scholarly journals Numerical investigations of work of driven pile on claystones

Vestnik MGSU ◽  
2019 ◽  
pp. 188-198
Author(s):  
Evgeniya N. Sychkina ◽  
Vadim V. Antipov ◽  
Yan V. Ofrikhter
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Software Package ◽  
Field Experiments ◽  
Field Tests ◽  
Full Scale ◽  
Elastic Model ◽  
Element Analysis ◽  
Pile Settlement ◽  
Plaxis 3D

Introduction. Reviewed the features of the work of the pile on Permian claystones with the help of numerical and field experiments, analytical calculations. Materials and methods. Numerical modeling was performed in the Plaxis 3D and Midas GTS NX software packages. Full-scale tests of driven piles are made in accordance with the requirements of GOST 20276-2012. The obtained results are compared with the results of analytical calculations according to SP 24.13330.2011. Results. The scientific novelty of the investigation consists in a comparative analysis of the results of numerical modeling of the interaction of a driving pile with claystones with the results of field tests and analytical calculations. Finite element analysis in software package Plaxis 3D using Hardening Soil model shows higher values of settlement (up to 6 times) in relation to stabilized settlement of full-scale pile tests. Calculations in the software package Midas GTS NX showed overestimated values of pile settlements in relation to full-scale pile tests (13-24 times). Analytical calculations in accordance with SP 24.13330.2011 also showed overestimated (up to 3 times) values of the maximum pile settlement in relation to the stabilized settlement during full-scale pile tests. Conclusions. The calculations by the finite element method in the package Plaxis 3D and Midas GTS NX, by the analytical method according to SP 24.13330.2011, show overestimated values of settlement in relation to the stabilized settlement of piles on claystones. Using the Linear-Elastic model for claystones in numerical calculations in Plaxis 3D provides a value close to the settlement of full-scale pile. However, the use of this model is not fully justified for claystones due to the presence of residual deformations and the nonlinear character of pile settlement during loading. Necessary to correct the existing numerical and analytical methods for calculating pile foundations on claystones. It is necessary to continue the work on the further generalization of the experience of arranging piles on weathered claystones in order to evaluate the long-term work of not only a single pile, but also a pile foundation.

scholarly journals 3-D finite element analysis of laterally loaded short shafts in soil

2021 ◽  
Author(s):  
Jasinthan Arulanantham
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Field Tests ◽  
Lateral Load ◽  
Numerical Results ◽  
Accurate Estimation ◽  
Optimized Design ◽  
Element Analysis ◽  
Laterally Loaded ◽  
Plaxis 3D

The objective of this research is to conduct an optimized design of drilled shaft foundation for noise barrier walls. A non-linear three-dimensional (3D) finite element method (FEM) program, Plaxis 3D, is used to investigate the behaviour of laterally loaded shafts. Two published cases are used to calibrate the modelling method and validate the numerical results. In the case of a field test performed by Helmers (1997), FEM results agree very well with field tests in terms of ultimate load and deflection curves. In the laboratory test conducted by Uncuoglu & Laman (2011) case, numerical results agree well with their results except the soil-shaft interface modelling part. The Plaxis 3D embedded pile model tends to overestimate the lateral load capacity of a smooth pile. Though it is satisfactory in modelling a pile with a “rough” surface. Two theoretical formulas in estimating lateral capacity of piles are also compared with the FEM results. It is found that Broms’s (1964b) theory for cohesionless soils has underestimated the lateral load capacities and Brinch-Hansen’s (1961) theory provides a more accurate estimation. In summary, 3-D FEM is able to accurately simulate the behaviour of laterally loaded drilled shafts in soil.

scholarly journals 3-D finite element analysis of laterally loaded short shafts in soil

2021 ◽  
Author(s):  
Jasinthan Arulanantham
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Field Tests ◽  
Lateral Load ◽  
Numerical Results ◽  
Accurate Estimation ◽  
Optimized Design ◽  
Element Analysis ◽  
Laterally Loaded ◽  
Plaxis 3D

The objective of this research is to conduct an optimized design of drilled shaft foundation for noise barrier walls. A non-linear three-dimensional (3D) finite element method (FEM) program, Plaxis 3D, is used to investigate the behaviour of laterally loaded shafts. Two published cases are used to calibrate the modelling method and validate the numerical results. In the case of a field test performed by Helmers (1997), FEM results agree very well with field tests in terms of ultimate load and deflection curves. In the laboratory test conducted by Uncuoglu & Laman (2011) case, numerical results agree well with their results except the soil-shaft interface modelling part. The Plaxis 3D embedded pile model tends to overestimate the lateral load capacity of a smooth pile. Though it is satisfactory in modelling a pile with a “rough” surface. Two theoretical formulas in estimating lateral capacity of piles are also compared with the FEM results. It is found that Broms’s (1964b) theory for cohesionless soils has underestimated the lateral load capacities and Brinch-Hansen’s (1961) theory provides a more accurate estimation. In summary, 3-D FEM is able to accurately simulate the behaviour of laterally loaded drilled shafts in soil.

