[en] Materials testing performed on various specimen materials with different techniques often reveal measuring method problems which cannot be solved by using commercial devices which are either too expensive or else are non-existent altogether. The institute remedied this situation by developing a number of laboratory devices of their own make two of which, i.e. a special displacement transducer and a device for the calibration and characteristics determination of transducers, are demonstrated in this report. (orig./HP)

[en] A special type of pressure indicators, more or less well known under the name of 'membrane pressure indicators' is dealt with. In principle, they consist of a pipe socket which is open at one end and sealed by the 'membrane' at the other end. In case of internal pressure from the open side, the membrane will begin to arch. This arch, which is proportional to the internal pressure, is measured by suitable methods. A special form of strain ganges, so-called 'membrane pressure roses' have turned out to be particularly suitable here. The article gives general guidelines for the construction of membrane pressure indicators. (orig./HT)

[en] The tests were carried with two new cables at temperatures up to 600⁰C. The low long term shift was confirmed, but there were some outlying values which show the need for predrifting the gages before use. Satisfactory reproducibility of thermal calibration of the gages would be obtained by cutting off the welding spots. Due to the great deviation of the apparent strain it was found necessary to calibrate each single gage. In summary the tests confirmed the qualification of capacitive strain gages for creep measurements and static measurements up to 600⁰C as well. (orig./DG)

[en] This study presents the analysis of shear buckling resistance of the corrugated web of SIN girders reinforced with tension diagonal braces. The analysis is based on the determination of interactive buckling resistance. Experimental investigations into shear buckling resistance were carried out using girders with the web height of 500, 1000 and 1500 mm. The girders were reinforced with tension diagonal braces located in the girder support zones, i.e. in the intervals in which the load produced by a shear force is greater than the web shear resistance. Load displacements paths LDPs P(y) and the results of strain gauge measurements of simply supported SIN girders were analysed. The girders employed in experimental investigations were modelled using FEM. On the basis of strain gauge measurements and separated load-displacements paths, shear buckling resistance of the corrugated web of SIN girders reinforced with tension diagonal braces was estimated. That was performed for the experiment and FEM analysis. It was demonstrated that tension diagonal braces increase the linear-elastic region of LDP P(y), thus causing an increase in the global buckling force that affects the value of the design shear buckling resistance of the web. The strengthening of girders with tension diagonal braces leads to an increase in shear stiffness of the system consisting of the web and diagonal braces. The results of investigation into shear buckling resistance were compared with those obtained using the method proposed for design buckling resistance estimation, and also the computational model in accordance with Eurocode. (paper)

[en] This paper attempts to adapt the well-known procedure for measuring residual stresses using strain gauge technology for application to wood. (orig.)

[en] Full text: The electric properties of the films of PP and compositions on their vase are investigated. As the filler are used the piezoceramics of PCR-3M and PCR-7. The obtained experimantal results is analyzed considering the composition of polymer-segnetoelectric as the manylayer dielectric consisting of a polymer, active piezophase (ceramic) and transition layer. It is found, that at the optimal polarization temperature on the dependence of piezoelectric phase, the maximal charging of composite electret takes place at the 5% vol. for romboedric and 10% vol. for tetragonal structure. It is established that at the same conductivity of polymer phase and piezoelectric particle is obtained the optimal charging regime of electret. It is suggested, the mechanism of formation of stable electret effect in the system of polymer-segnetopiezoelectric at thermopolarization

[en] A master-slave remote handling device incorporates a set of electric resistance strain gages which monitor the forces applied by the operator to the handle to actuate an alarm if the forces are likely to damage the device. The strain gages are attached to a tubular section of the master side of the device between the handle and the first joint and comprises twelve gages arranged in groups of four. 3 figs

[en] Strain gauges are used in various applications such as wearable strain gauges and strain gauges in airplanes or structural health monitoring. Sensitivity of the strain gauge required varies, depending on the application of the strain gauge. This paper reports a tunable strain gauge based on a two-dimensional percolative network of silver nanowires. By varying the surface coverage of the nanowire network and the waviness of the nanowires in the network, the sensitivity of the strain gauge can be controlled. Hence, a tunable strain gauge can be engineered, based on demands of the application. A few applications are demonstrated. The strain gauge can be adhered to the human neck to detect throat movements and a glove integrated with such a strain gauge can detect the bending of the forefinger. Other classes of two-dimensional percolative networks of one-dimensional materials are also expected to exhibit similar tunable properties. (paper)

[en] The report describes an investigation of the only two capacitive strain gauges that are commercially available. It was found that static strain measurements are possible up to 650⁰C using CERL-Planer strain gauges. Their use at higher temperatures remains doubtful, but there is hope that improved production techniques will widen the temperature range for future lines of strain gauges. (orig./RW)

[en] The invention refers to a strain gage for measuring surface extensions in circular sections of work pieces with three measuring grids arranged on a circular mounting plate, the connection of which are situated on the mounting plate. The strain gage is built in such a way that it can simply be pasted on the measuring point as an integrated unit. A direct connection to the testing wires is also possible. (RW)