Combined tension-torsion multi-axis fracture experimental system and experimental method

Abstract

The invention provides a combined tension-torsion multi-axis fracture experimental system. The experimental system comprises a dynamic tension-torsion testing machine and a control device connected with the dynamic tension-torsion testing machine. The dynamic tension-torsion testing machine has an upper chuck, a lower chuck and a force sensor, and is clamped with a sample through the upper chuck and the lower chuck. The sample is a thin-walled tube with a notch, and is provided with a speckle. A deformation measurement system comprises a non-contact three-dimensional strain optical measurementsystem connected with the control device through a synchronous trigger device which comprises two cameras connected with the synchronous trigger device and an image acquisition and data processing device connected with the two cameras respectively. The invention also provides a combined tension-torsion multi-axis fracture experimental method. The invention adopts a sample of a thin-walled tube with a notch, which can obtain a low-stress triaxial level and different Rhodes parameter levels by changing different combined tension-torsion loading ratios. In addition, since the experimental systemcomprises a non-contact three-dimensional strain optical measurement system, measurement of full field strain can be achieved.

Description

technical field [0001] The invention relates to the field of material performance testing, in particular to a tensile-torsion combined multiaxial fracture experimental system and an experimental method. Background technique [0002] Structural components in engineering are mostly in a state of multiaxial stress. Studying the fracture performance response of materials in a state of multiaxial stress is of great engineering significance to ensure the safe operation of engineering structural components. The multiaxial stress state has an important influence on the ductility, damage mechanism and failure mode of metal materials. It is generally characterized by the stress triaxiality (the ratio of the average stress to the Mises stress) and the Rhodes parameter. Many damage models are also Based on stress triaxiality and Rhodes parameters. [0003] At present, most of the experiments are focused on the higher stress triaxiality level and the stress state with the Rhodes paramet...

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Problems solved by technology

[0003] At present, most of the experiments are focused on the higher stress triaxiality level and the stress state with the Rhodes parameter of -1, 1, 0, and the experimental schemes at the low stress triaxiality level and other values ​​of the Rhodes parameter level are still very limited. Rare, which also leads to the lack of support and verification of experimental data for damage models at low stress triaxiality levels and other Rhodes parameters

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