189 citations · 815 across the 21 of their papers we have counts for
21 papers
TinyDEM: Minimal open granular DEM code with sliding, rolling and twisting friction
Roman Vetter
This article introduces TinyDEM, a lightweight implementation of a full-fledged discrete element method (DEM) solver in 3D. Newton's damped equations of motion are solved explicitl…
Disorder-to-order transition of long fibers contained in evaporating sessile drops
S. Sannyamath, R. Vetter, H. Bonart +3
A liquid drop containing a long fiber is a complex system whose configuration is determined by an interplay of elastic stresses in the fiber and capillary forces due to the liquid.…
Reply to: Assessing the precision of morphogen gradients in neural tube development
Roman Vetter, Dagmar Iber
In a recent article [Vetter and Iber, Nat. Commun. 13, 1145 (2022)], we demonstrated that single morphogen gradients in the developing mouse neural tube can carry sufficient positi…
A Geometric Mapping from Rectilinear Material Orthotropy to Isotropy: Insights to Plates and Shells
Wenqian Sun, Cody Rasmussen, Roman Vetter +1
Orthotropic shell structures are ubiquitous in biology and engineering, from bacterial cell walls to reinforced domes. We present a rescaling transformation that maps an orthotropi…
PolyHoop: Soft particle and tissue dynamics with topological transitions
Roman Vetter, Steve V. M. Runser, Dagmar Iber
We present PolyHoop, a lightweight standalone C++ implementation of a mechanical model to simulate the dynamics of soft particles and cellular tissues in two dimensions. With only…
Bacterial biofilms use chiral branches to escape crowded environments by tracking oxygen gradient
Mustafa Basaran, Tevfik Can Yüce, Yusuf Ilker Yaman +2
Bacterial biofilms collectively develop distinct and ordered structures, including fibers, bundles, and branches. Often, it is unclear how these structural motifs convey specific a…
Large-scale orientational order in bacterial colonies during inward growth
Mustafa Başaran, Y. Ilker Yaman, Tevfik Can Yuce +2
During colony growth, complex interactions regulate the bacterial orientation, leading to the formation of large-scale ordered structures, including topological defects and microdo…
Modelling the Effects of using Gas Diffusion Layers with Patterned Wettability for Advanced Water Management in Proton Exchange Membrane Fuel Cells
Jaka Dujc, Antoni Forner-Cuenca, Philip Marmet +3
We present a macrohomogeneous two-phase model of a proton exchange membrane fuel cell (PEMFC). The model takes into account the mechanical compression of the gas diffusion layer (G…
Simulating isothermal aging of snow
Roman Vetter, Stephan Sigg, Herman M. Singer +3
A Monte Carlo algorithm to simulate the isothermal recrystallization process of snow is presented. The snow metamorphism is approximated by two mass redistribution processes, surfa…
Collapse of orthotropic spherical shells
Gautam Munglani, Falk K. Wittel, Roman Vetter +2
We report on the buckling and subsequent collapse of orthotropic elastic spherical shells under volume and pressure control. Going far beyond what is known for isotropic shells, a…
Emergence of active nematics in bacterial biofilms
Yusuf Ilker Yaman, Esin Demir, Roman Vetter +1
Growing tissue and bacterial colonies are active matter systems where cell divisions and cellular motion generate active stress. Although they operate in the non-equilibrium regime…
Experimental parameter uncertainty in PEM fuel cell modeling. Part II: Sensitivity analysis and importance ranking
Roman Vetter, Jürgen O. Schumacher
Numerical modeling of proton exchange membrane fuel cells is at the verge of becoming predictive. A crucial requisite for this, though, is that material properties of the membrane-…
Experimental parameter uncertainty in PEM fuel cell modeling. Part I: Scatter in material parameterization
Roman Vetter, Jürgen O. Schumacher
Ever since modeling has become a mature part of proton exchange membrane fuel cell (PEMFC) research and development, it has been plagued by significant uncertainty lying in the det…
Free open reference implementation of a two-phase PEM fuel cell model
Roman Vetter, Jürgen O. Schumacher
In almost 30 years of PEM fuel cell modeling, countless numerical models have been developed in science and industrial applications, almost none of which have been fully disclosed…
Orthotropic rotation-free thin shell elements
Gautam Munglani, Roman Vetter, Falk K. Wittel +1
A method to simulate orthotropic behaviour in thin shell finite elements is proposed. The approach is based on the transformation of shape function derivatives, resulting in a new…
Simulating Thin Sheets: Buckling, Wrinkling, Folding and Growth
Roman Vetter, Norbert Stoop, Falk K. Wittel +1
Numerical simulations of thin sheets undergoing large deformations are computationally challenging. Depending on the scenario, they may spontaneously buckle, wrinkle, fold, or crum…
Packing of elastic wires in flexible shells
Roman Vetter, Falk K. Wittel, Hans J. Herrmann
The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists and biologists alike. How linear threads pack and coil i…
Particle-fluid-structure interaction for debris flow impact on flexible barriers
Alessandro Leonardi, Falk K. Wittel, Miller Mendoza +2
Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, a numerical tool for rat…
Morphogenesis of filaments growing in flexible confinements
Roman Vetter, Falk K. Wittel, Hans J. Herrmann
Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack the…
Subdivision Shell Elements with Anisotropic Growth
Roman Vetter, Norbert Stoop, Thomas Jenni +2
A thin shell finite element approach based on Loop's subdivision surfaces is proposed, capable of dealing with large deformations and anisotropic growth. To this end, the Kirchhoff…
Finite Element Simulation of Dense Wire Packings
Roman Vetter, Falk K. Wittel, Norbert Stoop +1
A finite element program is presented to simulate the process of packing and coiling elastic wires in two- and three-dimensional confining cavities. The wire is represented by thir…