A macroscopic strain-space model of anisotropic, cyclic plasticity with hardening

2018 ◽  
Vol 149 ◽  
pp. 365-372 ◽  
Author(s):  
Harshad M. Paranjape ◽  
Aaron P. Stebner ◽  
Kaushik Bhattacharya
Keyword(s):  
Cyclic Plasticity ◽  
Macroscopic Strain ◽  
Space Model ◽  
Strain Space

Endochronic Theory of Cyclic Plasticity With Applications

1984 ◽  
Vol 51 (2) ◽  
pp. 367-374 ◽  
Author(s):  
K. C. Valanis ◽  
C. F. Lee
Keyword(s):  
Plastic Strain ◽  
Mild Steel ◽  
Strain Amplitude ◽  
Cyclic Plasticity ◽  
Strain History ◽  
Endochronic Theory ◽  
Theoretical Predictions ◽  
Cyclic Relaxation ◽  
Strain Stress ◽  
Strain Space

Integral constitutive equations of the endochronic type with only two easily determined material constants are shown to predict with computational ease the stress (plastic strain) response of normalized mild steel and Grade 60 steel to a variety of general strain (stress) histories, without a need for special unloading-reloading or memory rules. These equations are derived from the endochronic theory of plasticity of isotropic materials with an intrinsic time scale defined in the plastic strain space. Close agreement between theoretical predictions and experiments is obtained in the case of normalized mild steel in a variety of uniaxial, constant, strain-amplitude histories, variable strain-amplitude histories, and cyclic relaxation. Similar results are shown in the case of Grade 60 steel subjected to a random uniaxial strain history.

Strain Space Formulation of the Armstrong-Frederick Family of Plasticity Models

1998 ◽  
Vol 120 (3) ◽  
pp. 230-235 ◽  
Author(s):  
Haiyang Wang ◽  
M. E. Barkey
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Development ◽  
Cyclic Plasticity ◽  
Numerical Implementation ◽  
Element Analysis ◽  
Surface Theory ◽  
Space Formulation ◽  
Strain Space

Strain space based plasticity models have certain advantages in theoretical development and numerical implementation. Previous efforts have been made to formulate cyclic plasticity models in strain space using the idea of multiple-yield surface theory. Recently, however, Armstrong-Frederick type plasticity models have received increasingly more attention because of their enhanced performance in predicting ratchetting behavior. In this paper, the strain space formulation of the Armstrong-Frederick family of cyclic plasticity models is established, and several representative strain controlled loading paths are used to compare the results from the proposed formulation and previous experimental data. The excellent agreement suggests the proposed strain space formulation is very promising in strain controlled cyclic plasticity such as finite element analysis, strain gage rosette applications, and multiaxial notch analysis using pseudo-stress or pseudo-strain approaches.

Positional Estimation Within a Latent Space Model for Networks

Methodology ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Susan Shortreed ◽  
Mark S. Handcock ◽  
Peter Hoff
Keyword(s):  
Random Effects ◽  
Network Data ◽  
Random Effects Models ◽  
Space Model ◽  
Network Analyses ◽  
Recent Advances ◽  
Latent Space ◽  
Latent Space Model ◽  
Modeling Data

Recent advances in latent space and related random effects models hold much promise for representing network data. The inherent dependency between ties in a network makes modeling data of this type difficult. In this article we consider a recently developed latent space model that is particularly appropriate for the visualization of networks. We suggest a new estimator of the latent positions and perform two network analyses, comparing four alternative estimators. We demonstrate a method of checking the validity of the positional estimates. These estimators are implemented via a package in the freeware statistical language R. The package allows researchers to efficiently fit the latent space model to data and to visualize the results.

Comparative study of the effective parameters on residual stress relaxation in welded aluminum plates under cyclic loading

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Relaxation ◽  
Stress Amplitude ◽  
Cyclic Plasticity ◽  
Mean Stress ◽  
Effective Parameters ◽  
Perfect Plasticity ◽  
Residual Stress Relaxation ◽  
Aluminum Plates

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.

Information space model in tasks of distributed mobile objects managing

2019 ◽  
Vol 2019 (47) ◽  
pp. 80-86
Author(s):  
V.O. Filatov ◽  
◽  
A.L. Yerokhin ◽  
O.V. Zolotukhin ◽  
M.S. Kudryavtseva ◽  
...  
Keyword(s):  
Information Space ◽  
Space Model ◽  
Mobile Objects

Pencarian File Gambar Berdasarkan Dominasi Warna

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Vina Chovan Epifania ◽  
Eko Sediyono
Keyword(s):  
Digital Image ◽  
Retrieval System ◽  
Color Image ◽  
Color Space ◽  
Image Data ◽  
Image Search ◽  
Test Results ◽  
Application Form ◽  
Space Model ◽  
Image File

Abstract. Image File Searching Based on Color Domination. One characteristic of an image that can be used in image searching process is the composition of the colors. Color is a trait that is easily seen by man in the picture. The use of color as a searching parameter can provide a solution in an easier searching for images stored in computer memory. Color images have RGB values that can be computed and converted into HSL color space model. Use of HSL images model is very easy because it can be calculated using a percent, so that in each pixel of the image can be grouped and named, this can give a dominant values of the colors contained in one image. By obtaining these values, the image search can be done quickly just by using these values to a retrieval system image file. This article discusses the use of the HSL color space model to facilitate the searching for a digital image in the digital image data warehouse. From the test results of the application form, a searching is faster by using the colors specified by the user. Obstacles encountered were still searching with a choice of 15 basic colors available, with a limit of 33% dominance of the color image search was not found. This is due to the dominant color in each image has the most dominant value below 33%.   Keywords: RGB, HSL, image searching Abstrak. Salah satu ciri gambar yang dapat dipergunakan dalam proses pencarian gambar adalah komposisi warna. Warna adalah ciri yang mudah dilihat oleh manusia dalam citra gambar. Penggunaan warna sebagai parameter pencarian dapat memberikan solusi dalam memudahkan pencarian gambar yang tersimpan dalam memori komputer. Warna gambar memiliki nilai RGB yang dapat dihitung dan dikonversi ke dalam model HSL color space. Penggunaan model gambar HSL sangat mudah karena dapat dihitung dengan menggunakan persen, sehingga dalam setiap piksel gambar dapat dikelompokan dan diberi nama, hal ini dapat memberikan suatu nilai dominan dari warna yang terdapat dalam satu gambar. Dengan diperolehnya nilai tersebut, pencarian gambar dapat dilakukan dengan cepat hanya dengan menggunakan nilai tersebut pada sistem pencarian file gambar. Artikel ini membahas tentang penggunaan model HSL color space untuk mempermudah pencarian suatu gambar digital didalam gudang data gambar digital. Dari hasil uji aplikasi yang sudah dibuat, diperoleh pencarian yang lebih cepat dengan menggunakan pilihan warna yang ditentukan sendiri oleh pengguna. Kendala yang masih dijumpai adalah pencarian dengan pilihan 15 warna dasar yang tersedia, dengan batas dominasi warna 33% tidak ditemukan gambar yang dicari. Hal ini disebabkan warna dominan disetiap gambar kebanyakan memiliki nilai dominan di bawah 33%. Kata Kunci: RGB, HSL, pencarian gambar

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