@article{oai:kagawa-u.repo.nii.ac.jp:00005790, author = {石川, 浩 and Ishikawa, Hiroshi and 谷本, 敏夫 and Tanimoto, Toshio and 木村, 等 and Kimura, Hitoshi}, issue = {6}, journal = {香川大学経済論叢, Kagawa University economic review}, month = {Feb}, note = {Investigations were made on the fatigue properties of satin woven glass cloth FRP under multi-step program loading of rotating bending, with special emphases on the effects of the primary stress level, its cycle ratio and the sequence of loading. Rotating bending fatigue tests under constant stress amplitudes were also carried out to form the comparison basis. In each case, fatigue test under a certain loading condition was repeated several times so as to produce statistical fatigue life data for the analysis of fatigue life dispersion of the material with the aid of a two-parameter Weibull probability model., To clarify the fatigue properties of the material under service loads, the effect of stress wave form would be one of the most interesting subjects which must be dealt with. Hence the associated investigation was incorporated in the present study., The following delineates the main conclusions:, (1) According to the results of basic two-step program loading fatigue tests, the cycle ratio at the secondary stress level, n2/N2, is always equal to or greater than unity. Futher, it is of practical interest to note that the fatigue life at the secondary stress level is longer than that at the same stress level under constant amplitude loading. This tendency was particularly observed in the case of High-Low type loading sequence. Hence, it would be considered that Miner's rule could not be applied for fatigue life estimation of the FRP under program loading. It has to be modified to an appropriate form, thus giving the proposed prediction formula., (2) Fatigue life estimation by the proposed equation indicates that a fairly good agreement can be obtained between the experimental and the estimated fatigue lives throughout the present study., (3) Sinusoidal stress wave form can cause a longer fatigue life in comparison with those triangular and/or pulse type.}, pages = {554--595}, title = {プログラム荷重に対するFRPの疲労寿命分布と信頼性}, volume = {52}, year = {1980}, yomi = {イシカワ, ヒロシ and タニモト, トシオ and キムラ, ヒトシ} }