Modeling of 316 Stainless Steel (17.12 Sph.) Mechanical Properties Using Biaxial Experiments—Part I: Experiments and Basis of the Model

1987 ◽  
Vol 109 (4) ◽  
pp. 449-454 ◽  
Author(s):  
P. Delobelle ◽  
C. Oytana

Experimental results aimed at establishing the relationship existing between plastic instantaneous and creep strains are reported. They are chiefly tensile at constant strain rates and tensile or tensile-torsion creep experiments. Recovery and hardening are also measured. It is shown that two types of viscous behavior may occur according to whether the loading path is an active loading or an unloading. The features of these two types of viscoplastic behavior are such that they can be modeled with the same plastic state equation using a single internal variable. But according to a criterion based on internal variables, the single internal variable of the plastic state equation may split into the sum of an isotropic and a kinematical variable with small strain hardening (case of large viscoplastic strains) or remain a single kinematical variable with very high hardening (case of unloadings). The bases of the model are described.

1987 ◽  
Vol 109 (4) ◽  
pp. 455-459 ◽  
Author(s):  
P. Delobelle ◽  
C. Oytana

A rheological model aimed at accounting for the existence of two types of viscoplastic flow (microplastic and macroplastic) in 316 stainless steel is described in the most general state of stress. A distribution between active loadings (macroplastic strains) and unloadings (and/or loadings in a microplastic domain) made through a criterion essentially based on internal variables. A single internal variable is introduced in a single plastic state equation, the different behaviors being accounted for by the choice of the internal variable and of its hardening rules. Identification of these hardening laws are reported. It is seen that this model can predict a lot of various experimental observations in tensile, tensile-compression or tensile-compression-torsion tests. Numerical simulations of various tests extending from the tensile one to complex stress or strain paths in biaxial proportional loading are in a good quantitative agreement with the experimental results.


2019 ◽  
Vol 3 (2) ◽  
pp. 117-137
Author(s):  
Mustaqim Makki

Zakat merupakan salah satu sendi pokok ajaran Islam. Urgensi zakat yang merupakan anjuran agama Islam untuk menunaikan zakat dan memberikannya kepada yang berhak dengan ketentuan mencapai nishabnya, (kadar minimum harta tertentu) mempunyai nilai sangat signifikan dalam kehidupan manusia. Seorang insan yang sarat akan segala permasalahan pada fitrahnya menuntut untuk selalu berinteraksi kepada sesama, baik berupa materi maupun non materi. Zakat merupakan maliyah ijtima’iyyah yang mengandung nilai-nilai filantropi yang sangat tinggi, karena ketika mengaplikasikan kewajiban zakat kita telah membantu sesama serta mengurangi kesenjangan yang disebabkan beberapa sifat manusia diantaranya adalah sifat kikir, dengki dan iri hati. Menguatnya kembali harapan banyak kalangan terhadap implementasi filantropi Islam, baik dalam bentuk zakat, infak, sedekah, dan wakaf, memiliki keterkaitan erat dengan kondisi bangsa yang belum sepenuhnya bangkit dari keterpurukan sebagai dampak dari krisis ekonomi yang berkepanjangan. Kondisi ini berakibat kesenjangan penguasaan perekonomian antar warga negara menjadi kian lebar. Pada saat itulah, ziswaf (zakat, infak, sedekah, dan wakaf) kembali dilirik dan diharapkan menjadi alternatif solusi terhadap problem kemiskinan umat. Manusia sebagai khalifah fil ardh dalam Al Qurán menekankan muatan fungsional yang harus diemban oleh manusia dalam melaksanakan tugas-tugas kesejarahan dalam kehidupannya di muka bumi. Kaitan dengan konsep tersebut, ada dua fungsi manusia. Pertama: Manusia sebagai hamba (ábid), dituntut untuk sukses menjalin hubungan secara vertikal dalam hal ini hubungannya dengan ketuhanan (Teologis). Kedua adalah manusia sebagai khalifah, dituntut untuk sukses menjalin hubungan secara horizontal dalam hal ini hubungan terhadap manusia.Kata kunci: tafsir ayat zakat, filantropi, ekonomi keummatanAbstract:Zakat is one of the main points of Islamic teachings. The urgency of zakat which is suggested by Islam to fulfill and give it to those who are referred to with the provisions to reach their nishab, (minimum level of certain assets) has a very significant value in human life. A person who is full of all problems in his/her natural demands will always get interaction with other people, either material or non-material. Zakat is maliyah ijtima’iyyah which contains very high philanthropic values, because when applying the obligation of zakat we have helped others and reduced the gaps caused by some human traits including miser, jealousy and envy. The reinforcement of the expectations (estimation) from any levels on the implementation of Islamic philanthropy, which in the form of zakat, donation, alms and endowments, has a close relationship with the condition of the country that has not fully risen from bad economic adversity due to economic crisis. This condition causes a widening of the economic mastery among the citizens. At that moment, ziswaf (zakat, infaq, alms, and waqf) was again given a serious attentition and expected to be an alternative solution to the problem of poverty among citizens. Humans as khalifah fil ardh in the Qur'an emphasize the functional content that must be carried by humans in carrying out historical tasks in their lives on earth. In accordance with this concept, there are two human functions. First: Humans as servants (ábid), are required to succeed in establishing a vertical relationship in this case the relationship with God (Theological). Second, humans as caliphs, are required to succeed in establishing horizontal relationships in this case the relationship to humans.


