GEOMETRIC FORMS OF COMPOSITE SAMPLES, FACILITATING THEIR DESTRUCTION IN AREA UNDER STUDY IN FATIGUE TESTS Russian patent published in 2018 - IPC G01N3/02 G01N3/32 

FIELD: testing equipment.

SUBSTANCE: pre-fabricated structure of the test piece (10) comprises of a plurality of layers, made of a fiber-reinforced polymer material, co-forming a laminated material of constant thickness. The laminated material has a geometry including the first and second trapezoidal portions (16, 18) connected through the area under study, in which said sample has a minimum width. The first trapezoidal part, the second trapezoidal part and the area under study form the corresponding parts of the front surface and the corresponding parts of the rear surface of the test specimen. Each of the front and rear surfaces has a profile with a shape similar to a "bow-tie" shape and is made parallel to the specified layers. The first and second projections, glued to the first trapezoidal part on the respective first portions of the front and rear surfaces. The third and fourth protrusions, glued to the second trapezoidal part on the respective second portions of the front and rear surfaces. Each of the first, second, third and fourth protrusions is made of a fiber-reinforced polymer material and has a trapezoidal profile. The test specimen has a minimum width in the test area (20) and a constant thickness. The first trapezoidal part (16) has the first and second rectilinear bevelled sides (12a and 12b). The second trapezoidal part (18) has the third and fourth rectilinear bevelled sides (12c and 12d). The area under study (20) comprises of the first and second radial sides (14a and 14b). The first radial side (14A) is connected to the first and third rectilinear bevelled sides (12a and 12 c), and the second radial side (14b) is connected with the second and fourth rectilinear bevelled sides (12b and 12d). The height of said first radial portion does not exceed 3% of said height of the test specimen (10).

EFFECT: guaranteed destruction in the area under study in fatigue tests.

6 cl, 7 dwg