This paper presents a consistent approach in dynamic analysis of geometrically exact three-dimensional beams with quaternion description of rotational degrees of freedom. This article is a result of a successful cooperation with the researchers at Fraunhofer Institute for Industrial Mathematics.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 6328929In this contribution, recent achievements in the field of ultrasonic (US) monitoring of the hydration process and formation of structure of cement based materials are described with the emphasis on the results published by the authors. Among others, a possibility of using the US wave transmission and US wave reflection method to determine setting times of different cement based materials is described. Sensitivity of these US methods to the presence of different chemical and mineral admixtures is presented and a possibility of using different US parameters to estimate various mechanical characteristics of the materials is also discussed (compressive strength, E modulus, etc.).
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 6210401In the paper a new setup for measuring a setting and hardening process of cementitious materials, using a non-destructive ultrasonic shear wave reflection technique and designed with the objective to be easily used in-situ, is described. Using the developed setup, the measurements can be performed by slight deepening of a measuring head into a paste in a mold or by placing the paste into a mold fixed on a measuring head. To test the proposed methodology, cement pastes with different compositions were prepared and exposed to different curing temperatures. Significant differences in the evolution of a change of a shear wave reflection coefficient Δr in time were observed, indicating the ability of the method to monitor setting process of cement pastes. Moreover, some interesting phenomena in the solidification process of materials can be identified. A linear relationship between development of the Δr and penetration resistance dP values in time was found, allowing development of a simplified procedure to determine both initial and final setting times of the material. This presents a significant contribution to the development of new advanced non-destructive techniques to evaluate early age properties of cementitious materials and expands the range of applicability of ultrasonic methods to a high degree.
F.08 Development and manufacture of a prototype
COBISS.SI-ID: 6202721We have been organizing the National Competition in Structural Mechanics for 19 years. In 2013 the 19th competition was organized and the report with solutions was also presented on internet. The competition was prepared for students of several secondary schools in Slovenia with the goal to increase popularity of the field of structural mechanics and an increase of knowledge. The excellent response from students and their mentors - secondary school teachers - was experienced.
D.10 Educational activities
COBISS.SI-ID: 273004544