Ruixian Qin

To address the issues of traditional integrated honeycomb structures, such as complex manufacturing processes, high production costs, fixed mechanical properties, and difficulty in adapting to varying engineering demands, this paper proposes a circular self-locking honeycomb structure (CSHs) based on a node-locked strategy. The structure cleverly utilizes a spiral path to achieve nested assembly of circular elements. By adjusting the spiral radius and the number of curled layers, geometric interference between elements can be effectively eliminated, resulting in stable and reliable self-locking assembly. Through theoretical analysis and finite element simulations, the effects of the spiral radius and the number of curled layers on the crashworthiness of CSHs are systematically investigated. The results indicate that the optimal values for these parameters are R15 for the spiral radius and N0.75 for the number of curled layers, under which the specific energy absorption of the structure reaches 16.814 kJ kg ⁻¹ . With standardized elements and on-demand assembly, the structure can be shaped into square, hexagonal, or other forms as needed, achieving high energy absorption while remaining easy to fabricate and assemble. This study thus establishes a design basis for self-locking honeycomb structures in crashworthiness applications, including vehicle impact protection.

In recent decades, the search for lightweight and high-performance energy-absorbing structures and materials has made porous thin-walled structures a prominent research area due to their light weight and high energy-absorbing properties. However, due to the more intricate nonlinear interaction between the energy absorption properties and the multicellular structure topologies, it is still challenging to identify the optimal configuration effectively. Therefore, a deep-learning-based technique for predicting the energy absorption properties of thin-walled structures is presented using rib-reinforcement multi-cell tubes (RMTs) as an example. The energy absorption parameters of the thin-walled structure with varied reinforced rib configurations were derived through finite element analysis. Based on the acquired energy absorption properties, the neural network was trained and verified. The rib configuration with the optimum energy absorption performance was identified using a trained neural network. Finally, using the non-dominated sorting genetic algorithm II (NSGA-II), a thickness gradient based on multi-objective optimization of the discovered optimal configuration was carried out. The results indicate that the artificial neural network (ANN) is able to predict the energy absorption performance of RMTs with a high degree of precision, and the optimized structure effectively suppresses the peak crushing force (PCF) with a significant improvement in both the specific energy absorption (SEA) and the crushing force efficiency (CFE). In summary, the prediction capabilities of MLP in addressing difficult engineering issues are not only proven in this study, but an effective prediction tool is also offered for finding the optimal design of thin-walled structures in the future.

Thin-walled tubes have been predominantly utilized in passive vehicle safety systems as crash energy absorbers. With the increasing popularity of additive manufacturing technique, it is feasible to fabricate novel internal reinforcement structures to further reinforce the crashworthy performances of thin-walled tubes. In the present work, a novel nonuniform Lattice-reinforced multi-cell tube based on topology optimization was put forward to explore the crashworthy performances under axial loading and lateral bending. Numeric models validated against the experiments were established to reveal the crashworthy performances of lattice material infilled multi-cell tubes (MCTs). It is observed that the optimized nonuniform lattice structure absorbs more energy than the uniform counterpart. In addition, the hybrid multi-cell filled tubes exhibit remarkable improvements in terms of energy absorption and crushing force efficiency in contrast to the corresponding empty tubes. Furthermore, the specific energy absorption of the three-layer hybrid multi-cell tube is improved by 38.2% and 20.0% under two loading conditions respectively relative to the sum of individual components on account of interplay effect. Collectively, the hybrid nonuniform lattice reinforcement tube provides a promising method for the crashworthy design of MCTs, which can be recommended as an underlying candidate for passive safety protection applications.

Due to the low manufacture cost and easy installation, tubal structures are common utilized as energy absorbers in automotive and other engineering industries. In the present work, four novel reinforced multi-corner columns (RMCs) were investigated using numerical, theoretical, and experimental approaches, results showed that the RMCs had prominent crushing performances compared with other typical multi-cell tubes. Furthermore, the TOPSIS method and multi-objective optimization were conducted to find the best structure and its optimal design parameters, respectively. The optimized column showed excellent crashworthiness capacities and had great potential to be used as energy-absorbing components in engineering applications.

