ATENA-C4A
ATENA Concrete for ANSYS
Predict how reinforced concrete really behaves — from first cracks to collapse. ATENA-C4A brings ATENA’s proven material modeling technology directly into ANSYS Mechanical, with no need to leave your workflow.
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Powered by ATENA
ATENA-C4A is an ANSYS extension developed by DESIGNTEC and Červenka Consulting.
ATENA-C4A builds on ATENA’s nonlinear concrete material model, developed by Červenka Consulting, specialists in nonlinear concrete simulation since 1992.
DESIGNTEC team integrates ATENA-C4A into ANSYS and has built its own portfolio of ANSYS extensions. We provide ATENA-C4A consulting, deployment, training, sales, and support, building on extensive CAE/FEM experience since 2009.
17 years
in CAE/FEM consulting and
software development
34 years
in nonlinear concrete analysis
and material modeling
Technology proven by over 2500 ATENA installations worldwide
Universities & Research
Engineering Consultancies
Industry & Manufacturing
ATENA-C4A Features and Capabilities Overview
ATENA’s nonlinear material model is well proven. Does ATENA-C4A reproduce its behavior within ANSYS? The benchmark studies below validate flexural, shear, and punching failures against both ATENA results and experimental test data.
From first load to limit state: NEW LEVEL of nonlinear concrete modeling in ANSYS
Assess and Strengthen Existing Structures
ATENA-C4A enables assessment of existing reinforced concrete structures — bridges (including prestressed ones), high-rise buildings, dams, nuclear and industrial facilities. The results identify critical weak points, indicate where strengthening is required, and even capture crack closure effects through ATENA-C4A’s nonlinear material modeling capabilities.
R&D for Reinforced Concrete Behavior
Develop new structural concepts and validate numerical models against full-scale experimental results — now
directly in ANSYS Mechanical. ATENA-C4A relies on ATENA’s advanced nonlinear material model, already
trusted by hundreds of universities, research institutions
and engineering companies worldwide, delivered as
a ready-to-use ACT extension for ANSYS.
Beyond First Cracking
ATENA-C4A goes far beyond conventional code checks. It simulates the complete nonlinear response of reinforced concrete, from first cracking and reinforcement yielding to crushing and ultimate failure. Instead of a simple pass-or-fail assessment, ATENA-C4A reveals structural behavior, pinpoints weak regions, and quantifies reserve load-carrying capacity.
Seismic and Dynamic Response
Combined with the ANSYS structural solver, ATENA-C4A enables nonlinear dynamic analysis of reinforced concrete structures — including the effects of human-induced and natural seismic activity. Its ability to simulate crack closing under cyclic loading is key to capturing these effects realistically, and it’s unique among solutions currently available on the market.
More Than a Material Model
One Environment, Native Integration
ATENA-C4A combines the full power of ANSYS — nonlinear modeling, structural dynamics, contact modeling, Multiphysics, and Python or ACT automation — with ATENA’s specialized concrete material model, all in one environment.
No need to switch between two separate programs.
Independent Meshing of Concrete and Reinforcement
With ANSYS, concrete and reinforcement can be meshed independently, eliminating the need for shared nodes and complex geometry partitioning. This significantly reduces preprocessing effort, accelerates model creation, and enables efficient scaling to large, highly detailed 3D FE models — including heavily reinforced structures.
Detailed Output and
Crack Visualization
Watch cracks form and grow, concrete crush, and reinforcement yield — directly on your 3D model in ANSYS. Results are easy to interpret and document without leaving the ANSYS environment, down to 67 state variables from the ATENA material model, including crack width, orientation, and reinforcement strain
at each load increment.
Under the hood – What Makes ATENA-C4A Different
Advanced Crack Opening and Crack Closure Mechanics
Most concrete models only open cracks. ATENA-C4A tracks the full cycle:
- Crack re-contact and gap-closing once a crack is compressed again
- Restored normal stiffness at the closed crack surface
- Reactivated compressive stress transfer across that surface
- Continuous tracking of open/closed transitions through the load history
- Realistic stiffness recovery under cyclic and reversing loads
- Directly applicable to seismic and other reversing-load scenarios
Unique Capabilities for Reinforced Concrete Analysis
ATENA-C4A’s CC3DNonLinCementitious2 material model adds:
- Mesh-objective crack propagation via fracture-energy regularization
- Compression weakening after cracking (transverse crack effects)
- Shear transfer across cracked concrete
- Fixed, rotating, or transitional crack models
- Cyclic loading/unloading with stiffness recovery
- Coupled cracking, crushing, and crack-closure in one model
The Power of ANSYS, Enhanced for Concrete
ATENA-C4A runs on the full ANSYS simulation ecosystem:
- Static, nonlinear, and transient dynamic analyses
- Staged construction using element birth and death
- Geometric nonlinearity and large deformations
- Linear and quadratic element technologies
- Contact, Multiphysics, and automation
- Optimization and advanced post-processing tools
Validation
Six published reinforced concrete tests, analyzed in ANSYS with ATENA-C4A and checked against the original experimental data: beam and slab geometry, reinforcement layout, boundary conditions, and the resulting load-deflection response. Each benchmark study is available as a downloadable report with key input data and results.
Debernardi T3 Three-Point Bending RC Beam
A 2 m reinforced concrete beam (200 × 100 mm cross-section, 3⌀12 tension reinforcement), loaded to ultimate deflection. We modeled the symmetric half of the beam and compared the resulting load-deflection curve and crack pattern with the published test data.
