Search

Rocket NG is a startup with experts in civil engineering, electronics, and network engineering. We offer and operate a self‐developed end‐to‐end IoT system for condition monitoring, condition assessment and predictive maintenance. The system is reliable and ease to apply. In this paper the autonomous monitoring system is discussed regarding security, reliability, ease of use and artificial intelligence on the edge (smart algorithms used on the nodes). Additionally, the importance of an easy installation and an intuitive data representation are on discussion. Five applications will be presented. The first application is a crack monitoring on a cantilever bridge. There, different data acquisition modes will be shown for the assessment of static loads, dynamic loads and temperature induced displacements. The second application shows the crack width opening due to heavy transport. The third application addresses the wetting and drying of chloride contaminated water in a concrete wall beside a motorway. The fourth is a monitoring of a passive cathodic protection system. Finally, a digitalization of an analog legacy Extensometer is shown. [ABSTRACT FROM AUTHOR]

The infrastructure of ASFiNAG is mainly built from reinforced and prestressed concrete, which despite all regular maintenance measures, is subject to ageing and degradation. The major degradation process is chloride attack, followed by carbonation, which both lead to corrosion of the reinforcing steel. A new method, which represents a significant improvement on previous assessments, is used in this paper to analyze chlorides in concrete. The paper also introduces a new concept for the durability assessment by using objective indicators, like chloride content, electrical resistivity, and corrosion potential. For objectivity and a reliable determination of the condition state, an overall performance index derived from the condition indices using an analytic hierarchy process (AHP) is adapted. The model is applied to excellent and dense data from a monitoring system and investigations taken from reinforced concrete components beside a motorway. [ABSTRACT FROM AUTHOR]

Hyperelastic material models are derived from strain energy potentials expressed in terms of strain invariant or principal stretches. For a (nearly) incompressible material, the strain energy density depends on the first and second strain invariant; the third invariant describing a change in volume is equal to one. If the material is not highly confined it may be satisfactory to select an incompressible approach. However, for seismic beatings a highly confined situation does exist, and the compressibility must be included to obtain realistic results. Further, cavitation and associated stiffness reduction in bearings are shown based on experimental observations. In fact, it was noticed that a hydrostatic tensile stress in rubber causes internal rupture and a significant reduction in the bulk modulus. Thus, a hyperelastic formulation based on a variable bulk modulus does suggest a simple approach to realistically represent the mechanics of cavitation in rubbery solids.