scholarly journals STUDY ON ONE-DIMENSIONAL CONSOLIDATION OF SATURATED CLAY BASED ON THE RELATIONSHIP BETWEEN EFFECTIVE STRESS RELAXATION AND CREEP STRAIN

Author(s):  
Jonghwa BAEK ◽  
Hiroshi MATSUDA ◽  
Ryohei ISHIKURA ◽  
Wonjin BAEK ◽  
Kazumasa YAMADA
2013 ◽  
Vol 401-403 ◽  
pp. 920-923 ◽  
Author(s):  
Jin Quan Guo ◽  
Hui Chao Shi ◽  
Wu Zhou Meng

An estimation method to predict creep performances of high temperature structural materials has been proposed. The method is to use a simplified and normalized model of stress relaxation to derive creep strain rates and creep strain vs. time curves from stress relaxation measurements through an integrated analytical procedure according to the relationship between stress relaxation and creep. In order to validate the approach, the predicted results are compared to the experimental results of uni-axial isothermal creep tests conducted on 1Cr10NiMoW2VNbN steel with the same temperature of stress relaxation tests. Good agreement between results of relaxation tests and the predicted results indicates that the developed method can be recommended in the creep behavior evaluation of high temperature materials.


Author(s):  
Isaac Land

This chapter is central to the volume’s chronological contentions, as its argument accounts for the specialized, one-dimensional Dibdin of ‘Tom Bowling’ that has endured into recent scholarship. Focusing on Dibdin’s posthumous reception, it examines the moral and rhetorical difficulties of repackaging Dibdin’s works for a Victorian sensibility; it explores the specifics of mid-century concert culture previously highlighted by Derek Scott and William Weber as central to changes in nineteenth-century taste and programming; and it develops the theme of nostalgia into a revelatory consideration of the relationship between new naval technologies, national pride, and military training, and the songs, people, and language of a remembered Napoleonic ‘golden age’—to which Dibdin proves to have been as central, in the Victorian imagination, as Nelson.


1998 ◽  
Vol 25 (1) ◽  
pp. 81-86 ◽  
Author(s):  
N Hearn ◽  
J Aiello

Experimental work on prismatic concrete specimens was conducted to determine the relationship between mechanical restraint and the rate of corrosion. The current together with the changes in strain of the confining frame were monitored during the accelerated corrosion tests. The effect of mix design and cracking on the corrosion rates was also investigated. The results show that one-dimensional mechanical restraint retards the corrosion process, as indicated by the reduction in the steel loss. Improved quality of the matrix, with and without cracking, reduces the rate of steel loss. In the inferior quality concrete, the effect of cracking on the corrosion rate is minimal.Key words: corrosion, concrete, repair.


2021 ◽  
Vol 11 (5) ◽  
pp. 1980
Author(s):  
Kazimierz Józefiak ◽  
Artur Zbiciak ◽  
Karol Brzeziński ◽  
Maciej Maślakowski

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil.


2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Tao Wu ◽  
Zhenghong Deng ◽  
Qingyue Gu ◽  
Jiwei Xu

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.


1998 ◽  
Vol 2 (2/3) ◽  
pp. 159-171 ◽  
Author(s):  
H. Kooi ◽  
J. J. de Vries

Abstract. A one-dimensional model is used to investigate the relationship between land subsidence and compaction of basin sediments in response to sediment loading. Analysis of the model equations and numerical experiments demonstrate quasi-linear systems behaviour and show that rates of land subsidence due to compaction: (i) can attain a significant fraction (>40%) of the long-term sedimentation rate; (ii) are hydrodynamically delayed with respect to sediment loading. The delay is controlled by a compaction response time τc that can reach values of 10-5-107 yr for thick shale sequences. Both the behaviour of single sediment layers and multiple-layer systems are analysed. Subsequently the model is applied to the coastal area of the Netherlands to illustrate that lateral variability in compaction-derived land subsidence in sedimentary basins largely reflects the spatial variability in both sediment loading and compaction response time. Typical rates of compaction-derived subsidence predicted by the model are of the order of 0.1 mm/yr but may reach values in excess of 1 mm/yr under favourable conditions.


2021 ◽  
Vol 18 (6) ◽  
pp. 7648-7665
Author(s):  
Jiaqi Liu ◽  
◽  
Zhenyin Fu ◽  
Yinglan Gong ◽  
Ling Xia

<abstract> <sec><title>Background</title><p>The utility of T wave alternans (TWA) in identifying arrhythmia risk has been demonstrated. During myocardial ischemia (MI), TWA could be induced by cellular alternans. However, the relationship between cellular alternans patterns and TWA patterns in MI has not been investigated thoroughly.</p> </sec> <sec><title>Methods</title><p>We set MI conditions to simulate alternans. Either prolonging Ca<sup>2+</sup> release or increasing spark-induced sparks (secondary sparks) can give rise to different patterns of APD alternans and TWA. In addition, different ischemic zones and reduced conduction velocity are also considered in one dimensional simulation.</p> </sec> <sec><title>Results</title><p>Delay of Ca<sup>2+</sup> release can produce discordant Ca<sup>2+</sup>-driven alternans in single cell simulation. Increasing secondary sparks leads to concordant alternans. Correspondingly, morphology and magnitude of TWA vary in two different cellular alternans. Epi ischemia results in alternans concentrating in the first half of T wave. Endo and transmural ischemia lead to fluctuations in the second half of T wave. In addition, slowing conduction velocity has no effect on TWA magnitude.</p> </sec> <sec><title>Conclusion</title><p>Specific ionic channel dysfunction and ischemic zones affect TWA patterns.</p> </sec> </abstract>


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