Linear and non-linear analysis of complex RC/Composite/Generic cross-sections

BiaxialPRO is an advance enginnering tool developed by STRUANG for complex cross-section analysis. 

It allows the biaxial bending calculation of complex reinforced concrete and composite cross-sections. 

BiaxialPRO studies the section using fibers method by defining a high-level mesh. The software can be used for generic composite material, written mainly for composite concrete/steel and timber/concrete elements. 

It provides several results including Curvature, Ductility and Crack-width calculation. 

Once calculation process is complete user can export all the relevant output in a detailed report.

Fun fact: This program was originally known as BiaxialCrack

Main features

• Output
o Stress and strain colored map for any type of analysis (matrix material reacting or not to the tensile stress),with the capability to show a section cut for a specific plan of the cross-section
o Ultimate cross-section resistance 3D domain with all the external forces plotted against the domain. This allow a quick verification of all the external forces in terms of ultimate resistance
o Ultimate cross-section resistance 2D domain for a specified set of forces (Mx,My and N)
o Moment vs Curvature diagram for any Biaxial bending direction. This graph shows the resistance of the cross section by increasing the curvature, showing all the relevant achieved point during the element loading (I.e. concrete spalling, reinforced yielded, concrete plasticisation, failure)
o Ductility calculation for seismic request UNI EN 1998 (ITA annex)
o Crackwidth calculation (UNI EN 1992-1-1 - method1: based on rebate stress, diameter and distances inside the tensile zone; method2: rebar stress based)
o Shear studs connection for a generic non homogeneous composite cross-section (included timber/concrete)
o Detailed report of all the relevant calculation (excel and word documents). Report Lang. : English, Italian and German. Report Format : Word, Excel and .txt

• Verifications
o UNI EN 1992-1-1 SLS and ULS verification. A general verification panel shows the cross-section utilization factor for any verification type and for all the combinations (unlimited)
o Minimum and maximum amount of reinforcement according EN1992-1-1

• Import/export
o Import and export of un-limited forces combinations
o Import and export of reinforcement
o Import export of cross-section dxf (CAD)
o Cross-section mesh export in dxf

• Further calculation

o Concrete cover according to EN 1992

o Anchorage and lap length according to EN 1992

o Column analysis

o Simpli supported and cantilever beam analysis

o Winkler beam analysis

o Recatangular pad foundation analysis and reinforcement

o Shear reinforcement design for rectangular RC cross-section

o Reinforcement area comparison by varying diameter numbers and spacing 

o Loads assessment for a user defined floor (dead loads)

BiaxialPRO is a software for the analysis and verification of a generic reinforced section or composite section with a very complex geometry.

BiaxialPRO is very practical for every day design work with simple and clear interface. 

It allows different analysis for a generic reinforced cross-section which may comprises irregular geometry of the concrete area, openings with generic geometry, user defined arrangement of the reinforcement rebars and embedded steel profiles.

Input data

For standard sections, the cross-section geometry can be defined using the interface, while for complex sections directly from CAD drawing (.dxf file). 

BiaxialPRO provides the standard materials but it always allows user defined matrials. 

Uls and sls external forces can be defined on the interface or imported from external .txt file.

Method of analysis and design checks

BiaxialPRO allows user to define different materials stress-strain relationship. For steel the elastic plastic and the elastic plastic with hardening diagrams can be define. For the concrete both linear and parabolic elastic behaviour can defined. We are currently working on a new release which will consider the confinement behaviour of the concrete according to Eurocode 2.

