円管の衝撃軸圧縮塑性座屈実験

Abstract

Progressive plastic buckling appears in the axial symmetric behavior of circular tubes subjected to static loads or low velocity impacts, when the inertia effect is negligible. For high velocity impacts in which inertia cannot be neglected, the studies by Tanaka and Kurokawa revealed the appearance of the same modes as those in static tests. However, a series of impact tests on tubes by Florence et al. recorded the phenomenon of dynamic plastic buckling in which the deformation consists of many waves superposed on a uniform plastic deformation. This phenomenon was found for moderately thick circular tubes subjected to high velocity axial impacts. Ren et al. observed that dynamic plastic buckling developed on thin circular tubes. Thus, the plastic buckling behavior for high velocity impact tests on circular tubes consist of both progressive plastic buckling and dynamic plastic buckling, but the detailed behavior is not clear yet.The purpose of this study is to clarify the characteristics for the transition process from progressive plastic buckling to dynamic plastic buckling. In particular, the following features are examined:(1) The comparison and consideration of various experimental methods used in the previous impact test results.(2) The influence of end condition on the static buckling behavior of circular tubes.(3) The consideration of some impact test results.