Projects / Programmes
Development of quasi-periodic deformation patterns in viscoelastic structures
| Code |
Science |
Field |
Subfield |
| 2.05.01 |
Engineering sciences and technologies |
Mechanics |
Analytical mechanics |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
Periodic deformation patterns; viscoelasticity; transient phenomenon; out-of-equilibrium patterns; finite strain theory; active remodeling; load function; elastic limits; numerical modeling;
Researchers (11)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
52619 |
Matej Bogataj |
Mechanical design |
Researcher |
2020 |
0 |
| 2. |
24560 |
PhD Miha Brojan |
Mechanical design |
Head |
2020 - 2023 |
393 |
| 3. |
54915 |
Tomaž Brzin |
Mechanical design |
Researcher |
2020 - 2023 |
0 |
| 4. |
36726 |
PhD Matjaž Čebron |
Mechanical design |
Researcher |
2020 - 2023 |
76 |
| 5. |
54895 |
Enej Istenič |
Mechanical design |
Researcher |
2021 - 2023 |
7 |
| 6. |
50821 |
PhD Tadej Kocjan |
Mechanical design |
Researcher |
2020 |
45 |
| 7. |
57154 |
Aljaž Robek |
Mechanical design |
Researcher |
2022 - 2023 |
0 |
| 8. |
13088 |
PhD Viktor Šajn |
Mechanical design |
Researcher |
2020 |
151 |
| 9. |
32031 |
PhD Urša Šolinc |
Mechanical design |
Researcher |
2020 |
28 |
| 10. |
16148 |
PhD Tomaž Videnič |
Mechanical design |
Researcher |
2020 |
99 |
| 11. |
53904 |
Jan Zavodnik |
Mechanical design |
Researcher |
2020 - 2023 |
36 |
Organisations (1)
Abstract
The traditional analysis of stress-strain states in engineering systems is associated with the prediction and prevention of undesired failure of the functionality due to exceeding the stress or strain limits. Currently, many advanced applications are being developed on the basis of theoretical and experimental discoveries beyond these limits - in the nonlinear regime. The deformation shapes and mechanisms, such as various periodic patterns with favorable physical properties, metastable states, jumps between deformation modes, etc., enable innovative functional properties that can be used for actuation or control. In these systems, the deformations are not purely elastic if the materials exhibit a viscoelastic behavior. Although the viscoelasticity of materials is known, structures are usually modeled as elastic (in limits) even in rigorous mechanical models of organogenesis, simply because of the extreme computational complexity (discussed in the project proposal). The major goal of the proposed research project is to investigate the interaction of viscoelastic material and the theory of large deformations during drying/swelling/growth of engineering and natural systems. We will show that if the active deformation process (e.g. growth) is much faster than viscous relaxation, the system can be driven out of equilibrium and exhibit various deformation patterns that are unattainable for purely elastic structures. For this purpose we will first develop a prototypical theoretical model to investigate the influence of viscous deformation components on the deformation state of a structure. Secondly, we will describe the transient deformation phenomena during the transition from the shorter to the longer time limit and identify the influencing parameters that keep the structure in a local energy minimum or "freeze" it in an out-of-equilibrium state. In the final phase of the project we will develop a computational model to investigate the influence of curvature on the development of the deformation pattern on real spatial viscoelastic structures. Rigorous analytical and numerical tools will be developed on the basis of a thermodynamically consistent visco-hyperelastic material model within the finite strain theory. Several different load functions will be applied to flat and curved systems. To solve highly nonlinear systems of differential equations we will use the finite element method. Since the mechanics of active deformations is not implemented in standard commercial packages, we will integrate specifically developed algorithms like dynamic relaxation, continuation method etc. into the configurable AceFEM and FEniCS packages. Since the viscoelastic system is time-dependent and the method of dynamic relaxation itself introduces a pseudo-time, the computational complexity of the problem will be greatly reduced by only a few adjustments of the method. Our theory will be validated by macroscopic precision model experiments on viscoelastic material samples. A combined principle of objective-oriented and discovery driven research will be applied. The research will be carried out in the Laboratory for Nonlinear Mechanics (LANEM) under the supervision of the project leader, dr. Miha Brojan (head of LANEM) and in close collaboration with dr. A. Košmrlj from the Princeton University, dr. B. Brank from UNI-LJ and Assist. dr. K. Jawed from UCLA. The LANEM laboratory is well equipped with the research infrastructure to carry out the proposed research and to complete the objectives. Nevertheless, we will collaborate with the group of dr. Brank during the first phase, regarding the application of the nonlinear Mindlin-Reissner shell theory to FEM. Analogies from biology to test our theory on will be discussed with dr. Košmrlj, whereas dr. Jawed will be consulted for the application of our theory to soft robotics.
