Dear Friends of ATENA,

We hope this message finds you in good health and high spirits.

It is with great enthusiasm that we announce the release of the novel ATENA 2024, featuring an innovative preprocessor that marks a significant milestone in our software evolution. In a pivotal move, we have seamlessly integrated our 2D and 3D Engineering GUIs into a singular, more efficient ATENA 2024 GUI. Our journey doesn't stop here; we are committed to incorporating these enhancements into ATENA Science, promising further advancements. We will keep you abreast of our progress.

For those with active ATENA maintenance, access to ATENA 2024 is just a click away. Newcomers to ATENA, we haven’t forgotten you – a 30-day trial, full-featured and unrestricted, awaits. Embrace the opportunity to explore ATENA 2024's capabilities by activating your trial here.

Responding to the enthusiastic inquiries from our community, we are excited to announce the planning of an exclusive seminar in Prague. This gathering will not only showcase ATENA 2024’s extensive features but also provide a platform to address your inquiries regarding your existing ATENA models. Details on the dates and registration can be found below. For our international friends unable to join us in Prague, we are preparing a series of webinars to bring the essence of ATENA's latest developments and features to you, wherever you are.

We eagerly anticipate further collaboration and hope to welcome you at our planned international events and exhibitions (detailed in the "Where You Can Meet Us" section).

Warmest regards from Prague,

Your ATENA Team

Fig.1: Wind tower foundations designed and analysed by ATENA software.

ATENA version 2024

The new preprocessor in ATENA 2024 replaces old 2D and 3D pre-processors for ATENA Engineering. The first releases support only static analysis, but other modules for creep, transport and dynamic will follow soon. The new version is compatible with the current Science version. This means you can import *.gid data files and continue the processing them in this new environment. The list below contains a summary of the main improvements in this new ATENA 2024 Preprocessor, if compared to the existing ATENA 2D & 3D Engineering:

- 2D and 3D modelling and preprocessing is combined into a single environment,
- curved NURBS lines and surfaces are supported,
- stronger compatibility with ATENA Science,
- import of *.gid models,
- scripting support using Python programming language,
- import of other data formats such as: iges, (ifc will follow later this year)
- support for layers as in other modelling programs,
- possibility to develop user defined material libraries as well as materials,
- support for construction process modelling both in 2D and 3D,

Fig. 2: Overview of the main user interface of ATENA 2023 pre-processor showing the multiple windows for model definition and automatic mesh generation.

Fig. 3: ATENA 2023 uses ATENA Studio for runtime analysis visualization and post-processing.

- durability models for reinforcement corrosion and alkali-silica reaction,
- BIM based internal data format,
- our popular AtenaStudio program is used for unique runtime visualization and control,
- fully built on 64-bit technology and supporting larger computer memory capacity and speed.

The release of this new version represents an important step in ATENA history.

Our future development plans are to gradually combine our Engineering and Science product lines into a single transparent environment allowing users to perform all modelling and simulation in a single, powerfull and user-friendly package.

The new ATENA 2024 release replaces the original ATENA 2D and 3D Engineering programs, which were based on the old 32-bit technology. The new version allows to fully exploit the current 64-bit computer technology. The compatibility with previous 2D and 3D programs is preserved, which means that it is possible to import the old *.cc2 and *.cc3 files.

The new ATENA 2024 version can be downloaded from our website from the section downloads.

Fig. 4: 3D model of a historical bridge in the environment of the new ATENA 2023 pre-processor.

Fig. 5: Large scale 3D model of a composite steel-concrete cable stayed bridge in ATENA 2023 imported from a previous GiD model.

Please, make sure your maintenance licence is valid before downloading this new version or contact our sales representatives (cervenka@cervenka.cz) to be eligible for this new upgrade.

You can check the validity of your maintenance by launching ATENA Studio using the Help / About dialog. To be eligible for the latest ATENA 2024 download your maintenance date should be after April 30th, 2024.

The ATENA User Seminar 2024 seminar will take place in Prague, the Czech Republic on June 19-21, 2024. The seminar will focus on the new developments and features in our latest version ATENA 2024. In addition we cover theoretical backgrounds on ATENA material models and solution techniques.

