Frequency‐dependent dynamic behavior of a poroviscoelastic soil layer under cyclic loading

2020 ◽  
Vol 44 (9) ◽  
pp. 1336-1349
Author(s):  
Weiyun Chen ◽  
Yumin Mou ◽  
Lingyu Xu ◽  
Zhihua Wang ◽  
Junhui Luo
Keyword(s):  
Cyclic Loading ◽  
Dynamic Behavior ◽  
Soil Layer ◽  
Frequency Dependent

scholarly journals Dynamics of Biochar-Silty Clay Interaction Using In-House Fabricated Cyclic Loading Apparatus: A Case Study of Coastal Clay and Novel Peach Biochar from the Qingdao Region of China

2020 ◽  
Vol 12 (7) ◽  
pp. 2599 ◽  
Author(s):  
Junwei Liu ◽  
Suriya Prakash Ganesan ◽  
Xin Li ◽  
Ankit Garg ◽  
Aman Singhal ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Shear Modulus ◽  
Dynamic Behavior ◽  
Void Ratio ◽  
Water Pressure ◽  
Damping Ratio ◽  
Cyclic Strength ◽  
Silty Clay ◽  
Amended Soils ◽  
Amended Soil

Biochar has been recently investigated as an eco-friendly material in bio-engineered slopes/landfill covers. A majority of recent studies have focused on analyzing water retention behavior while very few have examined dynamic behavior (i.e., cyclic loading due to earthquake, wind, or wave) of biochar amended soil. As far as the authors are aware, there is no study on the dynamic behavior of biochar amended soils. Considering the above mentioned study as a major objective, field excavated soil was collected and mixed with in-house produced biochar from peach endocarps, at three amendment rates (5%, 10%, and 15%). The un-amended bare soil and biochar amended soil were imposed to a cyclic load in a self-designed apparatus and the corresponding stress-strain parameters were measured. Dynamic parameters such as shear modulus and damping ratio were computed and the results were compared between bare and biochar amended soil. Furthermore, the residual cyclic strength of each soil types were correlated with an estimated void ratio to understand the interrelation between dynamic loading responses and biochar amended soils. The major outcomes of this study show that the addition of biochar decreases the void ratio, thereby increasing the shear modulus and residual cyclic strength. However, the modulus and strength values attenuates after 15 cycles due to an increase in pore water pressure. In contrary, at higher amendment rates, Biochar Amended Soils (BAS) forms clay-carbon complex and decreases both shear modulus and residual cyclic strength.

scholarly journals Consolidation of Soils Under Cyclic Loading

1974 ◽  
Vol 11 (3) ◽  
pp. 420-423 ◽  
Author(s):  
N. E. Wilson ◽  
M. M. Elgohary
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Soil Layer ◽  
Saturated Soil ◽  
Theoretical Solution ◽  
Loading Cycle ◽  
Sustained Loading ◽  
Pore Water Pressures

A theoretical solution for the progress of consolidation of a saturated soil layer subjected to cyclic loading is obtained.Consolidation, proceeding inwards from the drainage face, is slower than consolidation under an equivalent sustained loading because positive and negative pore-water pressures, produced during the loaded and unloaded portion of the cycle, cause flow of water from and into the soil. An equilibrium, or finalized, consolidation ratio is reached which is dependent on the pattern of loading cycle; it is not possible to reach 100% consolidation under cyclic loading.

Dynamic Behavior of Complex Fluid-Filled Tubing Systems—Part 1: Tubing Analysis

1998 ◽  
Vol 123 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Forbes T. Brown ◽  
Stephen C. Tentarelli
Keyword(s):  
Frequency Response ◽  
Dynamic Behavior ◽  
Transmission Matrix ◽  
Matrix Approach ◽  
Frequency Dependent ◽  
Long Wavelength ◽  
System Models ◽  
Analogous System ◽  
Complex Fluid ◽  
Poisson Coupling

A general transmission-matrix approach is given for finding the frequency response of linearized long-wavelength models for the vibration in systems with straight and curved fluid-filled tubes. Couplings between the fluid and wall motions include the Bourdon effect, frequency-dependent wall shear, the Poisson coupling and the effect of discontinuities. The introduction of a global transmission matrix allows nonplanar tubing systems of virtually any complexity to be analyzed, overcoming the round-off error problem that plagues the basic transmission-matrix approach for this and analogous system models. Corroborating experiments focus on the Poisson and Bourdon effects.

scholarly journals Transient and Harmonic Unipolar Hysteresis Model of Piezoelectric Actuators Using a System-Level Approach

2020 ◽  
Vol 10 (20) ◽  
pp. 7268
Author(s):  
Mickaël Lallart ◽  
Kui Li ◽  
Zhichun Yang ◽  
Shengxi Zhou
Keyword(s):  
System Dynamics ◽  
Dynamic Behavior ◽  
Transfer Functions ◽  
Piezoelectric Actuators ◽  
Good Choice ◽  
Fine Tuning ◽  
System Level ◽  
Driving Voltage ◽  
Hysteresis Model ◽  
Frequency Dependent

Thanks to their integrability and good electromechanical conversion abilities, piezoelectric actuators are a good choice for many actuation applications. However, these elements feature a frequency-dependent hysteresis response that may yield complex control implementation. The purpose of this paper is to provide the extension of a simple hysteresis model based on a system-level approach linking the strain derivative to the driving voltage derivative and taking into account the dynamic behavior of the hysteretic response of the actuator. The proposed enhancement consists of transient and harmonic regimes, allowing to extend the quasi-static model to dynamic behavior with any frequency. In particular, initial strain shift arising from stabilization and accommodation effects as well as frequency-dependent hysteresis shape are considered. The inclusion of the system dynamics in the model is obtained thanks to fractional derivatives and associated fractional transfer functions, allowing the consideration of the full actuator history as well as a fine tuning of the system dynamics over a wide frequency band. Finally, a numerical example of linearized control through compensation loop is provided, demonstrating the interest in the proposed approach for providing a computationally-efficient, simple yet efficient way for finely predicting the actuator response and thus designing appropriate controllers.

scholarly journals Undrained Dynamic Behavior of Reinforced Subgrade under Long-Term Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Min Geng ◽  
Debin Wang ◽  
Peiyong Li
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Dynamic Behavior ◽  
Vibration Frequency ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Confining Pressure ◽  
Reinforced Soil ◽  
Dynamic Elastic Modulus

To study the dynamic behavior of reinforced subgrade, a series of undrained cyclic triaxial tests of reinforced soil (the specimen a height of 50 cm and a diameter of 20 cm) were performed in this paper. The specimens were tested by varying confining pressure, vibration frequency, dynamic stress amplitudes, and reinforced layers. Orthogonal experiment is a better way to optimize the process of experiment. Impact on dynamic behavior of the reinforced soil specimens is discussed through orthogonal design of experiments in four factors and three levels. This study has demonstrated that the order of dynamic elastic modulus of reinforced soil is influenced by dynamic stress amplitude, frequency, reinforced layer, and confining pressure within changing in factor level. The dynamic stress amplitude has great influence on the dynamic elastic modulus of reinforced soil. The bearing capacity and dynamic elastic modulus of reinforced subgrade decrease slightly with the increase of dynamic strain. Frequency has an influence on the dynamic elastic modulus. It is shown that the cumulative strain of reinforced soil is related to the vibration frequency. The test results also exemplify the reinforced subgrade restrict lateral displacement of subgrade and reduce settlement of subgrade under long-term cyclic loading.

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