RCsteel7

Reinforced concrete design +

Steel design for Strand7 FEA

BCDsteel has been renamed RCsteel7 with the introduction of Reinforced concrete design Sep 2023

Australia: AS 4100 + AS 3600

Europe: EC3 + EC2

US: AISC 360 + ACI 318

Reinforced concrete + Structural steel design software for Strand7 FEA

Steel to AS 4100

The section capacity is calculated for bending about both the major and minor principal axes - including Slender sections.
Star battened equal leg angle sections used for bracing are analysed to Clause 6.4.3.
Equal leg angle web members in trusses can be analysed in accordance with Clause 8.4.6. This can result in significantly higher capacity than Clause 8.4.5.
The calculation of out-of-plane capacity to Clause 8.4.4.1 uses the highest tier equation using a value of βm that is applicable to members with transverse loads as well as no transverse loads. Details of the method of calculating βm are described in the Help file.

Overview

RCsteel7 software is for the design of steel and concrete structures modelled with Strand7 FEA.

Structural steel members are checked to AS 4100:2020, Eurocode EC3 1993-1-1, AISC 360-22 (LRFD and ASD).

Reinforced concrete columns and beams are checked to AS 3600:2018, Eurocode EC2 1992-1-1, ACI 318-19

The Strand7 model can include any combination of structural steel and/or reinforced concrete columns and beams.

The members to be analysed must be modeled using beam elements. All other Strand7 features may be included in the model including links, plates and brick elements as well as multiple freedom cases, stage analyses, groups, and tapered beam elements.

The model can be analysed with first or second order elastic global analyses. In Strand7, these are the linear static solver or nonlinear static solver with nonlinear geometry.

The Strand7 API is used to display the model, using the normal Strand7 tools to control the view such as Dynamic Rotate, Show or Hide Bricks/Plates/Links/Beams/Nodes, and Show or Hide Groups etc.

The steel solvers use the highest tier equations for all codes when possible.

The concrete solver creates 3D Interaction Diagrams that define the strength for bending about both principal axes, with axial compression or tension. For column design, 2D Interaction Diagrams are created from these, that are displayed on the main form.

The tools provided are designed to minimise user input, and to provide output in a clear format that is ideal for design or for inclusion in reports.

RCsteel7 is simple to use; it is self explanatory, and does everything well. And it is enjoyable to use!

RCsteel7 has been developed independently of Strand7. The AS 4100 solver has been commercially available since 2011. The EC3 solver was added April 2017, and the AISC 360 solver added June 2018. The reinforced concrete solvers were added September 2023.

Steel to EC3

All section types supported by RCsteel7 are analysed for Class 2 to 4. Class 1 is simply treated as Class 2. The exception is Class 4 round hollow sections which are presently not supported.
For Class 2 sections, RCsteel7 calculates an “exact” solution to (6.31) for all section types supported and for any combination of N My Mz without needing to use the approximate equations in 6.2.9.1.
For 6.3.3 Bending and axial compression, Equations (6.61) and (6.62) are analysed using Annex B. The advantage of Annex B is that it requires no user input - RCsteel7 calculates all variables required. Annex A is not available at this time.

Steel to AISC 360

The user can select either Load and Resistance Factor Design (LRFD) or Allowable Strength Design (ASD).
The solver is intended for use with the Direct Analysis Method. Alternatively, the Effective Length Method can be used for structures that satisfy the limitations specified in Appendix 7.
Ch E5(a), E5(b) is included as an option for equal leg angle compression members.
Ch F buckling modification factor Cb includes the equations in the commentary and the reference documents for singly symmetric I-shapes in reverse curvature, and a load height factor for destabilizing loads.

Features

All the information relevant to the design is contained within the models data File. This means a model analysed by one person can be re-analysed by someone else even if it includes non-standard materials or sections properties.
It is possible to have multiple copies of RCsteel7 open at the same time, with a different model open in each.
The program will automatically define members and restraints, based on the geometry of the structure and taking into account node restraints, beam end release, orientation / alignment etc. Tools are provided to manually over-ride these if necessary.
RCsteel7 places no limitations on the number of load cases / combinations or number of nodes / beam elements etc.
The section property may vary along the length of a member, and the beam elements may be tapered or stepped as illustrated below here.

Reinforced concrete

RC columns are analysed for axial force + biaxial bending, including slenderness requirements.
RC beams are analysed for biaxial bending, including minimum reinforcement requirements.
Deflections, shear and torsion are not checked. These must be checked by the user.
The solver can analyse almost any cross-section shape and distribution of reinforcement.
The cross-section shape may be uniform or may vary along the length of a member.
The reinforcement may be uniform or may vary along the length of a member.
Templates must be created that define the shape and reinforcement in each different column or beam. In practice, a template can be created simply by clicking on a member in the Strand7 model. With circular and rectangular shaped templates, RCsteel7 automatically assigns initial reinforcement details.

The templates are assigned to the columns and beams in the model. A single template can be assigned to any number of members.

Having run the solver and checked the concrete members, the reinforcement in the RC templates can be simply modified as required and the model re-analysed.
RCsteel7 provides a method of satisfying code requirements for column slenderness that requires minimal user input. This avoids the use of moment magnification and moment curvature methods for calculating second order moments from a linear static analysis.
For RC beams, the minimum reinforcement is calculated from the cracking moment of a plain (unreinforced) section. This method is applicable for any shaped member, and for bending about both principal axes.

Steel shapes analysed

The solvers will analyse all the shapes shown below. The major principal axis may be oriented either direction as indicated.

Calculation speed

Analysis of structural steel members is fast:

About 1000 members are analysed per second per load combination, depending on the solver and the model details.

Concrete members take significantly longer to analyse than steel members. The 3D Interaction Diagrams are calculated for each RC template before the columns and beams are analysed. Then:

Concrete beams take about 4 times longer to analyse than steel members.
Concrete columns take about 20 times longer to analyse than concrete beams.

They include solid rectangular and solid round shapes, mirrored channels, star battened angles, and cruciform.

The pink and grey section is a boxed-in I-section that must be modelled as a BXS section. (Other BXS sections cannot be analysed).

The above figure shows a Box section with 1 internal stiffener per face. RCsteel7 will analyse a Box section with between 0 and 3 discontinuous longitudinal stiffeners per face as in the following figures:

Data File

A separate file is generated for each model that contains information required for steel and concrete design. This includes the different beam elements along the length of each member as well as information that has been assigned to each member such as: restraints along the length of the member and effective lengths.

For steel members, the data file includes a copy of the steel specifications used in the model.

For concrete members, the data file includes details of the reinforcement templates.

Help file

A context sensitive help file is included that is accessed by pressing F1.

As well, a short Help is displayed when the Mouse Pointer rests on a Control for a few seconds:

Accuracy

The target accuracy for all solvers is better than 1%.

Verification tests for the concrete solver indicate its accuracy is typically about 0.5% increasing to about 1.5% in extreme cases.

Concrete shapes analysed

RCsteel7 can analyse beams and columns that are modelled with the following Strand7 Standard shapes:

Solid round, Hollow round or Solid Rectangle.

Any other shape can be analysed provided it is modelled as a BXS shape. The only restriction on member shape is that tapered BXS shapes must be symmetric about either the major and or minor axis.

Australia: AS 4100 + AS 3600​

Europe: EC3 + EC2​​

​​US: AISC 360 + ACI 318​