scholarly journals Maxwell model geotextile encased stone column in soft soil improvement

2021 ◽  
Vol 4 (1) ◽  
pp. first
Author(s):  
Phạm Tiến Bách ◽  
Võ Đại Nhật ◽  
Nguyễn Việt Kỳ ◽  
Lê Quân
Keyword(s):  
Ground Improvement ◽  
Soft Soil ◽  
Great Influence ◽  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Soil Improvement ◽  
Time Dependent ◽  
Dependent Behavior ◽  
Generalized Maxwell Model ◽  
Matlab Programming

In the field of geotechnical – soft soil improvement, the mathematical model or mechanical model is one of the important input parameters for the design calculations or studies. The determination of the appropriateness of the models has a great influence on the accuracy results of design and calculation as well as the sustainable stability of soft ground after improvement. On the contrary, the selection of inadequate calculation models will lead to increased costs of soft soil improvement, possibly even leading to the destabilization of the work and causing immense loss of people and property. Recently, many projects major highway after construction design in use has not meet the requirements of the standard, leading to wasted money and time of individuals, organizations, and the state of post-treatment. Therefore, the research and application of using mathematical or mechanical models in accordance with the new soft soil improvement method will greatly help as well as add additional options for soft soil improvement in Vietnam. The soft soil deformation is not only related to load but also to load time. The change in stress and deformation of weak soil over time is called rheology, and in this study is the viscoelastic behavior. From the above reasons, we try to apply a generalized Maxwell model to explain the viscoelastic behavior of a soft soil. In particular, the time-dependent behavior of a viscoelastic soft soil was represented by using the Maxwell rheological model. The Matlab programming code helps to solve numerically all the equation of the mathematical exhibition of the generalized Maxwell model results. We acknowledge that the generalized Maxwell model is superior in demonstrating the time-dependent behavior of soft soil. The results probably show that this is one of the effective models to predict the behavior of soft soils in ground improvement with GEC.

scholarly journals Constitutive Modeling of Time-Dependent Response of Human Plantar Aponeurosis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
P. G. Pavan ◽  
P. Pachera ◽  
C. Stecco ◽  
A. N. Natali
Keyword(s):  
Experimental Data ◽  
Stress Relaxation ◽  
Constitutive Model ◽  
Transverse Isotropy ◽  
Model Fitting ◽  
Viscoelastic Behavior ◽  
Time Dependent ◽  
Plantar Aponeurosis ◽  
Structural Conformation ◽  
Dependent Behavior

The attention is focused on the viscoelastic behavior of human plantar aponeurosis tissue. At this purpose, stress relaxation tests were developed on samples taken from the plantar aponeurosis of frozen adult donors with age ranging from 67 to 78 years, imposing three levels of strain in the physiological range (4%, 6%, and 8%) and observing stress decay for 240 s. A viscohyperelastic fiber-reinforced constitutive model with transverse isotropy was assumed to describe the time-dependent behavior of the aponeurotic tissue. This model is consistent with the structural conformation of the tissue where collagen fibers are mainly aligned with the proximal-distal direction. Constitutive model fitting to experimental data was made by implementing a stochastic-deterministic procedure. The stress relaxation was found close to 40%, independently of the level of strain applied. The agreement between experimental data and numerical results confirms the suitability of the constitutive model to describe the viscoelastic behaviour of the plantar aponeurosis.

Linking Internal Dissipation Mechanisms to the Effective Complex Viscoelastic Moduli of Ferroelectrics

2016 ◽  
Vol 84 (2) ◽  
Author(s):  
Charles S. Wojnar ◽  
Dennis M. Kochmann
Keyword(s):  
Microstructure Evolution ◽  
Domain Switching ◽  
Constitutive Models ◽  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Hysteretic Behavior ◽  
Ferroelectric Ceramics ◽  
Internal Variables ◽  
Viscoelastic Parameters ◽  
Generalized Maxwell Model

Microstructural mechanisms such as domain switching in ferroelectric ceramics dissipate energy, the nature, and extent of which are of significant interest for two reasons. First, dissipative internal processes lead to hysteretic behavior at the macroscale (e.g., the hysteresis of polarization versus electric field in ferroelectrics). Second, mechanisms of internal friction determine the viscoelastic behavior of the material under small-amplitude vibrations. Although experimental techniques and constitutive models exist for both phenomena, there is a strong disconnect and, in particular, no advantageous strategy to link both for improved physics-based kinetic models for multifunctional rheological materials. Here, we present a theoretical approach that relates inelastic constitutive models to frequency-dependent viscoelastic parameters by linearizing the kinetic relations for the internal variables. This enables us to gain qualitative and quantitative experimental validation of the kinetics of internal processes for both quasistatic microstructure evolution and high-frequency damping. We first present the simple example of the generalized Maxwell model and then proceed to the case of ferroelectric ceramics for which we predict the viscoelastic response during domain switching and compare to experimental data. This strategy identifies the relations between microstructural kinetics and viscoelastic properties. The approach is general in that it can be applied to other rheological materials with microstructure evolution.

scholarly journals Investigation on viscoelastic behavior of virgin EPDM/ reclaimed rubber blends using Generalized Maxwell Model (GMM)

2021 ◽  
Vol 93 ◽  
pp. 106989
Author(s):  
Atefeh Salimi ◽  
Foroud Abbassi-Sourki ◽  
Mohammad Karrabi ◽  
Mir Hamid Reza Ghoreishy
Keyword(s):  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Rubber Blends ◽  
Generalized Maxwell Model

scholarly journals APPLICATION THE POINT FOUNDATION (PF) METHOD FOR SOFT SOIL IMPROVEMENT: A CASE STUDY FROM VETNAM

2020 ◽  
Vol 53 (2D) ◽  
pp. 1-18
Author(s):  
Bui Truong Son
Keyword(s):  
Bearing Capacity ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soil Improvement ◽  
Static Compression ◽  
Successful Case ◽  
Soft Ground Improvement ◽  
Final Settlement ◽  
Shallow Footing

