Testing machinery cellfiber clamper and method for measuring tensile strength

Abstract

The invention provides a tester single fibre clamp and a tensile strength measuring method relating to a clamp and tensile strength measurement. The invention provides a tester single fibre clamp and a method for measuring the tensile strength of ceramic single fibre. The clamp is provided with an upper collet device of a tester, a load sensor, a tenaculum device, an upper and lower clamping device, a horizontal adjusting device and a lower collet device of the tester. The adjusting clamp in proper alignment measures the load linearity in vertical direction and rectifies the focus of a photoelectric extensometer; the parameters of an measuring program are set; single fibre is put on the centerline of a hole of a square paper frame, then placed in the middle of the upper and lower clamping device; the vertical direction of the single-fibre is adjusted; the edge of the square paper frame is burned off; a strain collecting device is started to trace the edge distance between the upper and the lower paper frames; a tensile program is started up to begin the measurement; the relation between the load and the strain is recorded to obtain a fibre fracture load value and deformation data, thereby measuring a fibre strain value; a diameter value of a fracture is observed and input to the tester in order to acquire the fracture strength of the single fiber.

Description

technical field [0001] The invention relates to a clamp and the measurement of tensile strength, in particular to a clamp and a method for measuring the tensile strength of ceramic single fiber on a testing machine. Background technique [0002] As the reinforcing phase of ceramic matrix composites, high-performance SiC ceramic fibers have excellent stability in thermal, physical, chemical and mechanical properties, especially in aerospace and advanced weaponry. It has the advantages of high strength, hardness, thermal stability and oxidation resistance, low thermal expansion coefficient and density, so it is the best reinforcing fiber for high-temperature ceramic matrix composites. [0003] Tensile strength is an important mechanical property of ceramic fibers, especially SiC ceramic fibers. At present, in the tensile test for direct determination of the tensile strength of SiC ceramic fibers, the diameter of the fiber is ten A few microns, the original long gauge length ...

AI Technical Summary

Problems solved by technology

(2) The effective number of the load is only 4 digits, and the coaxiality cannot be corrected

(3) The sample and the clamping part of the sample may undergo relative displacement during the stress deformation process, and the measured strain value is the sum of the deformation of each part of the sample, resulting in a large error

(4) The verticality of the sample cannot be guaranteed during the clamping process, the load has shear force, and the position reproducibility and accuracy are poor

(5) The obtained data needs to be output by a printer, and the experimental data is obtained by manual calculation, resulting in large errors

However, this method cannot clamp ceramic single fibers

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