交叉及顺次加载下螺栓交互作用的有限元分析

Finite Element Analysis to Elastic Interaction between Bolts during Cross and Sequential Tightening

弹性交互作用系数法是解决螺栓之间弹性交互作用的有效途径,但交互作用系数矩阵的获取较为困难。采用有限元数值模拟方法,研究PN40的3个规格DN100,DN200,DN300的法兰在交叉及顺次加载下的弹性交互作用规律。建立了相应模型,并采用DN100装置的试验结果验证了模型的正确性。模拟结果表明,与DN100试验结果类似,DN200,DN300法兰在交叉或顺次加载时,弹性交互作用依然可分为正作用和负作用。正、负作用使交叉及顺次加载的最终载荷分布呈现W和N形。交叉加载的W形分布与螺栓数目有关,顺次加载N形分布与螺栓数目无关。随螺栓数目的增多,正作用变化不大,负作用明显增强。

The elastic interaction coefficient method is an efficient way to solve the interaction between bolts during tightening. Obtaining the interaction coefficient matrix is complicated. The interaction rules in DNIO0, DN200 and DN300 flanges were studied in cross and sequential pattern by finite element simulation. The finite element model was established and validated with experiment in DN100 flange. The numerical results indicate that, the elastic interaction can also be divided into positive effect and negative effect in cross pattern and sequential pattern in DN200 and DN300 flanges as in DN100. The combination of the two kinds of effect makes the final load distribution as W shape in cross pattern and N shape in se- quential pattern. The W shape distribution is influenced by the number of bolts, whereas the N shape distribution is not. As the number of bolts increases, the positive effect is more obvious, while the positive effect is changeless.