Author(s):  
Evi Rosita ◽  
Siti Nurnaningrum

There are about 2.8 million incident of perineal rupture in maternal physiological labor. In 2050,it is estimated that the incidence of perineal rupture can be 6.3 million if it is not accompanied by a good midwifery care. In 2016, in Trawas, there was (89%) perineal rupture in primiparas and (57%) perineal rupture in multiparas. Perineal rupture incidences due to parity were still very high. This study aims to analyze the relationship between parity and the incidence of perineal rupture . It is quantitative studyusing a cross sectional approach, by using analysis of physiological maternity women  medical record data from January to April 2017 of 130 peoplein Trawas Public Health Center, Mojokerto Regency.The dataanalysis used was Chi - Square , indicated by p value = 0,000 with ɑ = 0,05. It means that the value of p <ɑ, so H1 is accepted. It can be concluded that there is a relationship between parity and the incidence of perineal rupture on physiological maternity women in Trawas Public Health Center,Mojokerto Regency. Midwives can apply collaboration with patients and their families to have physical and psychologicalpreparation with an alternative of hypnobirthing methods.


2020 ◽  
Vol 48 (3) ◽  
pp. 1-11
Author(s):  
Qiyi Lin ◽  
Nan Zhou ◽  
Hong Fu

We investigated the prevalence of Chinese children's imaginary companions (ICs) and the internal variables of IC types (personified object or invisible friend) and child–IC relationship qualities (egalitarian or hierarchical child–IC relationship). Participants were 266 children aged 4 to 6 years. Only in the 5-year-old group was the proportion of children with ICs significantly higher among girls than among boys, implying that the relationship between gender and IC was not consistent across age groups. Children from families in the highest annual income group engaged in more IC play than did children from families in the lowest annual income group, indicating a relationship between family socioeconomic environment and children's imaginary play. IC types were not associated with child–IC relationship qualities in any of the age groups, implying that these qualities may represent different dimensions of IC play as early as 4 years old.


2021 ◽  
Vol 11 (12) ◽  
pp. 5509
Author(s):  
Hongjin Choi ◽  
Seonghwan Choi ◽  
Soo-Chang Kang ◽  
Myoung-Gyu Lee

A fully implicit stress integration algorithm is developed for the distortional hardening model, namely the e−HAH model, capable of simulating cross−hardening/softening under orthogonal loading path changes. The implicit algorithm solves a complete set of residuals as nonlinear functions of stress, a microstructure deviator, and plastic state variables of the constitutive model, and provides a consistent tangent modulus. The number of residuals is set to be 20 or 14 for the continuum or shell elements, respectively. Comprehensive comparison programs are presented regarding the predictive accuracy and stability with different numerical algorithms, strain increments, material properties, and loading conditions. The flow stress and r−value evolutions under reverse/cross−loading conditions prove that the algorithm is robust and accurate, even with large strain increments. By contrast, the cutting−plane method and partially implicit Euler backward method, which are characterized by a reduced number of residuals, result in unstable responses under abrupt loading path changes. Finally, the algorithm is implemented into the finite element modeling of large−size, S−rail forming and the springback for two automotive steel sheets, which is often solved by a hybrid dynamic explicit–implicit scheme. The fully implicit algorithm performs well for the whole simulation with the solely static implicit scheme.


2020 ◽  
Vol 45 (3) ◽  
pp. 311-318
Author(s):  
Qiang Yang ◽  
Zhuofu Tao ◽  
Yaoru Liu

AbstractIn the kinetic rate laws of internal variables, it is usually assumed that the rates of internal variables depend on the conjugate forces of the internal variables and the state variables. The dependence on the conjugate force has been fully addressed around flow potential functions. The kinetic rate laws can be formulated with two potential functions, the free energy function and the flow potential function. The dependence on the state variables has not been well addressed. Motivated by the previous study on the asymptotic stability of the internal variable theory by J. R. Rice, the thermodynamic significance of the dependence on the state variables is addressed in this paper. It is shown in this paper that the kinetic rate laws can be formulated by one extended potential function defined in an extended state space if the rates of internal variables do not depend explicitly on the internal variables. The extended state space is spanned by the state variables and the rate of internal variables. Furthermore, if the rates of internal variables do not depend explicitly on state variables, an extended Gibbs equation can be established based on the extended potential function, from which all constitutive equations can be recovered. This work may be considered as a certain Lagrangian formulation of the internal variable theory.


