7D DESIGN OF STEEL STRUCTURES BASE BOLT JOINT

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7D DESIGN OF STEEL STRUCTURES BASE BOLT JOINT

• Markku Heinisuo1), Ville Laine2)
• 1)Tampere University of Technology, Tampere,
  Finland
• 2)KPM-Engineering Oy, Tampere, Finland

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7D DESIGN On-going partly industrial
(Rautaruukki, FMC, KPM, SS-Teracon, Ramboll)
project, main finansing Seinäjoen Elinkeinokeskus
Simulation of accidents (fire, explosions,
generally robustness and safety of structures) gt
1D
Search engines (optimisation) gt 1D Risk
management (included or one D more?)
Solver user interface to control all Ds
Product model gt 3D Duration gt 1D
Cost functions and cost databases gt 1D
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• 7D applications in this research project (steps
  in design process)Step 1 Product model of
  steel skeleton (Tekla Structures), new
  intelligent joint macrosStep 2 Structural
  analysis model. Where is intelligence? Analysis
  model includes component model of Eurocodes for
  joints extended to 3D gt joint stiffnesses
  automatically taken into accountStep 3
  Structural analysis (Robot, Staad)Step 4 Check
  of resistances of joints. Where is intelligence?
  Resistance checks embedded into Tekla
  macrosStep 5 Check of costs of steel skeleton
  including fabrication costs of members and joints
  using the first version of Solver (not shown
  here)Step 6 Iterations if needed

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Joint model development in EN line
EN 1993-1-8 Component model Tchemmemegg at al,
1987
Modified component model Sheffield
model Includes fire resistance checks
Modified Sheffield model TUT model, this
paper Extension to three dimensions
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TUT model for base bolt joints
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Example 1
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Example 2
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CONCLUSIONS Local analysis models (TUT models)
can be generated from the geometrical entities of
the joints. This means automatic generation from
the product model. The TUT model enlarges the
component method of Eurocodes to three
dimensions. The use of non-linear TUT model
leads to the very good agreement in the cases
considered when comparing the results to the test
results available dealing with the resistances
of the joints and the stiffnesses of the joints
in the normal situation. In the fire situation
the similar research will be done in the near
future. The use of non-linear TUT model leads to
the application of the geometrical non-linear
theory for the entire frame. The stiffnesses of
joints are automatically taken into account in
the structural analysis. No extra checks due to
the second order theory is needed after the
analysis, because they are involved into the
non-linear analysis. The proposal is given (TUT
linear) to linearize the non-linear case using
the mean of rotational stiffnesses without axial
forces. This may be used in the preliminary
design stage. The errors of 20 in the utility
ratios of the joints (safe and unsafe) are shown
using this approach in one extremely simple case.
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CONCLUSIONS, cont. It is recommended, that the
final design will be done using the non-linear
theory if the computational times are reasonable.
The computational times are highly dependent on
the sizes of the problems. Applications to other
structural steel joints are given in the near
future. Next task is to implement the results to
the design software in the near future including
the fabrication cost information and the
development of the cost estimation module for the
practical use for the engineers. The user
interface to the joint macro dealing with the
choice of the analysis model of the base bolt
joint was proposed. Estimating variations are
given, too. After the implementation the search
of good solutions can be done fluently also in
the preliminary design stage. Modern computers,
computational tools and programs have made it
possible to develop this kind of method and the
results can be used by the practising engineers,
because they have these modern systems in every
day use nowdays. This project has been completed
in the close interaction between practising
engineers and the research staff. Term near
future means that the tasks are included in the
on-going national 7D project.
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