Dynamic strength evaluation of straight pipe using energy balance method

エネルギーの釣合に着目した直管の動的強度評価

皆川 佳祐*; 藤田 聡*; 北村 誠司 ; 岡村 茂樹

Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki

The ultimate strength of a mechanical structure is investigated from a viewpoint of the energy balance equation. The energy balance is adequate for an investigation into the influence of cumulative load. Authors have already confirmed a relationship between fatigue failure and the input energy from results of experiments using simple single degree of freedom models in a previous study. In this paper, straight pipe models are adopted, and the relationship between fatigue failure and the input energy is investigated. The investigation is implemented by forced vibration experiments that lead the experimental model to fatigue failure. As a result of the experiment, much input energy for failure is needed in case of small input level. This tendency is same as the result of the previous study using simple single degree of freedom model. Therefore it is expected that any actual piping satisfy this tendency, and time for failure can be expected by using energy balance.