METHOD TO DETERMINE MECHANICAL PROPERTIES OF BRITTLE MATERIALS AT TENSION Russian patent published in 2015 - IPC G01N1/28 G01N3/08 

FIELD: machine building.

SUBSTANCE: pads with dimensions and shape identical to the sample which are made from the material providing for total rigidity of both pads that is less or equal to the rigidity of the sample being tested, are glued to two opposite surfaces of the sample thus a laboratory assembly is produced and then set in collet clamps of a testing machine. Each clamp is located between the edge of the end face and the beginning of fillet arc of the assembly. An extensometer is installed on the assembly surface. Load is applied to the assembly and basing on the extensometer readings the curve "deformation - stress" of the laboratory assembly is drawn up and used to restore the diagram of the sample deformation. Stress in the sample σ_s is expressed via the stress of the laboratory assembly σ_la and the pad σ_p, provided with deformation equality, according to the formula σ_s=3·σ_la-2·σ_p.

EFFECT: possibility to implement Saint-Venant principle and provision for homogeneous stress in the working part of a sample made from brittle material, provision for uniaxial tension in the working part of the sample from tested material, prevention of bending, provision for more force measurement points on the equal deformation base.

2 cl, 4 dwg