Department of Civil Engineering




VecTor5 is a nonlinear modeling software developed specifically for concrete frames. It provides:

  • Simple yet accurate modeling process suitable for design office applications.
  • Simplified material modeling developed for only concrete frames with pre-set material models.
  • Proven track record: 25 years of development and experimental verification at the University of Toronto.
  • Great addition to any consulting engineering office involved in frame analysis and design.



  • Discover expected behavior at the serviceability and ultimate limit states, including
      ▫ concrete and reinforcement stresses,
      ▫ crack pattern and widths, and
      ▫ deformations and deflections,
  • Discover governing damage mechanisms; improve or refine the design
  • Verify the reinforcement design obtained from linear-elastic analysis (SAP2000, ETABS, etc.)
  • Analyze unusual or unique systems
  • Perform proof-of-concept analysis of critical design details
  • Conduct performance-based design
  • Perform nonlinear dynamic analysis for seismic, impact, and blast load cases
  • Analyze existing structures when problems arise; assess their performance and safety
  • Perform retrofit or upgrade analysis; determine most suited retrofit or upgrade scheme
  • Train junior engineers for a better understanding of structural behavior and modeling.


Download button for VecTor5

  • Basic Version 3.7, June 2022
  • Includes pre- & post-processors FormWorks+ and Janus
  • See: VecTor5 Spec Sheet
  • Contact VTAG for obtaining the full version.


  • VecTor5 is validated with 100+ large-scale experimental tests.


  • VecTor5 uses a distributed-plasticity, layered section approach without requiring the definition of any plastic hinges.
  • It is based on a total load, secant stiffness formulation for exceptional convergence characteritics even in the heavily damaged post-peak stages.
  • Modified Compression Field Theory (MCFT) is used.

    ▫ a rational theory adopted by design codes worldwide,
    smeared, rotating crack model with concrete-specific constitutive (i.e., stress-strain) formulations,
    shear cracking and failure modes are captured
    ▫ validated extensively in the past 35 years.


  • Vector5 is capable of considering
    ▫ material and geometric nonlinearities,
    ▫ compression softening due to transverse cracking,
    ▫ tension stiffening due to load transfer between cracked concrete and reinforcement,
    ▫ tension softening due to fracture-related mechanisms, ▫ shear slip along crack surfaces,
    ▫ nonlinear concrete expansion,
    ▫ confinement effects,
    ▫ previous loading history,
    ▫ effects of slip distortions on element compatibility relations,
    ▫ membrane action,
    ▫ time- and temperature-related effects,
    ▫ nonlinear degradation of concrete and reinforcement due to elevated temperatures,
    ▫ concrete prestrains, and
    ▫ reinforcement dowel action.
  • Required for the dynamic analyses, Vector5 also considers strain rate effects on the concrete and reinforcement as well as damping effects on the structure. Refer to journal articles section for more information.


  • Static loads include monotonic, cyclic and reversed-cyclic load cases.
  • Dynamic loads include base accelerations (time-history analysis under an earthquake accelerogram), impulse, impact and blast loads, initial velocity and constant acceleration load cases.
  • Temperature loads include nonlinear thermal gradients. 

wHY VecTor5?

  • Concrete material models are calculated from a single input (f’c)
  • Most suited concrete and reinforcement material models are pre-selected as default models; many other models are also available.
  • Validated with 100+ large-scale experimental tests (13 journal papers provide details - see second page of  VecTor5 Spec Sheet)
  • Simple modeling process via graphical user interface FormWorks+
  • Secant stiffness solution algorithm ensures robust convergence even in the heavily cracked post-peak stages of the analysis
  • Total load formulation eliminates the need to use small load steps – the load step size has no influence on the solution accuracy
  • Concrete cracking, concrete crushing, and reinforcement yielding are calculated
  • Failure modes including flexure, shear, compression, and reinforcement buckling are provided
  • Crack spacing, widths, and orientation are presented in the graphical interface Janus

other frame analysis software

Most frame analysis software uses plastic-hinge approach, with the following limitations:

  • Exact determination of hinge locations is required.
  • Proper calibration of the moment and shear hinge properties is required.
  • Default hinge models may have low accuracy even for typical cross sections.
  • Consideration of the shear-moment-axial force interaction is not possible unless advanced modeling approaches are undertaken.
  • Once a hinge yields, an analysis typically terminates, being unable to predict the load redistribution and post-peak ductility.
  • Cracking and serviceability information is not provided.
  • Deflections are only approximately calculated using an effective stiffness value input by the user.


Flowchart describing constitutive formulation matrices for concrete, reinforcement and  reinforced concrete

Who is VecTor Analysis Group?

Since 1979, VecTor Analysis Group (VTAG) has been pushing the bounds of advanced modelling and analysis of concrete structures under the leadership of Dr. Frank J. Vecchio at the University of Toronto. VTAG now comprises eight professionals with a wide spectrum of expertise and experience.

VTAG has employed a comprehensive six-phase approach:
theory development,
▫ large-scale structural testing,
▫ formulation of material models,
▫ implementation into analysis algorithms,
▫ corroboration, and application to real structures.
This approach has led to industry-leading analysis software.  


youtube tutorials

Subscribe to our YouTube Channel to get the latest tutorial videos and more. Subscribe 

Learning center
Please review User Bulletins and Youtube Tutorials
Source Codes for Researchers
User's Manuals
Please review User's Manuals.
Please review the spreadsheets
VecTor Analysis Group
Last Updated: 9/16/22