between closely spaced multiple circular holes. The analytical model utilizes the technique of asymptotic homogenization and the complex variable method to obtain explicit expressions for the effective elastic properties of a completely perforated plate under uniaxial loading. The analytical predictions are then compared with a finite element model and the results of both techniques are verified experimentally using uniaxial testing under controlled conditions. The findings of the present work are also compared with earlier solutions and efforts are made to highlight inconsistencies and limitations of the three techniques.

scholarly journals A Novel Method for Tooth Bending Stress Calculation of Gears With Asymmetric Teeth

2021 ◽  
Author(s):  
Oguz DOGAN ◽  
Celalettin YUCE ◽  
Fatih KARPAT
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Experimental Studies ◽  
Element Model ◽  
Bending Stress ◽  
Element Analysis ◽  
Stress Calculation ◽  
Bending Stresses ◽  
New Equation ◽  
Asymmetric Factor

Abstract Today, gear designs with asymmetric tooth profiles offer essential solutions in reducing tooth root stresses of gears. Although numerical, analytical, and experimental studies are carried out to calculate the bending stresses in gears with asymmetric tooth profiles a standard or a simplified equation or empirical statement has not been encountered in the literature. In this study, a novel bending stress calculation procedure for gears with asymmetric tooth profiles is developed using both the DIN3990 standard and the finite element method. The bending stresses of gears with symmetrical profile were determined by the developed finite element model and was verified by comparing the results with the DIN 3990 standard. Using the verified finite element model, by changing the drive side pressure angle between 20° and 30° and the number of teeth between 18 and 100, 66 different cases were examined and the bending stresses in gears with asymmetric profile were determined. As a result of the analysis, a new asymmetric factor was derived. By adding the obtained asymmetric factor to the DIN 3390 formula, a new equation has been derived to be used in tooth bending stresses of gears with asymmetric profile. Thanks to this equation, designers will be able to calculate tooth bending stresses with high precision in gears with asymmetric tooth profile without the need for finite element analysis.

scholarly journals Elastic buckling of thin plate with circular holes in bending

2019 ◽  
Vol 136 ◽  
pp. 04043
Author(s):  
Guo Yanli ◽  
Song Xiaoqing ◽  
Li Xiao ◽  
Yao Xingyou ◽  
Xia Zhifan ◽  
...  
Keyword(s):  
Finite Element ◽  
Perforated Plate ◽  
Thickness Ratio ◽  
Thin Plates ◽  
Elastic Buckling ◽  
Buckling Mode ◽  
Element Analysis ◽  
Short Side ◽  
Finite Element Software ◽  
Circular Holes

Stress redistribution will occur around the hole for the perforated plate under bending, and the buckling mode of bending plate is changed, which makes the design of bending plate more complicated. The finite element software ABAQUS is used to establish the perforated plate under bending model, analyze the degree of influence of the plate aspect ratio, width-thickness ratio, size and position of the holes, meanwhile, the distance between holes is also discussed. The results show that the thickness of the plate size and width-thickness ratio have little influence on the elastic buckling performance of thin plates with holes in bending. As the size of the holes increase, the influence is greater, and there is a certain regularity. The opening position is closer to the short side of the plate, the buckling coefficient of plate will be significantly decreased. The effect is greater with the increase of opening size, the distance between holes have a safe value, the position of the opening is more obvious for the buckling of the bending plate. Finally, based on the data from finite element analysis, the proposed formula of buckling stability coefficient k for the bending perforated plate is given.

Numerical Analysis of High Pressure Cold Bend Pipe to Investigate the Behaviour of Tension Side Fracture

2012 ◽  
Author(s):  
Celal Cakiroglu ◽  
Amin Komeili ◽  
Samer Adeeb ◽  
J. J. Roger Cheng ◽  
Millan Sen
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Internal Pressure ◽  
Experimental Studies ◽  
Element Model ◽  
Combined Loading ◽  
Element Analysis ◽  
Bend Pipe ◽  
Bending Load ◽  
Bending Loads

