SHPB TEST SYSTEM-BASED DYNAMIC LATERAL STRAIN MEASUREMENT DEVICE AND METHOD FOR TEST PIECE

摘要

An SHPB test system-based dynamic lateral strain measurement device and method for a test piece (7), which belong to the field of testing dynamic mechanical properties of a brittle material such as coal rock by using an SHPB test system. Said device comprises a fixing system, an oil pressure system and a data acquisition system; the fixing system is used for fixing the whole device on an SHPB test stand and adjusting the height of the device; the oil pressure system is used for applying a desired confining pressure to a test piece (7) and converting a volume change signal of the test piece (7) into an oil pressure change signal; and the data acquisition system is used for capturing the oil pressure change signal and deriving a time-course change curve of lateral strain. Said device and method use the oil pressure system to apply a confining pressure to the test piece (7) so as to simulate comprehensive confining pressure loading of the test piece (7), and work together with an axial acting force caused by a split-Hopkinson pressure bar device, thereby achieving the simulation of a complex stress state of the test piece (7); in addition, said device and method determine a relationship between an oil pressure and a lateral strain by means of an oil pressure change signal caused by the lateral strain, so as to calculate the lateral strain.