scholarly journals Comparison of beam theory and finite-element analysis with in vivo bone strain data from the alligator cranium

2005 ◽  
Vol 283A (2) ◽  
pp. 331-348 ◽  
Author(s):  
Keith A. Metzger ◽  
William J.T. Daniel ◽  
Callum F. Ross
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Beam Theory ◽  
Bone Strain ◽  
Element Analysis ◽  
Strain Data

Characterization of cancellous and cortical bone strain in the in vivo mouse tibial loading model using microCT-based finite element analysis

Bone ◽  
2014 ◽  
Vol 66 ◽  
pp. 131-139 ◽  
Author(s):  
Haisheng Yang ◽  
Kent D. Butz ◽  
Daniel Duffy ◽  
Glen L. Niebur ◽  
Eric A. Nauman ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cortical Bone ◽  
Bone Strain ◽  
Element Analysis

Natural frequency analysis of a functionally graded rotor-bearing system with a slant crack subjected to thermal gradients

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Arnab Bose ◽  
Prabhakar Sathujoda ◽  
Giacomo Canale
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Power Law ◽  
Beam Theory ◽  
Functionally Graded ◽  
Thermal Gradients ◽  
Element Analysis ◽  
Rotor Bearing ◽  
Natural Frequency Analysis ◽  
Bearing System

Abstract The present work aims to analyze the natural and whirl frequencies of a slant-cracked functionally graded rotor-bearing system using finite element analysis for the flexural vibrations. The functionally graded shaft is modelled using two nodded beam elements formulated using the Timoshenko beam theory. The flexibility matrix of a slant-cracked functionally graded shaft element has been derived using fracture mechanics concepts, which is further used to develop the stiffness matrix of a cracked element. Material properties are temperature and position-dependent and graded in a radial direction following power-law gradation. A Python code has been developed to carry out the complete finite element analysis to determine the Eigenvalues and Eigenvectors of a slant-cracked rotor subjected to different thermal gradients. The analysis investigates and further reveals significant effect of the power-law index and thermal gradients on the local flexibility coefficients of slant-cracked element and whirl natural frequencies of the cracked functionally graded rotor system.

Verification of a Finite Element Analysis Procedure for Modeling the Nonlinear, Monotonic In-Plane Behavior of 4 Inch, Schedule 10, Stainless Steel, 90° Elbows

2003 ◽  
Author(s):  
James K. Wilkins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stainless Steel ◽  
Nonlinear Behavior ◽  
Shell Element ◽  
Analysis Procedure ◽  
Hoop Strain ◽  
Element Analysis ◽  
Butt Welding ◽  
Strain Data

A project has been conducted to verify a finite element analysis procedure for studying the nonlinear behavior of 90°, stainless steel, 4 inch schedule 10, butt welding elbows. Two displacement controlled monotonic in-plane tests were conducted, one closing and one opening, and the loads, displacements, and strains at several locations were recorded. Stacked 90° tee rosette gages were used in both tests because of their ability to measure strain over a small area. ANSYS shell element 181 was used in the FEA reconciliations. The FEA models incorporated detailed geometric measurements of the specimens, including the welds, and material stress-strain data obtained from the attached straight piping. Initially, a mesh consisting of sixteen elements arrayed in 8 rings was used to analyze the elbow. The load-displacement correlation was quite good using this mesh, but the strain reconciliation was not. Analysis of the FEA results indicated that the axial and hoop strain gradients across the mid-section of the elbow were very high. In order to generate better strain correlations, the elbow mesh was refined in the mid-section of the elbow to include 48 elements per ring and an additional six rings, effectively increasing the element density by nine times. Using the refined mesh produced much better correlations with the strain data.

Analysis and Optimization of Bellows With General Shape

1998 ◽  
Vol 120 (4) ◽  
pp. 325-333 ◽  
Author(s):  
B. K. Koh ◽  
G. J. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Beam Theory ◽  
Inequality Constraints ◽  
Shell Element ◽  
Scalar Function ◽  
Programming Algorithm ◽  
Multiple Objective ◽  
Axially Symmetric ◽  
Element Analysis

A bellows is a component in piping systems which absorbs mechanical deformation with flexibility. Its geometry is an axially symmetric shell which consists of two toroidal shells and one annular plate or conical shell. In order to analyze the bellows, this study presents the finite element analysis using a conical frustum shell element. A finite element analysis program is developed to analyze various bellows. The formula for calculating the natural frequency of bellows is made by the simple beam theory. The formula for fatigue life is also derived by experiments. A shape optimal design problem is formulated using multiple objective optimization. The multiple objective functions are transformed to a scalar function with weighting factors. The stiffness, strength, and specified stiffness are considered as the multiple objective function. The formulation has inequality constraints imposed on the natural frequencies, the fatigue limit, and the manufacturing conditions. Geometric parameters of bellows are the design variables. The recursive quadratic programming algorithm is utilized to solve the problem.

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