scholarly journals Practice-Oriented Validation of Embedded Beam Formulations in Geotechnical Engineering

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1739
Author(s):  
Andreas-Nizar Granitzer ◽  
Franz Tschuchnigg
Keyword(s):  
Numerical Analysis ◽  
Composite Structures ◽  
Research Effort ◽  
Skin Resistance ◽  
Engineering Application ◽  
Beam Element ◽  
Computational Effort ◽  
Deep Foundation ◽  
Beam Type ◽  
Interaction Surface

The numerical analysis of many geotechnical problems involves a high number of structural elements, leading to extensive modelling and computational effort. Due to its exceptional ability to circumvent these obstacles, the embedded beam element (EB), though originally intended for the modelling of micropiles, has become increasingly popular in computational geotechnics. Recent research effort has paved the way to the embedded beam element with interaction surface (EB-I), an extension of the EB. The EB-I renders soil–structure interaction along an interaction surface rather than the centreline, making it theoretically applicable to any engineering application where beam-type elements interact with solid elements. At present, in-depth knowledge about relative merits, compared to the EB, is still in demand. Subsequently, numerical analysis are carried out using both embedded beam formulations to model deep foundation elements. The credibility of predicted results is assessed based on a comprehensive comparison with the well-established standard FE approach. In all cases considered, the EB-I proves clearly superior in terms of mesh sensitivity, mobilization of skin-resistance, and predicted soil displacements. Special care must be taken when using embedded beam formulations for the modelling of composite structures.

PROGRESS ON THE DEVELOPMENT OF SHAPE-MEMORY-ALLOY METACOMPOSITES

2021 ◽  
Author(s):  
DUSAN MILOSAVLJEVIC ◽  
QIANLONG ZHANG ◽  
MARCO MOSENEDER ◽  
HONGFEI ZHU ◽  
NORA LECIS ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Composite Structures ◽  
Dynamic Properties ◽  
Research Effort ◽  
Mechanical Energy ◽  
Engineering Application ◽  
Operating Conditions ◽  
Development Effort

Shape memory alloys (SMA) have long been explored as a semi-passive approach to mechanical energy dissipation particularly, but not exclusively, for application to vibration control. More recently, the integration of SMAs in composite materials has opened the opportunity to synthesize tunable composite structures exhibiting significantly enhanced energy dissipation characteristics and a certain degree of adaptability to different operating conditions. Despite the significant progress in the development and manufacturing of SMAs over the past several decades, the cost of common Ni-based alloys has remained an important factor hindering their widespread engineering application. The long-term goal of this research effort is to model, design, and fabricate shape-memory-alloy (SMA) meta-composites employing lower volume fractions of a more affordable Cu-based alloy, while still enabling enhanced and tunable dynamic properties. This paper summarizes recent progress in the development of the meta-composite platform and focuses on aspects involving both numerical modeling and fabrication of SMA materials. On the modeling side, particular emphasis is given to assess the ability to tune the dynamic performance of continuous SMA structures by exploiting the different phases and transformations of the alloy. On the other side, the material development effort focuses on the identification of the optimal chemical composition, mechanical and heat treatment processes. A combination of numerical and experimental results is presented to illustrate capabilities and opportunities presented by this material platform.

The Higher Order Asymptotic Fields for Plane Interfacial Crack with Physical Weak-Discontinuity

2011 ◽  
Vol 217-218 ◽  
pp. 1314-1318
Author(s):  
Yao Dai ◽  
Lei Zhang ◽  
Peng Zhang ◽  
Jun Feng Liu
Keyword(s):  
Experimental Investigation ◽  
Numerical Analysis ◽  
Asymptotic Analysis ◽  
Theoretical Basis ◽  
Engineering Application ◽  
Interfacial Crack ◽  
Higher Order ◽  
Weak Discontinuity ◽  
Displacement Method ◽  
Asymptotic Fields

The higher order discontinuous asymptotic fields which are similar to the Williams’ solutions of homogenous material are obtained by the displacement method and asymptotic analysis for a plane crack at the physical weak-discontinuous interface in non-homogeneous materials. The results provide a theoretical basis for the numerical analysis, experimental investigation and the engineering application of physical weak-discontinuous fracture.

scholarly journals A model for ultimate bearing capacity of piles in unsaturated soils under elevated temperatures

2020 ◽  
Vol 205 ◽  
pp. 05003
Author(s):  
Sannith Kumar Thota ◽  
Farshid Vahedifard
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soils ◽  
Elevated Temperatures ◽  
Skin Resistance ◽  
Ultimate Bearing Capacity ◽  
Temperature Dependent ◽  
Deep Foundation ◽  
Energy Applications ◽  
Temperature Dependent Model ◽  
Pile Resistance

Geo-energy applications such as energy piles can expose unsaturated, deep foundation soils to elevated temperatures. This paper presents a closed-form equation for the ultimate bearing capacity of piles in unsaturated soils subject to elevated temperatures under drained conditions. For this purpose, a temperature-dependent effective stress model was incorporated into calculations of skin resistance and end bearing resistance of piles. The proposed temperature-dependent model is an extension of the modified β method for determining the ultimate pile bearing capacity of unsaturated soils under drained conditions. Employing the proposed model, a parametric study was carried out to evaluate the ultimate pile bearing capacity for hypothetical clay and silt soils at temperatures ranging from 25 °C to 55 °C. For both clay and silt, the results indicated that the ultimate pile bearing capacity varies with an increase in temperature. Different trends with temperature were observed for clay and silt. A monotonic increase in pile resistance was observed in clays. For silt, the pile resistance increased at relatively low matric suction whereas it decreased at higher matric suctions.