Program:
Day 1 (13:30 - 17:00): Overview of the latest ATENA development   
Introduction and work-flow in ATENA 2024 Engineering
Step by step tutorial of the new ATENA 2024 pre-processor

Day 2 (10:00 - 17:00): New Topics in ATENA - Science
GiD preprocessing - basic overview and usage (tutorial example)
GiD preprocessing - tips & tricks and overview of recommended practices (meshing techniques, working with layers, interface elements)

Fig. 6: Jan Červenka with participants of ATENA seminar in a classroom in Prague.

Fig. 7: Participants of ATENA seminar working.

Post-processing in ATENA Studio - overview and usefull tips & tricks (understanding structural behavior, failure modes, how to make nice figures, cuts, diagrams of internal forces, animation, report generation)
Modelling of 3D concrete printing
Durability modelling (chloride, carbonation, reinforcement corrosion, alkali-silica reaction)
Hydration heat development modelling and data exchange between transport and stress analysis
Dynamic and cycling analysis
Creep analysis

On day 2 in the evening, workshop participants will be invited to a dinner and party with official celebration on the release of ATENA 2024.

Day 3 (10:00 - 16:00): Advanced topics on ATENA2024
Modelling of contacts & interfaces
Scripting in ATENA 2024 preprocessor
Python programming in ATENA 2024
Development of user defined material libraries
Theoretical background of ATENA material models

The registration fee will be 290 € by MAY 31, 2024 and 390 € since JUN 1, 2024 payable to the bank account in the registration form. Please, register on-line HERE. It is recommended to register as soon as possible, the number of participants is limited. For more information you can follow the seminar website.

Fig. 8: Dinner at Strahov brewery restaurant in Prague.

Youssef Elmezayen, Nouman Khattak and Tamer El-Maaddawy: Prediction of Nonlinear Flexural Behavior of Continuous RC Beams Pre-Damaged by Corrosion, Buildings 2023, 13, 1398.
https://doi.org/10.3390/buildings13061398

Numerical simulation models capable of predicting the nonlinear flexural behavior of continuous reinforced concrete (RC) beams with corroded reinforcement were developed. Laboratory tests were conducted to validate predictions of the numerical models. A parametric study was carried out to examine the effect of varying the location and severity of corrosion on the nonlinear flexural behavior of continuous RC beams. The load capacity of continuous RC beams decreased linearly with an increase in the severity of corrosion, regardless of its location. The corrosion of reinforcement in the sagging region was, however, more detrimental to the load capacity than hogging corrosion. 

Fig. 9: Crack pattern of specimen - numerical and experimental.

Fig. 10: Numerical vs. experimental load-deflection response of beams with hogging corrosion.

The rate of the strength reduction for the beam models with sagging corrosion was approximately 70% higher than that of the models with hogging corrosion. The beam models with sagging and hogging corrosion concurrently exhibited the poorest performance. The rate of the strength reduction of the beam models with corrosion in both sagging and hogging regions was approximately 2.7 times that of the models with hogging corrosion only. The moment redistribution ratio at the ultimate load for the beam models with sagging corrosion only ranged from 2–22%. The beam models with corrosion in the hogging region only exhibited the highest moment redistribution ratio of 22–50% at the ultimate load. The beam models with sagging and hogging corrosion simultaneously exhibited a constant moment redistribution ratio of 18% at the ultimate load.

Nicolas El-Joukhadar, Farah Dameh, Stavroula Pantazopoulou: Seismic Modelling of Corroded Reinforced Concrete Columns, Engineering Structures, Volume 275, Part A, 15 January 2023, 115251, https://doi.org/10.1016/j.engstruct.2022.115251

Deterioration of seismic resistance of columns due to existing corrosion damage is investigated using advanced non-linear finite element simulation and analysis of a large database of tests with the objective to develop performance criteria for seismic evaluation and assessment. 

Fig. 11: Hysteretic responses of the finite element analysis plotted over the hysteretic response of experimentally tested columns reported by Goksu & Ilki.

Fig. 12: Stress distribution and crack pattern from FEA.

Current guidelines for structural seismic evaluation do not address how to account for the condition of the reinforcement. Incorporating the degree of bar corrosion in the evaluation procedures would complicate significantly the problem of seismic assessment. 

