Solutions for Prestressed Reinforced Concrete Structures

Report
Solutions for Prestressed
Reinforced Concrete Structures
The state-of-the-art technology for
the civil engineering world
Prestressing Material Library
When selecting a material from
the library all properties are
automatically defined
Any property used for
prestressing loss calculation
can be easily modified
Prestressed Concrete Structures
Model Creation
• The first step in the use of the Advanced Prestressed Concrete
module is the model creation. The prestressing forces are applied
later on in each one of these kinds of models:
• Beam element model
• Shell element model
• Solid element model
Prestressed concrete structures
checking
• ANSYS®+CivilFEM® includes the Checking and Design
of hyperstatic prestressed concrete structures, taking
into account shear and torsion effects, conforming to the
following codes:
• Eurocode 2
• ACI
• EHE
Prestressed structures
• The calculation of prestressing
losses distinguishes between
Pre-tension and Post-tension
structures.
• Therefore, for the Pre-stressed
structures, CivilFEM
incorporates, for example, the
reinforced thermal expansion
due to the heating process, in
addition to the pull-in losses and
elastic concrete deformation,
long-term losses (creep and
shrinkage, etc)
3D Tendon Geometry Editor
•
It allows the definition and edition of the geometric and strength
properties of all tendons of a structure. The geometry may be shown
and edited either graphically or by coordinates
Tool Bar
Object Tree
Elevation
View
Info/Edit
Window
Plan
View
3D Tendon Geometry Editor
• It is possible to visualize the corresponding cross section
and the location of the tendons along the structure.
3D Tendon Geometry Editor
• Graphical visualization of all prestressing losses for each
tendon along the structure.
Prestressed Concrete Module
1
ELEMENTS
MAT
JAN
NUM
7 2004
13:54:12
• From this version v12, it is possible to define tendons
with complex geometry without using the support beam
Y
Z
X
Prestressing Losses
• The prestressing loss calculation allows to obtain the
instantaneous and the long-term prestressing losses for
the tendons defined within the CivilFEM tendon editor.
• Instant losses: P1, P2, P3, Px
• Friction losses (P1)

2
P0

1

1
2
3
x
Friction losses
P = P - P
3
x
0
1
Prestressing Losses
• Pull-in Losses (P2)
P
w
P0
P1 (x)
Sp (w)
P (max)
2
P (x)
Jack force
2
Loss due to the
pull-in of weges
P(x) = P0 - P1 (x)
Anchored end
x
Loss due to pull-in (theoretical approach)
• Elastic concrete deformation (P3)
• Others (Px)
Prestressing Losses
• Apart from the instantaneous losses, the program also
calculates the following long-term losses:
• Concrete shrinkage (P4)
• Concrete creep (P5)
• Steel relaxation (P6)
Prestressing Losses
• The tendon properties and the calculated losses can be
listed in an HTML document.
List
Calculate losses
View Results
Prestressing Losses
• User Defined Prestressing Losses
Reads the prestressing losses from a file
2D/3D Deviation Forces
• CivilFEM calculates the deviation forces produced by the
prestressing tendons on any 2D or 3D solid or beam
structure defined in ANSYS®.
• The deviation forces are defined as a specific load set
automatically located on nodes and/or distributed on the
elements.
Prestressed Forces and Moments
• Both isostatic and hyperstatic
effects corresponding to
Prestressing actions are
calculated
1
Y
11
Z
1
Y
11
Z
X
ANSYS 8.0
FEB 19 2004
10:07:19
PLOT NO. 16
LINE STRESS
STEP=1
SUB =1
TIME=1
CFETAB_ICFETAB_J
MIN =-.101E+08
ELEM=19
MAX =.173E+08
ELEM=37
-.101E+08
-.707E+07
-.402E+07
-984594
.206E+07
.510E+07
.814E+07
.112E+08
.142E+08
.173E+08
X
1
Y
11
Z
X
ANSYS 8.0
FEB 19 2004
10:07:19
PLOT NO. 17
LINE STRESS
STEP=1
SUB =1
TIME=1
CFETAB_ICFETAB_J
MIN =-.203E+08
ELEM=31
MAX =.738E+07
ELEM=25
-.203E+08
-.173E+08
-.142E+08
-.111E+08
-.802E+07
-.494E+07
-.186E+07
.122E+07
.430E+07
.738E+07
ANSYS 8.0
FEB 19 2004
10:07:19
PLOT NO. 18
LINE STRESS
STEP=1
SUB =1
TIME=1
CFETAB_ICFETAB_J
MIN =-.869E-06
ELEM=50
MAX =.116E+08
ELEM=37
-.869E-06
.129E+07
.257E+07
.386E+07
.515E+07
.643E+07
.772E+07
.901E+07
.103E+08
.116E+08
Prestressed Forces & Moments
• Stresses in the support and in the middle of span.
Checking of Prestressed Structures
• Serviceability Limit State
• Checking of cracking according to codes
taking into account the prestressing cables
Checking of Prestressed Structures
• Ultimate Limit State (Axial+Bending checking)
Other Utilities
• Although the prestressed utilities are mostly focused on bridge
calculation, it’s also possible to make use of them in other kind of
structures such as prestressed slabs, silos, etc
Prestressed Concrete Structures
Other Projects
• A group of loads, equivalent to the effect of the prestressing
tendons will be created on the model and transferred to its nodes.
• This method can be applied to any kind of model or mesh (even
on a model made up of beam elements)
Prestressed Concrete Structures
Other Projects
Prestressed Concrete Module

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