Objectives In the context of the ship industry's demand for lightweight and high energy - absorbing structures, this research aims to enhance the mechanical properties of lattice structures under lightweight conditions. A novel improved body - centered cubic (BCC) lattice structure (BCCZ) is designed based on the multi - configurational combination design method. This is crucial because traditional BCC lattice structures have limitations in load - bearing capacity and energy absorption, and the new design is expected to overcome these drawbacks, providing better solutions for ship - building and other related fields.

Methods To achieve this goal, a series of methods are adopted. Firstly, compression tests are carried out. BCC and BCCZ lattice structures with specific parameters (L₁ = 15.0 mm, θ = 45.0°, L₂ = 10.6 mm, D = 2.5 mm) are prepared by the selective laser melting (SLM) method. The mechanical properties and energy absorption characteristics of these two structures under quasi - static compressive loading are compared and analyzed. Secondly, numerical simulations are conducted. By changing the diameter - to - length ratio (D/L) while keeping other parameters constant, 12 different structures are designed. The finite - element method is used to study the influence of D/L on the mechanical properties and energy absorption characteristics of BCC and BCCZ lattice structures. This combined experimental and simulation approach ensures a comprehensive and in - depth understanding of the structures' behaviors.

Results The results show significant differences between the two structures. In terms of deformation modes, both structures' deformation processes can be divided into three stages: the initial linear elastic stage, the nonlinear damage stage, and the densification stage. However, the BCC structure is more stable during the nonlinear damage stage, while the addition of vertical struts in the BCCZ structure changes its deformation mode from a bending - dominated structure to a coupled structure of vertical strut tension - dominated and inclined strut bending - dominated. Regarding mechanical properties, as the D/L increases, the elastic modulus, compressive strength, and specific energy absorption of both structures increase. The BCCZ structure always has better performance in these three aspects. Specifically, the compressive strength of the BCCZ structure is greater than that of the BCC structure, with an improvement rate of more than 100%, but the overall improvement rate of compressive strength shows a downward trend as D/L increases. In contrast, the improvement efficiency of specific energy absorption becomes more obvious. In terms of energy absorption efficiency, the BCC structure is superior to the BCCZ structure, but this difference gradually decreases as D/L increases.

Conclusions In conclusion, this research provides valuable insights for the design of new energy - absorbing and protective structures in ships. The design of the BCCZ structure and the study of its performance under different D/L ratios offer a theoretical basis and practical reference for optimizing lattice structures in engineering applications. It also paves the way for further research on lattice structures, such as exploring more complex multi - configurational combinations and studying their behaviors under dynamic loading conditions. The results can guide the selection of appropriate lattice structures in different engineering scenarios, promoting the development of lightweight and high - performance structures in the ship industry and other related fields.