Stochastic Filtering Back Analysis of Elastic Modulus of Box Shaped Beam

2015 ◽  
Vol 1096 ◽  
pp. 557-561
Author(s):  
Bo Yu ◽  
Tao Hong ◽  
Jian Zhang
Keyword(s):  
Elastic Modulus ◽  
Analytical Procedure ◽  
Back Analysis ◽  
Shell Element ◽  
Mechanical Analysis ◽  
Displacement Function ◽  
Shaped Beam ◽  
Stochastic Filtering ◽  
Practical Engineering ◽  
Element Theory

With the development of civil engineering, the box shaped beam has been widely applied in practical engineering. In general, it is composed of concrete and steel and compared with mechanical analysis, little research has been carried on the back analysis of elastic modulus of box shaped beam. With degraded solid element theory, the shell element is deduced and the displacement function is obtained. The necessary observation revision equation and Kalman regenerative matrix are derived. The stochastic filtering back analysis steps of elastic modulus of the box shaped beam are presented and the analytical procedure is compiled. Through analysis of a classic example, some important conclusions about stochastic filtering back analysis of elastic modulus of box shaped beam are obtained.

Stochastic Gaussian Optimized Inversion of Mechanical Parameters of Reinforced Concrete Single T-Shaped Beam

2010 ◽  
Vol 163-167 ◽  
pp. 1874-1878 ◽  
Author(s):  
Jian Zhang ◽  
Wen Gai Lan ◽  
Bo Yu
Keyword(s):  
Reinforced Concrete ◽  
Error Function ◽  
Optimization Method ◽  
Mechanical Analysis ◽  
Displacement Function ◽  
Inversion Problem ◽  
Mechanical Parameters ◽  
Shaped Beam ◽  
Solid Element ◽  
Element Theory

The reinforced concrete single T-shaped beam is of common use. Compared with mechanical analysis, little attraction has been put on the stochastic optimized inversion problem. The present study is aimed to carry out stochastic optimized inversion of mechanical parameters of reinforced concrete single T-shaped beam based on degraded solid element theory. Firstly for the reinforced concrete single T-shaped beam, degraded solid element theory is deduced and the displacement function is obtained. Then Gaussian error function of mechanical parameters of the reinforced concrete single T-shaped beam is founded and the corresponding formulas of Gaussian expectation and variance are derived. The stochastic optimized inversion computing formulas are also obtained by adopting optimization method including conjugate gradient method. Then the steps of stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are listed. Through analysis of a classic example, some important conclusions about stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are drawn.

Theoretical Model of Revised Powell Back Analysis of Composite T-Beam with Error Function

2010 ◽  
Vol 146-147 ◽  
pp. 1519-1523
Author(s):  
Jian Zhang ◽  
Wen Gai Lan ◽  
Jing Lin
Keyword(s):  
Theoretical Model ◽  
Error Function ◽  
Back Analysis ◽  
Optimization Method ◽  
Mechanical Analysis ◽  
Displacement Function ◽  
Mechanical Parameters ◽  
T Beam ◽  
Element Theory ◽  
Powell Method

Composite T-beam in general use is composed of concrete and steel. Compared with mechanical analysis, little research has been carried on deriving the theoretical model for back analysis of composite T-beam. Firstly for composite T-beam, degraded solid element theory is deduced and the displacement function is obtained. Then Markov error function of mechanical parameters of composite T-beam is founded. The back analysis computing formulas are also obtained by adopting optimization method including revised Powell method. Then the steps of back analysis of mechanical parameters of the composite T-beam are given. Through analysis of a classic example, some important conclusions about revised Powell back analysis of mechanical parameters of composite T-beam are obtained.

