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.

SENST*: approaches for reducing the energy consumption of smartphone-based context recognition

Abstract: Modern smartphones provide sensors that can be used to describe the current context of the device and its user. Contextual knowledge allows software systems to adapt to personal preferences of users and to make data processing context-aware. Different sensors or measurement approaches used for recognizing the values of particular context elements vary greatly in their energy consumption. This paper presents approaches for reducing the energy consumption of utilizing smartphone sensors. We discuss sensor substitution strategies as well as logical dependencies among sensor measurements. The paper describes the first milestone towards a generalization of such strategies. Furthermore,We show that energy awareness benefits from a more abstract view on context elements.

A quadratic piezoelectric multi-layer shell element for FE analysis of smart laminated composite plates induced by MFC actuators

Abstract: Macro fiber composite (MFC) actuators developed by the NASA have been increasingly used in engineering structures due to their high actuation power, compatibility, and flexibility. In this study, an efficient two dimensional quadratic multi-layer shell element by using first order shear deformation theory (FOSDT) is developed to predict the linear strain-displacement static deformation of laminated composite plates induced by MFC actuators. FOSDT is adapted from the Reissner-Mindlin plate theory. An eight-node quadratic piezoelectric multi-layer shell element with five degrees of freedom is introduced to prevent locking effect and zero energy modes observed in nine-node degenerated shell element. Two types of MFC actuators are used: (1) MFC-d 31 and (2) MFC-d 33, which differ in their actuation forces. For result verification, the electro-mechanically coupled quadratic finite element (FE) model is compared with the ABAQUS results in various examples. Comparison of the results showed good agreement. The proposed quadratic FE formulation is simple and accurate, which eliminates the need for costly FE commercial software packages. It was observed that earlier studies have mostly emphasized on the effect of actuation power and MFC fiber orientations on mechanical shape deformation of smart composite plates. In this study, a more comprehensive, in-depth investigation is conducted into host structure performance such as boundary conditions, laminate stacking sequence configuration, and symmetry/asymmetry layups.

Testing Unsaturated Soil for Plane Strain Conditions: A New Double Wall Biaxial Device

Abstract: In this paper a new experimental device for unsaturated soil testing is presented. The new Double Wall Biaxial Cell was designed to study the behavior of unsaturated granular material under plane strain conditions. The required calibration of the new device is presented in detail. Saturated soil samples were tested in the new device under isotropic consolidation conditions. The volume changes of the specimen were measured by two alternative methods to check the reliability of the new device. To verify the independent two stress state variables concept proposed by Fredlund and Morgenstern, Null-tests were performed on sand-kaolin mixture specimen. Axis translation technique was used for creating the desired matric suction. The details of the new device and the test procedures are described. The obtained result are presented and discussed in detail.