Mohammed Y. AHMED Supervisor: İnan KESKİN Karabuk University-Turkey

1. The Finite Element Analysis for Dynamic
Soil-Structure Interaction with
ABAQUS/Explicit
Supervisor: İnan KESKİN
mohammedyadgar@ogrenci.karabuk.edu.tr
Slide:1
Mohammed Y. AHMED
Karabuk University-Turkey

2. CONTENTS
Slide:2
 What is the Numerical Computing?.............................................Slide:3
 Applications of Numerical Methods………………………………………….Slide:5
 What is Finite Element Method?..................................................Slide:6
 The Methodology of FEM Working…………………………………….….....Slide:8
 What is The Dynamic Soil-Structure Interaction?.........................Slide:9
 What are the effects of Soil-Structure Interaction?.....................Slide:12
 The Finite Element Method with
The Dynamic Soil-structure Interaction…………………………….……….Slide:14
 The Finite Element Method with
The Dynamic Soil-structure Interaction equation………………………Slide:15
 What is ABAQUS/Explicit?.............................................................Slide:17
 Simulation…………………………………………………………………………………Slide:19
 Abaqus/Simulation of Finite Element Analysis
for Dynamic Soil-Structure Interaction………………………………………Slide:20
 Reference………………………………………………………………………………….Slide:23

3. What is the Numerical Computing ?
Slide:3

4. Numerical Computing
Numerical Computing : Is an approach for solving complex mathematical
problems, Engineers use mathematical modeling (equation and data )to describe
and predict the behavior of modeling, “Use a computer for calculation this
approach called Numerical Method ”.
Slide:4

5. A few applications of Numerical Methods in Engineering
1- Finite Element Method (FEM) 2- Finite Difference Method (FDM)
3-Boundary Element Method (BEM) 4-Discrete Element Method (DEM)
5-Smoothed Particle Hydrodynamics (SPH) 6- Applied Element Method (AEM)
7-Material Point Method (MPM) 8-Computational Fluid Dynamics (CFD)
Slide:5

6. What is the Finite Element Method?
Slide:6

7. Finite Element Method (FEM)
Finite Element Method : is a numerical technique for solving problems which are
described by partial differential equations or can be formulated as functional
minimization.
Slide:7

8. The Methodology of Finite Element Method Working
Slide:8
Select interpolation functions: Interpolation functions are used to interpolate the field variables over the element.
Find the element properties: The matrix equation for the finite element should be established which relates the nodal
values of the unknown function to other parameters.
Assemble the element equations: To find the global equation system for the whole solution region we must assemble all the
element equations.
Solve the global equation system: The finite element global equation system is typically sparse, symmetric and positive
definite.
Compute additional results: In many cases we need to calculate additional parameters. For example, in mechanical
problems strains and stresses are of interest in addition to displacements.
Discrete the continuum: The first step is to divide a solution region into finite elements.

9. What is The Dynamic Soil-Structure Interaction?
Slide:9

10. The Dynamic Soil-Structure Interaction
Slide:10
In structures founded on non-rigid formations, the soil flexibility influences structural response
and vice versa. This phenomenon is called SSI.

11. The Dynamic Soil-Pile Interaction
Slide:11
Pile usually represents as lender structural element that is driven into the ground. However, a pile often used
as a generic term to represent all types of deep foundations. When care the lode or effective dynamic load
laterally and vertically, the starting soil responsible and the pile frailer.

12. What are the effects of Soil-Structure Interaction ?
Slide:12

13. Slide:13
The effects of the SSI are more focused on its detrimental effects, There is elongation of seismic waves when
it is on a site of soft soil sediments
The soil structure interaction can have two types of effects
1. Kinematic Interaction: The soil displacement caused by the earthquake ground motion is called as the
free-field motion. This free field motion is not followed by the foundation that is located on the soil. The
kinematic interaction is caused by the inability of the foundation to sink with the free field motion of the
ground.
2. Inertial Interaction: The study and researchers from the past and recent earthquakes show that the
overall response of the structure is affected by the:
a. Response from the foundation
b. Response from the soil
Effect of Soil-Structure Interaction and Structural Response

14. The Finite Element Method with The Dynamic Soil-structure Interaction
Slide:14
• Finite Element Method formulation: According to the differential equation
then the most popular method of them its Galerkin method and Variational
formulation selected Galerkin method because physical formulation of the
problem is know.
• Dynamic Soil-Structure Interaction formulation use beam on nonlinear
wenkler foundation and for find the lateral stiffness and vertical and
displacement use (p-y), (t-y) and (Q-y) method.

