TiNi合金圆柱薄壳静压屈曲失稳特性的实验研究

Experimental Investigation on Buckling Behavior of a Thin Cylindrical Shell Made of Tini Alloy under Static Compression

对马氏体相变支配的伪弹性TiNi合金圆柱薄壳进行了准静态屈曲实验研究和分析,结果表明,TiNi柱壳的屈曲模态以非轴对称钻石型为主,卸载时可恢复,与马氏体相变和相变铰的行为相关,明显不同于传统弹塑性柱壳。还讨论了长径比和边界条件对屈曲模态、比能、临界失稳阈值等的影响。研究发现:随着长径比和边界条件的变化,TiNi圆柱薄壳呈现出多样化的屈曲模态发展。相同长径比下,两端简支的TiNi圆柱薄壳比能Se较大;随着长径比增大,边界条件的影响有逐步弱化趋势。相同边界条件下,长径比较小的TiNi圆柱薄壳比能较大。

In this paper, quasi-static buckling response of a pseudo-elastic TiNi thin cylindrical shell dominated by martensitic phase transformation is experimentally studied and analyzed. Results show that the buckling mode of TiNi thin cylindrical shell is mainly the nonsymmetric diamond model and is related with martensitic phase transformation and the transformation hinge behavior. It recover upon unloading which is significantly different from the traditional elastic-plastic cylindrical shell. The influence of length-diameter ratio （L/D） and boundary condition on buckling mode, specific energy, critical instability threshold is also discussed in this paper. Results show that along with the change of length-diameter ratio and boundary condition, the buckling mode diversification of TiNi thin-wall cylindrical shell is presented under quasi-static loading. With the same length-diameter ratio, specific energy of TiNi thin cylindrical shell simply supported at both ends is larger; as the length-diameter ratio increases, influence of boundary condition has weakening tendency. Under the same boundary condition, the specific energy of TiNi thin cylindrical shell with smaller length-diameter ratio is larger.