Apr 8, 2020
The durability feature has been further improved and developed. ATENA can be used to evaluate the durability of reinforced concrete structures during its service life. In this durability model, the environmental conditions can be specified as a new boundary condition. This typically includes chloride concentration, CO2 content or relative humidity. Based on this information and the distance of reinforcement to this surface, the chloride or carbonation propagation is calculated in time taking into account the possible presence of cracks. When the propagation front reaches reinforcement, the corrosion model is activated, which results in the reduction of reinforcement area. This effect can be included in any reliability or strength assessment in ATENA calculation as shown for instance in Fig. 1.
Alkali-silica reaction (ASR) is a reaction in concrete between alkali hydroxides and reactive siliceous aggregates. This process causes the development of expansion strain in concrete, which may cause secondary cracking and can significantly reduce the concrete strength. ATENA models now cover the most important aspects of durability of reinforced concrete structures such as chloride and carbonation process, reinforcement corrosion and ASR.
Fig. 1: Application of ATENA durability model for the corrosion and service life analysis of a cantilevered bridge structure
Fig. 2: Construction process modelling from GeoProduction 4.0 project
The durability features are all available since version 5.7, and were developed in the DURACERV funded by Czech Technological Agency under the project #TA04031458.
This functionality has been further developed and improved. It can be used to simulate geotechnical problems (Fig. 2.), bridge construction or general repair or strengthening approaches.
ATENA Studio is one of the most popular tools in the ATENA simulation system. It allows runtime visualization of the analysis process as well as full post-processing capabilities even while the analysis is still running and the iterative process is not yet completed.
This very useful insight into the iterative process helps to discover any modeling errors and gives useful hints how to eliminate any divergence problems. One of the most useful features for engineers is also the possibility to evaluate the distribution of the classical engineering quantities such as moments or shear forces as shown in the example in Fig. 3. And the next main improvement is faster post-processing of large scale models, speed increase almost 100 times (Fig. 6.).
This new software tool can be used to test the behavior of individual material models in ATENA or for testing and debugging user defined material models. This tool allows to test the behavior of ATENA compatible material models under arbitrary loading paths. It support loading by both strain or stress increments or any combination thereof.
Fig. 3: Evaluation of moment and shear force diagrams in a nonlinear analysis of continuous reinforced concrete beam
Fig. 4: Screen shot of the new ATENA material driver for testing and understanding of material models
The resulting stress-strain curves are plotted in 2D graphs thus allowing clear and easy verification or understanding of the model behavior. The program also provides the actual values of any state variables associated with the tested material. Currently the driver supports only material models for stress analysis.
ATENA in the cloud
In the past year, the ATENA cloud has been further improved and developed. It provides two main functionalities:
(1) it can be used to execute all ATENA software tools on-line using a dedicated computer on the Google cloud. Free temporary account is available to first time ATENA users for testing and evaluating the software. Just go to “atenacloud/cervenka.cz” to obtain a free account and test the unique ATENA reinforced concrete simulation software.
(2) it can be also used for running large scale analysis by renting a computer with larger memory capacity or higher speed.
(3) the third application is for running parametric studies or probabilistic simulations from SARA Studio. In this case, a user can submit a zip file containing several ATENA input files generated by SARA Studio or other application. A dedicated virtual computer is created for each analysis, and the nonlinear analysis by ATENA is executed remotely. In this way all necessary analyses can be run simultaneously with huge time savings.
Fig. 5: Example of ATENA analysis on the cloud
Fig. 6: Analysis and post-processing of large scale models is much faster and easier in the new ATENA version as documented on these figures from a pushover analysis of a 18-storey building.
We strongly support our users in their analytic work with ATENA. Support is mainly provided by email and phone calls. The solution to many questions can be found also in our FAQ & Online Forum. New versions of ATENA are released every year.
Maintenance is provided for free for one year after the software purchase. After that is it can be prolonged at annual rate coresponding to 15% of the program price.