The point foundation method is the head enlarged cement deep mixing columns with high-quality control which can be used for soft ground improvement. The article aims to present the application of this method to treat soft soil for the foundation of Samse Vina factory, Ninh Binh province. The thickness of soft soil varies from 5.4 m to 7.4 m with high compressibility and low shear strength. Thus, point foundation was used to improve this layer. The prediction methods of soil bearing capacity and the settlement on the point foundation were calculated. After the treatment of soil, the unconfined compression strength of the point foundation column was determined and the static compression test for the point foundation column was also performed. The research results show that this method can significantly reduce the settlement of shallow footing and improved the bearing capacity of the soil. The final settlement of shallow footing was smaller than 2.54 cm and the bearing capacity of soil treatment can be satisfied with the requirement of construction building. This is a successful case of the application of point foundation to improve soft soil in Vietnam.

INNOVATIVE SOFT SOIL IMPROVEMENT BY VACUUM DE-WATERING AND DYNAMIC COMPACTION

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Tuncer B. Edil
Keyword(s):  
Large Scale ◽  
Ground Improvement ◽  
Soft Soil ◽  
High Vacuum ◽  
Cohesive Soil ◽  
Soil Improvement ◽  
Economic Benefits ◽  
Dynamic Compaction ◽  
Environmental Benefits ◽  
Improvement Method

Recently, an innovative soft soil improvement method was advanced in China by integrating and modifying vacuum consolidation and dynamic compaction ground improvement techniques in an intelligent and controlled manner. This innovative soft soil improvement method is referred to as “High Vacuum Densification Method (HVDM)” to reflect its combined use of vacuum de-watering and dynamic compaction techniques in cycles. Over the past ten years, this innovative soft soil improvement technique has been successfully used in China and Asia for numerous large-scale soft soil improvement projects, from which enormous time and cost savings have been achieved. In this presentation, the working principles of the HVDM will be described. A discussion of the range of fine-grained, cohesive soil properties that would make them ideal for applying HVDM as an efficient ground improvement method will be discussed. The economic benefits and environmental benefits of HVDM are elucidated.

scholarly journals A new identification method of viscoelastic behavior: Application to the generalized Maxwell model

2011 ◽  
Vol 25 (3) ◽  
pp. 991-1010 ◽  
Author(s):  
Franck Renaud ◽  
Jean-Luc Dion ◽  
Gaël Chevallier ◽  
Imad Tawfiq ◽  
Rémi Lemaire
Keyword(s):  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Identification Method ◽  
Generalized Maxwell Model

Viscoelastic Damping Effect on Brake Squeal Noise

2009 ◽  
Author(s):  
Gael Chevallier ◽  
Franck Renaud ◽  
Jean-Luc Dion
Keyword(s):  
Degrees Of Freedom ◽  
Viscoelastic Model ◽  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Element Model ◽  
Brake Squeal ◽  
Generalized Maxwell Model ◽  
Space Formulation ◽  
Damping Materials ◽  
Squeal Noise

Brake squeal remains a widespread cause for discomfort in automobiles. Manufacturers overcome this problem by adding damping materials in their systems. The purpose of this work is to take into account the damping in the modeling. As the materials exhibit a viscoelastic behavior, the authors chose to model the damping with the Generalized Maxwell model. Moreover, the authors have tested their method on a detailed Finite Element-model of a brake system. To compute the complex poles of the model, the authors have established a state-space formulation of the viscoelastic model with a new assumption that allows one to reduce the number of states. Making the computation on the whole model is rather difficult due to the number of Degrees Of Freedom, the model is thus reduced on a basis constituted with the eigenvectors of the undamped model. Several results are also presented and discussed as the observed phenomena are rather different from the results obtained with undamped systems.

Characterization and Modeling of Time-Dependent Behaviour of Braided Packing Rings

2016 ◽  
Author(s):  
Mehdi Kazeminia ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Viscoelastic Behavior ◽  
Material Behavior ◽  
Time Dependent ◽  
Nonlinear Material ◽  
Dependent Behavior ◽  
Sealing Performance ◽  
Proposed Model ◽  
Packing Rings ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic

The sealing performance of packed stuffing boxes used in valves and compressors depends on the ability of the structure to maintain a minimum threshold contact pressure through a sufficient period of time. Packing rings exhibit combined creep and relaxation behavior due to internal disordered porous structure and nonlinear material behavior in addition to the interaction with other structural components. A comprehensive understanding of the time-dependent behavior of packing rings is essential for increasing the sealing performance. In this paper, the time-dependent linear viscoelastic behavior of packing material is constitutively simulated. The experimental investigation is carried out in a special test bench which was designed and developed to study the characteristics of the time-dependent behavior of packing rings. The results show that the proposed model can successfully be exploited to determine the time-dependent behavior of packing rings for application in the design of packed stuffing boxes.

Generalized Maxwell model for the viscoelastic behavior of a soda-lime-silica glass under low frequency shear loading

1997 ◽  
Vol 36 (2) ◽  
pp. 173-186
Author(s):  
Lucas Duffrène *, † , Ren&#x ◽  
Hélène Burlet ◽  
Roland Piques ◽  
Annelise Faivre ◽  
Anas Sekkat ◽  
...  
Keyword(s):  
Silica Glass ◽  
Low Frequency ◽  
Viscoelastic Behavior ◽  
Maxwell Model ◽  
Soda Lime ◽  
Shear Loading ◽  
Generalized Maxwell Model ◽  
Soda Lime Silica Glass
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