Accuracy of Stress Analysis Using Numerical Integration of Elastic Half-Space

2013 ◽  
Vol 300-301 ◽  
pp. 1127-1135 ◽  
Author(s):  
Radim Čajka
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Numerical Integration ◽  
Half Space ◽  
Elastic Half Space ◽  
Rigidity Matrix ◽  
Interaction Solutions ◽  
Proposed Model ◽  
Isoparametric Elements

In case of constructions placed on subsoil, it is necessary to create a rigidity matrix for the element subsoil. That rigidity matrix should be then added up in respective positions with the rigidity matrix of an element. To clarify the proposed model of the subsoil, a method is derived for determination of vertical subsoil stress analysis under any shape of a slab construction by means of numerical integration and theory of isoparametric elements using the Jacobian transformation. This approach is rather original and represents the key contribution of this work in interaction solutions. Using the proposed approach, the method can be employed for any shape of a finite element.

Time Effects on Settlement of Rigid Pile Composite Foundation: Simplified Models

2018 ◽  
Vol 15 (07) ◽  
pp. 1850066 ◽  
Author(s):  
Meijuan Xu ◽  
Pengpeng Ni ◽  
Guoxiong Mei ◽  
Yanlin Zhao
Keyword(s):  
Numerical Integration ◽  
Half Space ◽  
Unsaturated Soils ◽  
Pressure Coefficient ◽  
Closed Form Solution ◽  
Elastic Half Space ◽  
Composite Foundation ◽  
Model Parameters ◽  
Time Effects ◽  
Rigid Pile

The behavior of pile composite foundation is studied using the flexibility method. During the analysis, determination of the flexibility matrix (settlement) is critical. However, conventional methods of Winkler and elastic half-space foundation models are incapable of considering the time effects of soil consolidation and creep. The foundation model of Zaretsky and Tsytovich [1965] can be used to evaluate settlement for unsaturated soils, but the complexity of numerical integration over an arbitrary loading area hinders its application. In this paper, a novel scheme is proposed for numerical integration by rotating the loading surface using the equiareal transformation technique. Therefore, a simplified closed-form solution is developed to calculate time dependent settlement for foundation soils. The efficacy of the proposed technique is demonstrated using illustrative examples of an elastic half-space, a rigid raft foundation without piles, and rigid pile composite foundations with multiple piles under surface loading. Furthermore, parametric study is conducted to evaluate the sensitivity of model parameters. The permeability [Formula: see text] and Poisson’s ratio [Formula: see text] are found to be important, whereas pore pressure coefficient [Formula: see text] and degree of saturation [Formula: see text] are less significant in the calculation.

Numerical Analysis of Deformations of the Shallow Square Foundations with Variable Relative Stiffness

2016 ◽  
Vol 837 ◽  
pp. 5-9
Author(s):  
Lubos Hrustinec ◽  
Jozef Sumec
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Half Space ◽  
Elastic Half Space ◽  
Relative Stiffness ◽  
Theoretical Assumptions ◽  
Bond Effect ◽  
Relative Deflection ◽  
Element Method

The paper deals with numerical analysis of deformations and relative displacements (relative settlement, relative deflection and flexibility) of the shallow square foundations depending on the variable relative stiffness. For solution of the problem finite element method was used with theoretical assumptions of the linearly elastic half-space. Foundation-subsoil contact was modelled by one-directional and bi-directional bond effect. Results of the solution are presented by graphical forms.

scholarly journals MODERN APPROACHES TO SOLVING THE CONTACT PROBLEM OF PRESSING A DOUBLESTAMP STAMP INTO AN ELASTIC HALF-SPACE

2021 ◽  
pp. 74-79
Author(s):  
Tetyana Zaytseva ◽  
Ivan Shmelov
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Contact Area ◽  
Software Package ◽  
Complex Shape ◽  
Element Model ◽  
Circular Ring ◽  
Elastic Half Space ◽  
Ansys Software ◽  
Java Language

The work is devoted to solving indentation problems into an elastic half-space of a cylindrical punch with a flat base by the vertical force. The force is aimed through the center of the base. The cross-section of the stamp is a doubly connected area bounded by two concentric lines. A concise review of methods for solving problems of analyzing the contact interaction of cylindrical dies with an elastic half-space is given. The solution of the problem in the form of decomposition by a small parameter is used when the equation of the edge curves depends on the same small parameter. To achieve it, in each approximation, the problem of indentation of a stamp with a doubly connected contact area in the form of a non-circular ring is reduced to a similar problem of indentation of a stamp with a contact area in the form of a circular ring. The software in the Java language has been developed for processing the analytical solution according to the obtained calculation formulas. With the help of the ANSYS software package, a finite element model of the contact interaction of an absolutely rigid stamp with an elastic half-space has been created. Numerical modeling was carried out using a licensed version of the program, free of charge. Several problems have been solved for square rings of different widths. The distribution of pressure under the stamp over different sections and the deepening of the stamp have been obtained. The pressure distribution graphs are plotted. When considering several test problems to assess the adequacy of the finite element model, the numerical results are compared with the results obtained analytically. The resulting model can analyze and predict loads, wear, and fracture of the contact area. The research prospects can include the solution of several problems of analysis of the stress-strain state of the interaction of dies of a complex shape with an elastic half-space, as well as groups of stamps of a complex shape, and the analysis of behavior models depending on the properties and characteristics of an elastic half-space. Keywords: contact problem, stamp, stress-strain state, modeling, JAVA language, finite element analysis, ANSYS software package.

Numerical Solution of Prestressed Foundation - Subsoil Interaction Using FEM

2020 ◽  
Vol 832 ◽  
pp. 81-88 ◽  
Author(s):  
Radim Čajka ◽  
Jaroslav Navrátil
Keyword(s):  
Numerical Solution ◽  
Numerical Integration ◽  
Half Space ◽  
Structural Strength ◽  
Elastic Half Space ◽  
Isoparametric Element ◽  
Foundation Soil ◽  
Fem Model ◽  
Interaction Task ◽  
Internal Forces

This paper deals with prestressed foundation - soil interaction. For interaction task is used FEM model of thick slab with shear influence which is supported by structural strength modified elastic half-space. The calculation of deformations, internal forces and contact stresses in subsoil is performed iteratively by means of isoparametric element and numerical integration. The results of settlement and stress of non-prestressed/prestressed slab - subsoil interaction are compared on example.

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