A Useful Curve Fitting Method for Concrete Uniaxial Compressive Experiment Data

2011 ◽  
Vol 291-294 ◽  
pp. 1015-1020 ◽  
Author(s):  
Chong Jin ◽  
Hong Wang ◽  
Xiao Zhou Xia
Keyword(s):  
Experimental Data ◽  
Orthogonal Polynomial ◽  
Least Square ◽  
Base Function ◽  
Concrete Material ◽  
Fitting Method ◽  
Orthogonal Base ◽  
The Matrix ◽  
Uniform Function ◽  
Curve Fitting Method

Based on the superiority avoiding the matrix equation to be morbid for those fitting functions constructed by orthogonal base, the Legendre orthogonal polynomial is adopted to fit the experimental data of concrete uniaxial compression stress-strain curves under the frame of least-square. With the help of FORTRAN programming, 3 series of experimental data is fitted. And the fitting effect is very satisfactory when the item number of orthogonal base is not less than 5. What’s more, compared with those piecewise fitting functions, the Legendre orthogonal polynomial fitting function obtained can be introduced into the nonlinear harden-soften character of concrete constitute law more convenient because of its uniform function form and continuous derived feature. And the fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material.

Study on Useful Concrete Elastic-Plastic Constitutive Model

2011 ◽  
Vol 117-119 ◽  
pp. 351-355
Author(s):  
Hong Wang ◽  
Chong Jin ◽  
Hong Yuan ◽  
Xiao Zhou Xia
Keyword(s):  
Orthogonal Polynomial ◽  
Least Square Method ◽  
Least Square ◽  
Plastic Behavior ◽  
Base Function ◽  
Constitutive Function ◽  
Elastic Plastic ◽  
Uniform Function ◽  
Curve Fitting Method ◽  
Convex Deformation

In order to simulate the elastic-plastic behavior of concrete better, an effective curve fitting method is employed to find the constitutive function based on Legendre orthogonal polynomial and least square method. And a new numerical analysis program using arch-length method to deal with nonlinear problem is designed. The most important consequence is that not only the fitting function, but also its derivative function and its definite integral are recursive. The fitting curve given by new method is applied in numerical analyzing. Cube model is examined under uniaxial compressing with completely restricted boundary conditions. The results show convex deformation and the damage on oblique section clearly. Compared with those piecewise fitting functions, the Legendre orthogonal polynomial fitting function obtained can be introduced into the nonlinear harden-soften character of concrete constitute law more convenient because of its uniform function form and continuous derived feature. And the fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material.

Numerical Analysis on Concrete Elastic-Plastic Constitutive under Different Restraints

2011 ◽  
Vol 374-377 ◽  
pp. 2442-2445
Author(s):  
Hong Wang ◽  
Chong Jin ◽  
Hong Yuan ◽  
Xiao Zhou Xia
Keyword(s):  
Nonlinear Function ◽  
Least Square Method ◽  
Least Square ◽  
Virtual Experiment ◽  
Nonlinear Method ◽  
Base Function ◽  
Concrete Material ◽  
Oblique Section ◽  
Orthogonal Base ◽  
Convex Deformation

The fitting curve given by least square method is applied in numerical analyzing. The results from semi-unrestrained and completely restricted modeling show convex deformation and damage on oblique section clearly. Advanced virtual experiment illustrates the differences between loading with displacement and pressure, due to the phenomenon that pressing by force will cause deformation on top surface but displacing load wouldn’t. The fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material. Otherwise, the progress of solving nonlinear function is discussed for designing new numerical analyzing tool, and the frame of programming based on nonlinear method is obtained

Solubility of Sn(IV) Oxide in Dilute NaClO4 Solution at Ambient Temperature

1996 ◽  
Vol 465 ◽  
Author(s):  
Takayuki Amaya ◽  
Tamotsu Chiba ◽  
Kazunori Suzuki ◽  
Chie Oda ◽  
Hideki Yoshikawa ◽  
...  
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Ambient Temperature ◽  
Equilibrium Constants ◽  
Inert Gas ◽  
Fitting Method ◽  
Naclo4 Solution ◽  
Safety Assessments ◽  
Curve Fitting Method ◽  
Image Position

ABSTRACTThe solubility of Sn(IV) oxide was determined in a dilute NaClO4 solution with pH 2 through 12 at ambient temperature. Both oversaturation and undersaturation experiments were carried out in an inert gas glovebox where the concentration of the oxygen and carbon dioxide were less than 1 ppm. The solubility of Sn(IV) oxide was 3×10-8 mol/1 at neutral pH, and increased at pH >7.5. Equilibrium constants of soluble reactions were calculated from the experimental data, using curve fitting method.The study suggests that the solubility of Sn(IV) oxide would be higher than that provisionally used in current safety assessments of HLW disposal sites.

