Crashworthiness Research Of Two-stage Thin-walled Tube From Theoretical Derivation And Experimental Study

As the most traditional and effective energy-absorbing structure,the metal-thin walled tube has been widely used in the engineering field of aerospace,automobile manufacturing and health care.Under the requirement of light-weight vehicles,the method of using less material to absorb more crash energy has nowadays become a hot spot of vehicle design.In recent years,many studies have been dedicated to improve the crashworthiness of metal-thin walled tubes and have gained a series of achievements.In the past,the crashworthiness of the two-stage thin-walled tube is discussed and optimized under the guidance of the super-folding element method,drop-hammer experiment and finite element simulation technique.From the theoretical point of view,this paper mainly introduces and compares the super-folding element method with its simplified ones,and analyzes the response of thin-walled structure under the dynamic impact loading.Based on the theoretical calculation model which performs single-stage structure under the impact loading,it then establishes the calculating model of two-stage structure.Meanwhile,it set up the corresponding two-model again from analyzing the dynamic effect of impact loading.By conducting the drop-hammer experiment of thin-walled structure,the laboratory equipments,experimental specimens,fixtures and experimental procedures have been introduced in detail,and the deformed mode and energy-absorbing characteristics of thin-walled structure have been studied under the effect of impact loading.Through exploiting the model of definite element simulation,the deformation and the energy-absorbing curve can basically consistent with the experimental result.Moreover,the finding of simulation can perfectly coincide with the theory basis,so it provided strong evidence for verifying the feasibility of the definite element model,and also technical support for the follow-up researches.Finally,aiming at the energy-absorbing feature of two-stage structure,a comparison has been made with the single-stage structure,the effect of the inner-wall's length and width on its energy-absorbing characteristic has been analyzed.Through selecting the relevant parameter to optimize the two-stage structure,we have obtained the most satisfying ones.What's more,a contrastive study has been given between the chosen theory and simulation practice to achieve the purpose of testing the validity(and reliability)of the optimized results.On the basis of previous studies,this paper has put forward a two-stage thin-walled energy-absorption structure and conducted a research on the energy absorption characteristics of it from the perspective of theory,experiment and simulation optimization.The research work has guiding significance for the application of the two-stage thin-wall structure into the engineering field,and the experimental results has great reference value for the selection of this mechanic in the process of structure designing.