Research On Vehicle Impact Performance Of Tridimensional Parking Structure Based On Multi-scale Model

With the rapid economic development and advancement in science and technology,the production and sales of automobiles have also been growing rapidly,and the number of vehicles has also been increasing.However,because of the rapid increase in the number of vehicles,the problem of traffic cong estion and parking have reached a very serious level.Almost all major cities have serious road congestion and parking problems.Because of the scarcity of urban land resources,changing the parking from the traditional plane mode to the spatial tridimensi onal mode is an effective way to alleviate the parking problems from the supply side.The intelligent high-rise tridimensional parking structure can make full use of the upper space of the land and improve the land utilization rate.The automated parking m ethod of the tridimensional parking structure is not only simple but fast,and it can also increase the security and protection of vehicles.As a parking facility,the high-rise tridimensional parking structure has a large traffic volume around it.In the process of using this structure,it is inevitable that vehicles crash into it.In addition to the prevalence of terrorism in recent years,it is necessary to study the situation of vehicles crashing the tridimensional parking structure,and use the research to guide the collision design of the tridimensional parking structure.At present,the impact research on the tridimensional parking structure is still in its infancy,the dynamic response test data and the impact force of the structure are very scarce.Therefore,the impact research guidelines and design principles of the tridimensional parking structure are not very clear.In view of the above,it is important to study the dynamic responses of the high-rise tridimensional parking structure subjected to the vehicle impact,and to further study the sizes and characteristics of the impact force.This research has important implications for the design of the tridimensional parking structure and the safety assessment after impact.This article takes the high-rise tridimensional parking structure of vertical lifting as the research object.The multi-scale and the refined finite element model of tridimensional parking structure were established based on the ANSYS/LS-DYNA finite element software.The dynamic responses and accuracy of the two models were compared,and the applicability of the multi-scale model was verified.Based on the multi-scale model and the research method of the tridimensional parking structure,the dynamic responses of the structure were studied,and the collision characteristics of the structure were summarized.Additionally,a series of researches were conducted on various factors affecting the dynamic response of the tridimensional parking structure.The influences were investigated of various factors,such as impact velocity,vehicle mass,impact position,and working condition.Finally,the influence of different parameters on the impact force was studied.The impact force peak data was summarized,then the impact force results were compared with the allowances given in the Chinese code,the American code,and the European code.We reached the following conclusions:(1)The multi-scale model can greatly improve the efficiency and it can also meet the requirements of the accuracy.(2)The vehicle impact has a local effect on the tridimensional parking structure.The plastic strain caused by the vehicle impact mainly concentrates on the impact area,the column foot area,and the column top area of the tridimensional parking structure.(3)The impact velocity and the vehicle mass have a great influence on the dynamic responses of the tridimensional parking structure.The dynamic responses of the structure increase with the impact velocity and the vehicle mass.While,the impact position and the working condition present no obvious effect.(4)The main factors affecting the impact force are the impact velocity and the vehicle mass,and the impact velocity has a greater influence on the impact force.Before the crashed column was failed,the peak value of the impact force increases with the increase of the impact velocity.But when the impacted column was failed,the peak value of the impact force will not change with the increase of the impact velocity or the vehicle mass.(5)Compare the impact force results with four current specifications.it is believe that when the tridimensional parking structure subjected to vehicle impact,the values of the impact force given in Chinese code and Europe code are not reliable in some cases but the value given in American code is safe.