Research on Dynamic Crack Propagation Behavior of Steel-HSC Interface Under Impact Loads

For steel-HSC (high-strength concrete) composite structures, the interface performance of steel and high-strength concrete is the key to determine the working mechanism of the two. To this end, the paper conducted experimental and theoretical research on the dynamic mechanical properties of the steel-HSC interface with shear studs under impact loads. The composite specimens under stress waves were experimentally studied using a split Hopkinson bar system, and the complex stress intensity factor at the crack tip of the composite specimen was obtained by an experimental numerical method. The research results showed that: 1) Under impact loads, the BNSCB specimen was not only prone to stress concentration at the shear studs, but also had a certain degree of inhibitory effect on the propagation of interface cracks. 2) When using a three-dimensional model to solve the stress intensity factor of the specimen, the average values of <italic>K</italic>₁ and <italic>K</italic>₂ along the thickness direction were taken as the numerical solution of the BNSCB specimen parameter <italic>K</italic>₁ and <italic>K</italic>₂. 3) The maximum and average velocities of the interface crack propagation of the BNSCB specimen increased with the increase of the high-strength concrete strength. 4) With the increase of the high-strength concrete strength, the fracture parameter <italic>K</italic>₁ value at the interface crack tip of the BNSCB specimen would increase.