Section 3: Diagnostics of wooden structures from the point of view of mechanical properties
Contact person: Lenka Kubíncová
The laboratory for diagnostics of building structures from the point of view of mechanical properties has robust computing tools for predicting and simulating the behaviour of structures based on wood and material engineering.
Experimental analysis describing the mechanical properties of elements or constructions is validated by an analytical approach using the robust software described below.
Dlubal RSTAB/RFEM software allows the solution of engineering and static issues of modern civil engineering and reflects the latest trends in the field. The tool is the basis of a modular software system and the sophisticated input method enables intuitive modelling of simple and complex rod structures.
The powerful solver of the RSTAB program performs linear and non-linear analysis of the task, calculations of internal forces, deformations, and bond reactions. RFEM is a powerful tool for static calculations of 3D structures using the finite element method, meeting all engineering and static requirements and demands of modern construction. The basic RFEM program is used to deal with structures, enter materials and loads for planar and spatial structures, which are formed by 2D elements represented by a plate, wall, or shell, and can also incorporate rod elements into the solution of tasks. Mixed structures or bodies and contact elements can also be modelled. RFEM calculates deformations, internal forces, stresses, support forces, and contact stresses in the subsoil. Load generators make it easy to account for wind and snow loads and more.
3D rod model of a high-rise building from wood-based construction (RSTAB):
Cross Laminated Plate Model (RFEM):
Flex PDE software is a powerful and robust platform for an original and unlimited scripted multi-physics finite element solution environment using and solving partial differential equations. It is an ideal platform for 1D, 2D, 3D tasks, or Multi-physics Partial Differential Equation (PDE). Analyses that can be carried out within the program are, for example: structural mechanics, heat flow, chemical analyses and reactions, electromagnetics, and diffusion. The platform takes the user from a mathematical model to a numerical solution and enables graphical postprocessing of solved tasks. Flex PDE applied to the topics that range from stress analysis, kinetics of chemical reactions, up to the valuation of stock options, and mathematical description of real-world systems, bases the solutions using partial differential equations. FlexPDE addresses the mathematical basis of all these areas by dealing with equations rather than an application.
Flex PDE is a platform that allows:
- analyse the description of your problem,
- symbolically form Galerkin finite element integrals, derivatives, and dependencies,
- creates a coupling matrix and solves the problem,
- displays the results,
- no other tool is needed to solve tasks, and no additional software modules are needed to deal with new fields of study and subsequent new issues.
Examples of solved tasks in Flex PDE: detail of the foundation of a wooden structure from the point of view of building physics
and a 3-point bend test of a plate element made of cross-laminated timber (CLT).
COMSOL MUTLIPHYSICS software is a very powerful and robust computing platform containing 34 expansion modules with a fine-tuned user interface and tools for optimization, electromagnetic, mechanical, acoustic, thermal, CFD, and electrochemical applications. The software is mainly based on the finite element method (FEM) but also benefits from other methods (boundary element method, discontinuous Galerkin, finite volume method, etc.). Also included is an abundance of material properties for solids, liquids, and gases available from integrated material libraries. For import/export and connection with CAD/ECAD modelers, spreadsheets, and other calculation software, COMSOL MULTIPHYSICS includes 14 linking modules. Another effective tool is COMSOL COMPILER for compiling self-executable applications. The software is an ideal environment for creating multiphysics models. In the case of solving one physics problem, a single user interface is applied which is specific to all physics problems, and a uniform approach across all sectors with the possibility of turning physics interfaces on and off, turning boundary conditions on and off, creating studies, etc. In the case of the definition of a multiphysics problem (coupling of physics interfaces is not limited), it is possible to simply connect two or more physics problems that influence each other (coupling, full coupling). This tool enables cross-discipline product development in a single software.
Samples of solved tasks in COMSOL MULTIPHYSICS: Description of the movement of the temperature and humidity field in a wooden frame structure.
Abaqus Unified Finite Element Analysis (FEA) software enables powerful and complete solutions for both routine and sophisticated engineering problems covering a wide range of scientific and practical applications. In the field of wood sciences, within the framework of material engineering or practical design applications, users can use and describe physical phenomena represented by mechanical static loading, mechanical dynamic loading, linear static analysis, non-linear static analysis, multiphysics analysis with coupling between mechanical force action fully connected with thermal and moisture action, and acoustic-structural coupling using a uniform data structure of the model.
Examples of solved tasks in SW Abaqus:
- 3-point bend test as a contact task on a 3D solid (brick elements) model of a cross-laminated timber (CLT) board,
- temperature analysis of a 2D element,