Numerical Methods Flashcards
1
Q
Name the main methods
A
Finite Element Method-FEM
Finite Difference Method-FDM
Boundary Element Method-BEM
Discrete Element Method-DEM
Coupled FEM/BEM
2
Q
Name method and software
A
FEM-Abaqus, Plaxis, Zsoil, SageCRISP
FDM-FLAC
BEM-BEASY, GPBEST
DEM-FLAC
3
Q
Advantages of FEM
A
-Plenty of available commercial packages
-Any shape of domain can be modelled, including holes
-Staged construction is easily modelled
-Most popular due to ease of use
4
Q
Disadvantages of FEM
A
- 3D analysis is v.time consuming and so v.expensive (days)
- Creation of initial mesh requires skill and experience
- Not easy deciding the number of increments in a non-linear and/or plastic analysis
5
Q
Advantages of FDM
A
- Very easy to use
- Mostly short computational time (minutes/hours)
- Very easy to understand mathematically
6
Q
Disadvantages of FDM
A
- Does not work as well as the FEM for complicated geometry
but mainly is as accurate
7
Q
Advantages of BEM
A
- Much better than other methods for unbounded domains such as infinite ground
- no. of simulataneous eq’ns is less than FEM so QUICKER and efficient for some problems
- Only surface of model is meshed so design changes are easier to accomodate
8
Q
Disadvantages of BEM
A
- Requires “fundamental” closed-form equations which require rigorous maths to obtain
- Requires thorough mathematical basis understanding of method
- Not a lot of commercial programs around
9
Q
Advantages of DEM
A
- Good for modelling highly dynamic effects such as fracturing
- Good for deformation and failure mechanisms
10
Q
Disadvantages of DEM
A
- Very hard to measure the parameters which are used to model behaviour (stress)
- Very high computational time-only 2D or simple 3D use
11
Q
Advantages of Coupled FEM/BEM
A
- Combines benefits of both methods
- Doesn’t require mathematical “fundamental solutions” as in BEM
12
Q
Disadvantages of Coupled FEM/BEM
A
- Needs solid mathematical background to apply method
- Very little researched
