Mechanical ratcheting of stainless-clad pipe subjected to internal pressure and cyclic axial load or cyclic bending.

承受内压和循环轴向载荷或循环弯曲的不锈钢复合管的机械棘轮。

基本信息

批准号：
02650073
负责人：
YOSHIDA Fusahito
金额：
$ 1.22万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

Mechanical ratcheting behavior of a stainless-clad pipe(SUS304/STPG38)subjected to internal pressure and cyclic axial straining or cyclic bending was investigated. An elastic-plastic FEM analysis of the mechanical ratcheting was perfomed and the analytical results were compared with the corresponding experimental results.(1)In the ratcheting of internal pressure with cyclic straining, circumferencial strain accumulated with strain cycles, and the higher ratcheting strain rate was observed under the conditions of larger cyclic strain range and larger internal pressure. Shakedown of ratcheting was obserbed in SUS304 after about 10 strain cycles, whearas remarkable ratcheting strain accumulated in every strain cycle in STPG38 steel. In the clad pipe remarkable ratcheting strain accumulation appearing in STPG38 was prevented by SUS304. and the ratcheting strain rate of the clad pipe was between the rates of SUS304 and STPG38. Ratcheting tests were performed in two levels of clad ratio(thickness ratio), SUS304/STPG38 = 0.5 and 1.0, but no apparent difference in ratcheting behavior was found.(2)In the ratcheting of internal pressure with cyclic bending, larger strain accumulation was observed compared with the ratcheting of internal pressure with cyclic axial straining.(3)The FEM analysis overestimated the ratcheting strain accumulation. It seems to come from the problem of constitutive modeling for the steels, and the improvement of the modeling is required.

研究了遭受内部压力和循环轴向应变或环状弯曲的不锈钢管道（SUS304/STPG38）的机械棘轮行为。对机械棘轮的弹性塑性fem分析进行了完善，并将分析结果与相应的实验结果进行了比较。（1）在内部压力的棘轮中，循环拉伤，循环菌株，与应变循环积累的周环应变，以及较高的棘轮应变率在较大的环状应变范围和较大的内部压力的条件下观察到。在大约10个应变循环后，在SUS304中观察到了棘轮，在STPG38钢中的每个应变循环中积累了明显的棘轮菌株。 SUS304阻止了STPG38中出现的明显棘轮应变积累。外壳管的棘轮应变速率在SUS304和STPG38的速率之间。进行棘轮测试以两个水平的外壳比（厚度比），SUS304/STPG38 = 0.5和1.0进行，但没有发现棘轮行为的明显差异。（2）内部压力与环状弯曲的棘轮，较大的应变积累是更大的应变积累。与循环轴向拉伤的内压棘轮相比，观察到的。（3）FEM分析高估了棘轮应变的积累。它似乎来自钢的本构建模问题，需要改进建模。