NUMERICAL ANALYSIS FOR VIBRATION CONTROL OF BEAMS WITH ACTIVE CONSTRAINED LAYER DAMPING TREATMENTS

IntroductionThe conventional passive constrained layerdamping (PCLD) treatments[1～ 3] are applied tomachines and structures widely over the lastcentu-ry because they are reliable and simple,however,they are not intelligent. Once the damping treat-ments are installed,they can not be adjusted andcan not adapt themselves to changeable environ-ment.Recently,active damping has received in-creasing attention in the aeronautic and astronauticindustries because of its significant and adjustabledamp…     

复合地层盾构施工安全影响因素及安全事故致因机理

为更好地开展复合地层盾构施工安全管理,研究该情境下盾构施工安全影响因素和安全事故致因机理。遵循文本挖掘范式,提炼基于"特征值字典"的文本挖掘方法,构建集成"频次-卡方优化"的文本挖掘算法,并基于此识别复合地层盾构施工安全的关键影响因素;选用ISM方法剖析关键影响因素的作用关系和多级结构,在此基础上研究复合地层情境下盾构施工安全事故致因机理;针对X项目开展实证分析。研究结果表明:本文构建的文本挖掘方法识别出环境类、人员类和机械设备类等关键影响因素;设计完备程度、人员安全影响因素和机械设备安全影响因素是开展复合地层盾构施工安全管理的关键,而完善安全组织有利于保障上述因素处于安全状态。