The Broyden Method for M-P-Φ Relationship of Beam-Column with Residual Stresses

2013 ◽  
Vol 712-715 ◽  
pp. 1071-1074
Author(s):  
Jian Qin ◽  
Yong Jun Xia ◽  
Jin Miao Zhang
Keyword(s):  
Numerical Calculation ◽  
Residual Stresses ◽  
Nonlinear Equations ◽  
Beam Columns ◽  
Broyden Method ◽  
Iterative Calculation ◽  
Relationship Problem ◽  
Calculation Process ◽  
Relationship Of ◽  
The Relationship

The Broyden method for the numerical calculation of Moment-Thrust-Curvature (M-P-Φ) relationship of beam-column is put forward, which is suitable for all combinations of moment, thrust and curvature considering the effect of residual stresses. The relationship problem is simplified as two nonlinear equations of four variables. When two of the 4 variables are given, the relationship can be obtained by Broyden method. The advantages of Broyden method are discussed and the iterative calculation process is listed. The method offers significant improvements in accuracy, robustness and calculation amount of the solution, which can be used for beam-columns with any type section.

scholarly journals Estimation for Two-Dimensional Nonsymmetric Coherently Distributed Source in L-Shaped Arrays

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Tao Wu ◽  
Zhenghong Deng ◽  
Qingyue Gu ◽  
Jiwei Xu
Keyword(s):  
Expectation Maximization ◽  
Two Dimensional ◽  
Signal Distribution ◽  
Distributed Source ◽  
One Dimensional ◽  
Least Squares Estimators ◽  
Iterative Calculation ◽  
Symmetric Source ◽  
Relationship Of ◽  
The Relationship

We explore the estimation of a two-dimensional (2D) nonsymmetric coherently distributed (CD) source using L-shaped arrays. Compared with a symmetric source, the modeling and estimation of a nonsymmetric source are more practical. A nonsymmetric CD source is established through modeling the deterministic angular signal distribution function as a summation of Gaussian probability density functions. Parameter estimation of the nonsymmetric distributed source is proposed under an expectation maximization (EM) framework. The proposed EM iterative calculation contains three steps in each cycle. Firstly, the nominal azimuth angles and nominal elevation angles of Gaussian components in the nonsymmetric source are obtained from the relationship of rotational invariance matrices. Then, angular spreads can be solved through one-dimensional (1D) searching based on nominal angles. Finally, the powers of Gaussian components are obtained by solving least-squares estimators. Simulations are conducted to verify the effectiveness of the nonsymmetric CD model and estimation technique.

Effect of Split-Sleeve Cold Expansion on the Fatigue Life of 7050-T7451 Aluminum Alloy

2014 ◽  
Vol 1082 ◽  
pp. 403-407 ◽  
Author(s):  
Hong Huang ◽  
Qing Yun Zhao ◽  
Feng Lei Liu
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Transgranular Fracture ◽  
Alloy Plate ◽  
Cold Expansion ◽  
Compressive Stresses ◽  
Aluminum Alloy Plate ◽  
Relationship Of ◽  
The Relationship

Split-sleeve cold expansion processing was employed on the 7050-T7451 aluminum alloy plate. Fatigue lives were compared according different expansion, then the relationship of fatigue life and expansion was analyzed. Residual stresses were measured with different expansion, and the fatigue fractograph was analyzed by SEM. The results show that the split-sleeve cold expansion can obtain longer life compared with the non-strengthen hole. When over the optimum expansion, fatigue life began to decrease. The maximum fatigue life increased to 2.92 times with 4.1% expansion. The maximum values of radial residual stresses grew with expansion. The depths of residual compressive stresses were more than 6mm with 2.6% and 4.1% expansion. The fatigue fractograph shows mixed transgranular fracture.

scholarly journals Underwater multi-sensor Bayesian distributed detection and data fusion

2019 ◽  
Vol 283 ◽  
pp. 07014
Author(s):  
Cheng Li ◽  
Guangping Zhu
Keyword(s):  
Data Fusion ◽  
Signal Detection ◽  
Nonlinear Equations ◽  
Numerical Solutions ◽  
Parallel Architecture ◽  
Distributed Detection ◽  
Detection Model ◽  
Topological Network ◽  
Relationship Of ◽  
The Relationship

The relationship of decision rule of sensor for each other is relevant to data fusion, so different topological network of sensors usually results in different performance. This paper considers the parallel and sequential topological data fusion in some detail and applies it to detect underwater signal with three sensors which respectively detects the energy, impulse width and frequency. In this paper, the signal detection model is specified for binary hypotheses testing problem. This paper compares the probabilities of error and Bayesian risk under both topologies corresponding to different value of priori probabilities of two hypotheses. Usually, the parallel architecture of detection and fusion with three sensors as specified in this paper needs to solve eleven nonlinear equations to determine the thresholds of three sensors and fusion rules, as to sequential architecture, five nonlinear equations need to be solved. So, this paper attempts to search numerical solutions for the parallel and sequential architecture of distributed detection and data fusion. Finally, this signal detection problem is simulated.

