SSAB’s Tubular Design Tools

SSAB has developed a unique tool for designing optimized roof trusses and frames with structural hollow sections. Finding optimal design is made easy and user just needs to input few key parameters; geometry, loads and steel grades. FrameCalc does the rest to either minimize the mass or manufacturing costs.

With FrameCalc it is easy to compare different steel grades in trusses and see the benefits of high strength steels yourself. In FrameCalc it is easy to change steel grade of components group to make comparative calculations. Often it is beneficial to utilize hybrid structure where heavy chords are higher grade to save weight and lighter braces are lower grade to enable smaller weld throat thickness.

The design rules for the structures are based on Eurocode 3 and the equations are selected according to the SSAB Hollow Section Handbooks where user can select to utilize SSAB specific design rules for tubes.

FrameCalc has built-in National Annexes of Finland, Sweden, Norway, Denmark, Lithuania, Estonia, Poland, Latvia, Germany and United Kingdom.

FrameCalc can also include 15 minutes fire design without protection or calculate critical temperature for components.

FrameCalc is easy to use tool for SSAB’s customers and designers who can quickly optimize structures which makes it an excellent concept for making quotations. It is also possible to check the concept in more detail with SSAB’s FrameFEM tool.

FrameCalc’s optimized structures provide a good starting point for iterative design process. With automatically generated report it is easy to document the design process with different selections. FrameCalc provides easy way to transfer results to FrameFEM where the structure can be analyzed in more detail. In addition to that it is possible to download models of the optimized structure in CIS and IFC formats and then import the information to 3rd party software.

With FrameFEM, you can design and specify steel frame structures — including their welded joints — according to built-in Eurocode 3 design rules. FrameFEM is suitable for designing welded 2D tubular assemblies and it fully leverages SSAB’s wide range of structural hollow sections when making the calculations. SSAB offers FrameFEM calculation tool for free of charge.

FrameFEM provides functions to easily design different 2D structures made of structural hollow sections by creating geometry from scratch or modifying existing geometry.

Designer can determine different load types such as dead, wind or snow load from which common load cases are automatically generated. Custom load cases can also be generated and all the used factors in the load combinations are shown to user.

The design rules in FrameFEM are based on Eurocode 3 and SSAB Hollow Section Handbooks. The buckling lengths for components can be selected manually.

Then you can download an automatically generated PDF of the results which includes all design equations with their limits. From the report it is easy to check the utilization rate for each component and joint.

SSAB profiles can be found from Section Viewer. The Section Viewer provides cross-section dimensions among with other strength related data.

PileCalc is a design program for SSAB steel piles. Eurocode design standards as well their National Annexes and national instructions are applied in the end-bearing pile design.

PileCalc covers the National Annexes of Finland, Sweden, Norway and Germany. Also other national design rules are built inside the program. For example the calculation of the buckling resistance of the pile, which is not well covered by the Eurocodes, is done according to these national regulations.

All SSAB’s pile sizes RR75…RR/RD1200 are included in the program. Also all steel grades available for the piles can be used in the program. The structure of the pile can be designed as a steel structure (empty steel pipe pile), a concrete filled steel pipe (without composite effect), a composite structure with or without reinforcement bars and a composite structure with an inner steel pipe.

PileCalc enables dimensioning of the pile based on required design resistance. The program searches the lightest pile dimension to fulfill the given design resistance required from the pile. Search functionality can be used with micropiles and large diameter piles. In search function the structure of the pile can be designed as a steel structure (an empty pile) or it can be filled with concrete (without reinforcement and inner pipe).

If the behavior of the pile needs to be analyzed more accurately, there is also an Advanced FEM feature in the PileCalc. In Advanced FEM the soil around the pile can be modeled in several layers. Also the type of spring models of the soil can be more advanced non-linear type (depending on the national regulations). Advanced FEM also enables different types of loads for the pile. Besides the usual vertical load, also horizontal load and bending moment are possible. Lateral displacements of the pile, bending moments and shear forces for the pile and lateral soil pressure can be printed as graphs after the Advanced FEM analysis.

Calculation of cross-section properties and bending resistances of the pile walls is easy with SSAB’s PileWallCalc design tool. The program calculates the bending resistances, normal force resistances and shear force resistances of RD pile wall, Combi wall and Zig-Zag Combi wall.

Calculations are done according to Eurocode design standards. Design tool includes pile sizes RD220…RR/RD1200, all steel grades used for SSAB’s piles and a comprehensive set of sheet pile profiles from several manufacturers. Resistance of a pile wall can be calculated in either elastic state or plastic state. Also, the structure of the pipe piles can be designed as a steel structure (empty steel pipe pile), a concrete filled steel pipe (without composite effect), a composite structure with or without reinforcement bars and a composite structure with an inner steel pipe.

Often the corrosion rate varies in different depths and also on different sides of a pile wall. To help the optimization of design, there is a possibility to design two cross-sections simultaneously. The diameter of the pile pipe is the same for upper part and lower part of the wall, but the wall thickness and the steel grade of the pile pipe can be changed.

Different corrosion rates during design service life for the pile pipes are considered in the calculations. The corrosion rates can be set separately for the upper part and the lower part of the wall also different corrosion rates can be set for the both sides of the wall and for the inner surface of the pile pipes. Total of six different corrosion rates can be set.

If the corrosion rate has different values at different sides of the wall, the cross-section will be asymmetric. Program calculates the bending resistance of the wall to both directions to consider the effect of different corrosion values to resistance. Beside resistance values, the program calculates the stiffness, the section modulus and the center of gravity for the structural steel part of the cross-section.

The program creates a report which contains the initial data, effective cross-section properties and several resistance graphs for combinations of normal force, shear force and bending moment. If the cross-section has different properties in upper and lower part of the wall, both resistance graphs are shown.