可控震源振动器平板-大地接触性质与能量传递研究

大地的表面形貌是影响可控震源振动器平板与大地之间接触性质的因素之一。为了掌握大地表面参数对可控震源振动器平板-大地接触系统接触性质及振动特性的影响规律，基于分形理论建立了三维粗糙大地表面形貌，构建了振动器平板-大地接触模型，得到了不同大地表面形貌及材料参数下振动器平板与大地之间的接触力-变形曲线；建立了振动器平板-大地接触振动动力学方程，并计算了振动器平板的位移响应以及能量传递。结果表明：振动器平板与大地之间接触力的非线性随大地表面粗糙度的增大而增大，振动器平板-大地接触系统的固有频率随大地表面粗糙度的增大而减小；粗糙表面的接触模型中振动器平板每一周期向大地传递的能量随时间的增大而减小。同时，大地表面材料参数的非线性也会影响平板-大地接触系统的振动响应和能量传递。由此可知，大地表面的粗糙度和材料的非线性是限制可控震源高频输出的重要原因。研究结果将为可控震源的优化和高频拓展提供参考。

Study on contact property and energy transfer between vibrator baseplate and ground

The surface topography of ground has great influence on the contact properties between the vibrator baseplate and ground. In order to investigate the effects of the ground surface parameters on the contact properties and vibration character of the vibrator baseplate-ground contact system, the three dimensional surface topography of rough ground was generated by the fractal function theory and then the vibrator baseplate-ground contact model was established. The contact curves between vibrator baseplate and ground under different ground surface topography and material parameters were obtained. The dynamics equation of the vibrator baseplate-ground contact model was further established, and the displacement response and energy transfer of the vibrator baseplate were calculated. The results showed that the nonlinearity of the contact force between the vibrator baseplate and the ground increased with the increase of the ground surface roughness. The natural frequency of the vibrator baseplate-ground contact system decreased with the increase of the ground surface roughness, as well as the energy transfer of the baseplate per cycle. Meanwhile, the nonlinearity of the ground material parameters also influenced the vibration response and energy transfer of the vibrator baseplate-ground contact system. Consequently, the ground surface roughness and material nonlinearity were important reasons which restricted the output of the vibroseis in high frequency phase. The study has a positive effect for optimization and high frequency expansion of the vibroseis.