Debernardi T8 Three-Point Bending RC Beam
A 6 m reinforced concrete beam (600 × 300 mm cross-section, lightly reinforced with 2⌀12 tension bars), loaded to ultimate deflection. We modeled the symmetric half of the beam and compared the resulting load-deflection curve and crack pattern with the published test data.
Debernardi T11 Three-Point Bending RC Beam
A 6 m reinforced concrete beam (600 × 300 mm cross-section, heavily reinforced with 18⌀12 tension bars), loaded to ultimate deflection. We modeled the symmetric half of the beam and compared the resulting load-deflection curve and crack pattern with the published test data.
Leonhardt Four-Point Bending RC Beam
A reinforced concrete beam under two-point loading (2× ⌀26 tension reinforcement), loaded to ultimate deflection. We modeled the symmetric half of the beam and compared the resulting load-deflection curve and crack pattern with the published test data.
Muttoni PG8 Punching Slab Test
A 750 × 750 × 130 mm reinforced concrete slab under punching load (8⌀8 mm and 2⌀4 mm reinforcement), loaded to ultimate deflection. We modeled a symmetric quarter of the slab and compared the resulting load-deflection curve and crack pattern with the published test data.
Yoshida YB2000-0 Large-Scale Beam Test
A 12 m reinforced concrete beam (2000 × 300 mm cross-section), loaded to ultimate deflection. We modeled the full beam and compared the resulting load-deflection curve and crack pattern with the published test data.
Interested? Questions about your project?
You talk directly to the developers of ATENA-C4A.
Licensing ATENA-C4A
ATENA-C4A is licensed separately as an annual subscription, independent of any ATENA license. To run ATENA-C4A, you’ll also need your own ANSYS license, since the two integrate directly.
We calculate the license price individually, based on your organization and how you plan to use ATENA-C4A.
Want to try it first? Get a free 30-day demo of ATENA-C4A.
Frequently asked questions
These are the questions engineers and researchers ask most often before starting with ATENA-C4A: how licensing works, which ANSYS and ATENA versions it supports, and what types of structures it’s built for. Answered directly, without sales language.
What is ATENA-C4A?
ATENA-C4A is a joint product by DESIGNTEC and Červenka Consulting, developed together to bring the ATENA concrete material model (CC3DNonLinCementitious2) directly into ANSYS.
It models crack formation and growth, concrete crushing, and reinforcement yielding — all within a single ANSYS environment, with no switching between two separate programs.
ATENA-C4A builds on ATENA’s proven material modeling technology from Červenka Consulting, trusted in over 2500 installations worldwide.
How is ATENA-C4A licensed?
ATENA-C4A is an ANSYS extension requiring its own license — you don’t need an ATENA license, and it isn’t part of any ATENA license package. You just need your own ATENA-C4A license and an ANSYS license, since the two work together.
ATENA-C4A is available on an annual license, separate from any ATENA license. Pricing is set individually based on your needs — contact our team for a tailored offer.
If you’d like to try it first, we offer a free 30-day demo. If it delivers value, you can then request an annual paid license.
Which ANSYS environments and versions does ATENA-C4A support?
ATENA-C4A comes in two forms: an ANSYS ACT extension for ANSYS Workbench and Mechanical, and an ANSYS UPF material library for ANSYS Mechanical APDL, the classic interface. That means ATENA-C4A also supports users working in APDL — not something you can take for granted, since many similar tools only cover Workbench.
The current version is tested and validated with ANSYS 2025 R1, and we’re expanding support for other ANSYS and ATENA versions over time — the latest supported version is always listed prominently on this page.
How does ATENA-C4A model reinforced concrete behavior?
The CC3DNonLinCementitious2 material model captures the key nonlinear mechanisms behind reinforced concrete behavior — crack closing, concrete crushing, creep, rotated crack modeling, and tension stiffening in densely reinforced beams — for a realistic prediction of cracking, failure, and long-term performance. Further details are available on the ATENA product page.
On top of that, ANSYS meshes concrete (SOLID185/186/187) and reinforcement (REINF264/265) independently, linking them at the integration-point level instead of requiring shared nodes. This greatly simplifies model development and enables efficient simulation of large-scale structures such as bridges, dams, and nuclear facilities.
Why choose ATENA-C4A over standard ANSYS concrete models or standalone ATENA?
ANSYS has been actively strengthening its own concrete modeling capabilities — recent developments such as the Dynardo acquisition and the MultiPlas material library integration clearly show that commitment, and we welcome this direction.
ATENA-C4A takes it a step further, bringing ATENA’s CC3DNonLinCementitious2 model into ANSYS — one of the market’s leading solutions for nonlinear reinforced concrete analysis, with a proven track record for predicting failure mechanisms and load-bearing capacity reserve.
Working in ANSYS also gives you the whole ecosystem beyond the material model itself, including SpaceClaim, which directly imports more than 40 standard CAD, CAE, ECAD, and mesh formats and significantly cuts the time needed to prepare a simulation-ready FE model.
Who is ATENA-C4A for, and what types of structures can it analyze?
ATENA-C4A is built mainly for universities and research institutions working on reinforced concrete, along with research organizations and engineering firms handling larger structures.
Typical uses include checking reinforcement design, assessing existing structures, and analyzing behavior beyond standard load scenarios to predict ultimate load capacity.
It works well across a wide range of structures: bridges (including prestressed ones), high-rise buildings, dams, nuclear power plant structures, underground structures, and large industrial and offshore facilities.
Who do I contact with questions or issues?
The DESIGNTEC team provides support for ATENA-C4A. For questions about installation, licensing, or usage, reach us at support@designtec.eu or through the contact form below.
Contact and Support
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Your contact person
Petr Vymlátil
Managing Director
DESIGNTEC s.r.o.
+420 777 568 356
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