Using shape memory polymer as matrix material to prepare negative Poisson’s ratio structure, the shape memory performance, impact resistance, light weight and other characteristics are integrated, which has great application prospects in vehicle collision, aerospace, military, medicine and other fields. PLA, TPU, and PETG materials were selected for shape memory performance test, and the shape recovery rate, shape recovery time and shape fixation rate were analyzed to show that the shape memory performance of PLA materials was better. The quasi-static compression test and simulation analysis were carried out for four typical negative Poisson’s ratio structures with PLA as the base material: concave hexagon, concave triangle, star and rotating cell. Through the analysis of Poisson’s ratio effect, impact resistance and energy absorption ability, the mechanical properties of the concave hexagonal structure are better, and the negative Poisson’s ratio effect is obvious. When the compressive strain is less than 15%, the rebound rate of other structures is above 90% except star structure. The response surface optimization method is used to optimize the impact response of the concave hexagonal structure with the maximum residual displacement after impact deformation. After optimization, the maximum displacement under energy impact deformation is reduced by 21.76% and the energy absorption is increased by 3.29%, and the optimized structure has better shape recovery performance, which provides a reference for designing the buffer structure with self-recovery performance.

In order to solve the dietary problems of patients with dysphagia, a mathematical model for predicting extrusion pressure is established. The predictive model parameters are determined with the aid of the finite element method, and a 3D printing nozzle capable of printing nutrient-rich sandwich food is designed according to the predictive model. Pumpkin puree and minced pork are verified according to IDDSI standards. Finally, the accuracy of the predictive model and the printing effect of the design nozzle are verified by extrusion and printing experiments, respectively. The results show that four groups of simulation experiments reveal that the extrusion pressure increases by 15.6%, 13.5%, 12.7% and 12.4%, respectively, with a 1 cm increase in nozzle length. When the nozzle length is in the range of 1–5 cm, the extrusion pressure increases with the increase of the volume flow rate in the extrusion cylinder. The extrusion speed has little correlation with the length of the nozzle outlet, but for every 1 cm³/s increase in the inlet volume flow rate, the extrusion speed increases by about 1.5%. The finite element simulation experiment determines that the parameters of the prediction model are σ₀ = 0.6, α = 1.1, m = 0.21, τ₀ = 0, β = 0.52 and n = 0.2; the error between the predictive value and the experimental value is 15%, and the printed sandwich food has smooth lines, good molding and complies with IDDSI standards.

As a typical buffer energy absorbing structure, thin-walled tube filled with foam aluminum has good mechanical properties and energy absorption characteristics. Therefore, the axial compression performance of square tube and foam aluminum filled square tube was experimentally studied by quasistatic mechanical loading method. On the basis of the existing experimental research and theoretical analysis, the strain rate is introduced into the dynamic compression theory, and the mathematical model of the average crushing force of foam aluminum filled square tube under the axial quasi-static and impact loads is obtained. By comparing the theoretical results with the simulation results, the error of quasistatic and impact state is 2.8 and 8%, respectively. The feasibility of the theoretical analysis is verified. This paper not only proves that foam aluminum filling can significantly improve the bearing capacity and energy absorption performance of square tube structure in the axial compression process, but also provides a more specific theoretical basis for the axial compression energy absorption design of square tube filled with foam aluminum.

The mining chute is an important equipment in the process of coal transportation and coal screening preparation. During the working process, the mining chute generates a lot of vibration and noise because of constant friction and impact of gangue and coal blocks. In order to reduce the vibration and noise during the operation of the chute, a new type of foam aluminum laminated structure is used to manufacture the mining chute. According to the characteristic of chute, the laminated structure is optimized by taking the vibration amplitude as the objective function and the thickness of the steel plate and the foam aluminum core plate as the design variables. Then, the vibration and noise reduction performance of two types of chute are evaluated through experiments and finite element simulation method. Results show that use of foam aluminum laminate structure to manufacture the chute can obviously increase the damping ratio of the system, which can effectively reduce the vibration amplitude of the chute. The average sound insulation performance of foam aluminum laminated chute is better than prototype chute, especially in the middle and high frequency section, which can be reduced by about 7.1 dB on average in comparison with prototype chute. So, the foam aluminum laminated structure chute has a more significant sound insulation and vibration reduction effects than the prototype chute.