【摘要】 文章运用I-DEAS软件强大的有限元分析功能,对JJ160/41-K型钻机井架进行模态分析。从数学概念出发,系统的结构模态是振动系统特性的一种表征,石油井架模态分析所得出的固有频率和振型,是井架承受动态载荷时的重要特性。根据固有频率和振型可以预测井架在各种振源作用下的实际振动响应和由于结构设计所产生的薄弱环节。文章通过分析在设计钩载为1568 kN时的前10阶自振频率和各阶主振型,得出了以下结论:井架以整体弯曲振动为主,四根立柱为主要承载构件,且前两立柱承载能力最为薄弱。并建议通过改变立柱截面大小和材料提高井架的稳定性和承载能力,可通过优化截面参数提高立柱刚度。同时,证明了运用模态分析方法来研究钢结构的动力特性是便捷有效的。更多还原

【Abstract】 In the paper, a modal analysis of JJ 160/ 41-k rig derrick is carried out by applying I-DEAS software being of mighty finite clement analysis function. In terms of the conception of mathematics, the structural modal is a characterization of vibration system, and the intrinsic vibration frequencies and modes concluded from the modal analysis of oil derrick are the important properties of the dynamic load borne by derrick. The practical vibration response under various vibration sources and the weak parts producing from structure design may be predicted according to the intrinsic vibration frequencies and modes. Through analyzing the free vibration frequencies of the first 10 steps with a designed hook load of 1568 kN and their main vibration modes, it is concluded that the derrick vibration is mainly the integral bending vibration;the four columns of derrick are the main load-bearing components; and the load-bearing capacity of the front two is most unsubstantial. For this reason, it is suggested that the stability and load-bearing capacity of the derrick can be raised by changing the sectional area and material of the columns, and their rigidities may be improved by optimizing section parameters. Meanwhile, it is also proved that it is convenient and effective to study the dynamic characteristics of steel structure by use of the modal analysis method.更多还原