Post on 10-Jul-2016
description
Midas International Symposium
Peter Reeves-Toy
Director, UAE
7th December 2015
Tony Gee Case Study
Seminar Contents
• Project Overview
– Doha Metro
• Structural Frame
– Construction Stages
– Load Manipulation
• Connection Modelling
– Solid Elements
Doha Metro
• Major Station
• Use of Construction stages to manage loads and
deflections
• Use of solid elements imported into line model
for complex connections
• Connection dxf exported from Civil, manipulated
in CAD and imported into FEA.
• Connection modelled in full in FEA, meshed and
then inserted in to Civil via MCT
Doha Metro
Msheireb
Msheireb Station
How we modelled
• Full 3d frame model in Midas civil
• Use of construction stages to control articulation
of supports
• Complex full moment connections modelled in
Midas FEA
• Connections imported back into Midas Civil
frame model for direct stress assessment
Structural Frame
• 3D Line Model
• Plate Elements use for the supporting walls
• Beam end releases modelled as per connection
design assumptions
• Offsets between connection centrelines
modelled with links for accurate load transfer
• Construction stages modelled to manipulate the
load distribution.
Structural Frame
1
2
7
654
38
Stage 1
• Activate the supporting walls (existing)
Stage 2
• Activate Module 6 Steelwork
• Apply selfweight
Stage 3
• Activate Module 6 tension rods
• Apply pretension to load
cantilevers
Stage 4
• Activate the Module 7 Steelwork
• Selfweight already active
Stage 5
• Activate Module 7 tension rods
• Apply pretension to load
cantilevers
Stage 6
• Activate Module 1 steelwork
• With props or self-
supporting
Stage 7
• Activate Module 2 Steelwork
• With or without props
Stage 8
• Activate Module 3 steelwork
• With or without props
• Apply all SIDL loads (cladding etc)
Stage 9
• Activate Module 4 steelwork
• With props
Stage 10
• Activate Module 8 steelwork
Stage 11
• Deactivate the tensile rods
• Apply post-construction variable loads
Connection Modelling
• Connection solid modelling
• Extraction of geometry from frame model
• Manipulation in AutoCAD
• Solid modelling in Midas FEA
• Meshing of connection in Midas FEA
• Importing solid model back in to frame model
Step 1
• Divide the incoming elements to at connection
• Export the elements immediately connected to
the node including shape and thickness
Step 2
• Import into AutoCAD or similar (can be done in
FEA directly)
• Rationalise the geometry
• Define additional connection elements, such as
fin plates and splice plates etc.
Step 3
• Import the AutoCAD DXF into Midas FEA
• Create surfaces at member ends and extrude
• Working from the primary elements first subtract
and fuse using the Boolean commands.
Step 4
• Use the auto mesh function setting a mesh size
similar to the plate thickness.
• Depending on geometry set mesh controls a
local discontinuities to help mesher
Step 5
• Set material number to the same as Midas Civil
• Renumber the nodes and elements
• Export to MCT and then import in to Civil
• Maintain the same coordinate system through
out.
• Connect the face of the solid to frame with rigid
link.
• Large coordinates presented an glitch
Example Stress Plot
Solid modelling top tips
• Follow the same convention each time
• Don’t rush or cut corners
• Make us of local coordinate systems to ensure
planar surfaces
• Label objects clearly including tools
• Use overlapping tools
• Subtract or fuse progressively
• Avoid narrow discontinuities
QUESTIONS!?