Bridge and non linearities.ppt

7/30/2019 Bridge and non linearities.ppt

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Bridges and Civil Non Linearities ModuleINGECIBER, s.a.


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CivilFEMfor

ANSYS

INGECIBER, s.a.

for

ANSYS

Introduction

This module includes a set of tools that make

easier and improves the analysis and design ofcomplex bridges, specially of prestressed concretebridges.

The module has been provided with utilities thathelp the engineer in all the calculation steps: layoutand cross sections definition, model generation,loads generation (overloads, moving loads,prestressed cable loads, etc), loads combination,construction process simulation, analysis of

results and so on.


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CivilFEMfor

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INGECIBER, s.a.

for

ANSYS

Bridge layout in plan view In plan view, the mileage points line is a succession of user-

defined stretches as: straight segments

circular arcs

clothoid arcs

(x,y)i i

(x,y)f f

R

i

f

s=s+Lo

R

ii

s

x

yClothoidaxis

cl

cl


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INGECIBER, s.a.

for

ANSYS

Bridge layout in elevation view In elevation view, the mileage points line is a succession of

user-defined stretches as: straight segments

parabolic

si

sf

i

f

f

L

zf

zi

s

Straightsection

Straightsection

Parabolicfillet

s

s

if

ii

z


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ANSYSINGECIBER, s.a.

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ANSYS

Bridge cross sections This module includes a library of typical bridge cross

sections, which are defined by the outline of the section: Slab cross sections (solid or hollow)

Box cross sections

Bridge Section Types

Rectangular section

Trapezoidal section

Trapezoidal section with flanges

Polygonal section with two bends

Polygonal Asymmetric with two bends Note: The upper line (deck) is alwayshorizontal. The slope must be laterdefined with the sections bank.

B

DEPTH

RS

BTOP

BBOT

DEPTH

TTOP

TS

DEPTH

BTOP

BM

BBOT

TTOP

TBOTTF

TBOT BBOT

BM2

BM1

BTOP

DEPTH

TTOP

TM

PS

BBOTR

BM2R

BM1R

BTOPRBTOPL

BM1L

BM2L

BBOTL

DEPTHL

TBOTL

TML

TBOTR

TTOPR

TMR DEPTHR

axis

PA

Tri-cell box section definition

a1

p11

b1

a2

t 22 t 21

t 11

p21p22

s31

1

1

p121

11

t 31

hL

vL

y

z

vCL

hCL

hCU

vCU

t41

vU vUr

hU hUr

a /20

vCUr

hCUr

hCLr

vCLr


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Slab concrete sections Its possible to define holes

The sections can be symmetric or asymmetric Sections and the hole diameters might differ along the bridge

Each section has associated an

axis coordinate system Oxy


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Box sections with variable depth Any generic box section can be easily defined

All the necessary input parameters can be introduced eitherby menu or using the corresponding command (allowsperforming a parametric design of cross sections, creatingmacros, etc).

Tri-cell box section definition

a1

p11

b1

a2

t 22 t 21

t 11

p21p22

s31

1

1

p121

11

t 31

hL

vL

y

z

vCL

hCL

hCU

vCU

t 41

vU vUr

hU hUr

a /20

vCUr

hCUr

hCLr

vCLr


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Assigning attributes (Sections/Layout)

For the automatic generation of the complete geometrical

and FE model, the defined cross sections should beassigned to the mileage points (MPs) that forms the

bridge layout.

The sections transition between MPs can be defined

defined using straight segments, splines and so on.

Cross sections

(MPs)

Trans = 0Trans=1

Section's transition definition

1

23

54

Road axis


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Assigning attributes (Sections/Layout)

The cross sections may have the following attributes:

Offsets Banks

Skew

Hollow or solid sections

z

yZoffs

Yoffs

MP,s line

Bank (Rotation's center P)P

Cross sections at supports

Hollow section(Solid=0 or blank Solid sectionAccording to original contour (Solid0)


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Model generation Once the layout and cross sections are defined the

geometrical and FE model can be automatically performedby the program.


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Model generation Its possible to automatically generate the finite element

model either with Solid elements or with Beam elements.

Beam element model

(eshape option)

Solid element model


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Model generation Allows for a trial and error process using beam elements

(less CPU and engineer time).

Automatic discretization of the beam elements crosssections in points and tessellas (allows for analyzingsection internal behavior using beam elements)

More accurate design can be performed using SOLIDelements by only changing the element type and runningagain.

Tessella discretization

Beam element model


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Special features Any of the bridge parameters (layout, sections, dimensions,

etc) can be easily parametrized by the user, allowing tomake very fast sensitivity analysis, making use of someadvanced features:

Log files- the program stores in a file all the ordersexecuted by the program during a job. This file can be

edited by the user at any time and the model can beexecuted again by just reading it

Macros (APDL)

Customization: the users are able to create their own

windows, commands, etc, customizing the program asmuch as possible to their needs


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Loads generation

CivilFEM automatically generates the

loads corresponding to the variousload hypotheses over a 2D or 3Dstructure, such as:

Moving loads (traffic loads)

Surface loads (Overloads) Prestressed tendons

Any kind of user defined loads

Smart load combination of al the

load steps generated during theanalysis


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Loads generation- Traffic loads From the vehicle's editor it is possible to create vehicles,

import from library, modify, copy, delete and list.

