Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: The invention relates to a solid core optic fiber (1) as used in optical fiber technology to transfer optical signals, but also to transmit light for illuminating purposes. The solid core optic fiber (1) comprises a glass fiber (2) with a coating (3). The coating (3) comprises the following composition: a mixture of polyetheretherketone and an inorganic filler material in an admixture of at least 10 and a maximum of 40 wt. % having a particle size of 0.08 ?m to 12 ?m. The outer diameter of the coating (3) is 0.2 mm to 1.2 mm. The ratio D/d between the outer diameter D of the coating (3) and the diameter d of the glass fiber (2) is 2 to 6. A pressure of the coating (3) on the glass fiber (2) is such that essentially no relative motion can occur between the glass fiber (2) and the coating (3).

Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 [mu]m and 12 [mu]m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: An optical strain gage (1) for multi-axis strain measurement includes at least two linear light waveguide sections (2, 3, 4) with Bragg gratings (5). These are arranged next to one another in a prescribed angle (19) of 90° or 45° on a support layer (6) and are supplied with lightwaves by a common infeeding waveguide section (7). All of the light waveguide sections(2, 3, 4, 7) are provided preferably linearly on the support layer (6), and a beam dispersion element (8) is arranged between the infeeding waveguide section (7) and the measuring waveguide sections (2, 3, 4) containing the Bragg grating (5).

Abstract: In an apparatus for determining loads on fiber composite components (1), especially of vehicle and aircraft parts, strain gages (3) are integrated in the components (1) for determining strains. The strain gages (3) are connected with an evaluating apparatus (4), for monitoring and determining loads that tend to cause damage. The strain gages (3) are preferably integrated into the fiber composite component (1) such that the measuring grids (5) thereof are laid between individual fiber layers (2) and are guided out of the component (1) ready for connection via special connecting pins (8) to the associated evaluating apparatus (4) via loose cable connections (12).

Abstract: The invention relates to an optical strain gage (1) for the multi-axis strain measurement, that includes at least two linear light waveguide sections (2, 3, 4) with Bragg gratings (5). These are arranged next to one another in a prescribed angle (19) of 90° or 45° on a support layer (6) and are supplied with lightwaves by a common infeeding waveguide section (7). This invention is characterized in that all light waveguide sections (2, 3, 4, 7) are provided preferably linearly on the support layer (6), and that a beam dispersion element (8) is arranged between the infeeding waveguide section (7) and the measuring waveguide sections (2, 3, 4) containing the Bragg grating (5).

Abstract: The invention relates to an apparatus for the determination of loadings on fiber composite components (1), especially of vehicle and aircraft parts, whereby the components (1) are provided with a prescribed number of sensor elements (3), for the determination of strains. The sensor elements (3) are connected with an evaluating apparatus (4), which is especially embodied for the monitoring and also for the determination of loadings that tend to cause damage. The apparatus is characterized in that the sensor elements are embodied as strain gages (3). In that regard, the strain gages (3) are preferably integrated into the fiber composite component (1) in such a manner so that the measuring grids (5) thereof are laid between the individual fiber layers (2) and are guided out of the fiber composite component (1) ready for connection via special connecting pins (8).