Dynamic Strain Effects in Elastomers

1963 ◽  
Vol 36 (2) ◽  
pp. 407-421 ◽  
Author(s):  
Glenn E. Warnaka
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Strain Amplitude ◽  
Loss Factor ◽  
Dynamic Strain ◽  
Dynamic Mechanical ◽  
Small Strains ◽  
Dynamic Mechanical Behavior ◽  
Elastomeric Materials ◽  
Practical Engineering

Abstract Many common elastomeric materials have two ranges of dynamic-mechanical behavior. Such materials behave as viscoelastomers at very small strains and as plastoelastomers at strains of practical engineering interest. The change from viscoelastic to plastoelastic behavior occurs at dynamic strain amplitudes of 0.001 inches per inch to 0.005 inches per inch. In the plastoelastic range, the dynamic elastic modulus decreases with increasing dynamic strain amplitude. Loss factor reaches a maximum in the plastoelastic range.

scholarly journals Numerical aspects for efficient welding computational mechanics

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 139-148
Author(s):  
Tarek Aburuga ◽  
Aleksandar Sedmak ◽  
Zoran Radakovic
Keyword(s):  
Residual Stresses ◽  
Three Dimensional ◽  
Shell Element ◽  
Element Model ◽  
Mechanical Analysis ◽  
Tensile Test Specimen ◽  
Integrity Assessment ◽  
Mass Scaling ◽  
Three Dimensional Models ◽  
Thermal Mechanical Analysis

The effect of the residual stresses and strains is one of the most important parameter in the structure integrity assessment. A finite element model is constructed in order to simulate the multi passes mismatched submerged arc welding SAW which used in the welded tensile test specimen. Sequentially coupled thermal mechanical analysis is done by using ABAQUS software for calculating the residual stresses and distortion due to welding. In this work, three main issues were studied in order to reduce the time consuming during welding simulation which is the major problem in the computational welding mechanics (CWM). The first issue is dimensionality of the problem. Both two- and three-dimensional models are constructed for the same analysis type, shell element for two dimension simulation shows good performance comparing with brick element. The conventional method to calculate residual stress is by using implicit scheme that because of the welding and cooling time is relatively high. In this work, the author shows that it could use the explicit scheme with the mass scaling technique, and time consuming during the analysis will be reduced very efficiently. By using this new technique, it will be possible to simulate relatively large three dimensional structures.

On Stresses in Pipeline Expansion Bellows

1988 ◽  
Vol 110 (2) ◽  
pp. 215-217 ◽  
Author(s):  
A. V. Singh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Procedure ◽  
Circumferential Stress ◽  
Shell Element ◽  
Shells Of Revolution ◽  
Axisymmetric Shell ◽  
Stress Components ◽  
Stress Patterns ◽  
Theory Of Shells

An analytical procedure employing the general theory of shells of revolution and finite element method is presented to examine the stress patterns along the convolution of the pipeline expansion bellows under axial compression. A simple three-node axisymmetric shell element is used to compute axial and circumferential stress components. Three example problems which include two corrugated-pipe-type and one U-type bellows, have been analyzed. Comparison of the present numerical results with the experimentally procured data from the open literature illustrates the reliability, accuracy, elaborateness and versatility of this approach.

Quantitative mechanical analysis of indentations on layered, soft elastic materials

Soft Matter ◽  
2019 ◽  
Vol 15 (8) ◽  
pp. 1776-1784 ◽  
Author(s):  
Bryant L. Doss ◽  
Kiarash Rahmani Eliato ◽  
Keng-hui Lin ◽  
Robert Ros
Keyword(s):  
Atomic Force Microscopy ◽  
Elastic Modulus ◽  
Cell Mechanics ◽  
Biological Samples ◽  
Mechanical Analysis ◽  
Elastic Materials ◽  
Mechanical Heterogeneity ◽  
Popular Method ◽  
Force Microscopy ◽  
Atomic Force

Atomic force microscopy (AFM) is becoming an increasingly popular method for studying cell mechanics, however the existing analysis tools for determining the elastic modulus from indentation experiments are unable to quantitatively account for mechanical heterogeneity commonly found in biological samples.

scholarly journals Investigation of the Residual Stress State in an Epoxy Based Specimen

2015 ◽  
Vol 651-653 ◽  
pp. 375-380
Author(s):  
Ismet Baran ◽  
Johnny Jakobsen ◽  
Jens H. Andreasen ◽  
Remko Akkerman
Keyword(s):  
Elastic Modulus ◽  
Stress State ◽  
Residual Stresses ◽  
Process Model ◽  
Coefficient Of Thermal Expansion ◽  
Numerical Models ◽  
Mechanical Analysis ◽  
Biaxial Stress ◽  
Image Correlation ◽  
Drilling Process

