Optimization Of Mechanical Properties Of Layered Gradient Honeycomb Sandwich Panels And Lightweight Study Of Paneled Shelters

Medical shelter has played a significant role in the filed such as combat wound treatment and disaster rescue.It has greatly enhanced the capability of the security service.With the continuous development of shelter technology,improving the ratio of load-wight and reducing the self-weight of shelters has become urgent problem in the shelter design.This paper proposes a lightweight scheme for the paneled shelter based on optimizing the load-bearing and impact resistance of the layered gradient honeycomb sandwich panel.It forms a "design-analysis-optimization-evaluation" research method for lightweighting the paneled shelter.The main research content and results are as follows.1.Based on the design concept of lightweight structure,the reinforced design of a layered gradient honeycomb sandwich panel is proposed with gradient tandem and foam filling.Based on the actual loading conditions of the shelter,the mechanical performance of the layered gradient honeycomb sandwich panel was studied by experiments of quasi-static flatwise compression and low-velocity impact.The mechanical property parameters of the sandwich panel component materials were obtained by tensile and compression tests,which provide original data for establishing the finite model.2.Quasi-static compression and low-velocity impact tests were conducted on layered gradient honeycomb sandwich panels according to test standards ASTM C365M-16 and ASTM D7766.The differences in compression response between single-layer honeycomb sandwich panels and tandem honeycomb sandwich panels were analyzed.The failure modes and impact resistance of the layered gradient honeycomb sandwich panels with different core types under low-velocity impact were investigated.The results suggest that the energy absorption of tandem honeycomb sandwich panel is better than that of single-layer honeycomb sandwich panel under quasi-static compression.The energy absorption of gradient tandem honeycomb sandwich panel is the best.The deformation of gradient tandem honeycomb sandwich panel always starts from the part with the lowest honeycomb strength,while the deformation of uniform tandem honeycomb sandwich panels has randomness.Under low-velocity impact,the impact resistance of gradient tandem honeycomb sandwich panel is better than that of single-layer honeycomb sandwich panel and uniform tandem honeycomb sandwich panel.The first peak force of gradient tandem honeycomb sandwich panel is improved by 18.58% and the maximum impact displacement is reduced by 23%,compared with that of single-layer honeycomb sandwich panel under50 J impact energy.The foam-filled uniform tandem honeycomb sandwich panel has the best impact resistance among the foam-filled structures,which the maximum impact displacement is reduced by 50.98% compared with the single-layer honeycomb sandwich panel.In addition,the difference between hemispherical and flat impactors was investigated on the impact damage to the sandwich panel.The damage caused by flat impactor to the sandwich panel is more severe than hemispherical under the same impact energy.The results of above study lighting the design direction for learning the enhanced design of the layered gradient honeycomb sandwich panel.3.The finite element model of the layered gradient honeycomb sandwich panel was established and had good agreeable validation according to the experimental conditions and results.The influence on its mechanical properties was investigated for the structural parameters.The results show that the deformation sequence of gradient tandem honeycomb sandwich panel can be achieved by adjusting the honeycomb order in flatwise compression.The compression response of the sandwich panel gets smoother by reducing the strength difference between adjacent honeycombs.In the low-velocity impact,the first peak force of the sandwich panel was height affected by the honeycomb height change.The impact resistance of the sandwich panel was significantly improved by increasing the thickness of the front panel.The best impact resistance among the preset core shapes is the foam-filled uniform tandem honeycomb sandwich panel with the filling strategy of "50-80-60".The study results provide an enhanced solution for achieving the lightweight design of the panels for paneled shelters.4.The experimental study and finite element simulation obtained the representative core shape with optimal impact resistance,and multi-objective optimization was carried out to achieve the lightweight design of paneled shelters.Large-size homogenized model of the shelter panel was established to analyze the applicability of lightweight shelter panels.Two shelter panels based on aluminum panels and carbon fiber panels were provided to form a lightweight solution for paneled shelters.The results show that the optimized layered gradient honeycomb sandwich panel has better mechanical properties than the traditional shelter panels,and the weight of single panel is lighter than the traditional shelter panels.For the 6 m fixed paneled shelter,the two lightweight solutions with aluminum panel and carbon fiber panel reduce the shelter weight by 16% and 26.03%,respectively,compared with the traditional paneled shelter.