1969 ◽  
Vol 28 (3) ◽  
pp. 715-720 ◽  
Author(s):  
Clyde Hendrick

Symmetry of the trait inference process was studied by having Ss rate how much trait X implied trait Y and how much trait Y implied trait X for each of 36 pairs of traits. Desirability of the traits ranged from very high to very low. The relationship between traits within a pair was varied from consistent to highly inconsistent. Differences between the implication ratings for the two orders of presentation revealed that a definite asymmetry in the strength of the inference existed. The direction of the asymmetry varied as a function of the degree of inconsistency between traits within pairs. The results were discussed in terms of a differential discounting process.


Author(s):  
Виктор Сергеевич Суров

Описан многомерный узловой метод характеристик, предназначенный для численного расчета упругопластической деформации твердого тела в рамках модели Прандтля-Рейса с уравнением состояния небаротропного типа. В качестве критерия перехода из упругого в пластическое состояние применялось условие текучести Мизеса. Рассмотренный численный метод базируется на координатном расщеплении исходной системы уравнений на ряд одномерных подсистем с последующим их интегрированием с помощью одномерного узлового метода характеристик. Метод использован для расчета ряда одно- и двумерных модельных задач A multidimensional nodal method of characteristics is described. The method is designed to numerically calculate the elastoplastic deformation of a solid body within the Prandtl-Reis model with the non-barotropic state equation. The Mises flow condition was used as a criterion for the transition from an elastic to a plastic state. The considered numerical method is based on the coordinate splitting of the original system of equations into a number of one-dimensional subsystems. Then the resulting equations were integrated using a one-dimensional nodal method of characteristics. The proposed method allows calculating a number of one- and two-dimensional model problems. The results of calculations that employ the multidimensional node method of characteristics were compared with data calculated using the Godunov hybrid method in the framework of a model that did not take into account the contribution of potential elastic compression energy to the total energy of the medium. There are some discrepancies in the calculation results that occur at high speeds of interaction of the aluminum striker with the barrier, exceeding 500 m/s, which are associated with omission of the potential energy due to the elastic compression of the solid within the original Prandtl-Reis model


2011 ◽  
Vol 71 (1 suppl 1) ◽  
pp. 241-253 ◽  
Author(s):  
HC Gonçalves ◽  
MA Mercante ◽  
ET Santos

The Pantanal hydrological cycle holds an important meaning in the Alto Paraguay Basin, comprising two areas with considerably diverse conditions regarding natural and water resources: the Plateau and the Plains. From the perspective of the ecosystem function, the hydrological flow in the relationship between plateau and plains is important for the creation of reproductive and feeding niches for the regional biodiversity. In general, river declivity in the plateau is 0.6 m/km while declivity on the plains varies from 0.1 to 0.3 m/km. The environment in the plains is characteristically seasonal and is home to an exuberant and abundant diversity of species, including some animals threatened with extinction. When the flat surface meets the plains there is a diminished water flow on the riverbeds and, during the rainy season the rivers overflow their banks, flooding the lowlands. Average annual precipitation in the Basin is 1,396 mm, ranging from 800 mm to 1,600 mm, and the heaviest rainfall occurs in the plateau region. The low drainage capacity of the rivers and lakes that shape the Pantanal, coupled with the climate in the region, produce very high evaporation: approximately 60% of all the waters coming from the plateau are lost through evaporation. The Alto Paraguay Basin, including the Pantanal, while boasting an abundant availability of water resources, also has some spots with water scarcity in some sub-basins, at different times of the year. Climate conditions alone are not enough to explain the differences observed in the Paraguay River regime and some of its tributaries. The complexity of the hydrologic regime of the Paraguay River is due to the low declivity of the lands that comprise the Mato Grosso plains and plateau (50 to 30 cm/km from east to west and 3 to 1.5 cm/km from north to south) as well as the area's dimension, which remains periodically flooded with a large volume of water.


Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 873-880
Author(s):  
Marzieh Mokarram ◽  
Dinesh Sathyamoorthy

Abstract. Soil genesis is highly dependent on landforms as they control the erosional processes and the soil physical and chemical properties. The relationship between landform classification and electrical conductivity (EC) of soil and water in the northern part of Meharloo watershed, Fars province, Iran, was investigated using a combination of a geographical information system (GIS) and a fuzzy model. The results of the fuzzy method for water EC showed 36.6 % of the land to be moderately land suitable for agriculture; high, 31.69 %; and very high, 31.65 %. In comparison, the results of the fuzzy method for soil EC showed 24.31 % of the land to be as not suitable for agriculture (low class); moderate, 11.78 %; high, 25.74 %; and very high, 38.16 %. In total, the land suitable for agriculture with low EC is located in the north and northeast of the study area. The relationship between landform and EC shows that EC of water is high for the valley classes, while the EC of soil is high in the upland drainage class. In addition, the lowest EC levels for soil and water are in the plains class.


Sign in / Sign up

Export Citation Format

Share Document