Crashworthiness Bionic Design And Analysis Of Thin-walled Tube Inspired By Bamboo Structure

Crashworthiness is an important direction of automotive safety research andhas significant implications for the protection of lives and safety of motorists.Automobile thin-walled tube structure is important energy absorption and bearingpart, therefore, the design of thin-walled tube structure with excellent energyabsorption and bearing performance is crucial to improve the car’s crashworthinessand structural strength, but also the key and difficult research scholars. Article usedengineering bionics completed the structural engineering bionic design, performanceanalysis and optimization in order to provide new methods and ideas for thestructural design and crashworthiness.Through similarity analysis, study selected bamboo (Phyllostachy pubescens)as a prototype bionic creature, tensile strength of small strain rate tensile testspecimens is191.16MPa, specific strength is2.36×105m2/s2, which is2.55times ofaluminum. Tensile strength of1-year-old bamboo under intermediate strain rate is251MPa, specific strength is3.10×105m2/s2, which is1.78times than strength ofaluminum. The total energy absorption were221.32J and203.67J, in thequasi-static compression test, respectively. The total energy absorption were568.47Jand409.3J, respectively in drop-weight test, which showed that bamboo joint playeda key role to improve the energy absorption of bamboo. According to the test results,this paper analyzed the energy-absorbing mechanism of bamboo and extracted thecharacteristics structure of the energy absorption, such as vascular bundles, matrixorganization and node, as the main load-bearing structure, vascular bundles had agradient distribution, vascular density showed a gradual decrease from outboardbamboo skin to inboard bamboo inner place through the observation of themacro-structure microstructure of bamboo.Study designed the bionic thin-walled tube with different structure, the numbersof the bionic units were18,12and8from the outer to the inner layer. Bionic tubehas two bionic joints radial bearing function and has three bionic inner tubes toconnect outer wall and bionic units. Paper analyzed axial energy absorption andradial load-bearing characteristics of bionic tube, taper pipe and cell-tube of throughthe method of finite element simulation. Five different levels of bionic units and bionic inner tubes were selected for experimental design, research created, theresponse surface of initial peak load, average load and energy absorption of a bionictube to obtain the optimal size of bionic tube with minimum peak load and themaximum energy absorption, under the condition of the average load value less than200kN.The results of finite element simulation and the response surface analysisshows that: For No.4and9bionic tube, the initial peak load were small, the averageloads were increased0.83times and0.89times than0.3taper four-cell tube, specificenergy absorptions were increased by13.3%and16%than0.3taper two-cell tuberespectively. The strongest radial load capacity of8bionic tube was51.8kN,increased63.9%than No.2bionic tube; Bending strength of No.9bionic tube was22.5MPa, which was more1.5times than four-cell tube. Research obtained optimalsolution of bionic tube that initial peak load and specific energy absorption were157.57kN and34.33kJ/kg, respectively through the application of response surfacemethod. These studies provided new methods and ideas for improvingcrashworthiness energy absorption of thin-walled structures.