15. The Finite Element Method with The Dynamic Soil-structure Interaction equation
Slide:15
𝑎
𝑑2 𝑢
𝑑𝑥2 + 𝑏 = 0 0 ≤ x ≤ 1
[K], {U} and {F} are global stiffness matrix, displacement vector and load vector
U(0)=0
U(1)=0
Boundary condition
𝐾 =
𝐴𝐸
𝐿
1 −1
−1 1
𝐹 = {𝐹𝑛}
𝑈 = {𝑈 𝑛}
[K]{U}={F}
For p-y Curve ( load - Displacement )
𝑛𝑜𝑑𝑒1
𝑛𝑜𝑑𝑒2
1 [𝐾1]
{𝑈1}{𝐹1}
𝐴𝐸
𝐿
[K]{U}={F}General Numerical equation

16. The Finite Element Method with The Dynamic Soil-structure Interaction equation
Slide:16
𝒌𝒋 = 𝒌𝒋 𝒂 𝟎, 𝒗 + 𝒊𝝎𝒄𝒋 𝒂 𝟎, 𝒗
𝑘𝑗; complex − valued impedance function
j; index denoting modes of translational displacement or rotation
𝑘𝑗; Static stiffness, 𝑘𝑗 = 𝑲𝑗 × 𝛼𝑗
𝛼𝑗; Terms are dynamic modifiers of the static stiffness depending on
dimensionless frequency (a0)
𝑎0 =
𝜔𝑟
𝑉𝑠
V; Poisson’s ratio
𝑐𝑗; foundation stiffness and damping
𝜔; angular frequency (rad
s)
6 springs for 3D system

17. What is ABAQUS/Explicit ?
Slide:17

18. Slide:18
ABAQUS/Simulation
ABAQUS: is a software Computer-Aided Engineering and The Abaqus Unified FEA product suite offers powerful
and complete solutions for both routine and sophisticated engineering problems covering a vast spectrum of
industrial applications static and dynamic.
• Abaqus/Implicit
• Abaqus/Explicit
Explicit means that the solution is performed with direct iterative calculations and Explicit may work better for
dynamic or quasi-static problems in a very short period of time that also involve nonlinearities
Implicit algorithms mean that the solution needs to be computed by adding another formulation(s) since some
terms can not be calculated explicitly at the searched step : this is an indirect calculation.

19. Slide:19
Simulation
Simulation: Computer simulation has become a useful part in the modelling of many natural systems in physics,
chemistry, biology and human systems in economics and social sciences, as well as in engineering to better
understand the functioning of these systems, for example Black Hole
Simulation

20. Slide:20
Abaqus/Simulation of Finite Element Analysis
for Dynamic Soil-Structure Interaction
When the thinking about this title really you know predate what I say and the primary question how can I
predate a simulation (near to same really) of pile embedding in soil. what happing?

21. Slide:21
Abaqus/Simulation of Finite Element Analysis
for Dynamic Soil-Structure Interaction
Modeling Video

22. Slide:22
Abaqus/Simulation of Finite Element Analysis
for Dynamic Soil-Structure Interaction
My Model

23. Slide:23
Reference
1. Abrahamson, N. A. (1992). “Spatial variation of earthquake ground motion for application to soil–structure interaction.” Rep. No. TR-100463, Electrical
Power Research Institute, Palo Alto, CA.
2. Crouse, C. B., Liang, G. C., and Martin, G. R. (1984). “Experimental study of soil-structure interaction at an accelerograph station.” Bull. Seismol. Soc. Am.,
74(5), 1995–2013.
3. Veletsos, A. S., and Wei, Y. T. (1971). “Lateral and rocking vibrations of footings.” J. Soil Mech. and Found. Div., 97(9), 1227–1248.
4. Vrettos, C. (1999). “Vertical and rocking impedances for rigid rectangular foundations on soils with bounded non-homogeneity.” Earthquake Eng. Struct.
Dyn., 28(12), 1525–1540.
5. Britto, A. M., and Gunn, M.J. Critical State Soil Mechanics via Finite Elements. Chichester U.K.: Ellis Horwood Ltd, 1987.
6. Canadian Geotechnical Society (2006). Canadian Foundation Engineering Manual, 4th Ed., Montreal, Quebec.
7. Abaqus 2004. User’s manual, Version 6.4.
8. Achmus, M. & Abdel-Rahman, K. 2003. Numerische Untersu-chung zum Tragverhalten horizontal belasteter Monopile-Offshore Wind energy anlagen. 19th
Chris-tian Veder Kolloquium, Graz/Austria.
9. Kavvadas, M., and Gazetas, G. (1993). “Kinematic seismic response and bending of free-head piles in layered soils.” Geotechnique, 43(2), 207–222.
10. Dobry, R., Vicente, E., O’Rourke, M. J., and Rosset, J. M. (1982). “Horizontal stiffness and damping of single piles.” J. Geotech. Eng. Div., Am. Soc. Civ. Eng.,
108(3), 439–459.