Research On The Application Of Carbon Fiber Composites In Structure Of Car Body

According to the Made in China 2035 plan put forward by the state,China’s manufacturing strategy has changed from being able to meet basic needs to the level of good and fast development.With the booming development of rail transportation,the development of new materials has put forward new requirements for the design and manufacture of rail vehicles.Carbon fiber composites,as a new material with low density and excellent mechanical properties,have been widely used in aerospace and other high-end manufacturing realm.The application of carbon fiber composites in rail vehicle bodies is an important future research direction.This thesis firstly introduces the current research status and level of performance analysis of rail vehicles domestic and abroad,and also explains the current status of the application of composite materials on rail vehicles.And then Fundamentals of composite mechanics,classical composite strength failure theory,and multi-objective optimization theory are presented in detail.Then a certain type of railroad vehicle body as a research object,finite element software Hyper Mesh as a research tool,simulation calculation and analysis.The calculation results show that the strength,stiffness and modulus of the vehicle body satisfy the relevant evaluation criteria.Some of the structural stresses are low,material redundancy is high,and there is a large scope for design optimization.Applying the equivalent design method,the door frame structure is selected to be partially dressed with carbon fiber composites,followed by composite material optimization of the carbon fiber door frame structure.The optimized design of the door frame reduces weight by 36% compared to the original aluminum alloy structure,with obvious lightweight effect.Applying the method of equivalent design,an equivalent design scheme of plywood-unidirectional reinforced panel-laminated panel is proposed for the roof structure,and then a multi-objective optimization is carried out for the car body structure,which is a new design scheme for the roof structure.Finally,the optimized body is calibrated and calculated.Calculation results show that the basic performance of the body structure of partially dressed carbon fiber composites meets the relevant evaluation standards.Composite design solutions are effective and feasible.The final weight reduction of the car body is 271 kg,and the failure factor of the composite parts is less than 1 in all places.Good optimization results were achieved.The method studied and analyzed in this thesis reduces the weight of the body while optimizing the stiffness and modal of the body structure.The equivalent design method used provides a theoretical basis for the future application of composite materials in railroad car bodies.It has some reference value for practical application.