Multi-wall profile as one of the most widely approaches can enhance the crashworthiness properties in thin-walled tubular structures. In actual application process as energy absorbers, there may be a variety of circumstances including axial crushing and lateral crushing. However, the crashworthiness in the multi-wall tubular structure considering both axial crushing and lateral crushing circumstances has rarely been evaluated in the existing literature. In the study, a new tailored-property multi-wall thin-walled structure (TMTS) is put forward to increase the ultimate strength of this material in the region of corner to accommodate two conditions including lateral and axial crushing conditions. Finite element models verified from experiments were established in PAM-CRASH to analyse the crashworthiness performance for this structure. Under lateral and axial crushing, it was revealed that TMTSs exhibited obvious superiority to the corresponding traditional structures. It was concluded that wall thickness, tailoring length and other geometry parameters could effectively influence the crushing performance of the TMTSs. In addition, the progressive deformation mode could be exhibited by the well-designed TMTSs under axial impact. Furthermore, the theoretical model of the TMTS was proposed according to the Super-folding Element Theory. Theoretical analysis is consistent with simulation results, which proves that the deformation formula and the analytical model are all correct. Finally, according to the multi-objective optimisation method, the thicknesses of tailored and non-tailored regions of the TMTS were reasonably configured to further enhance crashworthiness. The research results provide good guidance and theoretical support for the development of novel lightweight energy-absorbing structures under various loading circumstances.

Higher energy absorption efficiency and better crashworthiness performance are always the key objectives for different energy absorbing structures applied in numerous industries including aerospace, rail equipment transportation, and automotive. In this study, a functionally graded thickness (FGT) design method is introduced in the design of a hexagon honeycomb structure to improve energy absorbing efficiency on the basis of a traditional honeycomb with uniform thickness (UT). The validation of a numerical analysis model for a UT honeycomb under axial loading is implemented by a nonlinear finite element code LS-DYNA (V971). Furthermore, the multiobjective crashworthiness optimization of an FGT honeycomb subjected to axial quasi-static compression is conducted to maximize specific energy absorption (SEA) and minimize peak crashing force (PCF). In addition, three surrogate models, including radial basis function (RBF), response surface method (RSM), and kriging (KRG), are compared in the accuracy of predicting SEA and PCF and capacity for optimization design of FGT honeycomb structure; the Nondominated Sorting Genetic Algorithm (NSGA-II) is applied to obtain the Pareto optimal solutions for the maximum thickness, minimum thickness, and thickness variation gradient exponent of a honeycomb wall. The optimal points obtained by different surrogate models subjected to an SEA value of 18.5 kJ/kg, 20 kJ/kg, 22 kJ/kg, and 24 kJ/kg are validated, and corresponding optimal parameters are compared; RBF and RSM are more suitable in crashworthiness optimization design of the FGT honeycomb structure. It is indicated that the FGT honeycomb with optimal geometrical parameters presents remarkable enhancement and energy absorbing potential compared to the traditional honeycomb structure.

The implementation of graded thicknesses in structural designs is an efficient strategy for improving the energy absorption performance of thin‐walled columns. In this study, the mechanical responses of square columns with double‐surfaced gradients under axial crushing forces were analytically and numerically investigated. A mathematical expression for the mean crushing force on a novel tube design is derived according to the super folding element method by introducing two novel parameters: the average thickness of the efficient energy absorbing region (EEAR) and global average thickness. The analytical predictions show good agreement with the simulation results that were obtained using the nonlinear finite element program ANSYS/LS‐DYNA. The results demonstrate that a greater coefficient of average thickness of the EEAR versus global average thickness improves the energy absorption efficiency. However, increasing this coefficient largely depends on the sectional material distribution law. To explore the effects of this law on crushing responses, three different material distribution types were investigated. A significant improvement in specific energy absorption (approximately 30%) was obtained for a double‐surfaced column with an optimized material distribution type compared to that of a square column with a uniform thickness.