A curve-fitting method for experimental data

1988 ◽  
Vol 65 (4) ◽  
pp. A96
Author(s):  
Fred R. Hilgeman ◽  
Gary H. Richter
Keyword(s):  
Experimental Data ◽  
Curve Fitting ◽  
Fitting Method ◽  
Curve Fitting Method

Improved modified moving average analysis of T-wave alternans using least squares-based curve fitting method

2014 ◽  
Vol 07 (04) ◽  
pp. 1450044 ◽  
Author(s):  
Xiang-Kui Wan ◽  
Kang-Hui Yan ◽  
Ang Li ◽  
Ming-Hu Wu
Keyword(s):  
Curve Fitting ◽  
Moving Average ◽  
Least Square Method ◽  
Least Square ◽  
T Wave ◽  
Fitting Method ◽  
Average Analysis ◽  
T Wave Alternans ◽  
Improved Performance ◽  
Curve Fitting Method

T-wave alternans (TWA) in surface electrocardiograph (ECG) signal is considered a marker of abnormal ventricular function which may be associated with ventricular tachycardia. Several methods have been developed in recent years to evaluate the important feature. One such method is known as modified moving average (MMA) analysis, which performs well for different levels of TWA, but it is sensitive to the noise in T-waves. In this paper we propose an improved MMA algorithm, which adds a stage of T-wave curve fitting for the MMA method before intermediate averaging. The curve fitting is performed by means of least square method technique. Our assessment study demonstrates the improved performance.

Texture Image Segmentation Based on GLCM

2012 ◽  
Vol 220-223 ◽  
pp. 1398-1401 ◽  
Author(s):  
Min Li ◽  
Jian Jun Liao
Keyword(s):  
Image Segmentation ◽  
Curve Fitting ◽  
Gray Level ◽  
Texture Image ◽  
Object Contour ◽  
Fitting Method ◽  
Texture Image Segmentation ◽  
The Matrix ◽  
Curve Fitting Method ◽  
Occurrence Matrix

The paper proposed a method on marble texture image segmentation based on Gray Level Co-occurrence Matrix (GLCM). At first, compute the Contrast matrix on basis of GLCM. Then choose the maximum of the matrix as the threshold to segment the object. At last extract the object contour with curve fitting method. Experiment results show that the method is accuracy.

Modeling of Non-Linear Relations Among Different Design Evaluation Measures for Multi-Objective Design Optimization

2005 ◽  
Author(s):  
H. Yang ◽  
D. Xue ◽  
Y. L. Tu
Keyword(s):  
Design Optimization ◽  
Comparison Method ◽  
Least Square ◽  
Design Evaluation ◽  
Linear Relations ◽  
Evaluation Measures ◽  
Multi Objective ◽  
Fitting Method ◽  
Non Linear ◽  
Curve Fitting Method

This research introduces a new approach to model the non-linear relations among different design evaluation measures and to achieve the optimal design considering these different design evaluation measures through multi-objective optimization. In this approach, different design evaluation measures are mapped to comparable design evaluation indices. The non-linear relation between a design evaluation measure and its design evaluation index is identified based on the least-square curve-fitting method. The weighting factors for different design evaluation indices, representing the importance measures of these indices in the multi-objective design optimization, are achieved using the pair-wise comparison method. A case study example of automobile caliper disc brake design considering 4 different design evaluation measures is given to illustrate the effectiveness of the introduced approach.

A Statistical Constitutive Model of Continuous Damage for Fragile Solid Material

2012 ◽  
Vol 557-559 ◽  
pp. 2217-2220 ◽  
Author(s):  
Hua Lin Liao
Keyword(s):  
Experimental Data ◽  
Probability Distribution ◽  
Constitutive Model ◽  
Elastic Strain ◽  
Solid Material ◽  
Constructive Model ◽  
Rock Damage ◽  
Deformation Characteristics ◽  
Fitting Method ◽  
Curve Fitting Method

Based on the probability distribution theory of rock micro-unit strength and taking the Mohr-Coulomb damage criterion as the distribution variable, the theoretical equations for the evolution of damage variables and the statistical constitutive model of rock damage in triaxis test were established. The arbitrary triaxis experimental data w ere used to calculate the parameters in the model by using curve fitting method and extreme value method. The calculated results of the model agree well with the experimental data. This constructive model can reflect effectively the deformation characteristics of rocks under loads and the constructive relation between elastic strain and stress of rock damage.

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