The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity fa...The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity factor proposed by Wierzbicki et al. and modified by Singace et al. has been taken one step further to obtain the real load-displacement history and to investigate eccentricity effects. The influence of the eccentricity parameter m on the mean crushing load was discussed according to the present analysis. Experiments were carried out to verify the eccentricity effects. The results show that experimental and theo- retical load-displacement curves match perfectly, especially in terms of half wavelength. Unlike previous re- searchs, the results suggest that m is not a fixed value and may affect energy absorption.展开更多
镍钛形状记忆合金(nickel titanium shape memory alloys, Ni-Ti SMA)因为具有良好的生物相容性,在医学领域得到广泛应用。Ni-Ti SMA 的形状记忆性和超弹性增加了其管材的加工难度。总结了国内外学者对Ni-Ti SMA 管材塑性成形方法的研...镍钛形状记忆合金(nickel titanium shape memory alloys, Ni-Ti SMA)因为具有良好的生物相容性,在医学领域得到广泛应用。Ni-Ti SMA 的形状记忆性和超弹性增加了其管材的加工难度。总结了国内外学者对Ni-Ti SMA 管材塑性成形方法的研究成果。挤压和拉拔是制备Ni-Ti SMA 管材的主要方法,医用Ni-Ti SMA 管材仍是采用拉拔成形。介绍了多种提高Ni-Ti SMA 管材成形质量的加工工艺,包括软件模拟、改进模具和改变温度等方式。进一步探究Ni-Ti SMA 管材的加工成形方法仍是未来研究的趋势。展开更多
基金Supportedby the National Postdoctoral Science Foundation (No.2002-17) and the National Natural Science Foundation of China(No. 50275077)
文摘The classical problem of a round metal tube collapsing in concertina mode when subjected to axial compressive loading has been reexamined both theoretically and experimentally. The model including an eccentricity factor proposed by Wierzbicki et al. and modified by Singace et al. has been taken one step further to obtain the real load-displacement history and to investigate eccentricity effects. The influence of the eccentricity parameter m on the mean crushing load was discussed according to the present analysis. Experiments were carried out to verify the eccentricity effects. The results show that experimental and theo- retical load-displacement curves match perfectly, especially in terms of half wavelength. Unlike previous re- searchs, the results suggest that m is not a fixed value and may affect energy absorption.
文摘镍钛形状记忆合金(nickel titanium shape memory alloys, Ni-Ti SMA)因为具有良好的生物相容性,在医学领域得到广泛应用。Ni-Ti SMA 的形状记忆性和超弹性增加了其管材的加工难度。总结了国内外学者对Ni-Ti SMA 管材塑性成形方法的研究成果。挤压和拉拔是制备Ni-Ti SMA 管材的主要方法,医用Ni-Ti SMA 管材仍是采用拉拔成形。介绍了多种提高Ni-Ti SMA 管材成形质量的加工工艺,包括软件模拟、改进模具和改变温度等方式。进一步探究Ni-Ti SMA 管材的加工成形方法仍是未来研究的趋势。
