Abstract

The axial crushing of thin-walled metal circular tubes was addressed in this work for its importance in many engineering applications especially when failed in concertina mode. Theoretical estimates of the peak load were formulated for lower and upper bounds based on Rankine-Gordon principle and the elastic-plastic criterion of buckling, respectively. Numerical simulations were also made to validate these estimates using ABAQUS 14-2 finite element software. Previous findings were compared with both the theoretical and numerical results of the present work. It is found that the peak load is unique for a particular specimen, while the lower bound stress can be equal for different values of D, t and L, as long as the D/t ratio is the same. Moreover, the upper bound stress requires both D/t and L/D ratios. It was also found that all numerical results agree favorably with the theoretical predictions, but not with all of the experimental findings. This partial disagreement was proved to be attributed to the questionable data extracted from one of the cited work. Empirical relations for the available experimental findings were established to confirm the source of disagreement as well as to afford a unified relation which might represent data of different materials, and finally to offer an alternative prediction of experimental peak load.

摘要

薄壁金属圆管的轴向压碎在这项工作中得到了解决，因为它在许多工程应用中的重要性，尤其是在六角形模式下失败时。峰值载荷的理论估计值分别基于 Rankine-Gordon 原理和屈曲弹塑性准则制定了下限和上限。还进行了数值模拟以使用 ABAQUS 14-2 有限元软件验证这些估计。将先前的发现与当前工作的理论和数值结果进行了比较。发现对于特定试样，峰值载荷是唯一的，而对于不同的D、t和L值，下界应力可以相等，只要D / t比例是一样的。此外，上限应力需要D/t和L/D比率。还发现所有数值结果都与理论预测一致，但并非与所有实验结果一致。事实证明，这种部分分歧归因于从其中一项引用的工作中提取的有问题的数据。建立了现有实验结果的经验关系，以确认分歧的来源，并提供可能代表不同材料数据的统一关系，并最终提供实验峰值负载的替代预测。