Lightweight Design Of Passenger Loading Steps With Multi-body Dynamics And FEA Method

With the rapid development of the airline business， the technology of airport equipments is also like raging fire. As an essential part of an airport， passenger loading steps play important roles. As the automobile lightweighting technology development is the future of the modern automobile industry， it has important meaning to saving fuel， reducing emission， and the healthy development of the automotive industry. Passenger loading steps are no exception. The mass of them are becoming less and less. This essay takes WGKT5passenger loading steps of Weihai Guangtai Airport Equipment Co.， Ltd. as the main object of research. By reducing the mass of ladder lifting mechanism，we could reduce vehicle kerb mass， reduce fuel consumption and emission， and save costs.This paper established the overall3D model of this passenger loading steps. Through analysis， the author found that the ladders and lifting frames are of great value in weight lighting. Then simplify and assembly the3D models of these parts in Solidworks to get simple dynamic model. By the multi rigid body dynamic anlysis of it in lifting and loading conditions， the author found out two most dangerous working positions-the initial position of lifting and loading condition， and got the acting force of constraints between components.According to the actual work conditions of the simple dynamic model， the parameterized model， whiche coincide with the original model is established. And then， the parameterized model is conducted multi body dynamics optimization in two steps. Firstly， according to the loading status， the length of lifting frames and positions of the mechanism constraints are optimized， balancing the overall stress condition. Secondly， based on the initial position of the loading process， the best assemble position of hydraulic cylinder is found， balancing and reducing the stress of structure again and increasing the lightweight space.Adjust the geometric parameters of the original3D simple dynamic model from before multi rigid body dynamic optimization to after and simplify and change some structure of each component. Then found out the worst stress condition of each part and conduct FEM analysis. After those， the author found that the lower ladder has no lightweight space， while the lifting frames have huge optimization space. So， the lower and upper ligting frame is conducted size optimization. Changing the thickness of structural section and then checking. Finally， a quite good liftweight resault was achieved. The lower ligting frame is reduced44.37%of its initial mass， and the upper is reduced36.23%.Aiming at the ladders and lifting system on the chassis of passenger loading steps， this eaasy conduct multi rigid body dynamic optimization and FEM analysis to light weight， using Adams， Patran and Nastan. In the first step， through the multi rigid body dynamic optimization， the stress status of lifting mechanism in the most dangerous position is equalized， expanding the lightweight space. In the second step， using the FEA analysis to lightweight and then check. At last， satisfactory results were obtained. In the paper， multi rigid body analysis and FEA meathod are uesd to lightweight the passenger loading steps， which is decided by the structure characteristics of the object and is rare in other essays.