软化梁的动力行为
DYNAMIC BEHAVIOUR OF SOFTENING BEAMS
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摘要: 由于材料的应变软化,或是由于薄壁梁在挠曲变形时的截面畸变,梁的弯矩一曲率关系可能呈现先强化后软化的性态。近几年来北京大学一个研究组的工作证实,具有软化特性的半无限长梁在自由端受常速度冲击时,软化可能发展为一个有限长的区段,并在梁内移动,同时,英国UMIST的一个研究组以核电站中的管道甩动问题为工程背景,集中研究了具有软化特性的有限长梁的动力行为。提出了计及弹性、强化、软化和梁的几何大变形的理论模型,并发展了相应的有限差分程序。这一理论模型能够预报软化区的萌生、发展和局部化,同管道甩动实验观测极为符合。Abstract: Due to thstrain-softening of materials or due to the cross-sectional distortion of thin-walled beams in their large deflection,the moment-curvature relation of beams may display a hardening-softening characteristic.The recent work carried out by a research groupin Peking University has confirmed that when a semi-infinite beam with softening property is subjected to a suddenly applid constant velocity at its tip,softening may develop into asegment of finite length and travel along the beam. Meanwhile,in ord...
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Keywords:
- softening beam /
- pipe-whip phenomenon /
- dynamic beliaviour
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