Property window

Vehicles library: just

choose the vehicle andthe corresponding

properties are

automatically defined


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Loads generation- Traffic loads Allows to consider the breaking or starting load (horizontal) for

each vehicle wheel

One or more vehicles can be used at the same time


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Loads generation- Traffic loads Two different types of vehicles: Rigid (truck) or flexible

(train, adptable to the path)

User friendly path definition: road surface and road axis

are automatically detected by the program

MP,s

linecompone

Vehicletraject

Assemblyt hebr idgesnodesandelements,

wheret heloadsareapplied

Dist

Thetangencyoccursint hepoint( xLoc,yLoc) of t hevehicle

KP,s

Linescomponent

Vehicletrayect oryAssemblythebridgesnodes andelements,

wheretheloadsareapplied


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Loads generation- Surface loads Definition of an overload grid over the deck

Automatic load and combination of all possible loadcase scenarios

Definition of surface loads

KP,s Linescomponent

Overloadgrid

s1

d1d2

dm

Assembly with the bridges nodesand elements over which thesurface load will be applied


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Loads generation- Prestressed cables Definition of some points along the cables path (automatic

adjustment of the points using splines)

Introduce the tension force at specific locations of the tendons

path

Automatic introduction of the cable action over the structure: the

program finds an equivalent system of forces at each node of the

element that equilibrate the system

3D spline generation

PP

PPP

12

k+2k+1N

P'1 P'N

Pk

Transmision of the cable actions to the model

OP

xR

R

MRy

z

MRz

xMR

c.d.g.R

y

Kfx

Kfy

Kfz

T1

T2

1

2


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Load generation- Notes In addition to the automatic loads generation

explained here in, any other user-defined load canbe applied to the structure such as wind loads, snow,seismic (automatic definition of spectrum accordingto codes) and so on.

The automatic load generation feature, although is

inside the bridges module, can be applied to anyother structure by just defining the surface overwhich they are to be applied.


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Dynamic analysis A transient analysis can be automatically performed.

Possibility of introducing the velocity while definingthe moving loads


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Load combination- Example Where must be located the two engines to obtain

the maximum stresses at point P? What is the maximum bending moment at section A-

A ?

Which are the concomitant values?

P

A ---- A

??? ?? ?? ?


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Load combination In the bridge analysis process, a great number of

load steps are generated, which later on have to becombined looking for the worst case scenario.CivilFEM includes functionalities that automaticallyhandle with all the possible load cases

Obtains the envelop that considers the worst case

scenario for each structure point by specifying atarget

Concomitance at both global and element levels

Variable load coefficients can be defined

Combining the moving loads (traffic loads) The program automatically combine them as an

incompatible load (detects that the vehicle can

only occupy one position at the same time)


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Load combination Combining the surface loads (overloads)

The program automatically combine them as acompatible load (detects that these loads can be

located at any possible position over the surface)

To obtain theenvelop ofmaximum verticaldisplacements atall nodes

OBJECTIVE:


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Load combination Combining the prestressed cable loads

The program automatically combine them as anaddition load (adds all the loads and apply them

at the same time)

Combining user-defined loads

The same procedure is applied by just defining thecombination rule to be applied (compatible,incompatible, addition, selection, etc) to find thecombined results


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Families HTML list

Allows listing of load families properties


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Checking & Design Serviceability Limit State

Checking of cracking according to codes


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Checking & Design Ultimate Limit State

Checking and design of the bridge reinforcementaccording to codes, taking into account all theloads applied over the structure.


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Simulation of construction process The bridges module allows to simulate different types of

construction process

Normal Procedure


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Simulation of construction process Cantilever built bridge

Y

X

Puente construido mediante dovelas yuxtapuestas: Situacin despus del step #3

Y

Z

Pile Section: AreaU, I , I , AreaB, I ,I , HyyU

z

Bridge plant

Not builded zone

10 11 12 13

Sections

12

Steps

Live cable

7 8 9 14 15 161 2 3 4 5 6

23

11

2

3

H

Live pile support

Not live support

zzU yyB zzB

Pile section axis

Bridge section axis


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Bridge Model The finite element model of the bridge is automatically generated

by the program from its geometry and layout parameters (see cross

section and layout of a banked curve).


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Bridge ModelPlan view of a portion of the bridge deck


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Bridge ModelSolid cross section


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Bridge ModelHollow cross section


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Bridge ModelView of the hollow cross section

Documents

Bridge and non linearities.ppt