scholarly journals On controllability of a linear elastic beam with memory under longitudinal load

2014 ◽  
Vol 3 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Sergei A. Avdonin ◽  
◽  
Boris P. Belinskiy ◽  
Keyword(s):  
Elastic Beam ◽  
Linear Elastic ◽  
Longitudinal Load ◽  
With Memory

scholarly journals A Microstructurally Driven Model for Pulmonary Artery Tissue

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Philip H. Kao ◽  
Steven R. Lammers ◽  
Lian Tian ◽  
Kendall Hunter ◽  
Kurt R. Stenmark ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Collagen Fiber ◽  
Elastic Beam ◽  
Fiber Material ◽  
Orientation Distribution ◽  
Tissue Mechanics ◽  
Fiber Model ◽  
Linear Elastic ◽  
Disease States ◽  
Artery Tissue

A new constitutive model for elastic, proximal pulmonary artery tissue is presented here, called the total crimped fiber model. This model is based on the material and microstructural properties of the two main, passive, load-bearing components of the artery wall, elastin, and collagen. Elastin matrix proteins are modeled with an orthotropic neo-Hookean material. High stretch behavior is governed by an orthotropic crimped fiber material modeled as a planar sinusoidal linear elastic beam, which represents collagen fiber deformations. Collagen-dependent artery orthotropy is defined by a structure tensor representing the effective orientation distribution of collagen fiber bundles. Therefore, every parameter of the total crimped fiber model is correlated with either a physiologic structure or geometry or is a mechanically measured material property of the composite tissue. Further, by incorporating elastin orthotropy, this model better represents the mechanics of arterial tissue deformation. These advancements result in a microstructural total crimped fiber model of pulmonary artery tissue mechanics, which demonstrates good quality of fit and flexibility for modeling varied mechanical behaviors encountered in disease states.

Systematic Error in the Measure of Microdamage by Modulus Degradation During Four-Point Bending Fatigue

2007 ◽  
Author(s):  
Matthew D. Landrigan ◽  
Ryan K. Roeder
Keyword(s):  
Fatigue Testing ◽  
Elastic Beam ◽  
Beam Theory ◽  
Maximum Load ◽  
Beam Deflection ◽  
Linear Elastic ◽  
Four Point Bending ◽  
Specimen Width ◽  
Initial Modulus ◽  
Specimen Height

The accumulation of fatigue damage in bovine and human cortical bone is conventionally measured by modulus or stiffness degradation. The initial modulus or stiffness of each specimen is typically measured in order to normalize tissue heterogeneity to a prescribed strain [1,2]. Cyclic preloading at 100 N for 20 cycles has been used for this purpose in both uniaxial tension and four-point bending tests [1–3]. In four-point bending, the specimen modulus is often calculated using linear elastic beam theory as, (1)E=3Fl4bh2ε where F is the applied load, l is the outer support span, b is the specimen width, h is the specimen height, and ε is the maximum strain based on the beam deflection [2]. The maximum load and displacement data from preloading is used to determine the initial specimen modulus. The initial modulus and a prescribed maximum initial strain are then used to determine an appropriate load for fatigue testing under load control.

scholarly journals Numerical Implementation of Meshless Methods for Beam Problems

2012 ◽  
Vol 58 (2) ◽  
pp. 175-184 ◽  
Author(s):  
V. E. Rosca ◽  
V. M. A. Leitāo
Keyword(s):  
Elastic Beam ◽  
Weak Form ◽  
Computational Procedure ◽  
Meshless Methods ◽  
Numerical Implementation ◽  
Linear Elastic ◽  
Collocation Technique ◽  
Particle Hydrodynamics ◽  
The Difference ◽  
Element Free

Abstract For solving a partial different equation by a numerical method, a possible alternative may be either to use a mesh method or a meshless method. A flexible computational procedure for solving 1D linear elastic beam problems is presented that currently uses two forms of approximation function (moving least squares and kernel approximation functions) and two types of formulations, namely the weak form and collocation technique, respectively, to reproduce Element Free Galerkin (EFG) and Smooth Particle Hydrodynamics (SPH) meshless methods. The numerical implementation for beam problems of these two formulations is discussed and numerical tests are presented to illustrate the difference between the formulations.

Uniaxial Constitutive Equation of Ice From Beam Tests

1985 ◽  
Vol 107 (4) ◽  
pp. 511-515 ◽  
Author(s):  
P. C. Xirouchakis ◽  
T. Wierzbicki
Keyword(s):  
Strain Rate ◽  
Direct Method ◽  
Elastic Beam ◽  
Bending Moment ◽  
Uniaxial Stress ◽  
Analytical Technique ◽  
Linear Elastic ◽  
Beam Depth ◽  
Tension And Compression ◽  
Extensional Strain

A method is proposed to obtain ice uniaxial stress, strain, strain-rate relations from beam tests. The basic advantage of the proposed analytical technique is that it is a direct method of reducing beam test data. So, no assumption is made with regard to the ice constitutive behavior. The proposed method is an extension of Gillis and Kelly’s procedure to account for different ice response in tension and compression. It is also an extension of the procedure reported by Mayville and Finnie to account for ice response dependence on strain rate. Furthermore, it is shown that the expressions presented by Mayville and Finnie are only valid when the bending moment, with respect to the zero strain axis, is assumed independent of the centroidal extensional strain. A simple example of a linear elastic beam with a Young’s modulus that varies linearly with the beam depth is worked out to show that these earlier given expressions are not applicable in that case.

scholarly journals ANALYTICAL MODELS FOR ESTIMATION OF THE MAXIMUM STRAIN OF BEAM STRUCTURES BASED ON OPTICAL FIBER BRAGG GRATING SENSORS

2015 ◽  
Vol 22 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Se Woon CHOI ◽  
Jihoon LEE ◽  
Byung Kwan OH ◽  
Hyo Seon PARK
Keyword(s):  
Maximum Stress ◽  
Strain Sensor ◽  
Elastic Beam ◽  
Analytical Models ◽  
Structural Safety ◽  
Maximum Strain ◽  
Beam Structures ◽  
Linear Elastic ◽  
Measured Strain ◽  
Fbg Sensors

The structural safety of a beam structure is assessed by a comparison between the maximum stress measured during monitoring and the allowable stress of the beam. However, the strain directly measured from a fiber Bragg grat- ing (FBG) strain sensor may not be identical with the actual maximum strain induced in the structural member. Unless a FBG strain sensor is installed exactly on where maximum strain occurs, the reliability of the evaluated safety based on the measured strain depends on the number and location of sensors. Therefore, in this paper, analytical models are presented for estimation of the maximum values of strains in a linear elastic beam using the local strains measured from FBG sensors. The model is tested in an experiment by comparing estimated maximum strain from FBG sensors and directly measured strain from electrical gages. For the assessment of safety of typical beam structures in buildings and infrastructures, analytical models for various loading and boundary conditions are provided.

Sign in / Sign up

Export Citation Format

Share Document