The cold bend pipelines may be affected by the geotechnical movements due to unstable slopes, soil type and seismic activities. An extensive experimental study was conducted by Sen et al. in 2006 to understand the buckling behaviour of cold bend pipes. In their experiments, it was noted that one high pressure X65 pipe specimen failed under axial and bending loads due to pipe body tensile side fracture which occurred after the development of a wrinkle. The behaviour of this cold bend pipe specimen under bending load has been investigated numerically to understand the conditions leading to pipe body tension side fracture following the compression side buckling. Bending load has been applied on a finite element model of the cold bend by increasing the curvature of it according to the experimental studies conducted by Sen [1]. The bending loads have been applied on the model with and without internal pressure. The distribution of the plastic strains and von Mises stresses as well as the load–displacement response of the pipe have been compared for both load cases. In this way the experimental results obtained by Sen [1] have been verified. The visualization of the finite element analysis results showed that pipe body failure at the tension side of the cold bend takes place under equal bending loads only in case of combined loading with internal pressure.

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

Nonlinear Finite Element Analysis of Adaptive-Slit Shear Walls

2013 ◽  
Vol 275-277 ◽  
pp. 1207-1211
Author(s):  
Ying Ying Yin ◽  
Ming Jin Chu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Studies ◽  
Shear Walls ◽  
Element Model ◽  
Finite Model ◽  
Test Results ◽  
Element Analysis ◽  
Practical Engineering ◽  
Monotonic Loads

In order to further study the mechanism of adaptive-slit shear walls under horizontal loads, and facilitate it better applied to practical engineering. On the basis of experimental studies, the ABAQUS finite element analysis software is used to establish the finite model of adaptive-slit shear. The finite element model accuracy is verified by comparing the model and test results. A validated model is used to study the mechanical property of adaptive-slit shear walls under monotonic loads.

Dependence of Elastic Properties of Human Femoral Cortical Bone on Porosity

2015 ◽  
Author(s):  
Maryam Khosroshahi ◽  
Fred Barez ◽  
Amer El-Hage ◽  
James Kao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Cortical Bone ◽  
Elastic Properties ◽  
Transversely Isotropic ◽  
Element Model ◽  
Element Analysis ◽  
Age Related ◽  
The Finite Element Model

Hip fracture is one of the most serious and common health problems among elderly which may lead to permanent disability or death. Hip fracture commonly occurs in the femoral bone, the major bone in the hip joint. Microscopic age-related changes in the structure of cortical bone is one of the factors that is considered to be partially responsible for the increase of fracture risk in elderly. It is of great interest to develop a predictable model of such fractures for the aging population in preparation of a suitable therapy. These micro structural changes influence mechanical properties and, therefore, behavior of bone and are critical to understand risk and mechanics of fracture of bone. Correlation between cortical bone strength and porosity, as a microscopic structural factor, has been examined frequently as a function of age and/or porosity. These studies have investigated the effect of porosity experimentally and have not studied the effect of porosity independently from other structural factors such as bone mineral density. In this study effect of porosity on elastic properties of human femoral cortical bone was studied independently using finite element analysis assuming transversely isotropic behavior in terms of elastic properties with the axis of elastic properties along the longitudinal axis of femur shaft. In this study, published standard mechanical tests for transversely isotropic materials were simulated using finite element computer simulation on models with different porosities. The developed finite element model utilized material properties based on the best fit regression in previously published articles. Pores’ size, shape and distribution were also modeled based on previous experimental studies. The finite element model, in general, predicted behavior of five independent elastic mechanical properties, namely, longitudinal Young’s modulus, transverse poisson’s ratio, transverse shear modulus, transverse Young’s modulus and longitudinal poisson’s ratio, as a function of porosity. Furthermore, effect of porosity on the elastic properties across various age groups was investigated using published data on age-related changes in bone porosity. Mathematical models based on Finite Element Analysis results have been developed using linear least square regression. These models show negative linear relationship between studied elastic properties of human femoral cortical bone and porosity. The Finite Element Analysis results compared well with the previously published experimental data. Furthermore, the results obtained show the elastic properties as functions of age for females and males. The predicted values for elastic properties are lower for men compared to women of age 20 to 40 years old. However, after the age of 44, elastic properties of femoral cortical bone for men are higher than women. The Finite Element Model developed in this study will help to create a clinical bone model for the prediction of fracture risk or the selection of suitable therapy in orthopedic surgery.

Sign in / Sign up

Export Citation Format

Share Document