Multifunctional In-Situ Testing Device for Investigating the Service Performance of Materials

Abstract

To obtain the change rule of material/structure service performance under complex working conditions, this study developed a material/structure mechanical property testing device with multi-load and multi-physics loading functions. The features of this device include its ability to realize the composite mechanical loading of three loads (tension/compression–bending–torsion), as well as physical field loading, such as current field, magnetic field, and thermal field, to realistically simulate the actual service conditions of materials/structures. To monitor the surface topography change, temperature, and strain distribution of the specimen in real-time, various in-situ monitoring methods, including microscopic imaging, infrared thermal imaging, and digital image correlation method, were integrated into the device. To realize multi-load composite loading, a six-degree-of-freedom parallel drive platform was adopted in the device, and its control system was developed with a distributed double-layer structure to realize the closed-loop control of any combination of load forms. All functional modules of the device were calibrated, and a coaxial calibration method based on a six-dimensional force sensor was proposed. Lastly, several tests were performed to evaluate the effectiveness of the proposed device functions, and the test results revealed the broad application prospects of the device.