scholarly journals DEVELOPMENT OF SOIL FORMATION CORRESPONDING TO CYCLIC STRESS – DERIVED SHEAR STRAIN FUNCTION BASED ON STRATUM INDEX FACTOR

Author(s):  
Abdull Halim Abdul
2021 ◽  
Vol 11 (20) ◽  
pp. 9458
Author(s):  
Lan Cui ◽  
Qian Sheng ◽  
Zhenzhen Niu ◽  
Liuming Chang

An experimental study aimed at providing insights into the cyclic deformation behavior of saturated marine silt under principal rotation, as induced by wave loading, is presented. Using the GDS hollow cylinder apparatus, a series of undrained tests are performed and the specimens at identical initial states are subjected to combined axial–torsional cyclic loading that imposes different levels of stress rotation. The cumulative generalized shear strain γg is used to describe the deformation of the silt under complex stress paths. The test results show that the cumulative generalized shear strain is significantly dependent on the cyclic stress ratio (CSR) and cyclic loading amplitude ratio δ. The cumulative generalized shear strain increases with the increase in CSR and decreases with the increase in δ. The development trend of γg can be well predicted through the correct Monismith model in the non-liquefaction silt, with a low error that is generally less than 10%.


2019 ◽  
Vol 92 ◽  
pp. 08007
Author(s):  
Alper Sezer ◽  
Eyyub Karakan ◽  
Nazar Tanrinian

Site response analyses and solution of dynamic soil-structure interaction problems need determination of variation of shear modulus and damping ratio with shear strain. Since many studies in literature concern evaluation of behavior of sands and silty sands, a series of cyclic triaxial tests were performed to determine the variation of shear modulus and damping ratio of a nonplastic silt with shear strain. Stress controlled cyclic triaxial tests on silt specimens of initial relative densities ranging among 30%, 50% and 70% were performed. Tests were carried out on identical samples under different CSR levels, and the confining pressure was selected as 100 kPa. Variation of shear modulus and damping ratio of silts with cyclic stress ratio amplitude, relative density and number of cycles were investigated. It was understood that soil relative density and cyclic stress ratio amplitude has a significant influence on shear modulus and damping ratio of silts. It was also observed that, as the cyclic stress ratio amplitude is increased, greater shear modulus and lower damping ratio values were obtained.


2020 ◽  
Vol 15 (55) ◽  
Author(s):  
Slimane Merdaci ◽  
Adda Hadj Mostefa ◽  
Youcef Beldjelili ◽  
Mohamed Merazi ◽  
Sabrina Boutaleb ◽  
...  

The paper examines a static bending of porous functional plates (FGP) and rectangular plate solutions, based on an underlying high-order shear deformation theory. The proposed high-order shear deformation theory, as opposed to other theories, includes four unknowns. For this reason, a new shear strain function is considered. The technique of Navier is used in closed-form FGP solutions. Results of deflections and stresses are presented for simply supported border conditions. Current figures are contrasted with the non-poreous plate deflecting solutions and the literature's stresses. Effects of different parameters, including thickness, gradient index and porosity of FGM plates, are discussed.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (04) ◽  
pp. 231-240
Author(s):  
Douglas Coffin ◽  
Joel Panek

A transverse shear strain was utilized to characterize the severity of creasing for a wide range of tooling configurations. An analytic expression of transverse shear strain, which accounts for tooling geometry, correlated well with relative crease strength and springback as determined from 90° fold tests. The experimental results show a minimum strain (elastic limit) that needs to be exceeded for the relative crease strength to be reduced. The theory predicts a maximum achievable transverse shear strain, which is further limited if the tooling clearance is negative. The elastic limit and maximum strain thus describe the range of interest for effective creasing. In this range, cross direction (CD)-creased samples were more sensitive to creasing than machine direction (MD)-creased samples, but the differences were reduced as the shear strain approached the maximum. The presented development provides the foundation for a quantitative engineering approach to creasing and folding operations.


2020 ◽  
Vol 71 (1) ◽  
pp. 192-200
Author(s):  
Anca-Luiza Stanila ◽  
Catalin Cristian Simota ◽  
Mihail Dumitru

Highlighting the sandy soil of Oltenia Plain calls for a better knowledge of their variability their correlation with major natural factors from each physical geography. Pedogenetic processes specific sandy soils are strongly influenced by nature parent material. This leads, on the one hand, climate aridity of the soil due to strong heating and accumulation of small water reserves, consequences emphasizing the moisture deficit in the development of the vegetation and favoring weak deflation, and on the other hand, an increase in mineralization organic matter. Relief under wind characteristic sandy land, soil formation and distribution has some particularly of flat land with the land formed on the loess. The dune ridges are less evolved soils, profile underdeveloped and poorly supplied with nutrients compared to those on the slopes of the dunes and the interdune, whose physical and chemical properties are more favorable to plant growth.Both Romanati Plain and the Blahnita (Mehedinti) Plain and Bailesti Plain, sand wind shaped covering a finer material, loamy sand and even loess (containing up to 26% clay), also rippled with negative effects in terms of overall drainage. Depending on the pedogenetic physical and geographical factors that have contributed to soil cover, in the researched were identified following classes of soils: protisols, cernisols, cambisols, luvisols, hidrisols and antrosols.Obtaining appropriate agricultural production requires some land improvement works (especially fitting for irrigation) and agropedoameliorative works. Particular attention should be paid to preventing and combating wind erosion.


Soil Horizons ◽  
1992 ◽  
Vol 33 (3) ◽  
pp. 70 ◽  
Author(s):  
Simonson Roy W.

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