However, bar section loss, embrittlement, loss of material strength and interfacial bond, all affect the member’s residual mechanical properties, the hierarchy of failure modes and the consequences on seismic performance of complete structural components. In this work, simple modifications of existing nonlinear assessment procedures are proposed, in order to account for the effects of corrosion on seismic performance.

Reduction factors of reinforcement stress–strain properties and column stiffness, strength and deformation capacity were calibrated to an assembled database of experimentally tested corroded columns, and were verified through advanced nonlinear finite element analysis, after modeling the effect of mass loss on material properties.

Machine Learning for Multiscale Modelling of Spatial Variability and Fracture for Sustainable Concrete Structures (AI4FRACTURE)

Partners:
Cervenka Consulting, s.r.o.
Dep. of Structural Mechanics, Brno University of Technology,
Klokner's Institute, Czech Technical University in Prague,

AI4FRACTURE develops multiscale modelling methods for fracture initiation, development and localisation in RC structures. Improved fracture patterns and crack widths will be applied in the lifecycle assessment of structural durability and sustainability. Outcomes of AI4FRACTURE will help to overcome engineering issues when use of advanced probabilistic NLFEA for assessment of large RC structures is challenged. Proposed framework will provide new tools to overcome gaps in the existing knowledge and methods for RC fracture modelling and reliability assessment, utilising the most advanced theoretical tools and available experiments. 

Fig. 13: Multiscale approach to fracture localization in reinforced concrete structures supported by AI based surrogate models.

Vladimir Cervenka, founder of the company Cervenka Consulting, received the award “Fellow of Digital Transformation” during the conference EUROSTRUCT 2023 in Vienna on September 26, 2023. The award was handed over by professor Konrad Bergmeister for his contribution in the field of numerical simulation of concrete structures.   

We participate regularly the ACI events, it is the best opportunity to meet our North American customers and engineers in their home country.  We had the pleasure of attending both conventions in 2023, spring and fall. Enjoy the ACI Fall 2023 ATENA presentation here.

Fig. 14: Vladimir Cervenka and Konrad Bergmeister during the EUROSTRUCT award ceremony.

We would like to announce with pleasure that we have started a cooperation with a U.S. company X-Elastica LLC based in Boulder, Colorado.

X-Elastica will be working as the offical ATENA representative and distributor for the U.S. territory getting in touch with our existing customers as well as the new potential users. You can get in touch with the ATENA representatives at atena@xelastica.com.

X-Elastica will provide also technical support, but our technical hotline at cervenka@cervenka.cz can be used as well as our support forums: forums.cervenka.cz.

Fig. 15: ATENA information at the X-Elastica website.

June 5-7, 2024
ConCreep 12.org
Delft, Netherlands
Event website

June 30-July 5, 2024
18th World Conference on Earthquake Engineering (WCEE2024)
Milan, Italy
Event website

August 28-30, 2024
15th fib PhD Symposium
Budapest, Hungary
Event website

September 4-6, 2024
4th RILEM International Conference on Concrete and Digital Fabrication
Munich, Germany
Event website

September 22-25, 2024
14th Central European Congress on Concrete Engineering 
Mikulov, Czech Republic
Event website

November 3-7, 2024
ACI Fall Concrete Convention
Piladelphia, PA, USA
Event website

November 11-13, 2024
fib Symposium 2024, ReConStruct
Christchurch, New Zealand
Event website

Fig. 16: Jan Cervenka and Sasan Dolati from STANTEC with his poster during ACI Spring Convention 2024.

BARROS, J., SANZ, B., FILHO, M., FIGUEIREDO, F., KABELE, P., YU, R., C., MESCHKE, G., PLANAS, J., CUNHA, V., CAGGIANO, A., OZYURT, N., GOUVEIA, V., VAN DEN BOS, A., POVEDA, E., GAL, E., CERVENKA, J., E. NEU, G., ROSSI, P., DIAS-DA-COSTA, D., JUHASZ, P., K., CENDON, D., RUIZ, G., VALENTE, T: Blind Competition on the Numerical Simulation of Continuous Shallow Steel-fiber Reinforced Concrete Beams Failing in Bending, Structural Concrete, fib, https://doi.org/10.1002/suco.202200754

CERVENKA, J., CERVENKA, V., RYMES, J., Nonlinear Analyses for the Design of Safety-Critical Concrete Structures, The 5th ICCER 2023, Surabaya, Indonesia.

