Oblique Crashworthiness Analysis of Steel Circular Tubes: Parametric Study on Wall Thickness Effect and Critical Loading Angle Identification

The current work studied the crashworthiness behavior of thin-walled circular steel tubes against axial and oblique crushing. Parametric analyses of crushing angle and tube wall thickness were conducted aiming to identify their effect on dissipated energy, collapse initiation and deformation stability. Quasi-static experiments and finite element (FE) simulations in LS-DYNA were implemented for crushing angle parametric analysis, while the wall thickness effect was studied numerically for the same loading angle range. Both experiments and simulations revealed that an increase in crushing angle results in lower energy absorption (EA) and peak force. Low-angled oblique loading was indicated as the most efficient impact condition reaching sufficient EA and facilitating plastic collapse initiation. The occurrence of global bending mode revealed a critical loading angle value reacting to a significant EA drop due to unstable plastic deformation. Finally, higher wall thickness resulted in greater peak force and increased critical angle reacting to a smoother EA decrease with respect to loading angle by preventing unstable deformation mode.