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Friedrich + Lochner GmbH - Applications for structural calculation and design

Product details www.frilo.com As of: 09/05/2011

STS

Single-Span Steel Column

The STS application performsstructural safety analyses ofsteel column system. Single-piece and double symmetricalcross sections are allowed. Theverification is performed on thebasis of ideal bifurcation loadsfor lateral buckling, torsionalbuckling and lateral torsionalbuckling.

Column systems

The following structural sys-tems are supported:

- Cantilever column- Hinged column

- Column pinned on top andrestrained on bottom

- Column restrained on top andon bottom

These supporting conditionsalways apply to both main ax-es. Discrete lateral supportsand continuous elastic bedding

can be defined in addition. Formore complex supporting con-ditions, an interface to the BT IIapplication is available.

Appended hinged column

Cantilever columns are oftenused as bracing elements inhinged column systems. STScalculates automatically thecorresponding equivalent loadsand takes the change of the

effective length into account.

Basis of calculation

You can perform the designeither in accordance with

- DIN 18800-1/2 or- EN 1993-1-1

In combination with EN 1993-1-1, the regulations of the corre-sponding National Appendixare taken into account.

The following National Appen-dices are available yet:

- DIN EN 1993-1-1/NA- NORM B 1993-1-1- NA to BS EN 1993-1-1

- NEN EN 1993-1-1/NB- NBN EN 1993-1-1 ANB- CSN EN 1993-1-1/NA.

We currently work on the im-plementation of additional ap-pendices.

Analyses

The following verifications areperformed:

- Elastic or plastic cross sec-tional resistance.

- Resistance of the system tolateral buckling, torsionalbuckling and lateral torsionalbuckling

- Serviceability

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Cross sections

STS allows you to calculatecolumns with the followingtypes of cross sections:

- Standard I-sections

- User-defined double-symmetrical I-sections- Standard round and squarehollow sections

- User-defined round andsquare hollow sections

Lateral supports

Lateral supports can be definedto secure the columns againststability failure. You can enterlateral supports in STT either

as a continuous support in theform of elastic bedding or asdiscrete supports in

- the middle of the span

- the third points- the quarter points or- at a point x0.

Actions

You can expose the columnsystem to vertical and horizon-

tal loading and define head andbase moments. However, youcannot define loading that pro-duces planned torsion. Fur-thermore, you can define ap-pended hinged columns in thedirections of the both main axesand optionally apply the self-weight of the column as a resul-tant to the column head.

Combinations of actions

STS generates automaticallythe appropriate load cases andload case combinations, de-pending on the defined actions,and performs the necessaryanalyses, whereby the decisiveload case combination is de-termined for each limit state.

Pre-defined loads

In order to simplify the loaddefinition, STS offers a range ofpre-defined loads that are suffi-cient for most systems.

Optionally available are:

- Vertical loads

- Horizontal loads- Bending moments

You can enter

- wind from y/z direction and- accidental impact loads in y/z

directionas span loads applying to thecolumn head.

Calculation

STS calculates the internalforces and the deformations infirst-order analyses and deter-mines the ideal bifurcationloads, the slenderness ratiosand the reduction factors for thestability verifications in accor-dance with the equivalent barmethod.

The bifurcation loads are de-termined numerically with con-sideration to the torsional rigidi-ties. Therefore, the user canalso perform structural safetyanalyses in accordance with theequivalent bar method for morecomplex loading situations.

Interfaces to other applica-tions

The characteristic bearing forc-es can be transferred to the

applications FD, ST3 and ST6.If the real load conditions donot comply with the definedstandard or the loading situa-tion leads to planned torsion,you cannot use STS for thecalculation.

If you have a valid licence forthe BTII application (2nd OrderBuckling Torsion Analyses),you can transfer the structuralsystem to perform second order

buckling torsion analyses, ifrequired.