THE RULE OF COMBINING A PRIORI AND EXPERIMENTAL INFORMATION IN THE TASKS OF MANAGING TESTS OF COMPLEX TECHNICAL PRODUCTS ACCORDING TO THE BERNOULLI SCHEME

2020 ◽  
pp. 3-13
Author(s):  
Yu. I. Buryak ◽  
A. A. Skrynnikov
Keyword(s):  
Field Experiments ◽  
A Priori ◽  
Field Tests ◽  
Experimental Information ◽  
Full Scale ◽  
Testing Complex ◽  
Series Of Experiments ◽  
Full Scale Tests ◽  
Technical Products

The article is devoted to the substantiation of the procedure for testing complex technical systems to assess the probability of performing the task, taking into account a priori data obtained from the results of modeling, field tests of components and prototypes, operation of analogues, etc. The conditions for the formation of a combined sample consisting of field experiments and experiments counted on the results of modeling are justified. Data uniformity is checked using the Student's criterion. The minimum volume of full-scale tests is determined by the requirement of equality of the amount of Fischer information about the estimated parameter obtained during full-scale tests and at the expense of a priori data A strategy for conducting field experiments is proposed, in which the required quality of evaluating the probability of completing the task is achieved with the minimum possible number of field experiments. At the first stage, a series of experiments with a volume equal to half of the required sample size is performed. At the second stage, the experiments are conducted sequentially with an assessment after each experiment of the requirements for the amount of information about the evaluated parameter and for the uniformity of data. Experiments are terminated when the specified requirements are met, and then a combined sample is formed, which is used to evaluate the probability of the system performing the task. A model example is considered. The estimation of the gain in the number of experiments performed at different probability values was carried out.

Detailed Stress Analysis of a Spherical Acrylic Submersible by 3-D Finite Element Modeling

1999 ◽  
Author(s):  
Partha S. Das
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Dissimilar Materials ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
New Model ◽  
Ocean Exploration ◽  
Near Future ◽  
First Time

Abstract Harbor Branch Oceanographic Institution (HBOI) designed, built and has operated two JOHNSON-SEA-LINK (JSL) manned submersibles for the past 25 years. The JSL submersibles each incorporate a 66–68 in. (1.6764–1.7272 m) OD, 4–5.25 in. (0.1016–0.13335 m) thick acrylic two-man sphere as a Pressure Vessel for Human Occupancy (PVHO). This type of spherical acrylic sphere or submersible was first introduced in around 1970 and is known as Naval Experimental Manned Observatory (NEMO) submersibles. As the demand increases for ocean exploration to 3000 ft. (914.4 m) depth to collect samples, to study the ocean surfaces, the problem of developing cracks at the interface of these manned acrylic submersibles following few hundred dives have become a common phenomena. This has drawn considerable attentions for reinvestigation of the spherical acrylic submersible in order to overcome this crack generation problem at the interface. Therefore, a new full-scale 3-D nonlinear FEA (Finite Element Analysis) model, similar to the spherical acrylic submersible that HBOI uses for ocean exploration, has been developed for the first time in order to simulate the structural behavior at the interface and throughout the sphere, for better understanding of the mechanical behavior. Variation of the stiffness between dissimilar materials at the interface, lower nylon gasket thickness, over designed aluminum hatch are seemed to be few of the causes for higher stresses within acrylic sphere at the nylon gasket/acrylic interface. Following the basic understanding of the stresses and relative displacements at the interface and within different parts of the submersible, various models have been developed on the basis of different shapes and thickness of nylon gaskets, openings of the acrylic sphere, hatch geometry and its materials, specifically to study their effect on the overall performance of the acrylic submersible. Finally, the new model for acrylic submersible has been developed by redesigning the top aluminum hatch and hatch ring, the sphere openings at both top and bottom, as well as the nylon gasket inserts. Altogether this new design indicates a significant improvement over the existing spherical acrylic submersible by reducing the stresses at the top gasket/acrylic interface considerably. Redesigning of the bottom penetrator plate, at present, is underway. In this paper, results from numerical modeling only are reported in details. Correlation between experimental-numerical modeling results for the new model will be reported in the near future.

scholarly journals NUMERICAL MODELING AND FULL-SCALE EXPERIMENTS OF GLUED WOODEN STRUCTURES JOINT DESTRUCTION ON CARBON-FIBER DOWEL PINS

