膨胀套管中的橡胶筒尺寸设计分析

根据带有橡胶筒的膨胀套管有限元力学模型,对套管膨胀过程中橡胶变形和套管内的应力变化、橡胶筒两侧的接触压力,以及摩擦因数引起的膨胀参数变化等做了分析研究;对橡胶筒的厚度、长度做了定量和定性分析,发现在橡胶与套管之间的接触摩擦因数作用下,橡胶过长将会在纵向产生“堆积”现象,在有限空间中,使其受较大的接触压力而失效。研究结果表明为了使橡胶筒能有足够的支承力支承套管,可在膨胀套管外面安装多个橡胶筒,相邻橡胶筒之间的间距必须大于2.5倍的橡胶筒纵向伸长量,以免橡胶筒纵向伸长后相互间干扰而形成“堆积”现象。推荐本膨胀结构尺寸中橡胶筒壁厚1.7~2.0mm,橡胶筒长度170~250mm为最佳范围。

Analysis on the design of rubber sleeve size of expansion casings

Based on finite element dynamic model of expansion casing with rubber sleeve, casing deformation and stress change inside casing, contact pressure at both sides of rubber sleeve and expansion parameter changes caused by friction factors during the expansion are analyzed. The thickness and length of rubber sleeve are analyzed quantitatively and qualitatively. It is found out that under the action of contactfriction factors between the rubber and casing, over-length of rubber would produce an "accumulation" horizontally and failure is caused on it by higher contact pressure in limited space. The result of study indicates that to have sufficient force to support the casing, many rubber sleeves should be installed outside the expansion casing, the distance between the rubber sleeves should be 2.5 times bigger than that of horizontal expansion for avoiding the "accumulation" caused by the interference taken place after the horizontal expansion of rubber sleeve. Recommended rubber sleeve thickness is 17-20 mm, its length is 170-250 mm.