Bauhaus University, Weimar

About: Bauhaus University, Weimar is a education organization based out in Weimar, Thüringen, Germany. It is known for research contribution in the topics: Finite element method & Isogeometric analysis. The organization has 1421 authors who have published 2998 publications receiving 104454 citations. The organization is also known as: Bauhaus-Universität Weimar & Hochschule für Architektur und Bauwesen.

Tunable topological bandgaps and frequencies in a pre-stressed soft phononic crystal

Abstract: Topological insulators (TIs) have recently received significant attention due to the promise of lossless transport of various types of energy. Despite this interest, one outstanding issue is that the topological bandgap and the frequencies that are topologically permitted are typically fixed once the topological structure has been designed and fabricated. Therefore, an open and unresolved question concerns the ability to actively tune both the bandgap magnitude, as well as the frequencies, for which the energy is topologically protected. In this work, we report a mechanically tunable phononic TI using an acoustic analog of the quantum valley Hall effect. We propose a phononic crystal comprised of a soft, hyperelastic material where the phononic band structure is modulated through large deformation of the structure. In doing so, space-inversion symmetry can be broken, which leads to a phase transition between two topologically-contrasted states and the emergence of topologically-protected interface modes according to bulk-edge correspondence. We further demonstrate the robustness of this topological protection of the edge state along the interface, which demonstrates that mechanical deformation can be used to effectively tailor and tune the topological properties of elastic structures.

An integrated risk management system (IRMS) for PPP projects

Abstract: Purpose – Large infrastructure projects involve many different stakeholders. Risk allocation is negotiated between the public sector and the special purpose vehicle (SPV)/consortium. Moreover, risk allocation is negotiated between the shareholders of the SPV and between the SPV and its contractors, financiers/lenders and insuring companies. Since the individual understanding of risks associated with the project differs amongst the contract partners, negotiation is often very time consuming and may not lead to the best possible outcome. The variability of risk management approaches and a lack of coherent practices often prove to be problematic. The purpose of this paper is to address these issues.Design/methodology/approach – The study has been conducted using a questionnaire and expert interviews to identify the current state of public‐private partnership (PPP) risk management. As a result, a process model for risk management for each stakeholder has been developed.Findings – By developing an integrated r...

New concepts for moving least squares: An interpolating non-singular weighting function and weighted nodal least squares

Abstract: In this paper two new concepts for the classical moving least squares (MLS) approach are presented. The first one is an interpolating weighting function, which leads to MLS shape functions fulfilling the interpolation condition exactly. This enables a direct application of essential boundary conditions in the element-free Galerkin method without additional numerical effort. In contrast to existing approaches using singular weighting functions, this new weighting type leads to regular values of the weights and coefficients matrices in the whole domain even at the support points. The second enhancement is an approach, where the computation of the polynomial coefficient matrices is performed only at the nodes. At the interpolation point then a simple operation leads to the final shape function values. The basis polynomial of each node can be chosen independently which enables the simple realization of a p-adaptive scheme.

Consistent illumination within optical see-through augmented environments

Abstract: We present techniques which create a consistent illumination between real and virtual objects inside an application specific optical see-through display: the virtual showcase We use projectors and cameras to capture reflectance information from diffuse real objects and to illuminate them under new synthetic lighting conditions Matching direct and indirect lighting effects, such as shading, shadows, reflections and color bleeding can be approximated at interactive rates in such a controlled mixed environment