Study on dynamic energy dissipation mechanism and damage characteristics of high-temperature marbles

For the sake of investigate the effect of high temperature on the energy characteristics of marble， ANSYS/LS-DYNA was used to carry out dynamic compression tests on marble with six temperature gradients and five impact velocities，to analyse the mechanical properties of marble under high-temperature dynamic loading，the temperature effect of energy evolution，and ultimately，to explore the energy criterion of high-temperature marble strength failure from the perspective of energy dissipation. The results show that: (1) the Holmquist-Johnson-Cook（HJC）intrinsic model can reasonably and effectively simulate the dynamic change of marble damage process under different temperatures; (2) with the increase of temperature，the dynamic peak strength and dynamic elastic modulus of marble are quadratically negatively correlated with the temperature，and the dynamic peak strain is quadratically positively correlated with the temperature，and the damage morphology is changed from X-type to Conjugate shear damage. (3) The increase in temperature reduces the energy storage capacity of the marble specimen to a certain extent，while the effect of high temperature on the energy dissipation capacity of marble is transformed from a facilitating effect to an inhibiting effect with 600℃ as the cut-off point. When the temperature reaches 600℃，the peak strength is greatly reduced，the ductility of the marble increases，crushing damage is presented，and the dissipated strain energy reaches the maximum value. 600℃ can be used as the threshold temperature for the brittle-delayed transformation of the marble; (4) According to the characteristics of the energy evolution process，the point of steep increase of the dissipated strain energy will be (4) Based on the characteristics of energy evolution process，from the perspective of energy accumulation and dissipation，combined with the internal energy and kinetic energy evolution laws obtained by ANSYS/LS-DYNA，the point of steep increase of dissipated strain energy is regarded as the information point of the precursor of overall instability and damage of marble，and the inflection point of the first appearance of the growth rate of elastic energy consumption ratio is defined according to the curve of the stress-elastic energy consumption ratio-strain relationship as the criterion of the strength failure energy of the marble.