On the bending collapse of circular tubes with laser-welded localized reinforcements for enhanced crashworthiness

Flores-Sanchez M.; Lavayen-Farfan D.; Rodriguez-Hernandez J. · International Journal of Lightweight Materials and Manufacture (2026) · DOI: 10.1016/j.ijlmm.2026.09.009

Resumen

Thin-walled circular tubes are widely employed in lightweight structural applications due to their high strength-to-weight ratio and manufacturability. However, under severe bending loads, these members are susceptible to localized collapse governed by ovalization and plastic hinge formation. While this response can be exploited as an effective energy dissipation mechanism for crashworthiness applications, it is often limited by low peak bending capacity. This study investigates the enhancement of bending collapse performance through localized sleeve-type reinforcements manufactured from structural steel and joined via laser welding. A finite element model, validated against experimental three-point bending tests, is developed to quantify the influence of reinforcement geometry on peak bending moment and energy absorption. Results demonstrate substantial improvements, with increases of up to 108% in peak bending moment and 45.66% in the specific energy absorption. To support design optimization, a metamodel-based framework is proposed to determine optimal reinforcement length as a function of tube diameter, wall thickness, and reinforcement angle, maximizing specific energy absorption (SEA) subject to a peak moment (Mmax) constraint. The proposed reinforcement strategy provides a manufacturable and weight-efficient pathway for improving the crashworthiness of tubular structures, offering practical benefits for lightweight and safety-critical engineering applications. The Authors This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/

Instituciones: Pontificia Universidad Católica del Perú