匀速移动载荷激励浮冰层大幅响应的临界速度

Critical speed of a sharp response for floating ice sheet subjected to moving load with uniform speed

从弹性薄板振动微分方程和势流理论出发,基于二维傅里叶积分变换方法,建立了匀速移动载荷作用于弹性浮冰层的位移响应和临界速度的理论计算模型.通过数值计算获得了浮冰层的位移响应和移动载荷的临界速度,分析了水深、冰厚、载荷强度、载荷半径等因素对位移响应和临界速度的影响.计算结果表明:基于奇点法和能量法获得的临界速度具有很好的一致性;冰层的位移变形随载荷速度的增加先增后减,在临界速度时达到最大;水深的增加导致临界速度和位移变形增加,冰层厚度的增加导致临界速度增加,但位移变形减小;移动载荷强度的增大或载荷半径的减小虽然使冰层的位移变形增加,但对临界速度的影响很小.

Based on the differential equation of thin elastic vibrating plate and the potential flow theo‐ry ,the theoretical models about the critical speed and the displacement response of floating ice sheet subjected to moving load with uniform speed were established by applying the two‐dimensional Fourier transform method .T he displacement response of floating ice sheet and the critical speed of moving load were solved by numerical method .The influences of the depth of water ,the thickness of ice sheet ,the strength and the radius of load on displacement response and critical speed were analyzed . A good agreement exists between critical speeds acquired by singularity method and energy method . Vertical displacement deflection increases ,reaches its maximum value at critical speed ,and then de‐creases with the increasing speed of moving load .The increase of depth results in increasing critical speed and vertical displacement deflection ,the increase of thickness of ice sheet causes increasing criti‐cal speed but decreasing vertical displacement deflection .The increasing strength or decreasing the ra‐dius of moving load makes the vertical displacement deflection increasing ,but the critical speed is scarcely affected by them .