High Pressure Rotary Jet Grouting Pile with Undrained Caisson Combined Construction Technology on Nearby Yangtze River Levee Protection

2013 ◽  
Vol 718-720 ◽  
pp. 1938-1944
Author(s):  
You Sheng Zhao ◽  
Bin Zhou
Keyword(s):  
High Pressure ◽  
Yangtze River ◽  
Engineering Application ◽  
Reference Value ◽  
Construction Technology ◽  
The Yangtze River ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Jet Grouting

t is easy to cause the Yangtze River embankment soil of slip even collapse to have a deep foundation pit construction adjacent to the Yangtze River outsideembankment,there are a lot of risk. In this paper, a new combining technique of construction for large caisson is presented. Based on the construction environment, theconstructiontechnology,the smaller earthwork excavation of deep high pressure rotary jet grouting pile with undrained caisson combined construction technology combined with monitoring data for the open caisson excavation control is adopted. It has achieved relatively good results and summarized the advantages of deep high pressure rotary jet grouting pile with undrained caisson combined construction technology in engineering application owing the reference value for engineering applications.

Superior Research for Selection of Bracing Structure of Deep Pit Foundation Based on Fussy Theory

2013 ◽  
Vol 838-841 ◽  
pp. 214-218
Author(s):  
Dong Li
Keyword(s):  
General Model ◽  
Engineering Application ◽  
Hard Work ◽  
Deep Foundation ◽  
Scientific Methods ◽  
Deep Pit ◽  
Practical Engineering ◽  
Fuzzy Math ◽  
Selection Of

Before the construction of the deep pit foundation, we must choose a project. Although there aren't many projects to be chosen as usual, we often feel that it's a very complex and hard work. Actually there is no a mature and general model to use. In this paper, the author attempted to use the theory of fuzzy math to establish a former to select the best project, meanwhile provided two ways to solve how to quantify the qualitative targets and how to determine the weights of the targets. Finally they were confirmed to be useful and successful by a practical engineering application. It is worthily to popularize these scientific methods in construction and management in deep foundation pits.

scholarly journals Numerical Analysis on the Performance of the Underwater Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bo Li ◽  
Cangqin Jia ◽  
Guihe Wang ◽  
Jun Ren ◽  
Gaofeng Lu ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Retaining Wall ◽  
Lateral Wall ◽  
Surface Settlement ◽  
Design Parameters ◽  
Analysis Model ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Wall Deflection ◽  
Total Settlement

Based on the Yongdingmen Station of Beijing Metro, the underwater excavation method for deep foundation pit was introduced. This study constructed a numerical analysis model to analyze the performance of surface settlement and lateral wall deflection in the process of underwater excavation. Results showed that this method was better to control the surface settlement and lateral wall deflection compared with other dewatering excavations. In detail, most of the surface settlement was caused during the dry excavation stage and dewatering excavation stage while the deflection caused by underwater excavation only accounted for about 10% of the total settlement. Besides, the maximum settlement occurred 0.25∼0.5 H e behind the retaining wall and the value was 0.04% H e . Similar to the result of the surface settlement, most of the lateral wall deflection had been completed before the underwater excavation, which only caused about 7% of the total deflection. The maximum wall deflection and its location were approximately 0.06% H e and 0.5 H e , respectively. Moreover, a series of 3D numerical analyses were studied on the design parameters of the underwater excavation method. This study can be used as a reference for general performance and structural design of foundation pits with underwater excavation.

scholarly journals Numerical Analysis of the Effect of Microscale Components Interaction on Measurements of Fiber Optic Strain Sensors Used in Composite Structures

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Mikhail Tashkinov ◽  
Igor Shardakov
Keyword(s):  
Composite Material ◽  
Numerical Analysis ◽  
Optical Fiber ◽  
Composite Structures ◽  
Fiber Optic ◽  
Strain Tensor ◽  
Strain Sensors ◽  
Numerical Estimation ◽  
Structural Components ◽  
Fiber Optic Strain Sensors

The paper investigates the influence of structural components of a composite material on the strain values measured by using an embedded optical fiber with Bragg gratings. The effect of composite plies and intermediate epoxy layers on the transfer of deformations from the measured object to the optical fiber was studied taking into account various methods of the fiber attachment and surrounding media configurations. A numerical estimation of the effect of the longitudinal and transverse components of the strain tensor on the wavelength of the reflected spectrum is performed.

Studying the effect of reinforcement parameters on the mechanical properties of natural fibre-woven composites by Taguchi method

2019 ◽  
Vol 50 (2) ◽  
pp. 133-148 ◽  
Author(s):  
Senthil Kumar ◽  
S Balachander
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Composite Structures ◽  
Research Work ◽  
Engineering Application ◽  
Areal Density ◽  
Natural Fibre ◽  
Woven Fabrics ◽  
Woven Composites ◽  
Textile Composite

Process optimization is the key task of any engineering application to maximize the desirable output by optimizing the range of process parameters. In this research work, jute composites were fabricated by the hand lay-up method with the aim of optimizing the process parameter such as yarn linear density, fabric areal density and fabric laying angle on the mechanical properties of the textile composite structures using the Taguchi L9 orthogonal matrix. The plain-woven and twill-woven fabrics of Jute fabrics were produced through specialized handloom machine and used as preform for composite production. Epoxy resin was used as the matrix component. Signal-to-noise ratio ratio, analysis of variance and experimental verification of results were analysed. The results showed that fabric laying angle played major role to achieve high mechanical properties of composites and twill-woven structural reinforcement yields higher mechanical properties. Subsequent to this optimal process, parameters have been arrived for all the composites, and finally it was verified through the experimental results.

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