Structural Parameter Optimization of Deformable Energy-Absorbing Components for Impact Resistance in Heavy-Haul Freight Electric Locomotives

Heavy-duty freight electric locomotives, characterized by their enormous axle loads and complex operating conditions, are prone to unstable deformation modes in their front-mounted deformable energy-absorbing components when subjected to sudden axial impact loads. Such instability often leads to premature damage or functional failure, posing a serious threat to operational safety. Although extensive studies exist on thin-walled absorbers for passenger vehicles and railcars, the research on heavy-haul locomotive-specific structures under high kinetic energy conditions is scarce, and the coupled effects of triggering groove number, wall thickness, crushing displacement, and groove outer diameter have rarely been systematically investigated. Moreover, the inherent trade-off between lowering initial peak force and increasing mean crushing force remains unresolved in current designs. Motivated by this gap, the present study develops and validates a finite element model and then conducts a parametric study to reveal the influence of the four structural parameters. A multi-objective surrogate model for energy absorption, initial peak force, and mean crushing force is built using design of experiments (DOE) and response surface methodology (RSM), followed by Pareto optimization using the neighborhood cultivation genetic algorithm (NCGA). The optimized configuration improves stability by 6.72%, energy absorption by 17.68%, and means crushing force by 8.33%, while maintaining a relatively low peak force, thereby significantly enhancing overall crashworthiness. This work provides a valuable numerical reference and practical optimization guidelines for deformable energy-absorbing components in heavy-haul freight electric locomotives.