Statistical appendix

1962 ◽  
Vol 59 (1) ◽  
pp. 63-66 ◽  
Author(s):  
R. C. Campbell
Keyword(s):  
Least Squares ◽  
Unit Area ◽  
Crop Plants ◽  
Iterative Calculation ◽  
Least Squares Fit ◽  
Image Position ◽  
Relationship Of ◽  
The Relationship

Bleasdale & Nelder (1960) refer to several models which have been used in studying the relationship of yield and density in crop plants and indicate that they regard as most satisfactory the equation:where ω = yield/plant, ρ = number of plants/unit area and A and B are constants. The estimation of the constants for any given case is a very unattractive arithmetic exercise requiring a fairly large number of observations and a tedious iterative calculation; Nelder (1961) has discussed the least squares fit with the equation in the formwhich may readily be derived from (1) by the substitutionsThe data in the present case do not justify attempting this process but some progress can be made by the substitutionsby means of which it is easy to derive from (1) that

Research on Aerodynamic Characteristics of Morphing Aircraft with a Telescopic Wing

2013 ◽  
Vol 709 ◽  
pp. 257-261
Author(s):  
Xi You Zhao ◽  
Jun Hu
Keyword(s):  
Numerical Calculation ◽  
High Speed ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Aerodynamic Coefficient ◽  
Morphing Aircraft ◽  
Task Requirements ◽  
Before And After ◽  
Relationship Of ◽  
The Relationship

A kind of morphing aircraft based on the concept of telescopic wing was designed in this paper. With the numerical calculation, it compared the aerodynamic characteristics before and after the morphing of the aircraft, and analyzed the relationship of the aircraft aerodynamic coefficient to its length, angle of attack and flight Mach number. The result showed that through morphing the movable wing, the aircraft can significantly change the lift, drag and other aerodynamic characteristics; the morphing aircraft can satisfy the dual task requirements of low-speed cruise and high-speed attack. Compared with the traditional aircraft in fixed shape, it had a better aerodynamic performance.

The Relationship of Symmetric Modification Parameters and Contact Line of Worm Gear

2011 ◽  
Vol 121-126 ◽  
pp. 1717-1721
Author(s):  
Xiao Lin Wang ◽  
Xiao Ru Hao ◽  
Xiao Sheng Zhang
Keyword(s):  
Numerical Calculation ◽  
Contact Line ◽  
Accurate Method ◽  
Worm Gear ◽  
Line Equation ◽  
Meshing Equation ◽  
Relationship Of ◽  
The Relationship

By a reasonable transition of the meshing equation and the contact line equation based on the principle of spatial meshing, using matlab numerical calculation and graphical function to draw a diagram of modification parameters and contact line of worm gear. Proposing a fast and accurate method for distinguishing the type of contact line. For further analysis of worm gear meshing performance provided a useful value.

scholarly journals Icing Degree Characterization of Insulators Based on the Equivalent Collision Coefficient of Standard Rotating Conductors

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3326
Author(s):  
Zhijin Zhang ◽  
Yi Zhang ◽  
Xingliang Jiang ◽  
Jianlin Hu ◽  
Qin Hu
Keyword(s):  
Numerical Calculation ◽  
Complex Structure ◽  
Calculation Model ◽  
Ice Thickness ◽  
Test Results ◽  
Water Droplets ◽  
Relationship Of ◽  
The Relationship

Due to the complex structure of insulators, it is difficult to use parameters such as icicle length or ice thickness of an insulator to directly characterize the degree of icing of an insulator. Rotating conductors are widely used in monitoring icing degree on insulators, but the relationship between ice degree on the insulator and the rotating conductor has not been verified. In this paper, the water droplets collision coefficient α1 was put forward to characterize icing degree, and a new numerical calculation model where α1 on different regions of an insulator is calculated was proposed. Combining the freezing fraction α3 of the insulator and rotating conductor, the equivalent relationship of ice weight between insulator and rotating conductor can be established, which was afterwards verified through the icing tests. The test results indicate that ice weight on an insulator increases linearly with the increase of ice weight on the rotating conductor, and the model proposed in this paper can reflect actual results more accurately than previous models. In such cases, the method of using ice weight on a rotating conductor to predict that on an insulator based on the model proposed in this paper could be widely adopted.

Study on Binary-Medium Model of Fissured Loess

2012 ◽  
Vol 256-259 ◽  
pp. 240-244 ◽  
Author(s):  
Fu Rong Yan ◽  
Wen Fan ◽  
Ting Yin He
Keyword(s):  
Composite Material ◽  
Comparative Analysis ◽  
Numerical Calculation ◽  
Triaxial Test ◽  
Theoretical Framework ◽  
Stress Strain ◽  
Medium Model ◽  
Relationship Of ◽  
The Relationship ◽  
Breakage Mechanics

On the basis of the theoretical framework of breakage mechanics for geo-material ,the fissured loess can be regarded as a composite material consisting of bonded blocks and weakened bands，therefore a fissured loess binary-medium model is formulated. Then the model will be applied to the study of fissured loess. By the numerical calculation, the relationship of stress-strain can be obtained. A comparative analysis between calculation and triaxial test has been done. The results show that there is a good adaptability to apply the binary medium model to fissured loess.

The In-Plane Ultimate Load of I-section Beam-Columns with Slender Web

1997 ◽  
Vol 1 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Qian Gu ◽  
Shaofan Chen
Keyword(s):  
Residual Stresses ◽  
Analytical Method ◽  
Ultimate Load ◽  
Local Buckling ◽  
Test Results ◽  
Buckling Strength ◽  
Beam Columns ◽  
Plate Girders ◽  
Design Formula ◽  
Relationship Of

Similar to plate girders with slender web, a welded I-section beam-column does not fail when its web buckles. To take advantage of this post-local-buckling strength, this paper at first presents a method for calculating the M-P-φ relationship of I-sections with buckled web and residual stresses. The in-plane ultimate load of beam-columns with slender web can then be calculated by using this M-P-φ relationship. Nine eccentrically loaded specimens were tested to failure. The agreement between the calculated and test results confirms the validity of the analytical method. Furthermore, a simplified design formula is presented for predicting the in-plane capacity of beam-columns with slender web.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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