Application of the DIC Technique to Remote Control of the Hydraulic Load System

Abstract

Displacements or deformations of materials or structures are measured with linear variable differential transducers (LVDT), fibre optic sensors, laser sensors, and confocal sensor systems, while strains are measured with electro-resistant tensometers or wire strain gauges. Measurements significantly limited to a point or a small area are the obvious disadvantage of these measurements. Such disadvantages are eliminated by performing measurements with optical techniques, such as digital image correlation (DIC) or electronic speckle pattern interferometry (ESPI). Many devices applied to optical measurements only record test results and do not cooperate with the system that exerts and controls load. This paper describes the procedure for preparing a test stand involving the Digital Image Correlation system ARAMIS 6M for remote-controlled loading. The existing hydraulic power pack (ZWICK-ROELL) was adapted by installing the modern NI cRIO-9022 controller operating under its own software developed within the LABVIEW system. The application of the DIC techniques to directly control load on the real structure is the unquestionable innovation of the described solution. This led to the elimination of errors caused by the test stand susceptibility and more precise relations between load and displacements/strains which have not been possible using the previous solutions. This project is a synergistic and successful combination of civil engineering, computer science, automatic control engineering and electrical engineering that provides a new solution class. The prepared stand was tested using two two-span, statically non-determinable reinforced concrete beams loaded under different conditions (force or displacement). The method of load application was demonstrated to affect the redistribution of bending moments. The conducted tests confirmed the suitability of the applied technique for the remote controlling and recording of test results. Regardless of the load control method (with force or displacement), convergent results were obtained for the redistribution of bending moments. Force-controlled rotation of the beam section over the support was over 50% greater than rotation of the second beam controlled with an increase in the displacement.

Influence of soft layer thickness on the aggregate displacement in the backfill material of dynamic replacement columns – results of laboratory model tests

“…A photographic documentation was also made for each stage of the study. The software GOM [12] was used to analyse the paths of the backfill material grains in the soft hydrogel layer. The absolute displacement vectors of the driven particles were determined at each pounder drop and the final shape of the column was described.…”

Modification of Control Oil Feeding with PLC Using Simulation Visual Basic and Neural Network Analysis

“…The suggested concept is experimentally validated by both virtual and real commissioning in industrial conditions. The aspect of energy efficiency of the heat source control systems is also discussed, and for assessment of the energy supply performance, the energy error index is proposed [14][15][16]. Therefore, we designed the final assignment to wash the oil pan machine using the PLC to communicate with the mist collection.…”