BiaxialPRO stands out because it allows:

• Any type of section geometry (rectangular, polygonal, circular) based on CAD drawing
• Any type of openings with generic geometry
• For rebars
  • No limitation in terms of number of rebar
  • Customisation of rebar diameter
  • Customisation of rebar material properties (i.e. Elastic modulo, resistance and elongations)
• For embedded profiles
  •  Generic section geometry definition based on CAD drawing
  • Customisation of profile material properties (i.e. Elastic modulo, resistance and elongations)

Crack width calculation has been implemented according to EN 1992-1-1:2004 7.3.4 and considering the following parameters:

• For rebars inside tension zone:
• Equivalent diameter
• Rebar spacing
• Cover
• Effective rebars area and stress inside tensile zone
• Eurocode parameters: k1, k2, k3 and k43
• Evaluation of cracked section defining two calculation cases based on rebars spacing

Typical cases studies are represented by the analysis and verification of RC column, beam and bridge pier section.

BiaxialPRO provides several graphs and diagrams output using Matlab libraries.

Output information consists of:

• Figure
  • Section geometry
  • Section mesh
  • Centroid and ellipse of inertia
• Diagrams
• stress strain relations for rebar and matrice material
• 3D interaction domain (N Mx My)
• 2D interaction domain
• Moment Vs curvature diagram
• Stress diagram using colormap for each analysis type and each combination

• Calculation Report
  

  • All mechanical, geometrical, forces and settings assumptions 
  • Geometry information (i.e. reinforcement position, Inertia, neutral axis, etc)
  • Crack width calculation details based on 7.3.4 EN 1992-1-1
  • Maximum and minimum stress for each combination
  • 3D interaction domain points for each orientation defined
    
  • Curvature details with failure tables (yielding and plastic achievement at any curvature).

Comments
The program can easly deal with complex reinforced section geometry throught CAD drawing.
The software establishes a consistent section analysis, stress verification and crack width control in accordance with Eurocode 2.
User can carried out a reinforcement optimisation even though it is not automatic defined on BiaxialCrack. Current version does not includes post tension which is under construction and will be released with next version.

BiaxialPRO has been developed in MATLAB by Ing. Alessandro Angelini (STRUANG).
Copyright : STRUANG Ing. Alessandro Angelini Monteleone di Spoleto ITALY.

BiaxialCrack software. New features for crack control, stress analysis and non linear analysis of moment curvature diagram.

BiaxialCrack - Descrizione breve in Italiano

il software BiaxialCrack nasce per analizzare sezioni complesse costituite da un materiale matrice (che può essere il calcestruzzo oppure il legno) ed uno o più materiali resistenti a trazione (barre in acciaio, barre in fibra e/o profili annegati).
Il calcolo presuppone sempre che le sezioni si mantengano piane e che sussista sempre la perfetta aderenza tra il materiale matrice ed il materiale resistente a trazione. Probabilmente uno dei pochi software, se non l'unico in circolazione, a considerare la presenza combinata di barre di diverso tipo. La versione attuale contempla due differenti materiali per le barre che avviene attraverso il calcolo di due coefficienti di omogeneizzazione per tutti i calcoli proposti.

Le caratteristiche principali del software sono:

• Analisi lineare e non lineare considerando il calcestruzzo reagente a trazione, e considerando il calcestruzzo non reagente a trazione. Quindi inerzie variabili a seconda dello stato di sollecitazione;
• Tracciamento del diagramma momento curvatura con sigma/epsilon calcestruzzo (parabola-rettangolo o lineare) e sigma epsilon acciaio (elasto plastico perfetto o elasto plastico incrudente);
• La geometria delle sezioni può essere definita direttamente sull'interfaccia senza ricorrere a disegni cad per sezioni standard. Per sezioni complesse: qualsiasi forma, vuoti interni qualsiasi, disposizione qualsiasi di armature e profili annegati (a loro volta di geometria qualsiasi);

Steel rebars VS GFRP

We carried out some test on GFRP using BiaxialPRO.
Although fiberglass rebars are more resistant than steel ones, they have an elastic modulus about 5 times lower than that of steel. This has two immediate consequences: the first is that the stress in the concrete will be higher for a more limited compression area, the second concerns cracking (aesthetic reasons obviously).
The section with GFRP cracks 5 times more than that with steel rebars. Another important limitation is represented by the fact that the fiber rebars is not ductile like the steel one, so it has a lower ultimate strength.

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