2020 ◽  
Vol 16 (2) ◽  
pp. 101-112
Author(s):  
Mikhail Vodiannikov ◽  
Galina Kashevarova ◽  
Danil Starobogatov
Keyword(s):  
Numerical Modeling ◽  
Structural Analysis ◽  
Carbon Fiber ◽  
Structural Parameters ◽  
General Structure ◽  
Failure Process ◽  
Joint Destruction ◽  
Field Tests ◽  
Full Scale ◽  
Glued Laminated Timber

This paper presents the results of numerical modeling and full-scale experiments of the failure process of a glued laminated timber beam with rigid joint in the middle. All the connecting parts are made of carbon fiber. The structural analysis is done with the finite element method (ANSYS software). The nonlinear problem was solved. The contact interaction of the structural elements in the process of deformation and fracture, as well as orthotropy of the wood, the transversely isotropic properties of the plates, and the real diagrams of the deformation of carbon fiber dowel pins were taken into account. The influence of the structural parameters of the joint on the position of the most loaded dowel pin in the joint and the bearing capacity of the general structure are investigated. To verify the structural analysis results, field tests were carried out before destruction by a stepwise increasing load on a personally designed stand. The destruction of the structure occurred according to the forecast of the numerical model as a result of the mutual slip of the glued wood layers and the destruction of the polymer matrix of the glued dowel pins with the beginning of the formation of plastic joints and the formation of cracks in the wood at the junction.

Analyses of Full-Scale Tank Car Shell Impact Tests

2007 ◽  
Author(s):  
Y. H. Tang ◽  
H. Yu ◽  
J. E. Gordon ◽  
M. Priante ◽  
D. Y. Jeong ◽  
...  
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Three Dimensional ◽  
Full Scale ◽  
Collision Dynamics ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Closed Form Solutions

This paper describes analyses of a railroad tank car impacted at its side by a ram car with a rigid punch. This generalized collision, referred to as a shell impact, is examined using nonlinear (i.e., elastic-plastic) finite element analysis (FEA) and three-dimensional (3-D) collision dynamics modeling. Moreover, the analysis results are compared to full-scale test data to validate the models. Commercial software packages are used to carry out the nonlinear FEA (ABAQUS and LS-DYNA) and the 3-D collision dynamics analysis (ADAMS). Model results from the two finite element codes are compared to verify the analysis methodology. Results from static, nonlinear FEA are compared to closed-form solutions based on rigid-plastic collapse for additional verification of the analysis. Results from dynamic, nonlinear FEA are compared to data obtained from full-scale tests to validate the analysis. The collision dynamics model is calibrated using test data. While the nonlinear FEA requires high computational times, the collision dynamics model calculates gross behavior of the colliding cars in times that are several orders of magnitude less than the FEA models.

Internal magnetic field tests and magnetic field coupling model of a three-coil magnetorheological damper

2020 ◽  
Vol 31 (19) ◽  
pp. 2179-2195 ◽  
Author(s):  
Yang Yang ◽  
Zhao-Dong Xu ◽  
Ying-Qing Guo ◽  
Yan-Wei Xu ◽  
Jie Zhang
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Field Tests ◽  
Coupling Model ◽  
Magnetorheological Damper ◽  
Internal Magnetic Field ◽  
Magnetorheological Dampers ◽  
Element Analysis ◽  
Field Coupling ◽  
Magnetic Field Coupling

Magnetorheological damper is a typical semi-active control device. Its output damping force varies with the internal magnetic field, which is a key factor affecting the dynamic performance of the magnetorheological dampers. Existing studies about the magnetic field of magnetorheological dampers are limited to theoretical analysis; thus, this study aims to experimentally explore the complicated magnetic field distribution inside the magnetorheological dampers with multiple coils. First, the magnetic circuit of a three-coil magnetorheological damper was theoretically analyzed and designed, and the finite element model of the three-coil magnetorheological damper was set up to calculate the magnetic induction intensities of the damping gaps in different currents and numbers of coil turns. A three-coil magnetorheological damper embedded with a Hall sensor was then manufactured based on the theoretical and finite element analysis, and internal magnetic field tests under different conditions were carried out to obtain the actual magnetic induction intensities. At last, the magnetic field coupling model of the three-coil magnetorheological damper was proposed by introducing a coupling coefficient to describe the complex magnetic field distribution due to the strong coupling effect of the three coils, and the results calculated by the proposed model agreed well with the finite element analysis and magnetic field test data. The proposed model lays a foundation for the optimal design of the magnetic circuit and the mathematical model of multi-coil magnetorheological dampers.

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