Civil Engineering Reference
In-Depth Information
Table 4.3
Comparisons between different levels of structural models (
relative measure
).
Model
type
Discretization
type
Tridimensional
effects
Structure
prototype
Analysis
target
Complexity/
Accuracy
Computational
demand
Substitute
SDOF
Usually not
accommodated
Primarily
regular
structures
Global response
Low
Low
Stick
MDOF
Accommodated
All types of
structure
Global response
Medium
Medium
Detailed
MDOF
Accommodated
All types of
structure
Local and Global
response
High
High
M
ACROSCOPIC
M
ODELS
S
PATIAL
D
ISCRETIZATION
M
ODELS
I
NTERMEDIATE
M
ODELS
M
ICROSCOPIC
M
ODELS
A
CCURACY
Figure 4.4
Classifi cation of models for spatial discretization of structural systems
meshes are utilized for the piers, where inelasticity is expected. For buildings, detailed models are often
used to idealize the frame of the superstructure, while stick models are used for foundations. Where
walls and cores exist, there are possibilities of modelling them using 2D or even 3D continuum elements
to detect the spread of inelasticity.
Problem 4.1
Consider the medium-rise building and the suspension bridge shown in Figure 4.5. Sketch suitable
models for the analysis of the two structures. What type of analysis should be used and why? If
vertical and horizontal components of ground motion should be accounted for, how would they be
combined?
Problem 4.2
Sketch suitable models for the three structural systems shown in Figure 4.6 and justify the selection
of models.
