认识离心振动台-吊篮-岩土模型运动耦合关系对离心振动台发展和动力离心试验数值仿真具有重要意义,针对吊篮具有轻、柔特点,开展了大型离心振动台设计方法与耦合运动关系等相关问题研究。首先对比分析大型离心振动台关键问题和设计方法,建立了液压执行机构耦合关系等效简化模型;其次,推导离心振动台系统耦合运动传递函数,进行了一系列影响参数研究。结果表明,提高阻尼比和质量比是降低离心振动台与吊篮谐振现象的有效方法,其中质量比考虑离心机有效容量,推荐为4;吊篮刚度过大将加重二者谐振,橡胶剪切支座刚度对谐振无明显影响。
As clarifying coupling relationship among centrifugal shaker, bucket and soil sample is crucial to the de- velopment of centrifugal shaker and the numerical simulation of dynamic centrifuge experiment, and buckets are featured by lightmass and flexibility, several fundamental issues revolving around the design method, coupling char- acteristic and servo control of large centrifugal shakers are studied herein. Contrastive study is first conducted on critical problems and design methods of large centrifugal shakers and a simplified equivalent coupling model to hy- draulic actuators is established. The coupling systematic transfer functions of centrifugal shakers are then derived, and a series of parametric analyses are performed. The results show that increasing damping ratio and mass ratio of buckets are both effective means to mitigate resonant action between buckets and centrifugal shakers with a recom- mended value of 4 to mass ratio proposed by considering effective capacities of centrifuges. While large stiffness of bucket tends to aggravate the resonant action and insignificant influence of shear stiffness of rubber bearings on the resonant behavior is observed.