Shearing testing device and operation method thereof

Abstract

The invention discloses a shearing testing device and an operation method thereof. The shearing testing device comprises a fixture base, guide rails, a movable fixture, a fixed fixture, a center-aligning block, a first aligning plate, a second aligning plate, a wedge-shaped block, a first compressing block, a second compressing block and a fixture leveling plate, wherein the two guide rails are longitudinally fixed on the fixture base side by side; symmetrical bosses are arranged at two sides of the movable fixture, and are provided with through holes; the movable fixture sleeves the guide rails via the through holes; the top of the center-aligning block is provided with a bulge matched with a V-shaped notch of a test element; the first aligning block and the second aligning block are both hexahedron square blocks with bulged steps; the first compressing block is positioned below the upper clamping surface of the fixed fixture and is connected with the upper clamping surface; the second compression block is positioned below the upper clamping surface of the movable fixture and is connected with the upper clamping surface. According to the invention, the precise alignment of the shearing test element at the thickness direction and length direction can be ensured, and the clamping operation is very convenient.

Description

technical field [0001] The invention relates to the field of mechanical testing of composite materials, in particular to a shear testing device and an operating method thereof. Background technique [0002] Composite materials have high specific strength and specific modulus, so they are ideal materials for manufacturing aircraft structures. The shear performance of composite materials is an important performance index and an important basis for structural design. Therefore, the accuracy of composite shear performance testing is directly related to the reliability of structural design. [0003] At present, the shear performance test methods of composite materials mainly include: thin-walled circular tube torsion test, 10° off-axis tensile test, ±45° off-axis tensile test and Iosipescu (Iosipescu) shear test, etc. [0004] The thin-walled circular tube torsion test applies the shear load directly to the composite material, and the shear performance results measured by this ...

AI Technical Summary

Problems solved by technology

The shear test device disclosed in the V-notch shear performance test standard ASTM D5379 of composite materials only meets the requirements of the Iosipescu shear test in principle. In actual use, it is found that this shear device has many shortcomings, such as: It is difficult to ensure reliable centering of the test piece and the centering speed of the device is slow, and the clamping operation of the device is inconvenient, etc.

Some researchers (Melin L N, Neumeister J M. Measuring constitutive shear behavior of orthotropic composites and evaluation of the modified Iosipescu test[J]. Composite Structures, 2006,76(1–2):106-115.) on the ASTM D5379 standard The proposed fixture has been optimized to a certain extent, and it is expected to solve the problems in the test, but the optimization scheme is relatively complicated

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