Publications (2)0 Total impact
ABSTRACT: We propose a dynamic combined compressive and shear experimental technique at high strain rates (102-104 s-1). The main apparatus
is mainly composed of a projectile, an incident bar and two transmitter bars. The close-to-specimen end of the incident is
wedge-shaped with 90 degree. In each experiment, there are two identical specimens respectively agglutinated between one side
of the wedge and one of transmitter bars. When a loading impulse travels to specimens along the incident bar, because of the
special geometrical shape, the interface of specimen glued with the incident bar has an axial and a transverse velocity. Thus,
the specimens endure the combined pressure-shear loading at high strain rates. The compression stress and strain are obtained
by strain gages located on the bars; the shear stress is measured by two piezoelectric crystals of quartz with special cut
direction embedded at the end (near specimen) of transmitter bars; the shear strain is measured with a novel optical technique
which is based on the luminous flux method. The feasibility of this methodology is demonstrated with the SHPSB experiments
on a polymer bonded explosive (PBX). Square-shaped specimen is adopted. Experimental results show that the specimen is obviously
rate-dependent. Shear and compression failure occur for the specimen.
03/2011: pages 417-424;
ABSTRACT: An innovative Hopkinson pressure bar system for testing the shear response of materials at high strain rates has been developed.
A novel single-lap specimen of a polymer bonded explosive (PBX) is used. Instead of strain gauges mounted on the bars, one
quartz force transducer is sandwiched between the clamp and the transmission bar to directly measure the weakly loading forces.
A laser gap gauge is employed to monitor the shear strain of the specimen, which is based on the luminous flux method. Finite
element code ANSYS is used to analyze the stress state in the specimen. Experimental results show that this new method is
effective and reliable for determining the shear stress-strain responses of the soft materials at high strain rates.
01/1970: pages 223-228;
National University of Defense Technology