Process induced residual stresses may play an important role under service loading conditions for fiber reinforced composite. They may initiate premature cracks and alter the internal stress level. Therefore, the developed numerical models have to be validated with the experimental observations. In the present work, the formation of the residual stresses/strains are captured from experimental measurements and numerical models. An epoxy/steel based sample configuration is considered which creates an in-plane biaxial stress state during curing of the resin. A hole drilling process with a diameter of 5 mm is subsequently applied to the specimen and the released strains after drilling are measured using the Digital Image Correlation (DIC) technique. The material characterization of the utilized epoxy material is obtained from the experimental tests such as differential scanning calorimetry (DSC) for the curing behavior, dynamic mechanical analysis (DMA) for the elastic modulus evolution during the process and a thermo-mechanical analysis (TMA) for the coefficient of thermal expansion (CTE) and curing shrinkage. A numerical process model is also developed by taking the constitutive material models, i.e. cure kinetics, elastic modulus, CTE, chemical shrinkage, etc. together with the drilling process using the finite element method. The measured and predicted in-plane residual strain states are compared for the epoxy/metal biaxial stress specimen.

Characterization of Chemically and Topographically Modified Siloxane Elastomer for Controlled Cell Growth

2001 ◽  
Vol 711 ◽  
Author(s):  
Amy L. Gibson ◽  
Leslie H. Wilson ◽  
Wade R. Wilkerson ◽  
Adam W. Feinberg ◽  
Charles A. Seegert ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Cell Growth ◽  
Surface Energy ◽  
Cellular Response ◽  
Silicone Oil ◽  
Control Cell ◽  
Weight Percent ◽  
Mechanical Analysis ◽  
Specific Cell ◽  
Silicone Oils

ABSTRACTA main limitation of biomedical devices is the inability to start, stop, and control cell growth making it crucial to develop biomaterial surfaces that induce a desired cellular response. Micropatterns of ridges and pillars were created in a siloxane elastomer (Dow Corning) by casting against epoxy replicates of a micromachined silicon wafer. Silicone oils were incorporated to determine the change in modulus and surface energy caused by these additives. SEM and white light interference profilometry verified that the micropatterning process produced high fidelity, low defect micropatterns. Mechanical analysis indicated that varying the viscosity, weight percent and functionality of the added silicone oil could change the elastic modulus by over an order of magnitude (0.1-2.3 MPa). As a self-wetting resin, silicone oils migrate to the surface, hence changing the surface properties from the bulk. Both topographical and chemical features define the surface energy, which in combination with elastic modulus, dictate biological activity. The results imply that the morphology, mechanical properties and surface energy of the siloxane elastomer can be modified to elicit a specific cell response as a function of engineered topographical and chemical functionalization.

scholarly journals Viscoelastic and poroelastic mechanical characterization of hydrated gels

2009 ◽  
Vol 24 (3) ◽  
pp. 973-979 ◽  
Author(s):  
Matteo Galli ◽  
Kerstyn S.C. Comley ◽  
Tamaryn A.V. Shean ◽  
Michelle L. Oyen
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Mechanical Characterization ◽  
Element Model ◽  
Mechanical Analysis ◽  
Intrinsic Permeability ◽  
Unconfined Compression ◽  
Future Studies ◽  
Dependent Behavior

Measurement of the mechanical behavior of hydrated gels is challenging due to a relatively small elastic modulus and dominant time-dependence compared with traditional engineering materials. Here polyacrylamide gel materials are examined using different techniques (indentation, unconfined compression, dynamic mechanical analysis) at different length-scales and considering both viscoelastic and poroelastic mechanical frameworks. Elastic modulus values were similar for nanoindentation and microindentation, but both indentation techniques overestimated elastic modulus values compared to homogeneous loading techniques. Hydraulic and intrinsic permeability values from microindentation tests, deconvoluted using a poroelastic finite element model, were consistent with literature values for gels of the same composition. Although elastic modulus values were comparable for viscoelastic and poroelastic analyses, time-dependent behavior was length-scale dependent, supporting the use of a poroelastic, instead of a viscoelastic, framework for future studies of gel mechanical behavior under indentation.

Sign in / Sign up

Export Citation Format

Share Document