Deformation Behavior of Bellows Pipes for Laying Cables Under Ground by Axial Load and Bending Moment

摘要

Recently, electricity demand is rising steeply with advance of science. Additionally quantity of cables such as telephone and optical fiber is rising with communications development and increase of residence. These cables are untidily wired in the air with telephone pole. They impair cityscape and disturb pedestrian safety. Therefore improvement of procedures installing cables is requested. In order to solve it, the plan which buries cables protected in pipes under ground is progressing. They are called buried pipes and consist of straight pipe made from stainless steel or plastic. However there is concern that the buried pipe is crushed and broken by the complex load due to earthquake and ground subsidence. Thus, it is necessary to develop the buried pipe with function of flexibly against damage or rupture. We focus attention to U-type bellows pipe with function of flexibly. In this study, we conduct tensile, compressive, bending test and numerical analysis of those tests using finite element method. From result, we investigate for the relationship between mechanical characteristic and deformation behavior. We study application of bellows pipe to buried pipe. In this study, we examined and analyzed deformation behavior when axial load and bending moment were given to specimens. Examinations items are as (1) we measured load, elongation bending radius by using are experimental device which modeled ground subsidence. (2) We obtained deformation behavior by numerical analysis by using constituted equations of solid mechanics. (3) We conducted simulation analysis of models constructed by finite element method. By comparing these three items, the deformation behavior is clarified.