CS231754B1 - Device for sensing of threeaxial state of stress - Google Patents

Description

The invention solves the construction of a device for sensing triaxial tension in rigid materials. The device consists of a cat tumbled in its three axes and the openings are closed on both sides by strain gauges. The whole is shaped into a sphere by sticking canopies of flexible material. Three-axis stress evaluation is done through three bridges, with both strain gauges connected to each axis. The device can be used to determine the state of tension in non-rigid materials (eg. Dikes, etc.).

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The invention provides a device for sensing triaxial tension in non-solid matter. In building practice, but also in other fields, it is often important to know the tension of the non-solid matter environment under certain power conditions and to obtain the basis for serious decisions and calculations. We do not have suitable sensors for this purpose. Sensors imported from the boundary are large, constructed mainly on piezoelectric effect. Also known is a 19 mm diameter sensor designed on a resistive principle housed in the inner sphere. Since the sphere's surface is metal, the concentric pressure on the ball distorts the measurement from the adjacent stone.

These drawbacks are eliminated by the three-axis tension sensing device of the present invention, wherein the strain gauge-bonded membranes enclose the three-axis openings of the cat perpendicular to each other, with the canopy of the flexible material glued to the cat-membrane surfaces.

This embodiment allows two strain gauge membranes to be placed on each cat axis, increasing the measurement accuracy. Preferably, semiconductor sensors can be used which are up to 100 times more sensitive than resistive and are also more suitable for their small size. The canopy of flexible material adjusts the cat to a more suitable shape - balls and at the same time prevents the formation of concentrated pressure of the environment (for the first stone in the soil on the membrane.

The surface of the sensor mounted in the measured environment is subjected to the pressure of this environment, which is transmitted through the canopy to the membranes and to the glued strain gauge. Both strain gauges of each axis are connected in the measuring bridge so they sum. The evaluation device comprises three bridges whose data are recalculated to axial pressures after scaling.

The solution of the sensor of the invention achieves the necessary small dimensions, suitable shape and design, which allows to obtain more accurate results.

In the accompanying drawing, there is shown a device for sensing a triaxial tension in a section. It consists of cubes 1, membranes 2, strain gauges 3, terminal blocks 4, ball-shaped elastic canopy 5 and cable 6. The cat 1 is reamed by y axes and the resulting eu openings are closed by diaphragms 2 with strain gauges 3 whose leads go to terminal 4 and further through cable 6 to the evaluation apparatus. On the six surfaces of the cat 1 with the membranes 2, the canopy of the ball 5 of the flexible mass is glued.

The described device is particularly useful in building research. and exploration for various types of model measurements and in situ grid construction measurements.

Claims (1)

Device for sensing triaxial tension by means of spherical gauges with glued strain gauges, characterized in that the diaphragms (2) with glued strain gauges (3) close the openings of the VENTILASE drilled in three axes of the cocoon (1) perpendicular to each other, the cats (1) with the membranes (2J) are fastened by the ball cans (5) of elastic mass.