石油钻机井架结构梁单元计算精度分析

Calculation Precision Analysis of the Beam Element for Rig Derrick Structural Design

目前,对于如何提高BEAM188梁单元在石油井架结构设计中的计算精度研究不多。为此,在分别介绍BEAM188梁单元及其一次、二次和三次形函数之后,通过一悬臂梁算例,分析了一次、二次和三次形函数的适用条件,指出它们分别适合于计算常弯矩、一次弯矩和二次弯矩载荷作用。在侧风无立根条件下,对某ZJ30-1700DBF钻机井架进行了工程实例有限元应力计算。计算结果表明,井架梁结构划分为一个梁单元计算规模小,且采用二次及三次形函数具有较高的计算精度。

At present research on the improvement of the calculation precision of the BEAM188 beam element in the design of rig derrick structure is seldom seen. Therefore, after an introduction of the BEAM188 beam as well as its linear, quadratic and cubic shape functions, the application condition for the linear, quadratic and cubic shape functions was analyzed through a cantilever example. It is pointed out that they are respectively suitable for calculating constant bending moment, linear bending moment and quadratic bending moment. A finite element stress calcu- lation of an engineering example was conducted with a certain ZJ30 - 1700DBF drilling rig derrick in the condition of crosswind and with no stand. The calculation shows that the derrick beam structure is classified as a beam element. Thus, the calculation workload is small. Moreover, adoption of quadratic and cubic shape functions can achieve high calculation precision.