变速移动载荷激励浮冰层的位移响应特性

Characteristics of displacement response of floating ice sheet to variable-speed load

基于弹性薄板假设和势流理论,利用薄板振动微分方程以及运动学边界条件建立了变速移动载荷激励浮冰层位移响应的理论计算模型.采用傅里叶-拉普拉斯变换的方法进行求解,通过数值计算获得浮冰层的位移响应.将退化到匀速情况的计算结果与实冰实验数据进行比较,发现临界速度的值以及临界速度下冰层位移响应的波形特征与实验结果相一致;此外,以匀加速载荷为例,通过改变加速方式、冰厚、水深等参数,分析了不同加速方式下浮冰层位移响应的特征,明确了水深、冰厚等因素对浮冰层位移响应的影响,揭示了移动载荷加速度与破冰效率间的关系.

Based on the thin elastic plate assumption and the potential flow theory,the theoretical model about the displacement response of floating ice sheet to a variable-speed load was established by employing the differential equation of thin elastic vibrating plate and dynamical boundary conditions.The theoretical model was solved by Fourier-Laplace transform method and the displacement response of floating ice sheet was obtained by numerical calculation method.By comparing the calculation results derived from uniform speed situation with the data in field experiments,it can be seen that a good agreement exists among the value of critical speed and the wave profile of displacement response of ice sheet at the critical speed.Besides,as for a uniform accelerating load,by changing the accelerating modes,thickness of ice sheet and water depth,the characteristics of displacement response of floating ice sheet to different accelerating modes were analyzed,the influences of the water depth and the thickness of ice sheet on displacement response were illustrated,and the relationship between the acceleration of the moving load and icebreaking efficiency was revealed.