Structure Improvement Design And Research Of Maglev Train Air-conditioning Unit

The development of rail transportation in China is very rapid,and the speed of passenger trains has increased many times.High-speed rail became the preferred way for people to travel.Rail transit vehicles continuously upgraded,and maglev trains,especially low-and medium-speed maglev trains,as new urban transportation,developed rapidly in recent years.On the basis of ensuring that passengers can reach their destinations quickly and safely,the comfort level of the travel experience is getting more and more attention.Ventilation in the train compartment is mainly realized by air-conditioning in the passenger compartment.Different from civil air-conditioners,train air-conditioners have large size,complex internal structure and diverse working environment.In order to ensure the normal operation of train air-conditioners,it is necessary to conduct dynamic and fatigue analysis on the structural safety and operational stability of train air-conditioners by necessary means to ensure that the air-conditioning units meet the requirements.The dissertation describes the design scheme of the air-conditioning unit of the magnetic levitation vehicle.In order to reduce the weight,the aluminum alloy material is used to make the air-conditioning unit box.A finite element model of the box structure of the air-conditioning unit is established,and the static strength analysis,stepping condition analysis,modal analysis,and fatigue strength analysis are sequentially performed using ANSYS finite element analysis software.The details are as follows:(1)Use UG software to build a three-dimensional model of the air-conditioning unit box.Use HyperMesh software to convert the three-dimensional model into a finite element model using plate and shell elements.Use quadrilateral elements to divide the mesh.Each quadrilateral element is defined as 10 mm and loaded with a concentrated mass element.(2)Analyze the static strength of the box structure of the maglev train air-conditioning unit under six impact load conditions,and improve the design and verification of the weak points.Calculate and analyze the strength of the maglev train air-conditioning unit cover when the maintenance staff step on it,and carry out structural improvement design and verification.(3)The modal analysis of the box structure of the air-conditioning unit of the maglev train is carried out to obtain the first five orders of natural frequencies and mode shapes of the box structure of the air-conditioning unit.Compared with the natural frequency of the train,there is no resonance.(4)The fatigue strength analysis of the box structure of the maglev train air-conditioning unit under three fatigue loading conditions is performed,and the position of the important welds and the maximum stress position are evaluated.The improved structure can meet the fatigue strength requirements.(5)According to the railway vehicle standards,The simulated long-term life test,shock test and functional random test vibration test were performed on the prototype of the maglev train air-conditioning unit,to verify the structural reliability of the air-conditioning unit and the effect of the improved design.Through the research of the above content,the dissertation has certain reference significance to the reliability and safety of the box structure of the maglev train air-conditioning unit.