Thickness Distribution Of Tube Research Articles

Crush Analysis of External Inversion of Tubes with Variable Thickness Distribution

Axial crush tests on Uniform Thickness (UT) and Functionally Graded Thickness (FGT) tubes have been performed for external inversion process, and crashworthiness performance, and benefits of FGT tubes compared with their UT equivalents. Furthermore, in order to find detail verification about crush process of FGT tubes, Finite element (FE) models developed using explicit FE code under axial loading. Then, these FE models validated by experimental tests to ensure that they can accurately predict the responses of FGT inversion tubes. Our study shows that tube thickness distribution, die radius, and coefficient of friction between die and tube have great influence on the responses of FGT tubes inversion. The results give new design ideas to improve crashworthiness performance of inversion tubes. DOI: https://doi.org/10.52783/pst.272

Experimental and numerical investigation of dynamic plastic behavior of tube with different thickness distribution under axial impact

In this study, the dynamic behavior of uniform thickness, stepped thickness and functionally graded thickness tubes under axial impact are investigated experimentally and numerically. A striking mass has been used to impact tubes. Experimental tests are performed by using gas gun and numerical results are obtained by FE simulation. The effect of thickness distribution on shortening, energy absorption, axial force and buckling shape of tubes are investigated. It is found that a change in thickness distribution of tube can convert the buckling shape from buckling with mild folds to progressive buckling and vice versa. In addition, it is found that stepped thickness tube can be an approximate of functionally graded thickness tube which in this case almost, their behavior is identical. This study reveals that stepped thickness and functionally graded thickness tubes in comparison with uniform thickness tube absorb the same energy with more shortening and less peak load or less mean load; thus, they are better energy absorption specimens. With comparing experimental and numerical results, it is found that there is a good agreement between them.

Crush response of variable thickness distribution inversion tubes under oblique loading

Crush response of Variable Thickness Distribution (VTD) tubes subjected to oblique loading are investigated for external inversion process. Crashworthiness performance and benefits of VTD tubes compared with their Uniform Thickness (UT) equivalents. Furthermore, in order to find detail verification about crush process of VTD tubes, at first Finite element (FE) models established and then validated by experimental tests to ensure that they can accurately predict the responses of VTD inversion tubes. Our study shows that tube thickness distribution, die radius, and coefficient of friction between die and tube have great influence on the responses of VTD tubes inversion. The results demonstrated that different loading angles have different requirements on geometries of VTD inversion tubes. The outcome of this paper gives new design ideas to improve crashworthiness performance of inversion tubes under oblique loads.

An Approach for Analysis of Bulged Profile and Thickness Distribution of Tube in Free Hydro-Bulging Process

Tubular components are widely used in the areas of automotive and aerospace industries due to their excellent properties. A mathematical model considering the bulged region as a parabola curve is proposed to examine the plastic deformation behavior of a thin-walled tube during the free hydro-bulged process. The finite element simulations of the free hydro-bulging process are carried out to verify the approach indirectly. The results indicate that the model is accurate and acceptable to figure out the circumferential radius, wall thickness and axial radius of the bulged profile.