外套有/无约束条件下波纹管扭转特性的实验研究

波纹管是一种具有极高扭转刚度，但易于失稳的弹性薄壁壳体。由于波纹管通常在很小的扭转角度下就会发生失稳，限制了其在传递扭矩方面的用途。通过实验研究发现，波纹管扭转屈曲时其材料远未到达强度极限，使得材料的利用率较低。波纹管失稳以后依然可以在一定范围内承受增大的扭矩，其在弹性范围内的扭转角度远大于屈曲发生时的扭转角度。为提高波纹管在后屈曲阶段的承载能力，采用具有合适内径的刚性外套来约束其横向弯曲变形。通过实验研究与有限元分析相结合的方法，比较了后屈曲阶段外套在提高波纹管承载能力方面的作用，两者得到了一致的结论，外套约束对波纹管后屈曲阶段的承载增加作用明显。

Experimental Studies of Torsional Characteristics of Bellows with or without Outer Barrel Constraint

Bellows is a kind of elastic thin-walled shell structures with high torsion stiffness, but it is apt to be buckled. Usually a bellows will buckle only under a very small torsion angle, and thus its utilities on torque transmitting are limited. It is found that a bellows usually buckle far below its ultimate strength, so the material utilization is very low. A bellows can also carry increasing torsion load to some extent even after buckled, and its elastic torsion angle can be much lager than its buckling angle. A rigid outer barrel with a suitable inner diameter is used to constrain the lateral bending deformation for improving the load carrying ability of a bellows in postbuckling stage. Experiment and finite element analysis are implemented to study the effect of the outer barrel on the load carrying ability of a bellows in postbuckling stage. The two methods get the same conclusion that the barrel constraint significantly improves the load carrying ability of a bellows in postbuckling stage.