CERVENKA, J., CERVENKA, V., SKANDIS, U., REHOUNEK, L., Uncertainty in the Simulation of Concrete Fracture and Comparison with Blind Competitions, 11th International Conference on Fracture Mechanics of Concrete and Concrete Structures FraMCoS-11, Sept 10 - 14, 2023, IISc Bangalore.

CERVENKA, V., RIMKUS, A., GRIBNIAK, V., CERVENKA, J., Uncertainty of the Crack Width Model Based on Fracture of Concrete, Eurostruct 2023, First published: 25 September 2023 https://doi.org/10.1002/cepa.2203, Volume 6, Issue 5, ce/papers, 6(5), pp. 60-69. 

CERVENKA, J., RYMES, J., Digital Twin for Modelling Structural Durability, In: RILEM International Conference on Numerical Modeling Strategies for Sustainable Concrete Structures. Springer, Cham, 2023. p. 79-89, DOI 10.1007/978-3-031-07746-3_8. Z, publication from SSCS 2022 conference in Marseilles.

CERVENKA, J., RYMES, J., JENDELE, L., PUKL, R., Digital Twins for Reinforced Concrete Structures, fib International Symposium, Istanbul 2023, June 5-7, 2023, Cham: Springer Nature Switzerland, 2023. p. 1621-1630, DOI: 10.1007/978-3-031-32519-9_163, First Online: 01 June 2023.

CERVENKA, J., RYMES, J., JENDELE, L., & PUKL, R. (2023). Is Nonlinear Analysis Becoming a Standard Tool for Design and Assessment of Reinforced Concrete Structures?. In IABSE Congress New Delhi 2023: Engineering for Sustainable Development.

CERVENKA, J., SKANDIS, U., Lessons Learnt from Blind Competition of Shear Behavior of Fiber-reinforced Concrete T-beam, DOI: 10.1002/suco.202201187, Article in Structural Concrete (bude Vol. 24 (Issue 4), 1–20, First published: 09 February 2023 Journal Impact Factor ™ (2022) 3.2.

CERVENKA, J., RYMES, J., PUKL, R., Nelineární analýza a simulace jako nástroj pro navrhování a posuzování železobetonových mostů, sympozium Mosty 2023, 20-21. 4. 2023 v Brně, vyšel i sborník, článek vyšel v časopisu Silnice Železnice, vyd. KONSTRUKCE Media, s.r.o., Ostrava, vyšlo 11. 7. 2023, 18. ročník, 3/2023, ISSN: 1801-822X (Print), 1803-8441.

JENDELE, L., RYMES, J., & CERVENKA, J. (2023). Optimizing Digital 3D Printing of Concrete Structures. In Proceedings of the 77th RILEM Annual Week and the 1st Interdisciplinary Symposium on Smart & Sustainable Infrastructures (ISSSI 2023). 4-8 September, Vancouver, Canada.

NOVAK, L., CERVENKA, J., CERVENKA, V., NOVAK, D., & SYKORA, M. (2023). Comparison of Advanced Semi‐probabilistic Methods for Design and Assessment of Concrete Structures. Structural Concrete, 24(1), 771-787.

NOVAK, L., NOVAK, D., CAO, M., PUKL.R., Semi-probabilistic Assessment of Concrete Bridge Exploiting Additional Data from Experiments and Numerical Analysis, IALCCE 2023 Milan, Life-Cycle of Structures and Infrastructure Systems, IALCCE 2023, MILAN, ITALY, 2-6 JULY, 2023, CRC Press, 2023. p. 2697-2704, ISBN 978-1-003-32302-0 Z.

RYMES, J., CERVENKA, J., HERZFELDT, M., & PUKL, R. (2023). Advanced Life-cycle Assessment of Reinforced Concrete Bridges using Digital Twin Concept. In Life-Cycle of Structures and Infrastructure Systems (pp. 3300-3307). CRC Press.

RYMES, J., CERVENKA, J., & JENDELE, L. (2023). Material Modelling and Simulation of 3D Concrete Printing Process. In Proc. of the 11th Intern. Conf. on Fracture Mechanics of Concrete and Concrete Structures (FraMCoS-XI), J. M. Chandra Kishen, A. Ramaswamy, S. Ray and R. Vidyasagar Eds. 10-14 September, Bangalore, India.